Performance of a completely automated system for monitoring CMV DNA in plasma.

BACKGROUND: Completely automated systems for monitoring CMV-DNA in plasma samples are now available. OBJECTIVES: Evaluate analytical and clinical performances of the VERIS™/MDx System CMV Assay(®). STUDY DESIGN: Analytical performance was assessed using quantified quality controls. Clinical performance was assessed by comparison with the COBAS(®) Ampliprep™/COBAS(®) Taqman CMV test using 169 plasma samples that had tested positive with the in-house technique in whole blood. RESULTS: The specificity of the VERIS™/MDx System CMV Assay(®) was 99% [CI 95%: 97.7-100]. Intra-assay reproducibilities were 0.03, 0.04, 0.05 and 0.04 log10IU/ml (means 2.78, 3.70, 4.64 and 5.60 log10IU/ml) for expected values of 2.70, 3.70, 4.70 and 5.70 log10IU/ml. The inter-assay reproducibilities were 0.12 and 0.08 (means 6.30 and 2.85 log10IU/ml) for expected values of 6.28 and 2.80 log10IU/ml. The lower limit of detection was 14.6IU/ml, and the assay was linear from 2.34 to 5.58 log10IU/ml. The results for the positive samples were concordant (r=0.71, p<0.0001; slope of Deming regression 0.79 [CI 95%: 0.56-1.57] and y-intercept 0.79 [CI 95%: 0.63-0.95]). The VERIS™/MDx System CMV Assay(®) detected 18 more positive samples than did the COBAS(®) Ampliprep™/COBAS(®) Taqman CMV test and the mean virus load were higher (0.41 log10IU/ml). Patient monitoring on 68 samples collected from 17 immunosuppressed patients showed similar trends between the two assays. As secondary question, virus loads detected by the VERIS™/MDx System CMV Assay(®) were compared to those of the in-house procedure on whole blood. The results were similar between the two assays (-0.09 log10IU/ml) as were the patient monitoring trends. CONCLUSION: The performances of the VERIS™/MDx System CMV Assay(®) facilitated its routine use in monitoring CMV-DNA loads in plasma samples.

Prospective evaluation of a new automated nucleic acid extraction system using routine clinical respiratory specimens.

The aim of the study was to evaluate the MagNA Pure 96™ nucleic acid extraction system using clinical respiratory specimens for identifying viruses by qualitative real-time PCR assays. Three extraction methods were tested, that is, the MagNA Pure LC™, the COBAS Ampliprep™, and the MagNA Pure 96™ with 10-fold dilutions of an influenza A(H1N1)pdm09 sample. Two hundred thirty-nine respiratory specimens, 35 throat swabs, 164 nasopharyngeal specimens, and 40 broncho-alveolar fluids, were extracted with the MagNA Pure 96™ and the COBAS Ampliprep™ instruments. Forty COBAS Ampliprep™ positive samples were also tested. Real-time PCRs were used to identify influenza A and influenza A(H1N1)pdm09, rhinovirus, enterovirus, adenovirus, varicella zoster virus, cytomegalovirus, and herpes simplex virus. Similar results were obtained on RNA extracted from dilutions of influenza A(H1N1)pdm09 with the three systems: the MagNA Pure LC™, the COBAS Ampliprep™, and the MagNA Pure 96™. Data from clinical respiratory specimens extracted with the MagNA Pure 96™ and COBAS Ampliprep™ instruments were in 98.5% in agreement (P < 0.0001) for influenza A and influenza A(H1N1)pdm09. Data for rhinovirus were in 97.3% agreement (P < 0.0001) and in 96.8% agreement for enterovirus. They were in 100% agreement for adenovirus. Data for cytomegalovirus and HSV1-2 were in 95.2% agreement (P < 0.0001). The MagNA Pure 96™ instrument is easy-to-use, reliable, and has a high throughput for extracting total nucleic acid from respiratory specimens. These extracts are suitable for molecular diagnosis with any type of real-time PCR assay.

Evaluation of the QIAsymphony™ SP and Artus™ RealTime extraction-quantification systems for measuring HIV-1 virus load.

BACKGROUND: Automated HIV-1 RNA extraction and its quantification by real-time PCR assays provide improved sample processing and better analytical performances. The new Artus HIV-1 RealTime assay can be performed after automated extraction with the Qiagen Qiasymphony robot. OBJECTIVES AND STUDY DESIGN: To evaluate the sensitivity, reproducibility, linearity, ability to detect HIV-1 subtypes of the Qiagen Qiasymphony and RealTime Artus HIV-1 assay system and to compare with the Roche Cobas Ampliprep Cobas TaqMan assay, vs 2.0 (CAP/CTM; Roche Molecular Systems). RESULTS: The detection limit calculated by probit analysis was 65 c/ml using dilutions of a NIBSC. Assays of serially diluted clinical samples gave very good inter-assay and intra-assay reproducibilities (<10% CV) and linearity (2.2-6.5 log copies/ml). The results Artus™ HIV-1 and CAP/CTM assays provided very similar results: average difference=0.11 log copies/ml. The Artus™ titers for 18 (22%) of the 114 HIV-1 group M samples tested differed by over 0.5 log copies/ml from the CAP/CTM titers. The Artus™ values were lower than the CAP/CTM values in 83% of cases. Discrepant results were not associated with particular subtypes. CONCLUSION: The Artus™ HIV-1 assay reliably quantified the HIV RNA in clinical specimens. Analytical performances were good and it integrated well with the Qiasymphony automated RNA extraction procedure. It appears to be appropriate for monitoring therapy and the routine management of HIV-1 infections.

JC virus DNA in the peripheral blood of renal transplant patients: a 1-year prospective follow-up in France.

There is little information on JC virus (JCV) infection in renal transplant patients. A long-term prospective follow-up study was conducted to assess the incidence of JCV DNA in the blood of 103 adult renal transplant patients enrolled prospectively between 1 January and 31 December 2006. Patients were monitored until April 2008. JCV DNA was quantified by a real-time polymerase chain reaction in whole blood samples collected regularly for at least 1 year post-transplant. JCV was detected in seven patients (6.8%) (31/1,487 whole blood samples) at a median time of 139 days post-transplant. The median JC virus load of the first positive DNA blood sample was 3.4 log(10) copies/ml (1.9-5.7 log(10) copies/ml). Induction therapy were either anti-CD25 monoclonal antibodies (n = 5) or antithymocyte globulins (n = 2). Post-transplant immunosuppressive treatment included steroids with tacrolimus/mycophenolate mofetil (MMF) (n = 2), or ciclosporin/MMF (n = 1), or belatacept/MMF (n = 4). Two patients were also treated with rituximab. All seven patients infected with JCV had other viral infections(s): BK virus (3), Epstein-Barr virus (2), Cytomegalovirus (1) or both BK virus and Epstein-Barr virus (1). Three patients had BKV-associated nephropathy and decoy cells shedding. JCV infection was not associated with acute rejection episodes or nephropathy, regardless of the virus load. No patient developed progressive multifocal leukoencephalopathy during follow-up. Thus the incidence of JCV infection in renal transplant patients was low and not associated with any specific clinical manifestations. JCV replication must still be diagnosed and differentiated from BK virus infection because of its non-aggressive course.

Detection and quantitation of HCV RNA using real-time PCR after automated sample processing.

There is considerable evidence that the loss of hepatitis C virus (HCV) RNA during the first 3 months of treatment with pegylated interferon plus ribavirin is a prognostic marker of response to therapy. Real-time polymerase chain reaction (PCR) assays for quantifying HCV RNA in plasma or serum are now commercially available. The extraction of HCV RNA can also be automated. This report analyses the performance of the COBAS Ampliprep-COBAS Taqman 48 (CAP/CTM) real-time PCR assay and compares this new test with the COBAS Amplicor HCV Monitor v 2.0 assay (CAM). CAP/CTM was 100% specific. The assay was linear across a wide range of HCV RNA concentrations without sample dilution. The intra-assay variation was 0.3-3.3% and the interassay variation was 1.5-6.7%. A total of 118 clinical samples with different HCV genotypes were assayed using both methods. The results obtained using the two methods were well correlated (r = 0.89, P < 0.001). The mean difference [CAP/CTM-CAM] was 0.17 log IU/ml and it was not influenced by the HCV genotype or by the subtype. It is concluded that the new CAP/CTM system is adequate for quantifying HCV RNA in clinical practice.

Hepatitis C virus viral load after conversion from tacrolimus to cyclosporine in liver transplant patients: a pilot study.

UNLABELLED: We assessed whether conversion from tacrolimus (TAC) to cyclosporine (CsA) was associated with a reduction in hepatitis C virus (HCV) viral load among HCV-positive liver transplant (OLT) patients. PATIENTS AND METHODS: Nine OLT patients with recurrent HCV have TAC and prednisone immunosuppression. None received any HCV antiviral therapy. After the last intake of TAC, the patients underwent a 12-hour area under the curve (AUC(12)) measurement of both TAC and HCV viral loads. The next morning (D(0)) patients were given CsA (4 mg/kg bid). At the first intake of CsA and at 1 month (M(1)) later, the patients underwent AUC(12) for CsA and HCV viral loads. Biological data, including aspartate (AST) and alanine (ALT) aminotransferase, gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (AP), and bilirubin levels, were collected during AUC(12), and at M(1) and M(3). RESULTS: With respect to liver enzymes (AST, ALT, GGT), there was no significant difference between D(0), M(1), and M(3). Conversely, there was a significant decrease in AP between D(0) and M(3) (P = .02), and a significant increase in total bilirubin between D(0) and M(1) (P = .04), and between D(0) and M(3) (P = .01). HCV viral load significantly increased by M(3) (P = .01). At no time (D(0), M(1)) was there any correlation between the AUC(12) of TAC or CsA, and between AUC(12) HCV viral load. CONCLUSION: This pilot study found no acute or chronic anti-HCV effects from CsA that were evident within 12 hours after CsA administrations or beyond 1 month of CsA therapy, respectively.

Does cyclosporine have a beneficial effect on the course of chronic hepatitis C infection after renal transplantation?

The aim of our study was to assess the long-term liver histology in renal transplant patients infected with hepatitis C virus (HCV) who were treated with a cyclosporine-based regimen. Among 55 anti-HCV+/RNA+ patients, liver biopsies (LB) were requested every 3 to 4 years after transplantation: two LBs (n=55); three LBs (n=44); four LBs (n=10). Overall, the rate of liver fibrosis progression was 0.07+/-0.03 Metavir U/y. Only three patients out of 55 (5.4%) developed cirrhosis. Liver fibrosis remained stable throughout follow-up in 21 patients; increased in 21 patients; and improved in the remaining 13 patients. The incidence of posttransplant diabetes mellitus was low (9%). We concluded that HCV infection is not harmful to liver histology in more than 50% of renal transplant patients with grafts functioning more than 6 years. Cyclosporine might have beneficial effects on the natural course of HCV infection after renal transplantation.

Pegylated interferon and ribavirin therapy for chronic hepatitis C virus genotype 4 infection.

Hepatitis C Virus (HCV) is classified into six genotypes. Genotype 4 is now spreading in Europe, especially among drug users, who are often infected with both HCV and the human immunodeficiency virus (HIV). Previous studies have shown that HCV-4 responds poorly to interferon. Pegylated interferon (peg-IFN) associated with ribavirin is now the most effective treatment for eradicating the virus. We have now studied the response of HCV-4 to peg-IFN and ribavirin and investigated the influence of HIV infection on anti-HCV therapy. Twenty-eight patients infected with HCV-4 were given peg-IFN plus ribavirin for 48 weeks. Patients infected with HCV alone tended to have a better initial response (66%) than patients infected with both HCV and HIV (30%, P = 0.06) and eradication was better (50%) than in doubly infected patients (15%, P = 0.06). After controlling for major factors influencing virus response, the virus response 12 weeks after the beginning of treatment in patients infected with HCV-4 (50%) was similar to that of patients infected with genotype 1 (53%) and lower than that of patients infected with genotypes 2 or 3 (82%, P < 0.05). The response 24 weeks after the end of therapy in patients infected with HCV-4 (32%) was similar to that of patients infected with HCV-1 (28%) and lower than that of patients with HCV-2 or HCV-3 (62% P < 0.05). These results indicate that HCV-4 patients should be considered to be difficult-to-treat.

Efficacy and safety of induction therapy with rabbit antithymocyte globulins in liver transplantation for hepatitis C.

BACKGROUND: Hepatitis C virus (HCV)-related end-stage liver disease (ESLD) is the leading cause for orthotopic liver transplantation (OLT). However, in recent years, the long-term results of OLT in this setting are worsening, possibly due to the powerful immunosuppressants in use. The aim of our study was to assess the safety and efficacy of induction therapy using rabbit antithymocyte globulin antibodies (RATG). METHODS: Over an 18-month period from January 2000 to June 2001, 16 patients underwent OLT for HCV-related ESLD and survived more than 1 month posttransplantation. They received induction therapy based on RATG (Thymoglobulins, Sangstat, France) at 1 mg/kg per day for 3 consecutive days, and it was then adjusted to maintain a CD2 count below 50/mm(3). Overall, RATG was given for a median of 5 days for a total dose of 406 +/- 45 mg. Steroids were started pretransplant and tacrolimus on day 1. The primary end-points were patient and graft survivals at 6 months posttransplantation, incidence of rejection, infectious complications (bacterial, viral, and fungal) and recurrence of HCV infection based on biochemical, virological, and histologic criteria. RESULTS: The survival rates were 100% for patients and 93.7% for grafts. The acute rejection rate was 37.5%. The median time to acute rejection was 15.5 days. There was only one serum sickness case. Cytomegalovirus infections occurred in 25% of patients. The rate of de novo diabetes that required insulin therapy was at 50%. The rate of HCV recurrence was 56.25%. In addition, HCV RNA serum concentrations increased significantly posttransplantation (>1 log). In conclusion, RATG induction therapy is safe and efficient in HCV-positive liver recipients.

Use of two real-time polymerase chain reactions (PCRs) to detect herpes simplex type 1 and 2-DNA after automated extraction of nucleic acid.

Herpes simplex virus infections may be diagnosed by several techniques, including conventional cell culture and the polymerase chain reaction (PCR). This prospective study compares the analytical performances and usefulness of an in-house real-time PCR method and the Light Cycler HSV (1/2) detection kit (Roche Diagnostics, Mannheim, Germany). The results of both PCRs were then compared to those obtained by conventional cell culture. A total of 313 samples were tested (70 dermal samples, 81 cerebrospinal fluids (CSF), 47 ocular, 42 anogenital, 34 throat swabs, and 33 oral samples, 3 whole blood, 2 biopsies, and 1 bronchoalveolar lavage). Samples for molecular assays were extracted twice with the MagNa Pure instrument (Roche Molecular Biochemicals, Mannheim, Germany) and tested blind in parallel by the two PCR methods. Most (226) samples were also examined by cell culture. Forty three samples were found positive by both PCRs, whereas 267 were negative. The HSV-1 and -2 typing of positive samples was identical. Three of the samples were positive in the in-house PCR and negative in the Light Cycler HSV (1/2) detection kit. There was no statistically significant difference between the two tests. Only one sample gave an invalid result due to negative PCR and negative internal control result. Seven samples were positive by both real-time PCRs and negative in conventional culture. The PCRs were significantly (P < 0.05) more sensitive. The results show good agreement between the two real-time PCR methods, with the molecular tests being more sensitive than cell culture.

Virological exploration of individuals with discordant HIV screening tests.

Screening for HIV infection can use many algorithms. When two different HIV antibody assays are used, discordant results may occur. To discriminate between HIV seroconversion, HIV variant infection and false positive reactivity, 30 consecutive subjects with two discordant HIV antibody-screening assays were extensively investigated for HIV infection. No subject had HIV seroconversion or reached HIV seropositivity criteria after a follow-up of 3 months. By contrast 36% became HIV negative by the use of both HIV screening assays. p24 Antigen, HIV-1 RNA, HIV-1 DNA, HIV-2 DNA assays and HIV isolation by sensitive culture were unable to identify HIV infection in the 30 subjects with discordant HIV screening assays. The data suggest that the use of two HIV screening assays increase false-positive HIV results without increasing clinical sensitivity. To compliment follow-up of HIV screening, early testing for HIV RNA could be useful to identify or eliminate a recent infection.

Hepatitis C virus genotype 5: epidemiological characteristics and sensitivity to combination therapy with interferon-alpha plus ribavirin.

Twenty-six patients living in the Midi-Pyrenees region of France who were infected with hepatitis C virus (HCV) genotype 5 were investigated. Most of these patients were of advanced age and had been infected nosocomially or by blood transfusion. Our case-control study, in which we treated patients with interferon- alpha plus ribavirin, indicated that, 24 weeks after the beginning of treatment, the virus response in patients infected with HCV genotype 5 was better than that in patients infected with HCV genotype 1 (100% of patients negative for detectable HCV RNA vs. 36.3%, respectively; P < .01); furthermore, 48 weeks after the end of treatment, the virus response in patients infected with HCV genotype 5 was better than that in patients infected with HCV genotype 1 (63.6% vs. 22.7%, respectively; P < .05) and was similar to that in patients infected with HCV genotype 2 or 3 (66.6%). These results show that HCV genotype 5 might have good intrinsic sensitivity to combination therapy with interferon- alpha plus ribavirin.

Automated extraction and quantification of human cytomegalovirus DNA in whole blood by real-time PCR assay.

The measurement of human cytomegalovirus (HCMV) DNA in blood is becoming the standard method for monitoring HCMV infection in immune-suppressed and unsuppressed patients. As various blood compartments can be used, we have compared the HCMV DNA measured in whole blood (WB), peripheral blood leukocytes (PBL), and plasma by real-time PCR. We tested 286 samples: HCMV DNA was extracted automatically from WB and PBL with the MagNA Pure instrument (Roche Molecular Biochemicals) and manually from plasma samples. The HCMV DNA from WB, PBL, and plasma was measured by real-time Light Cycler PCR. Primers and probe were located in the UL 83 region. HCMV DNA was detected more frequently in WB (88.5%) than in the PBL (65.7%) (P < 0.0001) or the plasma (55.2%) (P < 0.0001). There was a good correlation between the positive results in WB and in PBL (r = 0.68; P < 0.0001), and 3.15 log(10) genome copies in 200000 PBL, equivalent to the threshold value of 50 pp65-positive polymorphonuclear cells per 200000 leukocytes, was equivalent to 3.4 log(10) genome copies in 200 microl of WB. WB was shown to be suitable for automated extraction and the quantitation of HCMV DNA by real-time Light Cycler PCR by analysis of serial samples from representative patients of various populations. This system may be very useful for monitoring of immune-suppressed and unsuppressed patients.

[Is there a place for ribavirin in the treatment for renal transplant patients infected by hepatitis C virus?]. / Y a-t-il une place pour la ribavirine dans le traitement des transplantés rénaux infectés par le virus de l'hépatite C?

Treatment of chronic hepatitis C in renal-transplant (RT) recipients with alpha-interferon is associated with a high rate of acute rejection. We therefore evaluated the biochemical, virological, histological efficacies, as well as the safety of one year ribavirin monotherapy in 16 HCV-(+) RNA (+) RT patients (group A) matched to 32 HCV-(+) RNA (+) RT patients (group B) who did not receive ribavirin. Ribavirin was initially started at a daily dose of 1000 mg and then adapted to hemoglobin level. Ribavirin monotherapy was associated with a significant decrease in AST, ALT and gamma glutamyl transpeptidase levels. Serum creatinine decreased as well. When proteinuria was present (n = 5), this decreased or disappeared. There was no significant changes in HCV viremia. The histological analysis of liver biopsies revealed a significant progression in liver fibrosis with no improvement in inflammation scores. There was a significant decrease in hemoglobin levels, despite an important support by recombinant erythropoeitin. However, in three cases, ribavirin therapy had to be stopped. In group B, after 1 year of follow up, there was a significant increase in serum ALT and creatinine values. Proteinuria decreased in only 2 of 12 patients. In conclusion, one year ribavirin therapy in HCV-(+) RNA (+)ve RT has no impact upon liver histology, although it improves liver enzyme levels. It impact upon renal function remains unknown. Nevertheless when proteinuria is present it disappears.

Determining hepatitis C genotype by analyzing the sequence of the NS5b region.

Assays to determine the hepatitis C virus (HCV) genotype have recently become useful for clinical decision making and may be suitable for epidemiological investigations, such as identifying HCV outbreaks in a given population. Molecular assays are the most common diagnostic tools for HCV genotyping. This study compares two genome typing assays, one, the Trugene 5'NC genotyping kit, uses the sequence of the 5' non-coding (5'NC) region and the other, a non-commercial assay, uses the non-structural 5b (NS5b) region. Serum samples from 203 chronically HCV-infected patients were tested. The 5'NC and the NS5b assays were both very effective in identifying the genotype (99 and 98.5%) and the results with the two methods were always concordant for the genotype. The NS5b analysis permitted the identification of the subtype in all samples, whereas the 5'NC region assay did not in 33% of samples. The NS5b analysis showed that one patient had a mixed infection with HCV subtypes 1a and 2c, while the 5'NC assay did not. It is concluded that phylogenetic analysis using both the 5'NC and the NS5b regions are reliable and convenient methods for HCV typing in clinical practice. But analysis of the NS5b region may be more useful for tracing the source of an HCV infection.

Screening for hepatitis B virus DNA in serum of organ donors and renal transplant recipients.

In order to determine the impact of screening potential organ donors for hepatitis B virus DNA using a standardized test, the serum of 145 donor candidates was tested. All of the candidates were negative for hepatitis B virus DNA, but the status of one donor was doubtful for hepatitis B virus surface antigen and seven donors tested positive for hepatitis B virus core antibody without hepatitis B virus surface antigen. Nine transplant recipients tested positive for hepatitis B virus surface antibody; they were given kidneys from the donor with a doubtful hepatitis B virus surface antigen result and from four of the seven donors who tested positive for hepatitis B core antibody. Follow-up revealed no case of hepatitis B transmission. In this study, screening for hepatitis B virus DNA was useful and did not lead to donor organ shortage. Patients with hepatitis B virus surface antibodies can safely be given kidneys from donors who are positive for hepatitis B core antibody but negative for hepatitis B virus DNA.