Assessment of D-dimer measurement by ELISA or latex methods in deep vein thrombosis diagnosed by ultrasonic duplex scanning

In 100 consecutive patients with clinically suspected deep vein thrombosis (DVT) of the legs, plasma D-dimer measurements based on an enzyme linked immunosorbent assay (ELISA) and on latex agglutination (Diagnostica Stago) were compared to the results of real time B mode ultrasound imaging combined with Doppler examination, which in a previous study has proved to be a very accurate method competitive with venography for the diagnosis of DVT.Forty five patients had DVT identified with the ultrasonic tests. We have obtained for ELISA and latex tests of D-dimer respectively: accuracy: 60%, 56%; sensitivity: 98%, 98%; specificity: 29%, 22%; predictive value of a positive test: 53%, 50% and predictive value of a negative test: 94%, 92%. These results confirmed those of previous studies using ELISA or latex assays, with venography as a reference test.We conclude that a negative D-dimer test, defined by a value lower than 0.5 μg/ml, excludes the diagnosis of DVT in 94% of cases by ELISA method and in 92% of cases by latex method. A reduction of venography or other objective testing of the venous circulation could be obtained if these methods were not performed in the case of a negative D-dimer test. However the safety of withholding anticoagulant therapy in out patients with negative tests needs confirmation in a prospective trial.     

Plasma D-dimer levels in patients with deep vein thrombosis]

Hemostatic abnormalities were examined in 40 patients with deep vein thrombosis (DVT), 40 patients treated with warfarin, and 30 healthy volunteers. Plasma D-dimer levels were measured by an enzyme linked fluorescent assay (ELFA; Vidas-D-dimer) and an enzyme immunosorbent assay (ELISA; D-dimer-ELISA). Plasma levels of D-dimer, thrombin-antithrombin complex (TAT), soluble fibrin monomer (SFM) were significantly higher in patients with DVT than in the other groups. Both the sensitivity and specificity of D-dimer for diagnosis of DVT were the highest among hemostatic molecular markers examined. The most adequate cut off value of Vidas-D-dimer was 0.6 microgram/ml. Plasma levels of Vidas-D-dimer were well correlated with D-dimer ELISA, SFM and TAT. As the time of measurement for Vidas-D-dimer is less than one hour, the measurement of D-dimer using a EFLA might be useful for the diagnosis of DVT in bed side.     

Fibrin degradation product D-dimer in the diagnosis of pulmonary embolism

Summary The study objective was to determine the specificity and sensitivity of plasma concentrations of D-dimer, a fibrin degradation product, as a marker for ongoing thrombotic and thrombolytic events in pulmonary embolism. A prospective study was performed in 74 patients with suspected pulmonary embolism who appeared in the emergency room with dyspnea and/or chest pain.The presence of pulmonary embolism was established by positive findings either in pulmonary angiography or lung scan. D-dimer concentrations were determined in all patients. In 11 patients with positive pulmonary angiography, D-dimer concentrations were monitored for 6–12 days.D-dimer concentrations were determined by a quantitative enzyme-linked immunoassay. Plasma probes of 26 patients (16 with/10 without positive pulmonary angiography) were reassayed with a semiquantitative latex agglutination assay. D-dimer levels were significantly higher in patients with pulmonary embolism (>1000 ng/mL in 41 out of 43) than in those without (<1000 ng/mL in all 21 patients) (p<0.01).The sensitivity and specificity for the ELISA were found to be 95% and 100%, respectively, for establishing the diagnosis of pulmonary embolism. In the latex assay the values were 81% and 60%, respectively.It is concluded that in patients with dyspnea and/or chest pain, determination of D-dimer in plasma by ELISA adds a valuable tool to the noninvasive diagnostic procedure for pulmonary embolism. From the time-course of D-dimer values we conclude that this assay might be valuable up to at least 6 days after symptom onset. The assay, however, is unreliable in malignancies or after surgery.Abbreviations apPE angiographically proven pulmonary embolism - hpPE highly probable pulmonary embolism - imPE highly improbable pulmonary embolism - rPE pulmonary embolism ruled out - pPE possible pulmonary embolism     

Determinants of plasma fibrin D-dimer sensitivity for acute pulmonary embolism as defined by pulmonary angiography

BACKGROUND: The reported operating characteristics of the plasma fibrin D-dimer level for the diagnosis of acute pulmonary embolism vary widely. OBJECTIVE: To determine the sensitivity, specificity, predictive value, and clinical utility of the D-dimer for the diagnosis of pulmonary embolism, and to describe the effect of D-dimer assay method (enzyme-linked immunosorbent assay [ELISA], latex agglutination, membrane ELISA) and discriminate level, patient location at onset, comorbid disease, duration and intensity of concurrent heparin administration, and duration of symptoms on these operating characteristics. DESIGN: Prospective laboratory investigation. SETTING: Community and tertiary care teaching hospital. PATIENTS: Consecutive patients with suspected acute pulmonary embolism referred for pulmonary angiography from April 1993 through March 1996. MEASUREMENTS: Baseline characteristics, the duration and intensity of heparin anticoagulation, the time interval between symptom onset and plasma D-dimer testing, pulmonary angiography, and the D-dimer level on the day of pulmonary angiography. RESULTS: Of 105 consenting patients, 33 (31%) had a positive pulmonary angiogram. The D-dimer sensitivity/ negative predictive value for the ELISA, latex agglutination (American Bioproducts Co/Diagnostica Stago and Biopool International), and membrane ELISA were 100%/100%, 94%/94%, 100%/100%, and 97%/96%, respectively, at a discriminate level of 250 microg/L or less. The clinical utility, defined as the prevalence of a negative test, ranged from 17% to 33%. D-dimer sensitivity was unaffected by patient location at onset, comorbid disease, or heparin therapy but was inversely related to the duration of symptoms. CONCLUSIONS: The sensitivity of the plasma fibrin D-dimer for the diagnosis of pulmonary embolism depends on the assay method, the assay-specific discriminate level, and the duration of symptoms. At the appropriate discriminate level, the plasma D-dimer is a sensitive but nonspecific test for the diagnosis of pulmonary embolism.     

Measurement of plasma fibrin D-dimer levels with the use of a monoclonal antibody coupled to latex beads

Recently, monoclonal antibody (DD-3B6) to fibrin D-dimer was prepared and coupled to latex beads to provide a specific test (Dimertest) for fibrinolysis. The purpose of this study was to evaluate the Dimertest assay as a clinical laboratory test for the measurement of plasma fibrin D-dimer derivatives. The Dimer-test assay specifically detected 2 micrograms/mL of purified fibrin D-dimer or fibrin D-dimer/fragment E complex added to afibrinogenemic plasma but did not detect 500 micrograms/mL of either fibrinogen fragments X, D, E, or 160 micrograms/mL cross-linked fibrinogen. The fibrin(ogen) degradation product (FDP) assays of American Dade or Wellcome Diagnostics detected 5.0 micrograms/mL of fibrin D-dimer and from 1 to 10 micrograms/mL of the other FDPs. Twenty-eight percent of 150 random plasma samples assayed from hospitalized patients were positive for fibrin D-dimer derivatives. Plasma samples from 152 patients suspected of having disseminated intravascular coagulation (DIC) were assayed for serum FDP (Wellcome Diagnostics) and plasma fibrin D-dimer derivatives. Samples from 69% of patients with serum FDP levels less than 10 micrograms/mL, and more than 90% of those with serum FDP levels greater than 10 micrograms/mL, were positive for fibrin D-dimer derivatives. Dimertest results were not modified by heparin, streptokinase, freeze-thawing, or clotting plasma. Serum fibrinogen-related antigens were immunoadsorbed from Dimer-test positive sera by anti-fibrinogen antibody and formalin-fixed Cowan I strain Staphylococcus aureus. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting with the use of monoclonal antibody DD-3B6 demonstrated a protein band with similar mobility to purified D-dimer. The measurement of plasma fibrin D-dimer derivatives by the Dimertest assay is a rapid, sensitive, and specific laboratory test for fibrinolysis. The Dimertest assay has proven to be a useful addition to the clinical laboratory and should be helpful in the diagnosis and management of patients with diseases associated with fibrinolysis.     

Analysis of available diagnostic tests for latex sensitization in an at-risk population

BackgroundLack of a Food and Drug Administration (FDA)–approved skin testing reagent for latex allergy in the United States requires reliance on patient history and serologic assays for diagnosis.ObjectiveTo determine the diagnostic sensitivity, specificity, and predictive values of an FDA-cleared antilatex IgE serology test and an enzyme-linked immunosorbent assay (ELISA) with various sources of latex protein antigens in an at-risk but unselected population of health care workers.MethodsHealth care workers underwent duplicate latex and serologic testing for latex specific IgE with the CAP assay and ELISA from June 1, 1998, through December 31, 2002. Logistic regression with receiver operating characteristic curve analysis determined the values, resulting in 98% and 99% specificity for the CAP assay and ELISA, respectively.ResultsResults of paired skin and serologic tests were available for 792 participants. Forty duplicate skin test results (5%) were positive. For the CAP assay, sensitivity was 35%; specificity, 98%; positive predictive value, 48.3%; and negative predictive value, 96.6%. ELISA demonstrated similar results. Multivariable logistic regression yielding a 98% or 99% specificity for the various ELISAs demonstrated that the adjusted odds of a positive skin test result significantly increased with positive CAP assay and ELISA results using a powdered glove extract.ConclusionsThe performance of the FDA-cleared antilatex IgE serologic test for latex allergy has much lower sensitivity than previously reported. This finding confirms that this serologic test should be used only for patients with a history of latex allergy and not for screening the population with a low prevalence of latex sensitization.     

Commercial latex agglutination test for detection of Clostridium difficile-associated diarrhea.

A commercially available latex agglutination test for Clostridium difficile was compared with a cell culture cytotoxin assay and bacteriological culture for the laboratory diagnosis of C. difficile-associated diarrhea and colitis (CAD). Stool specimens from 626 patients were tested by the three methods, and specimens from 118 patients (19%) were positive by at least one of the methods. The results of the three tests agreed in 88% of the specimens tested, overall, but they agreed in only 34% of the 118 positive specimens. Ninety-three patients were evaluated to assess the significance of positive and negative results for each assay. Of 40 patients found to have CAD, 70% were positive by the cytotoxin assay, 78% were positive by the latex agglutination test, and 90% were culture positive. Of 53 patients who did not have CAD, 2% were positive by the cytotoxin assay, 8% were positive by the latex test, and 4% were culture positive. The detection of CAD was improved by using the tests in combination, and 97% of specimens positive by two or three methods were from patients who had CAD. Testing of multiple specimens from individual patients also increased the sensitivity of detection of CAD. The results suggest that the latex agglutination test may be useful for rapid diagnosis of CAD, especially in laboratories that lack cell culture facilities. However, the accuracy of CAD detection is improved when the latex test is used in combination with culture or the cytotoxin assay.     

Comparison of a latex agglutination test with other serological tests for the measurement of antibodies to Toxoplasma gondii

One hundred sera from 49 patients with glandular toxoplasmosis were examined by a latex agglutination test, the dye test, an indirect haemagglutination test, and a double antibody sandwich enzyme linked immunosorbent assay (ELISA) for antitoxoplasma IgM. The results support previous findings that the dye test, indirect haemagglutination test, and latex agglutination test measure different antibodies to Toxoplasma gondii. In early glandular toxoplasmosis, when specific IgM was detected, the titres of both the latex agglutination test and the indirect haemagglutination test were lower than the dye test. Repeat specimens from 11 of the patients showed four cases in which the latex agglutination test titres never exceeded 1/256, whereas both the dye test and the indirect haemagglutination test showed significant titres and specific IgM was detected in every case. We conclude that the latex agglutination test should not be used as a substitute for the dye test in the serological diagnosis of glandular toxoplasmosis. All sera giving a positive latex agglutination test result should be referred for further tests. A combination of the dye test and double antibody sandwich ELISA gives the most reliable serological diagnosis of early glandular toxoplasmosis.     

Evaluation of the performance of commercial test kits for detection of Helicobacter pylori antibodies in serum.

We have compared the sensitivities, specificities, and predictive values of three commercial serological assays for the diagnosis of Helicobacter pylori infection. A qualitative latex method (Pyloriset; Orion Diagnostics), a semiquantitative enzyme-linked immunosorbent assay (ELISA) (GAP test IgG; Bio-Rad), and a quantiative ELISA (Helico-G; Porton Cambridge) were used in 109 untreated dyspeptic patients. The presence of H. pylori was established when the results of culture and/or histology of the gastric biopsies taken were positive. The prevalence of H. pylori infection was 62% (52% in 42 patients younger than 45 years of age and 69% in 67 patients older than 45 years of age). Sensitivities and specificities were 68 and 76% for Pyloriset, 89 and 77% for GAP test IgG, and 82 and 83% for Helico-G. The positive predictive values for all three tests were between 85 and 90%. The predictive values for the absence of disease with a negative result were 62, 82, and 74% for Pyloriset, the GAP test, and Helico-G, respectively. With Helico-G in the younger group (less than 45 years), sensitivity significantly lower (71 versus 87%) and a positive predictive value lower than those for the older group (greater than 45 years) were found. Either the sensitivities and specificities of commercial methods for the measurement of antibodies to H. pylori in serum must be improved or the relationship between the presence of antibodies and the presence of bacteria in the stomach at the time of investigation is too weak to allow the use of serological techniques instead of culture and histological investigation of gastric biopsy material.     

Evaluation of three commercially available rotavirus detection methods for neonatal specimens

Commercially available assay kits have now made detection of rotavirus in stool specimens possible as a routine laboratory test. One such kit, Rotazyme II (Abbott Laboratories, North Chicago, IL) has been reported to give a higher incidence of false positive results with neonatal stool than with stool from older patients. One hundred stool specimens from asymptomatic neonates (age range, two to five days) were tested by two ELISA methods and one latex agglutination method in order to evaluate the rate of false positivity in this group of patients. Negative staining electron microscopy was used as the reference method. The two ELISA methods were Rotazyme II and Rotavirus EIA (International Diagnostic Laboratories, St. Louis, MO), and the latex agglutination method was Meritec-Rotavirus (Meridian Diagnostics, Inc., Cincinnati, OH). The Rotavirus EIA and Meritec-Rotavirus tests gave 0% and 1% false positive results, respectively, while the Rotazyme II test gave a 4% false positive rate with an additional 19% equivocal results. This extensive comparative analysis of commercially available assays for detection of rotavirus in neonatal stool specimens suggests a false positive or equivocal rate with the Rotazyme II test that impairs clinical utility.     

Utility of cysticercus fasciolaris antigen in Dot ELISA for the diagnosis of neurocysticercosis

Background: Clinical diagnosis of neurocysticercosis (NC) is established by CT scan and MRI. However, absolute diagnosis is not possible in a fair number of cases, and serological assays are used as adjunct. Besides, CT scan and MR imaging are resource-intensive tests and not practical for screening in endemic areas. Aim: To provide a low-cost, efficient, and reproducible assay for the detection of antibodies against cysticerci. Hence we have attempted to standardize and evaluate the diagnostic utility of the cysticercus fasciolaris antigen in a Dot ELISA assay for diagnosis of NC. Setting and Design: Tertiary hospital-based, case-control series. Materials and Methods: Confirmed cases of NC diagnosed by presence of ring lesions in CT scan or MR imaging with presence of scolex were taken as positive controls (n = 50). Negative controls (n = 50) included subjects with normal CT scan studies (n = 30) and diseased controls with ring lesions in CT scan confirmed to be neurotuberculosis (n = 20). Dot ELISA was standardized and validated with commercially available ELISA (UBI, USA) using sera from the study groups. Statistical Analysis: Chi-square test was used to compare the immunodiagnostic performance of the two tests. P value less than .05 (P < 0.05) was considered significant. Results: The Dot ELISA had a sensitivity of 88% and specificity of 74% with a positive predictive value of 77.19% and negative predictive value of 81.06%. Likelihood ratios for a positive and a negative test were 3.4 and 0.2. The sensitivity and specificity of commercial ELISA were 92% and 84% respectively. Difference between the performances of the two tests was not significant statistically. Conclusions: Dot ELISA has sensitivity and specificity comparable to ELISA for the diagnosis of NC. The test is simpler, not requiring expertise and instrumentation. Further validation of the test as a screening tool is required.     

短暂性脑缺血发作患者脂蛋白(a)和D-二聚体水平的变化

目的探讨短暂性脑缺血发作(TC I)与血清脂蛋白(a)[Lp(a)]和血浆D-二聚体(D-d im er)的关系。方法99例TC I患者按病程划分为A、B、C三组,所有病例均在起病24 h内采用酶联免疫吸附法(ELISA)检测血清Lp(a)和血浆D-二聚体的含量,观察72 h内头CT或MR I后与正常对照组进行比较,结果进行组间比较。结果TC I患者血清Lp(a)和D-二聚体的含量明显高于正常对照组(P<0.01),B、C组Lp(a)和D-二聚体的含量均高于A组(P<0.01),而且C组高于B组(P<0.0 5),重型患者明显高于轻、中型患者。TC I各组Lp(a)和D-二聚体含量之间的相关性分析显示,Lp(a)与D-二聚体含量均呈显著正相关(A组r=0.692,P<0.01;B组r=0.731,P<0.01;C组r=0.794,P<0.01)。结论Lp(a)可能是D-二聚体含量升高的主要相关因素,Lp(a)和D-二聚体含量的升高是TC I患者的危险因素,可作为TC I患者诊断、治疗和预后评估的指标。     

Use of the Pastorex aspergillus antigen latex agglutination test for the diagnosis of invasive aspergillosis.

AIMS--To evaluate the Pastorex aspergillus antigen latex agglutination test for the diagnosis of invasive aspergillosis in patients undergoing liver or bone marrow transplantation. METHODS--Serum samples were taken at least twice weekly post-transplant and tested for Aspergillus antigen. Latex agglutination test results were compared with microbiological examination of respiratory, urine and bile specimens. Serum samples from liver transplant patients were also tested for antibodies to Aspergillus fumigatus by counter immunoelectrophoresis. RESULTS--Eight of the 91 patients studied developed invasive aspergillosis. Positive latex agglutination tests were obtained in eight of 187 (4.3%) serum samples from four of these eight patients. The other four patients with invasive aspergillosis gave consistently negative latex agglutination tests. A positive latex agglutination test was the first indication of invasive aspergillosis in two patients; these patients were already on amphotericin B. Positive latex agglutination tests were the only evidence of invasive aspergillosis in one patient who subsequently died of the infection. False positive latex agglutination tests were obtained in five of 83 (6%) patients with no evidence of invasive aspergillosis and misleading positive cultures seen in nine of 83 (10.8%). No antibodies were detected in three of four liver transplant patients with invasive aspergillosis. Conversely, antibodies were detected in 63 of 262 (24%) serum samples from 43 liver transplant patients with no evidence of invasive aspergillosis; one of these patients had an antibody titre of 1:2 on four separate occasions. CONCLUSIONS--The Pastorex aspergillus antigen latex agglutination test, when used alone, lacks sensitivity and specificity for the early diagnosis of invasive aspergillosis. A diagnosis was made in all patients with invasive aspergillosis when both culture and antigen tests were performed although using these criteria a false positive diagnosis would have been made in 13 of 83 (15.6%) patients. Microbiological and serial serological investigations for antigen should both be performed and the results considered in conjunction with radiological and clinical evidence.     

Comparison of immunological methods for diagnosis of pneumococcal pneumonia in biological fluids

Five immunological tests were evaluated for their ability to detectStreptococcus pneumonine antigen in serum and urine simultaneously as a means of rapid diagnosis in 40 patients with bacteremic or non-bacteremic pneumococcal pneumonia or pneumonia with other etiologies. Serum and urine were screened in parallel with counterimmunoelectrophoresis (CIE), two commercial latex agglutination kits — the Slidex pneumokit (LA-SPK) and the BactigenStreptococcus pneumoniae kit (LA-Bac) — the coagglutination Phadebact Pneumococcus test (CoA) and a newly developed enzyme-linked immunosorbent assay (ELISA) containing the immunoglobulin G fraction from rabbit pneumococcal antiserum. The detection rate for accumulated serum in bacteremic patients was 18 % for LA-Bac, 24 % for CIE, 47 % for LA-SPK and CoA and 76 % for ELISA, whereas antigenuria was present in only 29 % for LA-SPK, 24 % for CIE, 19 % for CoA, 14 % for LA-Bac and 5 % for ELISA. Detection by ELISA of pneumococcal antigen in severely ill patients can predict bacteremia and rapidly confirm the diagnosis of pneumococcal pneumonia if sputum and results of blood cultures are not available.     

Latex allergen IgE assays in the assessment of Veterans Affairs health care workers.

BACKGROUND: A previous multicenter study of Veterans Affairs health care workers evaluated hospital participants for latex hypersensitivity. Well-defined groups from that study allowed us to explore the diagnostic utility of newer antilatex allergen IgE immunoassays in the present study. OBJECTIVES: To determine whether an enhanced CAP (ENHCAP) assay or an enzyme-linked immunosorbent assay (ELISA) identifies latex glove symptomatic individuals with antilatex allergen IgE that had not been detected by the CAP assay used in the original study and to determine the specificity of the ENHCAP assay. METHODS: The ELISA measured IgE antibody to Malaysian nonammoniated natural rubber latex extract (MNA), Hev b1, Hev b5, and Hev b6. Four patient groups were tested: confirmed latex glove allergic, latex glove symptomatic, latex glove sensitized/asymptomatic, and latex glove nonallergic. RESULTS: The ENHCAP assay and the MNA ELISA were highly concordant with the original CAP assay. In the subgroup with latex glove symptoms that were previously negative by the CAP assay, the ENHCAP assay value was elevated in 7 (11%) of 64 samples, only 3 of which were class 2 or higher. The MNA ELISA result was positive in only 4 (6%) of these 64 samples, and 3 of these were fractionally above the cutoff value for this assay. CONCLUSIONS: The ENHCAP assay and the MNA ELISA identified a few additional positive individuals in the group that was latex glove symptomatic and originally CAP assay negative. The ENHCAP assay and the MNA ELISA produced only a modest improvement in diagnostic sensitivity over that of the original CAP assay.     

Variation of plasma D-dimer following surgery: implications for prediction of postoperative venous thromboembolism

The prognosis of venous thromboembolism is considerably influenced by an accurate and fast diagnosis. Although the role of D-dimer testing in the diagnosis of suspected venous thromboembolism is well established for out-patients, there is controversial evidence on the clinical usefulness of its measurement in surgical patients. In order to recognize patterns of variation of D-dimer following surgery and identify potential pitfalls in prediction of venous thromboembolic complications, plasma D-dimer was assayed in 30 patients undergoing major elective hip surgery and 20 patients undergoing laparoscopic cholecystectomy for acute cholecystitis. The postoperative variation of plasma D-dimer differed widely between the two subgroups. Patients undergoing laparoscopic cholecystectomy showed D-dimer concentrations persistently increased from the baseline to the 15th postoperative day, whereas patients undergoing hip surgery were characterized by a double peak, on the 1st and 7th postoperative days. Mean inter-individual daily coefficient of variations of plasma D-dimer throughout the postoperative period were 49% (range 39%–61%) for laparoscopic cholecystectomy and 101% (range 72%–156%) for orthopedic surgery. The markedly heterogeneous fluctuation of plasma D-dimer suggests that the postoperative activation of the hemostatic system depends on the type and time since surgery, thus limiting the clinical usefulness of D-dimer testing in the diagnostic approach to postoperative venous thromboembolism. Received: 15 June 2001 / Accepted: 18 September 2001     

Use of rapid dipstick and latex agglutination tests and enzyme-linked immunosorbent assay for serodiagnosis of amebic liver abscess, amebic Colitis, and Entamoeba histolytica Cyst Passage

A homemade enzyme-linked immunosorbent assay (ELISA) and a dipstick assay (Dipstick) for the detection of anti-Entamoeba histolytica antibodies in serum were developed and evaluated together with a commercially available latex agglutination test (LAT; Laboratoires Fumouze) for their use in serodiagnosis of amebiasis. The sensitivity of these assays was evaluated with sera from 27 patients with radiologically proven, cellulose acetate precipitation (CAP) test-positive amebic liver abscess, 7 patients with parasitologically and PCR-proven amebic colitis, and 11 patients with parasitologically and PCR-proven E. histolytica cyst passage. The sensitivities of the ELISA, Dipstick, and LAT were all 93.3% (42/45). With a combination of Dipstick and LAT, all abscess and colitis patients had at least one positive result. The specificity was assessed with 238 sera from patients with various parasitic, bacterial, viral, and fungal infectious diseases, sera containing autoimmune antibodies, and sera from healthy blood donors. The specificities of the ELISA, Dipstick, and LAT were 97.1%, 98.1%, and 99.5%, respectively. Of 61 sera from patients with PCR-proven E. dispar infection, 60 (98.4%) were negative in both Dipstick and LAT and 59 (96.7%) were negative in ELISA. Our data suggest that all three assays are sensitive serological tests. The rapid LAT and Dipstick provide fast results and can easily be applied in routine laboratories in order to facilitate the diagnosis of amebiasis.     

Analytic validation and clinical evaluation of the STA LIATEST immunoturbidimetric D-dimer assay for the diagnosis of disseminated intravascular coagulation

To evaluate the diagnostic performance of a quantitative, immunoturbidimetric D-dimer assay and compare it with other components of the proposed International Society on Thrombosis and Haemostasis disseminated intravascular coagulation (DIC) diagnostic algorithm, we retrospectively analyzed the D-dimer, platelet count, prothrombin time, and fibrinogen results for all eligible hospitalized patients (n = 241) who had a D-dimer assay ordered during a 12-month period. A receiver operating characteristic (ROC) curve constructed from the maximum D-dimer measurement for all patients was significant (P < .001) with an area under the curve (AUC) of 0.94. The ROC curves of the other tests were each significant (P < .001), but the AUCs of the prothrombin time (0.74), fibrinogen level (0.70), and platelet count (0.67) did not approach that of the D-dimer. A D-dimer cutoff of 8.2 microg/mL (8,200 microg/L) optimized sensitivity and negative predictive value for the total population and patients with a predisposing condition. Validation against 286 additional patients in a separate analysis verified the diagnostic performance of the aforementioned cutoff. A sensitive, immunoturbidimetric D-dimer assay, by itself provides excellent sensitivity and negative predictive value for the diagnosis of DIC.     

D-dimer test: diagnostic role in clinical and sub-clinical DIC

D-dimer test is used as a diagnosis test for acute disseminated intravascular coagulation (DIC). This study was undertaken to find out its sensitivity and specificity in the diagnosis of acute DIC and its role in diagnosis of sub-clinical DIC, as there is limited data available on the subject. Of the 29 patients of clinically acute DIC, all had positive D-dimer test, and markedly prolonged PT, APTT and TT were seen in 24 (83%) of these patients. D-dimer test was found to be highly specific but less sensitive for the diagnosis of acute DIC. Of the 29 patients predisposed to sub-clinical DIC. D-dimer was positive is 26 (90%) patients and PT, APTT and TT were mildly prolonged in 11 patients. It is suggested that D-dimer positivity for the diagnoses of sub-clinical DIC need to be considered with caution and to be supplemented by other coagulation test including serial follow up with d-dimer and coagulation tests.     

New rapid latex agglutination test for diagnosing Trichomonas vaginalis infection.

A newly developed latex agglutination test for Trichomonas vaginalis infection was compared for sensitivity, specificity, efficiency, and positive and negative predictive values with microscopy, culture, and an enzyme linked immunosorbent assay (ELISA) in the diagnosis of 395 women attending a genitourinary medicine clinic. T vaginalis infection was diagnosed in 42 (11%) women. The sensitivities of both the latex agglutination test and the ELISA were 95% compared with 74% for microscopy and 76% for culture. The latex test was specific and showed no cross reaction with a wide range of other genital tract infections. The latex agglutination test can detect antigen in both soluble and insoluble forms, and as it is simple to perform, can be undertaken during routine examination without recourse to special equipment or training. Further evaluation is required.