Performance of BRCA1/2 mutation prediction models in male breast cancer patients

To establish whether existing mutation prediction models can identify which male breast cancer (MBC) patients should be offered BRCA1 and BRCA2 diagnostic DNA screening, we compared the performance of BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm), BRCAPRO (BRCA probability) and the Myriad prevalence table (“Myriad”). These models were evaluated using the family data of 307 Dutch MBC probands tested for BRCA1/2, 58 (19%) of whom were carriers. We compared the numbers of observed vs predicted carriers and assessed the Area Under the Receiver Operating Characteristic (ROC) Curve (AUC) for each model. BOADICEA predicted the total number of BRCA1/2 mutation carriers quite accurately (observed/predicted ratio: 0.94). When a cut‐off of 10% and 20% prior probability was used, BRCAPRO showed a non‐significant better performance (observed/predicted ratio BOADICEA: 0.81, 95% confidence interval [CI]: [0.60‐1.09] and 0.79, 95% CI: [0.57‐1.09], vs. BRCAPRO: 1.02, 95% CI: [0.75‐1.38] and 0.94, 95% CI: [0.68‐1.31], respectively). Myriad underestimated the number of carriers in up to 69% of the cases. BRCAPRO showed a non‐significant, higher AUC than BOADICEA (0.798 vs 0.776). Myriad showed a significantly lower AUC (0.671). BRCAPRO and BOADICEA can efficiently identify MBC patients as BRCA1/2 mutation carriers. Besides their general applicability, these tools will be of particular value in countries with limited healthcare resources.     

Evaluation of the Dutch BRCA1/2 clinical genetic center referral criteria in an unselected early breast cancer population

In this study, we evaluated the diagnostic value of the Dutch Clinical Genetic Center (CGC) referral guidelines for BRCA1/2 mutation testing in 903 early breast cancer patients, unselected for family history, diagnosed in a cancer hospital before the age of 50 years in 1974–2002; most prevalent Dutch pathogenic BRCA1/2 mutations had been analyzed on coded DNA in a research setting. Forty-nine (5.4%) of the patients were proven to be BRCA1/2 mutation carriers. We found that 78% and 69% of BRCA1 and BRCA2 mutation carriers identified met the criteria for referral to the CGC based on age, family history and synchronous multiple tumors; reflected by a combined sensitivity of 75.5% and specificity of 63.2%. More than half of the BRCA1 mutation carriers, that is, 58% had a triple-negative tumor. The highest AUC was obtained by shifting the age at diagnosis threshold criterion from 40 to 35 years and by adding a ‘triple-negative breast cancer'' criterion with an age threshold of 45 years; the specificity increased to 71.2%, whereas the sensitivity remained the same; that is, a referral of fewer patients will lead to the identification of at least the same number of BRCA1/2 mutation carriers. Two-thirds of the BRCA1/2 mutation carriers identified in this research setting had been referred for counseling and testing. Our results indicate that, awaiting a possibly more extended mutation screening of all breast cancer patients, the triple-negative status of a breast cancer should be added to the CGC referral criteria.     

A new scoring system for the chances of identifying a BRCA1/2 mutation outperforms existing models including BRCAPRO

Methods: DNA samples from affected subjects from 422 non-Jewish families with a history of breast and/or ovarian cancer were screened for BRCA1 mutations and a subset of 318 was screened for BRCA2 by whole gene screening techniques. Using a combination of results from screening and the family history of mutation negative and positive kindreds, a simple scoring system (Manchester scoring system) was devised to predict pathogenic mutations and particularly to discriminate at the 10% likelihood level. A second separate dataset of 192 samples was subsequently used to test the model's predictive value. This was further validated on a third set of 258 samples and compared against existing models.

Results: The scoring system includes a cut-off at 10 points for each gene. This equates to >10% probability of a pathogenic mutation in BRCA1 and BRCA2 individually. The Manchester scoring system had the best trade-off between sensitivity and specificity at 10% prediction for the presence of mutations as shown by its highest C-statistic and was far superior to BRCAPRO.

Conclusion: The scoring system is useful in identifying mutations particularly in BRCA2. The algorithm may need modifying to include pathological data when calculating whether to screen for BRCA1 mutations. It is considerably less time-consuming for clinicians than using computer models and if implemented routinely in clinical practice will aid in selecting families most suitable for DNA sampling for diagnostic testing.

     

Detection of circulating Aspergillus fumigatus DNA by real-time PCR assay of large serum volumes improves early diagnosis of invasive aspergillosis in high-risk adult patients under hematologic surveillance

Detection of galactomannan antigen (GMA) in serum is the standard assay for the diagnosis of invasive aspergillosis (IA) in high-risk patients with hematological disorders. Detection of Aspergillus DNA in serum has been proposed, but its sensitivity is lower than that of GMA when small serum volumes (SSV) are used. In this study, we investigated whether extraction of DNA from large serum volumes (LSV) improves diagnostic yield. In a 13-month prospective study, we compared the performances of twice-weekly screening of serum for GMA by an enzyme immunoassay and weekly screening for Aspergillus fumigatus DNA by a real-time PCR (RT-PCR) assay of 1.0 ml (LSV) or 100 μl (SSV) of serum. We included 124 patients (138 treatment episodes), with 17 episodes of EORTC (European Organization for Research and Treatment of Cancer)/MSG (Mycoses Study Group)-documented IA. In all, 1,870 samples were screened for GMA. The sensitivity (Se), specificity (Sp), and positive and negative predictive values (PPV and NPV, respectively) of GMA for IA were 88.2%, 95.8%, 75%, and 98.3%, respectively. We screened 938 samples for Aspergillus DNA by using LSV; 404 of these samples were also tested with SSV. The Se, Sp, PPV, and NPV of RT-PCR were 100%, 96.7%, 81%, and 100%, respectively, with LSV and 76.5%, 96.7%, 81.3%, and 95.6%, respectively, with SSV. DNA detection gave a positive result when performed on LSV in two cases of IA where the GMA assay result remained negative. Furthermore, in four IA cases, DNA was detected earlier than GMA. The use of LSV for extraction improved the performance of the RT-PCR, which appears highly sensitive and specific for the early diagnosis of IA in high-risk patients with hematological disorders.     

PGD for hereditary breast and ovarian cancer: the route to universal tests for BRCA1 and BRCA2 mutation carriers

Preimplantation Genetic Diagnosis (PGD) is a method of testing in vitro embryos as an alternative to prenatal diagnosis with possible termination of pregnancy in case of an affected child. Recently, PGD for hereditary breast and ovarian cancer caused by BRCA1 and BRCA2 mutations has found its way in specialized labs. We describe the route to universal single-cell PGD tests for carriers of BRCA1/2 mutations. Originally, mutation-specific protocols with one or two markers were set up and changed when new couples were not informative. This route of changing protocols was finalized after 2 years with universal tests for both BRCA1 and BRCA2 mutation carriers based on haplotyping of, respectively, 6 (BRCA1) and 8 (BRCA2) microsatellite markers in a multiplex PCR. Using all protocols, 30 couples had a total of 47 PGD cycles performed. Eight cycles were cancelled upon IVF treatment due to hypostimulation. Of the remaining 39 cycles, a total of 261 embryos were biopsied and a genetic diagnosis was obtained in 244 (93%). In 34 of the 39 cycles (84.6%), an embryo transfer was possible and resulted in 8 pregnancies leading to a fetal heart beat per oocyte retrieval of 20.5% and a fetal heart beat per embryonic transfer of 23.5%. The preparation time and costs for set-up and validation of tests are minimized. The informativity of microsatellite markers used in the universal PGD-PCR tests is based on CEPH and deCODE pedigrees, making the tests applicable in 90% of couples coming from these populations.     

Potential Utility of Fecal Calprotectin in Discriminating Colorectal Polyps From Other Major Etiologies in Children Presenting With Isolated Hematochezia

BackgroundColorectal polyps are the most common cause of isolated hematochezia in children, which requires a colonoscopy for diagnosis. We aimed to investigate the potential utility of fecal calprotectin (FC) in assessing colorectal polyps detected by colonoscopy among children presenting with isolated hematochezia.MethodsPediatric patients of the age of < 18 years who had undergone both colonoscopy and FC tests for isolated hematochezia from June 2016 to May 2020 were included in the present multicenter, retrospective, cross-sectional study. Comparative analysis was conducted between major causes of isolated hematochezia and FC cut-offs for discriminating colorectal polyps were explored.ResultsA total 127 patients were included. Thirty-five patients (27.6%) had colorectal polyps, followed by anal fissure (14.2%), ulcerative colitis (UC; 12.6%), and others. A significant difference in FC levels was observed between patients with colorectal polyps (median, 278.7 mg/kg), anal fissures (median, 42.2 mg/kg), and UC (median, 981 mg/kg) (P < 0.001). According to receiver operating characteristic curve analysis, among patients diagnosed with colorectal polyp or anal fissure, the most accurate FC cut-off for discriminating colorectal polyps from anal fissures on colonoscopy was 225 mg/kg (sensitivity, 59.4%; specificity, 94.4%; positive predictive value [PPV], 95.0%; negative predictive value [NPV], 56.7%; area under the curve [AUC], 0.8; 95% confidence interval [CI], 0.678–0.923; P < 0.001), while among patients diagnosed with colorectal polyp or UC, the most accurate FC cut-off for discriminating colorectal polyps from UC on colonoscopy was 879 mg/kg (sensitivity, 81.2%; specificity, 56.2%; PPV, 78.8%; NPV, 60.0%; AUC, 0.687; 95% CI, 0.521–0.852; P < 0.001).ConclusionFC may assist in assessing the cause of lower gastrointestinal tract bleeding in children who present with isolated hematochezia.     

Prenatal Diagnosis of Congenital Cytomegalovirus Infection

We report here the results of a study on the prenatal diagnosis of congenital cytomegalovirus (CMV) infection. The study was carried out by both PCR and virus isolation from amniotic fluid (AF) for 82 pregnant women at risk of transmitting CMV for the detection of (i) seroconversion to CMV immunoglobulin G (IgG) positivity during the first trimester of pregnancy, (ii) symptomatic CMV infection in the mother during the first trimester of pregnancy or intrauterine growth retardation detected by ultrasound or abnormal ultrasonographic findings suggestive of fetal infections, and (iii) seropositivity for CMV-specific IgM. For 50 women, fetal blood (FB) was also obtained and tests for antigenemia and PCR were performed. The results indicate that AF is better than FB for the prenatal diagnosis of CMV infection. PCR with AF has a sensitivity (SNS) of 100%, a specificity (SPE) of 83.3%, a positive predictive value (PPV) of 40%, and a negative predictive value (NPV) of 100%; rapid virus isolation with the same material has an SNS of 50%, an SPE of 100%, a PPV of 100%, and an NPV of 94.7%. Fewer than 10% of the women positive for IgM by enzyme immunoassay (EIA) had a congenitally infected fetus or newborn infant. When EIA IgM positivity was confirmed by Western blotting (WB) and the WB profile was considered, the percent transmission detected among women with an “at-risk” profile was higher than that observed among IgM-positive women and was the same as that among women who seroconverted during the first trimester of pregnancy (transmission rates of 29 and 25%, respectively).     

Outcome of metastatic breast cancer in selected women with or without deleterious BRCA mutations

The aim of this study was to compare the time-to progression and overall survival (OS) in patients with metastatic breast cancer (MBC) with and without deleterious BRCA1/2 mutations. 195 women with MBC who were referred for BRCA genetic testing between 1997 and 2011 were included in the study. Logistic regression models and Cox proportional hazards models were fit to determine the associations between clinical variables and outcomes. Of 195 women with MBC, 21 % (n = 41) were positive for BRCA1/2 mutations. The number of metastatic sites at the time of metastatic disease was not different between BRCA1 versus BRCA2 carriers versus non-carriers (P = 0.77). The site of first metastasis was visceral-only in 70 % of BRCA1 carriers compared to 9 % in BRCA2 carriers and 37 % in non-carriers (P = 0.001). Median follow-up was 2.8 years. BRCA non-carriers and BRCA2 carriers had a longer time-to progression and OS compared to BRCA1 carriers (median time-to progression = 1.3 vs. 0.9 vs. 0.7 years; P = 0.31, and median OS = 4.88 vs. 4.94 vs. 1.34 years; P = 0.0065). In a multivariate model, no association was identified between BRCA positivity and time-to-event outcomes (P > 0.28). In addition, patients with triple-negative MBC carried a poorer prognosis irrespective of their BRCA status (P = 0.058 and P = 0.15 for the interaction term of BRCA status and triple-negative for time-to progression and OS, respectively). Our data indicate that BRCA1 carriers diagnosed with MBC have worse outcomes compared to BRCA2 carriers and non-carriers. However, the differences in outcome did not reach statistical significance likely due to small sample sizes.     

Clinical Application of Real-Time PCR to Screening Critically Ill and Emergency-Care Surgical Patients for Methicillin-Resistant Staphylococcus aureus: a Quantitative Analytical Study

The clinical utility of real-time PCR screening assays for methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) colonization is constrained by the predictive values of their results: as MRSA prevalence falls, the assay''s positive predictive value (PPV) drops, and a rising proportion of positive PCR assays will not be confirmed by culture. We provide a quantitative analysis of universal PCR screening of critical care and emergency surgical patients using the BD GeneOhm MRSA PCR system, involving 3,294 assays over six months. A total of 248 PCR assays (7.7%) were positive; however, 88 failed to be confirmed by culture, giving a PPV of 65%. Multivariate analysis was performed to compare PCR-positive culture-positive (P+C+) and PCR-positive culture-negative (P+C−) assays. P+C− results were positively associated with a history of methicillin-sensitive Staphylococcus aureus infection or colonization (odds ratio [OR], 3.15; 95% confidence interval [CI], 1.32 to 7.54) and high PCR thresholds of signal intensity, indicative of a low concentration of target DNA (OR, 1.19 per cycle; 95% CI, 1.11 to 1.26). P+C− results were negatively associated with a history of MRSA infection or colonization (OR, 0.19; 95% CI, 0.09 to 0.42) and male sex (OR, 0.40; 95% CI, 0.20 to 0.81). P+C+ patients were significantly more likely to have subsequent positive MRSA culture assays and microbiological evidence of clinical MRSA infection. The risk of subsequent MRSA infection in P+C− patients was not significantly different from that in case-matched PCR-negative controls. We conclude that, given the low PPV and poor correlation between a PCR-positive assay and the clinical outcome, it would be prudent to await culture confirmation before altering infection control measures on the basis of a positive PCR result.Methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) is endemic in hospitals and health care facilities in most countries of the world (5). It is frequently carried into the community on colonized, discharged patients, forming a reservoir which then returns to the health care facility when asymptomatic carriers are readmitted (9). Admitted carriers may then develop endogenous infection or become sources of nosocomial transmission to other patients. Screening for MRSA carriage on admission has therefore become a component of many infection control programs (2, 8, 26, 27, 38, 42). This facilitates targeted treatment and infection control measures for MRSA-positive patients while avoiding unnecessary isolation and treatment of noncarriers.Conventional culture-based screening may take several days to produce a result, and it is widely hypothesized that a reduced turnaround time would allow faster implementation of appropriate patient management. PCR-based MRSA screening assays have the potential to provide a result in 2 to 3 h of laboratory time and have a total turnaround time from specimen collection to ward report of approximately 20 h (1, 16, 21). The BD GeneOhm MRSA assay (previously known as IDI-MRSA; BD Diagnostics, San Diego, CA) and the Cepheid GeneXpert MRSA assay (Cepheid, Sunnyvale, CA) are two such PCR tests that detect the presence of characteristic MRSA DNA sequences bridging the SCCmec resistance cassette and the S. aureus-specific orfX open reading frame gene (18). However, concerns have been raised over false-positive and -negative results with these tests (11, 36).Previous estimates of the sensitivities, specificities, negative predictive values (NPV), and positive predictive values (PPV) of the BD IDI-MRSA test and other PCR-based assays have varied considerably (for a summary, see Table S1 in the supplemental material). In our own cluster-randomized crossover study of adult general ward patients admitted during 2006 and 2007, the overall prevalence of MRSA carriage on admission was 6.7% (4.9% of assays) and, in comparison with parallel culture screenings, the BD IDI-MRSA PCR test had a sensitivity of 88%, a specificity of 96%, an NPV of 99%, and a PPV of 55%. (21). With low carriage rates, a high NPV is to be expected, but the relatively low PPV exacerbated concerns about high rates of false positivity with this test.Our previous study did not demonstrate a difference in MRSA acquisition rates between admitted patients screened by PCR and by culture on general medical and surgical wards (21). Therefore, we now limit the use of PCR assays to the high-risk populations of patients in adult and pediatric critical care units and those admitted as surgical emergencies. In the present study, we investigate the performance of the BD GeneOhm MRSA PCR test for admission screening of these groups and consider its usefulness in guiding patient management.     

Widal Test in Diagnosis of Typhoid Fever in Turkey

We studied the value of the Widal tube agglutination test for the diagnosis of typhoid fever. The subjects were all adults >18 years of age and were divided into four groups: (i) 317 healthy blood donor controls, (ii) 31 bacteriologically confirmed patients with Salmonella enterica serotype Typhi, (iii) 21 patients with a clinical diagnosis of typhoid fever, and (iv) 41 febrile nontyphoid patients. Blood donor controls were screened with a slide agglutination test for the Salmonella enterica serotype Typhi O and H antigens, and positives were then tested with the Widal test. Acute- and convalescent-phase sera from patients in groups 2, 3, and 4 were obtained 7 to 10 days apart and tested by the Widal test. Using a cutoff of ≥1/200 for the O antigen test performed on acute-phase serum gave a sensitivity of 52% and a specificity of 88% with a positive predictive value (PPV) of 76% and a negative predictive value (NPV) of 71%. This increased to 90% sensitivity and specificity with a PPV of 88% and an NPV of 93% when the convalescent-phase serum was tested. We concluded that O and H agglutinin titers of ≥1/200 are of diagnostic significance. The Widal test is easy, inexpensive, and relatively noninvasive. It can be of diagnostic value when blood cultures are not available or practical. The results must be interpreted cautiously because of the low sensitivity of the test. The Widal test done on convalescent-phase serum gave more-reliable results with higher specificity and sensitivity.     

The contribution of germline rearrangements to the spectrum of BRCA2 mutations

Background

Few germline BRCA2 rearrangements have been described compared with the large number of germline rearrangements reported in the BRCA1 gene. However, some BRCA2 rearrangements have been reported in families that included at least one case of male breast cancer.

Objective

To estimate the contribution of large genomic rearrangements to the spectrum of BRCA2 defects.

Methods

Quantitative multiplex PCR of short fluorescent fragments (QMPSF) was used to screen the BRCA2 gene for germline rearrangements in highly selected families. QMPSF was previously used to detect heterozygous deletions/duplications in many genes including BRCA1 and BRCA2.

Results

We selected a subgroup of 194 high risk families with four or more breast cancers with an average age at diagnosis of ⩽50 years, who were recruited through 14 genetic counselling centres in France and one centre in Switzerland. BRCA2 mutations were detected in 18.6% (36 index cases) and BRCA1 mutations in 12.4% (24 index cases) of these families. Of the 134 BRCA1/2 negative index cases in this subgroup, 120 were screened for large rearrangements of BRCA2 using QMPSF. Novel and distinct BRCA2 deletions were detected in three families and their boundaries were determined. We found that genomic rearrangements represent 7.7% (95% confidence interval 0% to 16%) of the BRCA2 mutation spectrum.

Conclusion

The molecular diagnosis of breast cancer predisposition should include screening for BRCA2 rearrangements, at least in families with a high probability of BRCA2 defects.     

Performance of the Abbott RealTime CT/NG for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

A multicenter clinical study was conducted to evaluate the performance characteristics of the Abbott RealTime CT/NG assay, a multiplex real-time PCR assay, for simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae. The specimens were collected from a total of 3,832 male and female subjects at 16 geographically diverse sites. Specimens included male and female urine samples, male urethral swabs, female endocervical swabs, and self-collected and clinician-collected vaginal swabs. Specimens were tested with the automated Abbott RealTime CT/NG assay, Aptima Combo 2 assay (Gen-Probe), ProbeTec ET CT/GC assay (Becton Dickinson), and culture for N. gonorrhoeae. The Aptima Combo 2 assay, the ProbeTec assay, and the N. gonorrhoeae culture were used as the reference assays. For each subject, a patient infected status (PIS) was determined based on the combined results from the reference assays. The overall prevalence in female subjects was 8.9% for C. trachomatis and 3.8% for N. gonorrhoeae. The overall male prevalence was 18.2% for C. trachomatis and 16.7% for N. gonorrhoeae. The overall sensitivity and specificity of the Abbott RealTime CT/NG assay were 92.4% and 99.2% for C. trachomatis and 96.9% and 99.7% for N. gonorrhoeae, respectively. In comparison, the sensitivity and specificity, respectively, for the Aptima Combo 2 assay were 94.5% and 99.0% for C. trachomatis and 96.1% and 99.5% for N. gonorrhoeae, and those for the ProbeTec ET assay were 90.3% and 99.5% for C. trachomatis and 92.0% and 97.3% for N. gonorrhoeae in this study. The Abbott RealTime CT/NG assay offers C. trachomatis and N. gonorrhoeae dual detection with high sensitivity and specificity. The automated assay provides a useful alternative nucleic acid amplification assay for clinical laboratories and clinicians.Chlamydia trachomatis and Neisseria gonorrhoeae are the two most prevalent bacterial sexually transmitted infections (STIs) reported to the Centers for Disease Control and Prevention (CDC) (2). Together these two infections accounted for over 1.5 million cases of STIs in 2008. The CDC estimates that sexually transmitted diseases (STDs) cost the health care system $1.5 billion annually. Since these infections, especially chlamydia, are most often asymptomatic, the CDC recommends yearly screening for chlamydia in all sexually active women ages 16 to 25 years. Since coinfections are common, many diagnostic test platforms assay for both organisms. Although there are several commercial assays available for performing nucleic acid amplification tests (NAATs), which are now recommended by the CDC as the test of choice, new assays and new platforms are needed by both private and public health programs.The Abbott RealTime CT/NG assay is a new real-time PCR assay for the direct, qualitative detection of the plasmid DNA of Chlamydia trachomatis and the genomic DNA of Neisseria gonorrhoeae in female endocervical or vaginal swab specimens, in male urethral swab specimens, and in male and female urine specimens from symptomatic and asymptomatic individuals. There were several sets of objectives of this study: (i) to determine the performance characteristics of the Abbott RealTime CT/NG assay compared to those of other amplified assays using specimens obtained from symptomatic and asymptomatic male and female subjects from clinical sites with high or low prevalence of Chlamydia trachomatis and/or Neisseria gonorrhoeae; (ii) to demonstrate the precision of the Abbott RealTime CT/NG assay using a precision panel consisting of combinations of high and low concentrations of Chlamydia trachomatis and Neisseria gonorrhoeae specimens; (iii) to evaluate the clinical sensitivity, clinical specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Abbott RealTime CT/NG assay in symptomatic and asymptomatic individuals from high- and low-prevalence sites; (iv) to compare the performance of the new Abbott assay with that of the Gen-Probe Aptima Combo 2 assay for female endocervical and vaginal swabs, male urethral swabs, and male and female urine specimens; (v) to compare the performance of the Abbott assay with those of the Becton Dickinson ProbeTec ET Chlamydia trachomatis and Neisseria gonorrhoeae amplified DNA assays (ProbeTec ET) for female endocervical swabs and male and female urine specimens; and (vi) to evaluate the procedure for self-collection of a vaginal swab specimen using the Abbott multi-Collect specimen collection kit.     

Évaluation d’un test de diagnostic rapide pour le diagnostic de la toxoplasmose chez les femmes enceintes à Cotonou (Bénin)

The aim of the study was to evaluate the performance of the ImmunoComb® Toxo IgG and ImmunoComb® Toxo IgMassays (rapid diagnostic test) in the laboratory diagnosis of toxoplasmosis in pregnant women in Cotonou. We interviewed 266 pregnant women, who first answered an epidemiological questionnaire, and collected blood samples for measurement of IgG and IgM anti T. gondii antibodies with the ImmunoComb toxo assays and with the ARCHITECT CIMA method. The sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were calculated to determine the performance of the rapid test. The seroprevalences of IgG against T. gondii by CIMA technique and rapid test were respectively 48.9% and 48.5%. The prevalence increased with age. Performances for IgG were: sensitivity 97%, specificity 100%, PPV 100%, NPV = 97.10%. For IgM, Sensitivity: 33.3% Specificity: 100%, PPV 100%, NPV = 99.2%. Seroprevalence obtained shows that about half of the study population is not immune against T. gondii and requires regular serological monitoring until delivery. According to these results, and given the needs of toxoplasmosis diagnosis on the field characterized by an important decrease of immunized women, this test may be recommended in the laboratory diagnosis of toxoplasmosis in peripheral levels of the health pyramid.     

High Coxiella burnetii DNA Load in Serum during Acute Q Fever Is Associated with Progression to a Serologic Profile Indicative of Chronic Q Fever

PCR is very effective in diagnosing acute Q fever in the early stages of infection, when bacterial DNA is present in the bloodstream but antibodies have not yet developed. The objective of this study was to further analyze the diagnostic value of semiquantitative real-time PCR (qPCR) in diagnosing acute Q fever in an outbreak situation. At the Jeroen Bosch Hospital, in 2009, qPCR testing for Coxiella burnetii DNA was performed for 2,715 patients suspected of having acute Q fever (positive, n = 385; negative, n = 2,330). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the qPCR assay were calculated for patients with negative qPCR results with a follow-up sample obtained within 14 days (n = 305) and qPCR-positive patients with at least one follow-up sample (n = 369). The correctness of the qPCR result was based on immunofluorescence assay results for samples submitted for qPCR and follow-up testing. The sensitivity of the Q fever qPCR assay was 92.2%, specificity 98.9%, PPV 99.2%, and NPV 89.8%. Patients who later developed serologic profiles indicative of chronic Q fever infection had significantly higher C. burnetii DNA loads during the acute phase than did patients who did not (P < 0.001). qPCR testing is a valuable tool for the diagnosis of acute Q fever and should be used in outbreak situations when the onset of symptoms is <15 days earlier. Special attention is needed in the follow-up monitoring of patients with high C. burnetii DNA loads during the acute phase, as this might be an indicator for the development of a serologic profile indicative of chronic infection.     

Validation of Version 3.0 of the Breast Cancer Genetics Referral Screening Tool (B-RST™)

PurposeDespite increased awareness of hereditary breast and ovarian cancer among clinicians and the public, many BRCA1/2 mutation carriers remain unaware of their risk status. The Breast Cancer Genetics Referral Screening Tool (B-RST™) was created and validated to easily identify individuals at increased risk for hereditary breast and ovarian cancer for referral to cancer genetics services. The purpose of this study was to revise B-RST™ to maximize sensitivity against BRCA1/2 mutation status.MethodsWe analyzed pedigrees of 277 individuals who had undergone BRCA1/2 testing to determine modifications to the B-RST™ 2.0 algorithm that would maximize sensitivity for mutations, while maintaining simplicity. We used McNemar’s chi-square test to compare validation measures between the revised version (3.0) and the 2.0 version.ResultsAlgorithmic changes made to B-RST™ 2.0 increased the sensitivity against BRCA1/2 mutation analysis from 71.1 to 94.0% (P < 0.0001). While specificity decreased, all screen-positive individuals were appropriate for cancer genetics referral, the primary purpose of the tool.ConclusionDespite calls for BRCA1/2 population screening, there remains a critical need to identify those most at risk who should receive cancer genetics services. B-RST™ version 3.0 demonstrates high sensitivity for BRCA1/2 mutations, yet remains a simple and quick screening tool for at-risk individuals.     

The (1,3)β-d-Glucan Test as an Aid to Early Diagnosis of Invasive Fungal Infections following Lung Transplantation

The Fungitell assay for (1,3)β-d-glucan (BG) detection in serum has been evaluated in patients with invasive fungal infections (IFIs) and healthy controls and for the early diagnosis of IFI in cancer patients. We evaluated the BG assay for the detection of IFI in lung transplant recipients. Serial serum samples were prospectively collected from patients undergoing lung transplants at Duke Hospital. Fungal infections were classified according to revised European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. A receiver operator characteristic (ROC) curve was generated; possible causes for false-positive and false-negative tests were investigated by linear regression analysis. Seven hundred fifty-six serum specimens from 59 subjects without IFI and 41 specimens from 14 patients with proven or probable IFI were tested. The area under the ROC curve was 0.69. Based on a 60-pg/ml positive cutoff, per-patient sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 64%, 9%, 14%, and 50%, respectively; per-test estimates were 71%, 59%, 9%, and 97%, respectively. The majority (92%) of patients not diagnosed with an IFI had at least one BG level of ≥60 pg/ml, and 90% had at least one BG level of ≥80 pg/ml. Respiratory colonization with mold and hemodialysis significantly affected mean BG levels. In conclusion, the accuracy of the BG test is marginal and its utility as a tool for the early diagnosis of IFI is questionable in the lung transplant population. Although the NPV of the BG test is high, the low PPV limits its utility as a screening tool for early diagnosis of IFI.Lung transplant recipients are at relatively high risk for developing invasive fungal infections (IFIs). A recent national surveillance program reported the 1-year cumulative incidence of IFIs in lung transplant recipients to be 8.6%. The most common invasive fungal pathogen was Aspergillus species, responsible for 44% (109/248) of IFIs, followed by Candida (23%) and non-Aspergillus molds (20%) (11). Unfortunately, fungal infections are associated with high mortality, which is in part related to delayed or missed diagnoses owing to the lack of sensitive, noninvasive diagnostic tests.(1,3)β-d-Glucan (BG) is a cell wall constituent of many pathogenic fungi, including Aspergillus, Candida, and Pneumocystis, and is detectable in patient serum during invasive disease caused by these fungi. It is also detectable in patients with infections caused by species of Fusarium, Trichosporon, Saccharomyces, and Acremonium (14). The BG assay (Fungitell; Associates of Cape Cod, Falmouth, MA) was approved by the U.S. Food and Drug Administration (FDA) for the qualitative detection of BG in the serum of patients with symptoms of or medical conditions predisposing to IFIs and as an aid in the diagnosis of deep-seated mycoses and fungemia. The assay has been evaluated in a multicenter study of patients with IFIs that included healthy controls (10) as well as for the early diagnosis of IFIs in patients with hematologic malignancies (9, 12).However, the BG assay has not been extensively evaluated in the solid-organ transplant populations. (1,3)β-d-Glucan is known to be ubiquitous in the environment, and poor specimen handling, hemodialysis with certain cellulose membranes, exposure to surgical packing, bacteremia, and recent receipt of albumin, immunoglobulin products, or intravenous therapy with a beta-lactam/inhibitor combination may cause false-positive test results (5-8, 13). Many of these potential confounders of BG are present in the lung transplant population. Therefore, we conducted this study to assess the performance of the BG assay for the detection of IFIs by serial testing in the lung transplant population.     

BRCA1/2 testing in newly diagnosed breast and ovarian cancer patients without prior genetic counselling: the DNA-BONus study

Germline BRCA1/2 testing of breast and ovarian cancer patients is growing rapidly as the result affects both treatment and cancer prevention in patients and relatives. Through the DNA-BONus study we offered BRCA1/2 testing and familial risk assessment to all new patients with breast (N=893) or ovarian (N=122) cancer diagnosed between September 2012 and April 2015, irrespective of family history or age, and without prior face-to-face genetic counselling. BRCA1/2 testing was accepted by 405 (45.4%) and 83 (68.0%) of the patients with breast or ovarian cancer, respectively. A pathogenic BRCA1/2 variant was found in 7 (1.7%) of the breast cancer patients and 19 (22.3%) of the ovarian cancer patients. In retrospect, all BRCA1/2 mutation carriers appeared to fulfill current criteria for BRCA1/2 testing. Hospital Anxiety and Depression Scale (HADS) scores showed that the mean levels of anxiety and depression were comparable to those reported for breast and gynecological cancer patients in general, with a significant drop in anxiety symptoms during a 6-month follow-up period, during which the test result was forwarded to the patients. These results show that BRCA1/2 testing is well accepted in newly diagnosed breast and ovarian cancer patients. Current test criteria based on age and family history are sufficient to identify most BRCA1/2 mutation carriers among breast cancer patients. We recommend germline BRCA1/2 testing in all patients with epithelial ovarian cancer because of the high prevalence of pathogenic BRCA1/2 variants.     

Detection of Colonization by Carbapenemase-Producing Gram-Negative Bacilli in Patients by Use of the Xpert MDRO Assay

Detecting colonization of patients with carbapenemase-producing bacteria can be difficult. This study compared the sensitivity and specificity of a PCR-based method (Xpert MDRO) for detecting bla_KPC, bla_NDM, and bla_VIM carbapenem resistance genes using GeneXpert cartridges to the results of culture with and without a broth enrichment step on 328 rectal, perirectal, and stool samples. The culture method included direct inoculation of a MacConkey agar plate on which a 10-μg meropenem disk was placed and plating on MacConkey agar after overnight enrichment of the sample in MacConkey broth containing 1 μg/ml of meropenem. Forty-three (13.1%) samples were positive by PCR for bla_KPC and 11 (3.4%) were positive for bla_VIM; none were positive for bla_NDM. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay for bla_KPC were 100%, 99.0%, 93.0%, and 100%, respectively, compared to broth enrichment culture and sequencing of target genes. The sensitivity, specificity, PPV, and NPV of the assay for bla_VIM were 100%, 99.4%, 81.8%, and 100%, respectively. Since none of the clinical samples contained organisms with bla_NDM, 66 contrived stool samples were prepared at various dilutions using three Klebsiella pneumoniae isolates containing bla_NDM. The PCR assay showed 100% positivity at dilutions from 300 to 1,800 CFU/ml and 93.3% at 150 CFU/ml. The Xpert MDRO PCR assay required 2 min of hands-on time and 47 min to complete. Rapid identification of patients colonized with carbapenemase-producing organisms using multiplex PCR may help hospitals to improve infection control activities.     

Racial differences in the incidence of BRCA1 and BRCA2 mutations in a cohort of early onset breast cancer patients: African American compared to white women

Purpose

To evaluate the frequency and distribution of BRCA1 and BRCA2 mutations in a cohort of young women with breast cancer and to compare the distribution of mutations as a function of race.

Methods

After IRB approved informed consent, 170 white women and 30 African American women with known breast cancer diagnosed at a young age (45 years or less) underwent complete sequencing of the BRCA1 and BRCA2 genes. Each cohort represented approximately 40% of women of the same ethnic background aged 45 years or younger in a breast cancer database.

Results

Of the 200 patients tested, 131 (65%) had wild type mutations, 34 (17%) had deleterious mutations, and 35 (18%) had variants of uncertain significance. There were no significant differences between the white and African American cohorts regarding the percentage of deleterious mutations (17% v 17%). However, most African American patients had mutations in BRCA2 (4/5, 80%), while most mutations in the white cohort were in BRCA1 (20/29, 69%). In addition, 46% of the African American women had variants of uncertain significance, compared to only 12% of the white cohort.

Conclusions

Young African American women with breast cancer have a similar frequency of deleterious mutations as white women, but have a significantly higher frequency of variants of uncertain significance. Review of these variants revealed that the majority were unlikely to be associated with disease risk or were likely to be polymorphisms. The implications for genetic testing and counselling in young women with breast cancer are discussed.