Joseph D. C. Yao

A randomized, prospective, double-blinded evaluation of selective bowel decontamination in liver transplantation.

Background. Bacterial infection is a frequent, morbid, and mortal complication of liver transplantation. Selective bowel decontamination (SBD) has been reported to reduce the rate of bacterial infection after liver transplantation in uncontrolled trials, but benefits of this intervention have been less clear in controlled studies. Methods. Eighty candidates for liver transplantation were randomly assigned in a double-blinded fashion to an SBD regimen consisting of gentamicin 80 mg+polymyxin E 100 mg+nystatin 2 million units (37 patients) or to nystatin alone (43 patients). Both treatments were administered orally in 10 ml (increasing to 20 ml, according to predefined criteria), four times daily, through day 21 after transplantation. Anal fecal swab cultures were performed on days 0, 4, 7, and 21. Rates of infection, death, and charges for medical care were assessed from day 0 through day 60. Results. More than 85% of patients in both treatment groups began study treatment more than 3 days before transplantation. Rates of infection (32.4 vs. 27.9%), death (5.4 vs. 4.7%), or charges for medical care (median

Multi-center evaluation of the Abbott RealTime HCV Assay for monitoring patients undergoing antiviral therapy for chronic hepatitis C

194,000 vs.

Multicenter Evaluation of the VERSANT Hepatitis B Virus DNA 3.0 Assay

163,000) were not reduced in patients assigned to SBD. On days 0, 4, 7, and 21, growth of aerobic gram-negative flora in fecal cultures of patients assigned to SBD was significantly less than that of patients taking nystatin alone; growth of aerobic gram-positive flora, anaerobes, and yeast was not significantly different. Conclusion. Routine use of SBD in patients undergoing liver transplantation is not associated with significant benefit.

Risk stratification and targeted antifungal prophylaxis for prevention of aspergillosis and other invasive mold infections after liver transplantation

BACKGROUND Hepatitis C virus (HCV) RNA monitoring during antiviral therapy is essential for early prediction of treatment success and failure to peginterferon alfa/ribavirin (PEG-IFN/RBV) therapy. OBJECTIVES In this multi-center study we assessed the clinical utility of the Abbott RealTime HCV assay for monitoring patients undergoing antiviral therapy for chronic infection with HCV genotypes (GT) 1-3. STUDY DESIGN We analyzed serum from 361 patients with chronic hepatitis C who had been treated with PEG-IFN/RBV. The predictive value of rapid virologic response (RVR), partial (≥2log(10) decline) and complete (HCV-RNA undetectable) early virologic response (pEVR/cEVR) based on RealTime HCV for achieving sustained virologic response was evaluated. In addition, the utility of RealTime HCV to tailor treatment duration according to individual virologic responses was studied in a subset of 136 GT 1 patients and compared to the reference tests, Versant HCV Quantitative 3.0 (bDNA) and Qualitative (TMA) assay. RESULTS At week 4 of therapy, patients with RVR had a 100% and 93.5% probability to achieve an SVR in GT 1 and GT 2/3 patients, respectively. At week 12, patients who did not achieve a pEVR had a 97.2% and 100% probability of not achieving an SVR. In addition, assignment of GT 1 patients to abbreviated or extended treatment durations based on low baseline HCV-RNA (<800,000IU/mL) and RVR or pEVR was highly concordant between RealTime HCV and bDNA/TMA assays (97.8% and 91.9%, respectively). CONCLUSIONS The RealTime HCV assay is suitable for monitoring virologic response to PEG-INF/RBV therapy and tailoring treatment duration accordingly.

Virologic Suppression Measured by a Cytomegalovirus (CMV) DNA Test Calibrated to the World Health Organization International Standard Is Predictive of CMV Disease Resolution in Transplant Recipients

ABSTRACT The VERSANT hepatitis B virus (HBV) 3.0 Assay (branched DNA [bDNA]) (referred to herein as VERSANT 3.0) was evaluated at four external sites for analytical sensitivity, specificity, reproducibility, linearity of quantification, and limits of detection. In addition, each of the test evaluation sites provided HBV DNA-positive clinical samples that were previously analyzed by one of three commercially available HBV DNA quantitative tests: Digene Hybrid Capture II HBV DNA Test (Digene); VERSANT HBV DNA 1.0 Assay (bDNA) (VERSANT 1.0); and COBAS AMPLICOR HBV Monitor Test (COBAS AMPLICOR). These samples were reexamined using VERSANT 3.0. The results from these studies showed that VERSANT 3.0 has high specificity (99.3%), excellent reproducibility (between-run coefficient of variation [CV] = 1.6 to 9.4%; within-run CV = 6.5 to 20.7%), and a broad linear range of quantification (2.0 × 103 to 1.0 × 108 HBV DNA copies/ml) that facilitate the monitoring of HBV DNA levels at diagnosis and throughout the course of treatment. In general, correlation was very good between results obtained from clinical samples analyzed by VERSANT 3.0 and the comparative HBV DNA quantitative assays (VERSANT 1.0, R2 = 0.900; Digene, R2 = 0.985; COBAS AMPLICOR, R2 = 0.771). The greatest differences in comparative quantitation occurred at HBV DNA levels approaching the limits of the dynamic ranges for the comparative assays. The performance characteristics of the new VERSANT 3.0 assay demonstrated that it provides a reliable and robust method for routinely monitoring serum HBV DNA levels in assessing disease activity and determining response to antiviral treatment.

Comparison of the Abbott RealTime Human Immunodeficiency Virus Type 1 (HIV-1) Assay to the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test: Workflow, Reliability, and Direct Costs

Antifungal prophylaxis has been proposed for liver transplant recipients at increased risk for invasive mold infection. Risk factors for invasive mold infection after liver transplantation were selected to divide recipients into 3 groups: (1) high risk—transplantation on hemodialysis or delay of hospital discharge beyond day 7 after transplantation because of allograft or renal insufficiency; (2) intermediate risk—retransplantation or transplantation for fulminant hepatic failure; (3) low risk—absence of conditions in groups 1 and 2. During an intervention period (February 1999–April 2001), prophylactic administration of a lipid complex of amphotericin (Abelcet) at 5 mg/kg intravenously every 24 to 48 hours was recommended for high‐risk recipients. The frequency of mold infection was compared to that of a preintervention period (February 1998–January 1999) when antifungal prophylaxis was not provided. During the intervention period, invasive mold infection developed in 2 (6%) of 35 high‐risk recipients, 0 of 28 intermediate‐risk recipients, and 1 (0.5%) of 187 low‐risk recipients. Overall, of 58 liver transplant recipients, 3 (5%) developed an invasive mold infection during the preintervention period, compared with 3 (1%) of 250 during the intervention period (P = 0.08). The only death from invasive mold infection occurred during the preintervention period. Rates of pulse corticosteroid treatment of rejection and cytomegalovirus infection were lower during the intervention period. In conclusion, readily identifiable patient characteristics can be used to stratify liver transplant recipients for risk of invasive mold infection. Antifungal prophylaxis given to high‐risk recipients may provide cost‐effective prevention of these infections. (Liver Transpl 2005;11:656–662.)

Evaluation of the COBAS TaqMan HCV Test with Automated Sample Processing Using the MagNA Pure LC Instrument

BACKGROUND Cytomegalovirus (CMV) load measurement is used to assess the efficacy of treatment of CMV disease, but lacks standardization. Using the World Health Organization (WHO) international standard for reporting, we correlated viral load with CMV disease resolution. METHODS CMV load was quantified in plasma using a test calibrated to the WHO standard. Three predictive rules were predefined to determine association between CMV DNAemia and outcome: (1) pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL; (2) viral load declines of 1.0, 1.5, 2.0, and 2.5 log(10) IU/mL from baseline to days 7, 14, and 21 of treatment, respectively; and (3) viral suppression <137 (2.1 log(10)) IU/mL at days 7, 14, and 21. Analysis was performed using Cox proportional hazard models. RESULTS Of 267 patients, 251 had CMV disease resolution by day 49 of treatment. Patients with pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL had faster time to disease resolution (adjusted hazard ratio [AHR], 1.56; P = .001). Patients with CMV load suppression (<137 IU/mL [<2.1 log(10)]) at days 7, 14, and 21 had faster times to clinical disease resolution (AHRs, 1.61, 1.73, and 1.64, and P = .005, <.001, and <.001, respectively). Relative CMV load reductions from baseline were not significantly associated with faster resolution of CMV disease. CONCLUSIONS Patients with pretreatment CMV DNA of <18,200 (4.3 log(10)) IU/mL are 1.5 times more likely to have CMV disease resolution. CMV suppression (<137 [2.1 log(10)] IU/mL), as measured by a test calibrated to the WHO Standard, is predictive of clinical response to antiviral treatment. CLINICAL TRIALS REGISTRATION NCT00431353.

Disseminated Bartonella infection following liver transplantation

ABSTRACT The Abbott RealTime human immunodeficiency virus type 1 (HIV-1) assay (ART) and the Cobas AmpliPrep/Cobas TaqMan HIV-1 test (CTM) are commercially available assays for quantification of HIV-1 RNA in plasma. We evaluated performance characteristics, workflow, throughput, reliability, and direct costs of these assays. Both assays yielded good correlation of quantitative results (r = 0.95) among clinical specimens, with a mean difference of −0.34 log10 copies/ml. Testing of healthy donor plasma specimens yielded “target not detected” results by ART, with “HIV-1 RNA detected, <40 copies/ml” results for 3.3% (3 of 90 samples) of these specimens by CTM. Both the m2000sp/m2000rt (ART) and docked CAP/CTM96 (CTM) instrument systems were capable of operating with continuous, uninterrupted workflow. When daily maintenance and cleaning were included, ART and CTM run durations (5 h 52 min and 6 h 4 min, respectively) and hands-on times (53 min and 46 min, respectively) were similar for a run batch size of 24. While ART was more flexible in terms of run batch size, CTM required fewer user interventions and consistently produced higher specimen throughput rates at 8, 16, and 24 h. Assay run failure rates were 6.3% (1 of 16 runs) and 4.2% (1 of 24 runs) for ART and CTM, respectively (P = 1.000), with invalid specimen result rates of 1.0% (5 of 495 specimens) and 2.8% (11 of 399 specimens), respectively (P = 0.073). Direct reagent and consumable costs for each assay were comparable (difference of <10%). In selecting an assay for implementation, laboratories should consider how various assay and instrument features might impact laboratory operation and patient care.

Evaluation of the invader assay for genotyping hepatitis C virus.

ABSTRACT The COBAS TaqMan HCV Test (TaqMan HCV; Roche Molecular Systems Inc., Branchburg, N.J.) for hepatitis C virus (HCV) performed on the COBAS TaqMan 48 Analyzer (Roche Molecular Systems) currently relies on a manual sample processing method. Implementation of an automated sample processing method would facilitate the clinical use of this test. In this study, we evaluated the performance characteristics of TaqMan HCV following automated sample processing by the MagNA Pure LC instrument (MP; Roche Applied Science, Indianapolis, Ind.). The analytical sensitivity of TaqMan HCV following sample processing by MP was 8.1 IU/ml (95% confidence interval, 6.1 to 15.2). The assay showed good linearity (R2 = 0.99) across a wide range of HCV RNA levels (25 to 5 × 106 IU/ml), with coefficients of variation ranging from 10% to 46%. Among 83 clinical specimens, the sensitivity and specificity of TaqMan HCV were 100% and 95%, respectively, when compared to the COBAS AMPLICOR hepatitis C virus test, version 2.0 (COBAS AMPLICOR; Roche Molecular Systems), with TaqMan HCV detecting two more HCV RNA-positive specimens than COBAS AMPLICOR. Both specimens were confirmed to be HCV RNA positive by the VERSANT HCV RNA qualitative test (Bayer HealthCare LLC, Tarrytown, N.Y.). There was also strong correlation (R2 = 0.95) and good agreement between the results from TaqMan HCV and the VERSANT HCV RNA 3.0 assay (bDNA) (Bayer HealthCare LLC) among a group of 93 clinical specimens. The MP is a versatile, labor-saving sample processing platform suitable for reliable performance of TaqMan HCV.

Hepatitis C Virus Genotypes in Clinical Specimens Tested at a National Reference Testing Laboratory in the United States

Bartonella henselae has not only been identified as the causative agent of cat scratch disease, but it is also associated with other significant infectious syndromes in the immunocompromized population. We describe two cases of B. henselae associated diseases in liver transplant recipients who both had contact with cats. The first recipient developed localized skin manifestation of bacillary angiomatosis in association with granulomatous hepatitis. He tested positive for Immunoglubulin G (IgG) antibodies against B. henselae. The second patient developed axillary lymphadenopathy, with biopsy showing necrotizing granulomatous inflammation and polymerase chain reaction studies were positive for B. henselae DNA. Her serology for bartonellosis showed a fourfold rise in antibody titers during her hospitalization. Both patients responded to treatment with Azithromycin in combination with Doxycycline. These were the only cases within a series of 467 consecutive liver transplants performed in 402 patients performed during a 4‐year period. Although bartonellosis is a rare infection in liver transplantation recipients, it should always be included in the differential diagnosis of patients presenting with fever, central nervous system (CNS) symptoms, skin lesions, lymphadenopathy, and hepatitis especially if prior contact with cats is reported.