Relationship of cytomegalovirus viral load in blood to pneumonitis in lung transplant recipients.

We developed a multiplex, quantitative, real-time, polymerase chain reaction assay for cytomegalovirus (CMV) and used it to measure the CMV viral load in weekly blood specimens from 43 lung transplant recipients. The median viral load in blood samples immediately preceding bronchoscopy was 1150 copies/microg human DNA for 12 subjects with pneumonitis compared to 91 copies for 31 subjects without (P=0.02, Mann-Whitney U test). Each log10 increase in CMV viral load resulted in an increase of 1.92 in the odds ratio for CMV pneumonitis (95% confidence interval 1.03-3.56). CMV viral load was elevated (>100 copies/microg human DNA) for a median of 21 days before bronchoscopy in those subjects with pneumonitis versus 0 days in those without (P=0.004). We conclude that the risk of CMV pneumonitis after lung transplantation is related to the level of CMV DNA in blood. Quantitative PCR should be evaluated prospectively for the preemptive management of CMV in lung transplant recipients.     

Evaluation and significance of cytomegalovirus-specific cellular immune response in lung transplant recipients

In lung transplant recipients, cytomegalovirus (CMV) has been associated with direct ie, organ and systemic infection/disease, and indirect effects, including predisposition to develop acute rejection episodes and chronic allograft dysfunction. Cellular immune responses have been demonstrated to play a role in the control of CMV replication. We evaluated CMV-specific cellular responses among lung transplant recipients associated with the onset of organ infection/disease. Cellular responses were evaluated by an Elispot assay of 48 specimens from 24 patients. All samples were evaluated beyond 1 year after transplantation; CMV DNA was concomitantly detected in bronchoalveolar lavage (BAL) and whole blood specimens. Each patient received a combined prolonged antiviral prophylaxis with CMV Ig for 12 months and gancyclovir or valgancyclovir for 3 weeks after postoperative day 21. Nine patients (37.5%) showed transient or persistent CMV nonresponses including donor-recipient negative serologic matching in 2 cases. Positive CMV DNA results were observed in 18/48 BAL specimens (37.5%) from 12 patients (50%). A viral load of >10⁴ copies/mL was observed in only 3 cases, 2 of whom were positive also on whole blood. Among these 3 patients, 2 were responders and BAL (as well as whole blood) specimens collected subsequently were negative for CMV DNA; 1 nonresponder patient exhibited a viral load of 426,492 copies/mL BAL (DNAemia, <2,000 copies/mL), developed CMV pneumonia (confirmed by histopathology and immunohistochemistry) and died within 28 days. The prevalence of CMV DNA positivity on BAL did not differ in relation to the immune response; the mean viral load on BAL showed significantly higher results among nonresponders than responders, namely, 1.4 × 10⁵ ± 2.4 × 10⁵ copies/ml versus 7.9 × 10³ ± 1.4 × 10⁴ (P = .02). Evaluation of CMV-specific cellular immune responses by in vitro immunologic monitoring complements virologic monitoring, helping to identify lung transplant recipients at risk of developing organ infection/disease.     

Impact of prophylaxis with cytogam alone on the incidence of CMV viremia in CMV-seropositive lung transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection remains a serious problem after lung transplantation. The purpose of this study was to evaluate the efficacy of CytoGam, a CMV hyperimmune globulin (CMV-IGIV), as CMV prophylaxis after lung transplantation. METHODS: This prospective, randomized, open-label study compared prophylaxis with CMV-IGIV and no prophylaxis in 44 CMV-seropositive lung transplant recipients. The primary end-point was development of CMV viremia during the first year after transplantation. RESULTS: Cytomegalovirus viremia was detected in 13 of 22 recipients without prophylaxis and in 16 of 22 recipients with CMV-IGIV prophylaxis (p = 0.19). Cytomegalovirus pneumonitis developed in 8 controls vs in 11 CMV-IGIV recipients (p = 0.54). We found no significant difference between the groups in the incidence of positive shell vial assays (6.8% +/- 6.5% without vs 11.2% +/- 10.1% with prophylaxis, p = 0.09) or in the attack rate of CMV pneumonitis (0.41 +/- 0.59 episodes/patient without vs 0.86 +/- 0.99 episodes/patient with prophylaxis, p = 0.07). Similarly, no difference was apparent in the time to onset of CMV viremia, to detection of CMV DNA in peripheral blood leukocytes by polymerase chain reaction, or to development of CMV pneumonitis. The incidence of acute rejection and bronchiolitis obliterans syndrome and the survival rate during the first post-transplant year did not differ between the groups. CONCLUSIONS: Prophylaxis with CMV-IGIV alone did not decrease CMV viremia or pneumonitis, did not decrease the incidence of acute rejection or bronchiolitis obliterans syndrome, and did not affect 1-year survival of CMV-seropositive lung transplant recipients at our center.     

Cytomegalovirus Replication Within the Lung Allograft Is Associated With Bronchiolitis Obliterans Syndrome

Early studies reported cytomegalovirus (CMV) pneumonitis as a risk factor for development of bronchiolitis obliterans syndrome (BOS) following lung transplantation. While improvements in antiviral prophylaxis have resulted in a decreased incidence of CMV pneumonitis, molecular diagnostic techniques allow diagnosis of subclinical CMV replication in the allograft. We hypothesized that this subclinical CMV replication was associated with development of BOS. We retrospectively evaluated 192 lung transplant recipients (LTR) from a single center between 2001 and 2009. Quantitative (PCR) analysis of CMV viral load and histological evidence of CMV pneumonitis and acute cellular rejection was determined on 1749 bronchoalveolar lavage (BAL) specimens and 1536 transbronchial biopsies. CMV was detected in the BAL of 41% of LTR and was significantly associated with the development of BOS (HR 1.8 [1.1–2.8], p = 0.02). This association persisted when CMV was considered more accurately as a time‐dependent variable (HR 2.1 [1.3–3.3], p = 0.003) and after adjustment for significant covariates in a multivariate model. CMV replication in the lung allograft is common following lung transplantation and is associated with increased risk of BOS. As antiviral prophylaxis adequately suppresses CMV longer prophylactic strategies may improve long‐term outcome in lung transplantation.     

Cytomegalovirus (CMV) DNA quantification in bronchoalveolar lavage fluid of immunocompromised patients with CMV pneumonia

Cytomegalovirus (CMV) pneumonia causes major morbidity and mortality. Its diagnosis requires demonstration of viral cytopathic changes in tissue, entailing risks of lung biopsy. This study aimed to determine CMV viral load (VL) thresholds in bronchoalveolar lavage fluid (BALF) for diagnosis of CMV pneumonia in immunocompromised patients. CMV VL in BALF was studied in 17 patients (83% transplant recipients) and 21 control subjects with and without CMV pneumonia, respectively, using an FDA‐approved PCR assay (Cobas^® AmpliPrep/Cobas TaqMan^® CMV Test, Roche Molecular Systems, Inc.) calibrated to the WHO International Standard for CMV DNA (NIBSC: 09/162). Receiver operating characteristic curve analysis produced a BALF CMV VL threshold of 34 800, IU/mL with 91.7% sensitivity and 100.0% specificity for diagnosis of possible, probable, and proven CMV pneumonia in transplant patients, while a threshold of 656 000 IU/mL yielded 100% sensitivity and specificity among biopsy‐proven cases. For all immunocompromised patients, a VL threshold of 274 IU/mL was selected. VL thresholds also were normalized to BALF cell count yielding a threshold of 0.32 IU/10⁶ cells with 91.7% sensitivity and 90.5% specificity for possible, probable, and proven CMV pneumonia in transplant recipients. Monitoring CMV VL in BALF may be a less invasive method for diagnosing CMV pneumonia in immunocompromised patients.     

Association of cytomegalovirus DNA concentration in epithelial lining fluid and symptomatic cytomegalovirus infection in lung transplant recipients

BACKGROUND: The authors have investigated the effectiveness of virus detection from bronchoalveolar lavage (BAL) samples for the identification of symptomatic cytomegalovirus (CMV) infection in lung transplant recipients. METHODS: Thus, 275 BAL samples taken from 105 lung transplant recipients during follow-up were analyzed by quantitative polymerase chain reaction (PCR) and virus isolation. RESULTS: Quantitative PCR detected virus in all 24 BAL samples taken at onset of symptomatic disease, and virus culture in only 7 samples (29.2%). Twenty-three of 251 BAL samples (9.2%) were positive by PCR, although they were obtained in an asymptomatic phase. Quantitation of CMV DNA from BAL allowed no discrimination between symptomatic and asymptomatic infection in individual cases. However, when the urea dilution method was used to recalculate the CMV DNA concentration for the epithelial lining fluid (ELF) diluted in the BAL, a CMV DNA level of more than 10 copies/mL ELF was clearly associated with symptomatic disease. CONCLUSION: The CMV DNA level in ELF may be a marker for symptomatic CMV infection.     

Viremia after lung transplant: a cohort study on risk factors and symptoms associated with detection of Epstein-Barr virus

Background-The frequency and impact of detection of Epstein-Barr virus in the blood of lung and heart-lung transplant recipients in the postoperative period is poorly characterized.Objective-To investigate the frequency of virus detection, associated clinical symptoms and risk factors, and influence of virus detection on outcome.Methods-A cohort of 98 lung transplant recipients were monitored for Epstein-Barr virus in blood before transplant and during their posttransplant hospital stay (median 4 weeks, range 1-21 weeks). Patients were followed up for retransplant or death for a median of 17 months.Results-Epstein-Barr virus DNA was detected in 15 recipients (18.1%) before and in 39 recipients (41.5%) after transplant. Median viral load after transplant was 2300 copies per milliliter of blood (range, 900-45 000 copies/mL). Detection of Epstein-Barr virus DNA before transplant and mechanical ventilation before transplant were associated with detection of Epstein-Barr virus DNA after transplant. Shortness of breath, fatigue, and hoarseness were associated with detection of viral DNA after transplant. The incidence of retransplant or death was not increased in recipients who had viral DNA detected in their blood.Conclusions-Epstein-Barr virus DNA in the blood before transplant and mechanical ventilation before transplant were associated with detection of viral DNA after transplant. Detection of viral DNA after transplant was frequent and clinically relevant.     

Quantification of cytomegalovirus (CMV) viral load by the hybrid capture assay allows for early detection of CMV disease in lung transplant recipients.

BACKGROUND: We prospectively compared the hybrid capture system (HCS) assay with conventional cell culture and shell vial assay for the detection of cytomegalovirus (CMV) infection and disease in the lung transplant population. METHODS: Between January 1999 and February 2000, 34 lung transplant patients at Loyola University Medical Center, who were considered to be at risk for CMV disease, underwent surveillance testing for CMV cell culture, shell vial assay and HCS assay according to a pre-determined schedule. In addition, bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy were performed at regular intervals and for clinical indications. All BAL samples were sent for CMV cultures and biopsy specimens were analyzed for histopathologic evidence of CMV by immunoperoxidase staining using antibody to early immediate nuclear antigen. RESULTS: Ten patients developed CMV disease/syndrome during the course of the study. The sensitivity, specificity, positive predictive value and negative predictive value were >90% for the HCS assay. The sensitivity of the HCS assay (90%) was statistically significantly higher than the sensitivity of either the SV assay (40%) or the cell culture (50%). In addition, the HCS assay was able to detect CMV 50 +/- 67 days prior to clinical evidence of CMV disease and an average of 36 days prior to the other detection techniques. CONCLUSION: The HCS assay is a sensitive diagnostic technique able to reliably detect CMV disease earlier than other diagnostic methods in the lung transplant population. Future studies may be able to evaluate whether pre-emptive anti-viral therapy targeted to specific viral loads using the HCS assay will be beneficial in preventing morbidity associated with CMV disease.     

Detection of human cytomegalovirus antigenaemia: a rapid diagnostic technique for predicting cytomegalovirus infection/pneumonitis in lung and heart transplant recipients.

BACKGROUND--New rapid diagnostic techniques offer the opportunity of early diagnosis of human cytomegalovirus (CMV) infection in immunocompromised patients at risk of developing CMV disease. The use of human CMV antigenaemia as a predictor of clinical CMV infection and disease in lung and heart transplant recipients was studied prospectively. METHODS--Twenty three heart and nine lung transplant recipients who survived 40 days were observed by standard CMV surveillance with serological testing, culture, and by sequential testing for CMV antigenaemia. CMV antigenaemia testing is a rapid and quantifiable technique in which a viral lower matrix protein is detected in cytospin preparations of peripheral blood polymorphonuclear leucocytes (PMNLs) by immunofluorescent staining. RESULTS--Eleven patients developed CMV infection and five developed CMV disease (four pneumonitis, one duodenitis). These clinical events occurred at a median of 65 days following transplantation. CMV antigenaemia occurred in 17 patients at a median of 35 days following transplantation. Detection of CMV antigenaemia had a sensitivity of 100%, a specificity of 93.7%, and a positive predictive value of 94.1% for CMV related illness. CMV antigenaemia was positive at a significant interval before the clinical event. High levels of CMV antigenaemia (> 50 CMV antigen positive cells/2 x 10(5) PMNLs) occurred in 11 patients and five of these developed disease. CMV antigenaemia of > 50 CMV antigen positive cells/2 x 10(5) PMNLs had a positive predictive value of 45.5% for disease but a negative predictive value of 100%. Patients with disease had higher levels of antigenaemia than those without disease. CONCLUSIONS--CMV antigenaemia is a rapid diagnostic technique which can identify patients likely to develop CMV disease, potentially allowing early treatment.     

The impact of ganciclovir-resistant cytomegalovirus infection after lung transplantation

BACKGROUND: Cytomegalovirus (CMV) resistance to ganciclovir has become increasingly common in acquired immunodeficiency syndrome patients but has only rarely been reported in recipients of solid organ transplants. METHODS: A retrospective study of ganciclovir susceptibility testing of CMV isolates recovered from lung transplant recipients was performed. Patients with CMV isolates having partial (1 or =3 microg/ml) to ganciclovir determined by plaque reduction assay were included in a case-control study to identify risk factors for ganciclovir resistance. RESULTS: Between 2/91 and 5/98, 18 patients (5.2% of patients transplanted) were found to have CMV infections with some degree of ganciclovir resistance (4 partially, 14 fully resistant). More positive viral blood cultures (3.2+/-2.5 vs. 1.6+/-1.4 CMV positive cultures, P=0.02) and more episodes of CMV pneumonitis (0.24+/-0.23 vs. 0.10+/-0.17 episodes/bronchoscopy, P=0.02) occurring before the detection of resistance were seen among resistant patients than controls. Ganciclovir-resistant patients received more antithymocyte globulin during induction (70+/-44 vs. 45+/-39 mg/kg, P=0.03) and received ganciclovir for a greater number of days (79+/-52 vs. 64+/-53 days, P=0.005) before the detection of resistance than controls. Ganciclovir-resistant patients had a shorter survival and an earlier onset of bronchiolitis obliterans syndrome compared with patients in the transplant database at Washington University. CONCLUSIONS: Ganciclovir-resistant CMV infection is a serious complication of solid organ transplantation associated with more episodes of viremia, more frequent disease, earlier onset of bronchiolitis obliterans and shorter survival. The use of antithymocyte globulin and prolonged exposure to ganciclovir are risk factors for the development of ganciclovir resistance.     

Prospective study of pulmonary function for cyclomegalovirus infection after renal transplantation

Abstract Pulmonary involvement remains the main complication of cytomegalovirus (CMV) infection in renal transplantation (RT). Early diagnosis is required for the best management of patients, and preemptive therapy could be a successful approach. In order to define the predictive value of lung alveolocapillary abnormalities. We prospectively studied 26 renal transplant recipients for their diffusing capacity of carbon monoxide (DLCO) and their pulmonary clearance of a ^99mTc-DTPA aerosol. Patients were studied before transplantation and then every 2 weeks up to the end of the 3rd month following RT. Viral blood cultures and serological determinations were performed every week during these first 3 months. Bronchoalveolar lavage (BAL) was done in case of CMV disease. Statistic analysis was done using Student's t -test and Pearson's chi-quare test. During the 3-month follow-up, 13 patients remained free of CMV infection. Three non-infected and 8 infected patients showed DTPA clearance abnormalities (P < 0.05). Six non-infected and 7 infected patients showed DLCO disturbance (P > 0.50). DTPA clearance were significantly modified on days 45 and 60 in the infected group. Serial DTPA scanning, in association with viral blood cultures, could be a useful test to avoid unnecessary BAL in a preemptive therapy strategy.     

The risk of cytomegalovirus recurrence after kidney transplantation

Recurrent cytomegalovirus (CMV) infections commonly occur after kidney transplantation. We studied the impact of secondary prophylaxis and other factors on the risk of CMV recurrence. All kidney transplant recipients between 2004 and 2009 in our institution were analyzed (N = 254). Patients with CMV infection were included (N = 62). CMV infections were diagnosed with quantitative PCR. CMV D+/R- recipients received 6 months valganciclovir prophylaxis, after which DNAemia was monitored. After treatment, secondary prophylaxis with valganciclovir was given at the clinician's discretion for 2-26 weeks and CMV DNAemia was monitored. Altogether 43 reactivations and 19 primary infections occurred. Antiviral treatment with valganciclovir or ganciclovir was given to 45 patients; 34/62 (55%) patients received secondary prophylaxis for mean 62 days (range 14-180 days). CMV recurrence occurred in 14/43 (33%) seropositive patients and in 4/19 (21%) patients after primary infection. In logistic regression, delayed graft function (OR 3.4) and high viral load (>100 000 copies/ml) at initial diagnosis (OR 5.9) predicted recurrence. Use or length of secondary prophylaxis, CMV serostatus, level of immunosuppression, HLA mismatch, antiviral treatment, or time to clearance of viremia during treatment did not predict recurrence of CMV. CMV recurrences occur commonly despite secondary prophylaxis. High viral load at diagnosis predicted the risk of recurrent CMV infection.     

Interlaboratory Comparison of Cytomegalovirus Viral Load Assays

To assess interlaboratory variability in qualitative and quantitative cytomegalovirus (CMV) viral load (VL) testing, we distributed a panel of samples to 33 laboratories in the USA, Canada and Europe who performed testing using commercial reagents (n = 17) or laboratory-developed assays (n = 18). The panel included two negatives, seven samples constructed from purified CMV nucleocapsids in plasma (2.0–6.0 log₁₀ copies/mL) and three clinical plasma samples. Interlaboratory variation was observed in both actual (range, 2.0–4.0 log₁₀ copies/mL) and self-reported lower limits of detection (range, 1.0–4.0 log₁₀ copies/mL). Variation observed in reported results for individual samples ranged from 2.0 log₁₀ (minimum) to 4.3 log₁₀ (maximum)_. Variation was greatest at low VLs. Assuming ± 0.5 log₁₀ relative to the expected result represents an acceptable result, 57.6% of results fell within this range. Use of commercially available reagents and procedures was associated with less variability compared with laboratory-developed assays. Interlaboratory variability on replicate samples was significantly greater than intralaboratory variability (p < 0.0001). The significant interlaboratory variability in CMV VL observed may be impacting patient care and limiting interinstitutional comparisons. The creation of an international reference standard for CMV VL assay calibration would be an important step in quality improvement of this laboratory tool.     

Infectious diseases in kidney transplant recipients treated with cyclosporin

Cyclosporin (CYA) is now recognized as an effective immunosuppressant to lead to a marked improvement in graft survival in organ transplant recipients. Although the incidence of infection in the CYA group has been decreased compared with that in the azathioprine group, infectious diseases in 400 kidney transplant recipients treated with CYA were noted in our single center. Treatment strategy for infectious diseases: Antibiotics and/or gamma-Globulin were administered to all recipients with bacterial infections. Aciclovir was added in recipients with herpes simplex virus (HSV) infection or varicella zoster virus (VZV) infection. Human interferon-beta (HuIFN-beta) was used in recipients who had life-threatening viral infection, especially cytomegalovirus (CMV) pneumonitis. Glycyrrhizin was used for acute hemorrhagic cystitis and nephropathy due to adenovirus (AV). Trimethoprim sulfamethoxazole and/or pentamidine were added in recipients complicated with Pneumocystis carinii (Pc) pneumonitis or in order to prevent Pc pneumonitis. Infectious diseases: One hundred and six recipients had infectious diseases 129 times in this series, seventy-six percent of all infections occurred during the first 4 months after the transplantation. Urinary tract infection (UTI), herpes zoster and pulmonary infection were the most common infectious diseases, occurring in 28.7%, 24.0% and 23.2%, respectively. Septicemia or bacteremia developed in 9 recipients, secondary to UTI in 8 and to surgical wound infection in one. Sixty-one symptomatic viral infections occurred in 57 recipients. A total of 5 recipients (1.3%) died of interstitial pneumonitis. Infectious organisms: Viral and bacterial infections were most common, occurring in 47.3% and 41.9%, respectively. Viral species detected in these recipients with the frequency were HSV 14 times, CMV 9 times, VZV 31 times and AV 7 times. 1) The incidence of viral infections in kidney transplant recipients treated with CYA is relatively high compared to bacterial infections. 2) HuIFN-beta therapy is effective in the treatment of serious opportunistic herpes virus infections, especially CMV pneumonitis. 3) Glycyrrhizin therapy is effective in the treatment of acute hemorrhagic cystitis and nephropathy due to AV and hepatic dysfunction. 4) Aerosolised pentamidine therapy is very useful for prophylaxis of Pc pneumonitis.     

A Multicenter Study of Valganciclovir Prophylaxis up to Day 120 in CMV-Seropositive Lung Transplant Recipients

Seventy-six cytomegalovirus (CMV)-seropositive lung transplant recipients receiving valganciclovir (900 mg/day) for CMV prophylaxis were compared with a group of 87 patients receiving oral ganciclovir (3000 mg/day). Prophylaxis was administered to day 120 post-transplantation and follow-up was 1 year. In addition, a study was conducted on risk factors for CMV infection/disease. CMV disease incidence was 7.9% and 16.1% for valganciclovir and oral ganciclovir, respectively (p = 0.11). Patients receiving valganciclovir had fewer viral syndromes (2.6% vs. 11.5%, p < 0.05), a similar rate of tissue-invasive disease (5.2% vs. 4.6%, p = ns), longer time-to-onset of CMV infection/disease (197.5 vs. 155.2 days, p < 0.05), and a lower probability of infection/disease while on prophylaxis (1.3% vs. 12.6%, p < 0.01). Nonetheless, leukopenia incidence was higher with valganciclovir (15.8% vs. 2.3%, p < 0.01), as was the need for treatment withdrawal due to adverse effects (11.8% vs. 1.1%, p < 0.01). CMV infection was similar in both groups (32.9% vs. 34.5%). Induction therapy with basiliximab and glucocorticosteroid treatment were independent risk factors for developing CMV infection/disease. In conclusion, valganciclovir prophylaxis results in a low incidence of CMV disease in lung transplant recipients and appears more effective than oral ganciclovir. Despite the comparatively higher incidence of adverse events with valganciclovir, the drug can be considered safe for prophylaxis.     

A Trial of Valganciclovir Prophylaxis for Cytomegalovirus Prevention in Lung Transplant Recipients

Cytomegalovirus (CMV) infection is common after lung transplantation. We performed a prospective trial of valganciclovir prophylaxis in lung recipients with outcomes compared to matched historical controls. The valganciclovir group (n = 40) (including D+/R- and R+ patients) was prospectively enrolled, and received oral valganciclovir 900 mg once daily for 12 weeks. Historical controls (n = 40) received 12 weeks of daily intravenous ganciclovir if D+/R- or 12 weeks of oral ganciclovir if R+. CMV viral load testing was done at two-week intervals until 6 months posttransplant. Baseline demographics and immunosuppression were comparable in the two groups. The incidence of CMV viremia was 16/40 (40.0%) in the valganciclovir arm versus 18/40 (45%) in the ganciclovir arm (p = NS). The incidence of symptomatic CMV disease was 8/40 (20%) versus 7/40 (17.5%), respectively (p = NS). In both groups viremia, while on prophylaxis, was uncommon (valganciclovir: 0/40 and ganciclovir: 2/40). Peak viral load and time to viremia were similar in the two arms. High rates of viremia and symptomatic disease occurred in the D+/R- patients after discontinuation of prophylaxis. Genotypic CMV sequence analysis demonstrated low rates of ganciclovir resistance in both groups. Valganciclovir prophylaxis had similar efficacy to either intravenous ganciclovir (D+/R- patients), or oral ganciclovir (R+ patients) in lung recipients.     

Clinical utility of bronchoalveolar lavage cell phenotype analyses in the postoperative monitoring of lung transplant recipients.

OBJECTIVE: Bronchoalveolar lavage (BAL) fluid provides a crucial tool for investigation of the cellular component of the deep lung spaces and hence to approach the alloreactive response following lung transplantation. This study investigated whether BAL cell profiles can assist for the diagnosis of certain postoperative complications. METHODS: We conducted a retrospective analysis of both transbronchial biopsy and bronchoalveolar lavage materials in a series of 26 consecutive lung transplant recipients (LTR) in relationship with their clinical status at the time of the procedure. BAL fluid was subjected to cell morphology as well as flow cytometric phenotypic analyses. The samples were labeled as follows: normal transplant in clinically stable and healthy recipients, n=58; acute rejection (AR), n=58; infection (INF), n=31; and obliterative bronchiolitis/bronchiolitis obliterans syndrome (OB/BOS) n=27. RESULTS: Total BAL cell counts were the highest in INF. Lymphocytic alveolitis was suggestive of both acute allograft rejection and CMV viral infection, with a combined significant increased HLA-DR positive cells in AR. Alveolar neutrophilia with an increased CD4/CD8 ratio was correlated with the diagnosis of OB. The neutrophil percentages, HLA-DR and CD57 positive cells were significantly higher when an infection was present. CONCLUSION: These findings suggest that BAL cell analysis could give complementary information of histological data and further insight into immunologic events after lung allograft. A longitudinal surveillance of BAL cell profiles in an individual patient may be suggestive for a preclinical state of posttransplant acute rejection, bacterial infection and obliterative bronchiolitis.     

Emergence of multiple cytomegalovirus strains in blood and lung of lung transplant recipients

BACKGROUND: Cytomegalovirus (CMV) is a major pathogen in lung transplant recipients (LTRs). The emergence of different CMV strains in lung and blood after transplantation has not yet been analyzed. METHODS: In total, 75 serum and 91 broncheoalveolar lavage (BAL) samples obtained from 25 LTRs in the follow-up after transplantation were tested for the presence of different CMV strains. The gB, gN, and gO genes of the CMV isolates were analyzed by subtype-specific PCR, restriction fragment length polymorphism (RFLP), sequencing, and phylogenetic analysis. RESULTS: Mixed CMV-strain populations were detected after cessation of antiviral prophylaxis in up to 80% and 90% of the patients' BAL and serum, respectively, and this was independent of the CMV serostatus of donor and recipient. In five patients, the same single CMV strain was consistently detectable over at least 1 year in lung and blood, although in two of these cases donor and recipient had both been CMV-seropositive. Most CMV strains were distributed in the lung and blood compartment. Symptomatic CMV infection within the first year after transplantation was observed only in patients with mixed CMV-strain populations (P<0.05). CONCLUSION: Most LTRs harbor more than one CMV strain in their lung and blood compartment after cessation of prophylaxis, but the CMV strain distribution within and between the compartments varies between individuals and is not associated with the donor/recipient serostatus. The data further show that compartmentalization of CMV strains in lung versus blood seems to be a rare event and that the presence of mixed CMV-strain infections within the first year after transplantation may be disadvantageous for LTRs.     

Utility of cytomegalovirus viral load in renal transplant patients in Argentina

BACKGROUND: Cytomegalovirus (CMV) is the most prevalent viral disease in solid organ transplantation. Detection of CMV DNA in peripheral blood mononuclear cells (PBMC) by polymerase chain reaction (PCR) frequently occurs in renal allograft recipients, yielding false positive results in seropositive patients free of CMV disease. We evaluated the clinical utility of a quantitative PCR-enzyme-linked immunosorbent assay (ELISA) for identifying patients with CMV disease. METHODS: Three hundred and fifty samples from 65 consecutive renal transplant recipients were studied. DNA was extracted from PBMC weekly up to the day of discharge and after any further admission. Samples were tested by a qualitative PCR method, and all positive samples were further studied by a quantitative PCR-ELISA method. The quantitative PCR-ELISA method used an internal standard (IS) that contained the primer sequences used in the qualitative CMV PCR. Detection and quantification was performed in 96-well plates coated with IS or CMV specific probes. RESULTS: Forty-one of 65 patients (63.1%) showed positive results by the qualitative PCR, but only 8 of these patients were diagnosed with CMV disease. Positive samples were re-analyzed by the quantitative assay. The 8 patients with CMV disease had a mean CMV viral load of 1,438+/-687 viral copies (VC)/10(6) PBMC, and the 33 without CMV disease had a mean value of 219.6+/-117.2 VC/10(6) PBMC (P<0.01). None of the 33 patients without CMV disease had viral loads higher than 500 VC/10(6) PBMC. Using 500 VC/10(6) PBMC as a cut-off value for CMV disease, the quantitative PCR showed a sensitivity and specificity of 100% compare to clinical diagnosis. CONCLUSION: CMV viral load may be useful in the diagnosis of CMV disease in renal transplant patients.     

Clinical utility of quantitative cytomegalovirus viral load determination for predicting cytomegalovirus disease in liver transplant recipients

BACKGROUND: The early detection of cytomegalovirus (CMV) after liver transplantation may form the basis of a preemptive strategy for prevention of active CMV disease. METHODS: We prospectively analyzed the clinical use of weekly quantitative polymerase chain reaction-(PCR) based plasma viral load determinations and the antigenemia assay for predicting the development of active CMV disease in 97 consecutive liver transplant recipients. RESULTS: CMV disease occurred in 21/97 patients. Using a positive cut-off of >400 copies/ml plasma, PCR had a sensitivity of 100%, specificity 47.4%, positive predictive value 34.4% and negative predictive value 100% for prediction of CMV disease. Respective values for a positive antigenemia (>0 positive cells/slide) were 95.2, 55.3, 37.0, and 97.7%. Different cut-off points for a positive test were analyzed using receiver-operating characteristic (ROC) curves. The optimal cut-off for viral load was in the range of 2000-5000 copies/ml (sensitivity 85.7%, specificity 86.8%, PPV 64.3%, NPV 95.7% for >5000 copies/ml). The optimal cut-off for antigenemia was in the range of four to six positive cells/slide. Mean peak viral load in symptomatic patients was 73,715 copies per/ml versus 3615 copies/ml in patients with asymptomatic CMV reactivation (P<0.001). In a multivariate logistic regression analysis of risk factors for CMV disease (CMV serostatus, acute rejection, and induction immunosuppression), peak viral load and peak antigenemia emerged as the only significant independent predictors of CMV disease (for PCR, odds ratio=1.40/1000 copy/ml increase in viral load, P=0.0001; for antigenemia odds ratio=1.17/1 positive cell/slide). CONCLUSIONS: Plasma viral load by quantitative PCR is useful for predicting CMV disease and could be used in a preemptive strategy.