Subclinical Epstein-Barr virus viremia among adult renal transplant recipients: incidence and consequences.

The natural history and clinical significance of posttransplant Epstein-Barr virus (EBV) infection remain largely unknown. The aims of this study are to describe the incidence, risk factors and consequences of EBV infection after kidney transplantation. A total of 383 consecutive patients having received a kidney transplant between January 2002 and December 2010 were included. EBV polymerase chain reaction (PCR) was performed every 2 weeks for 3 months, and every 4 weeks for the next 9 months. A total of 155 of the 383 patients (40%) had at least one positive viremia during the first year posttransplant. The median time to viremia was day 31 posttransplant (14-329). A total of 73 (47%) had EBV viremia > 10(3) log and 23 (15%) had positive viremia for more than 6 months. EBV D+/R- patients (12/18 (67%) versus 143/365 (39%), p = 0.02) and those having received antithymocyte globulins (ATG) (54% vs. 35%; p<0.001) were more likely to develop EBV infection. EBV infection (hazard ratio [HR], 3.03; 95% confidence interval [CI], 1.72-8.29; p = 0.01) was associated with the occurrence of opportunistic infections. A positive EBV PCR during the first 6 months posttransplant was associated with graft loss (HR, 3.04; 95% CI, 1.36-6.79; p = 0.014). EBV reactivation is frequent after transplantation and reflects overimmunosuppression. Prospective studies should examine the association between EBV and graft loss.

Human cytomegalovirus-viruria in hematopoietic stem cell transplant recipients: Context and impact.

BACKGROUND: Episodes of CMV-viruria have been reported in hematopoietic stem cell transplant (HSCT) recipients, but their context of occurrence, pathophysiology, and clinical significance remain misunderstood. METHODS: Uurine samples from 517 recipients were collected. Clinical features of recipients with or without episodes of CMV-viruria were retrospectively compared. RESULTS: CMV-viruria was detected in 15.5 % of cases. Age, sex, type of transplantation, HLA-matching, conditioning regimen, and immunosuppressive therapies did not differ between patients with and without CMV-viruria. CMV-seropositive status (R + ) was more frequent among CMV-viruric recipients. Cumulated mortality did not differ between the two groups but graft-versus-host diseases occurred more frequently among CMV-viruric patients (p = 0.04). No reduction of the estimated glomerular filtration rates was observed in CMV-viruric recipients. CONCLUSIONS: CMV-viruria primarily occurs in CMV-seropositive recipients and is not related to the degree of immunosuppression. We suggest that CMV-viruria is primarily related to the inability of the graft immune system to contain CMV-replication in R + patients. CMV-viruria is not associated with increased mortality or renal dysfunction.

Macrophage activation and HIV infection: can the Trojan horse turn into a fortress?

Macrophages are infected early during HIV infection and are thought to play the role of a Trojan horse by spreading infection in tissues. Most recent studies point out to a more complex role for macrophages in HIV infection: macrophages could contribute to both host defense and viral persistence and pathogenesis. Infected macrophages are a reservoir for HIV and modulate apoptosis of T cells present in their vicinity. Also, a functional impairment of HIV-infected macrophages may play a role in AIDS pathogenesis. Nevertheless, both activation and differentiation of monocyte/macrophages can interfere with susceptibility of these cells to infection. Therefore, a wide variety of stimuli result in HIV suppression through macrophage activation. At present times, a dynamic view on the role of macrophages in HIV infection arises which indicates that macrophages are a target for the virus and at the same time regulate its replication. Therefore, macrophages are at the cross-road between protection and pathogenesis in HIV infection due to their involvement both as a viral target and a key modulator of non-specific and specific immune responses. Future studies will help unravel the cellular and molecular mechanisms that underlie HIV-macrophage interactions and might result in new vaccine and/or therapeutic strategies.

Detection of human papillomavirus and human cytomegalovirus in cervical lesions by in situ hybridization using biotinylated probes.

Infections with specific types of human papillomavirus (HPV) have emerged as necessary but not sufficient factors in the development of the majority of cervical cancers. The infection by human cytomegalovirus (HCMV) has also been implicated in both cervical intraepithelial neoplasia (CIN) and cancer. In order to test prevalence of these viral pathogens in genital lesions with suspect cytopathic changes after observation of smears, cervical biopsies from 131 patients were obtained under colposcopic guidance. The biopsies were tested for the presence of HPV and HCMV by the in situ hybridization technique using biotinylated DNA probes on paraffin-embedded sections. Presence of HCMV is twice more frequent in women with HPV-induced cervical lesions (40%) than in women with any detectable HPV (20%). It may be concluded that HCMV might contribute as one synergistic factor in the development of cervical dysplasia.

[Prevalence of and changes in hepatitis C virus antibodies in 64 patients with liver transplant]. / Prévalence et évolution des anticorps dirigés contre le virus de l'hépatite C chez soixante-quatre transplantés hépatiques.

The aim of this retrospective study was to assess the prevalence of hepatitis C virus antibodies and their follow-up in a series of 64 orthotopic liver transplantation patients. Indications for transplantation were cirrhosis in 28 cases, primary biliary cirrhosis in 6 cases, liver cancer in 11 cases, fulminant hepatitis in 2 cases, and alveolar echinococcosis in 17 cases. The prevalence of serum antibodies to hepatitis C virus was assessed by an ELISA test (Ortho-Diagnostic-Systems). Sera were tested before liver transplantation and every two months after. Twenty-nine patients seronegative before transplantation remained negative. Four patients seropositive before liver transplantation remained seropositive. Twenty-eight patients seropositive before transplantation, became seronegative after, and 3 patients seronegative before transplantation became seropositive after. The prevalence of seroconversion was 9.3 percent. The prevalence of seropositive patients after transplantation was 11 percent. The high number of seropositive patients before transplantation (50 percent) could be explained by false positive results. Seropositivity before transplantation appeared to be related to hypergammaglobulinemia (p less than 0.001). This hypothesis was confirmed a posteriori by a concomitant disappearance of both seropositivity and hypergammaglobulinemia after transplantation in 62 percent of patients.

[The other types of viral hepatitis]. / Les autres hépatites à virus.

Hepatitis due to viruses other than A, B, C, D, E are numerous but uncommon in adults. Among the group of Herpesviridae (HSV, CMV, EBV, VZV), clinical hepatitis is usually suggestive of disseminated viral infection. Fulminant hepatitis occasionally observed in immunocompromised hosts are due to HSV, and VZV, but exceptionally to EBV. Many new techniques using specific monoclonal antibodies permit an accurate and fast diagnosis. Three drugs (vidarabine, acyclovir, ribavirine) have been shown to be efficient in the treatment of severe forms of the disease. Hepatitis due to exotic viruses (Amaril, Ebola, Lassa) are exceptional in France, but require specific prophylactic measures.

Maribavir use in practice for cytomegalovirus infection in French transplantation centers.

Maribavir (MBV), a UL97 inhibitor, shows good oral bioavailability, low host cell toxicity, and theoretical benefits to inhibit cross-resistant viruses. We herein examined clinical and virological outcomes of 12 patients, including 3 bone marrow recipients and 9 organ recipients infected with resistant cytomegalovirus (CMV) and treated with MBV during 2011-2012. All received at least 800-mg daily doses. They had developed clinical (12/12) and/or virological (11/12) resistance to CMV infection. Based on a decrease of viral load in blood >1.5 log copies/mL half of them responded to MBV treatment. The individual changes varied from a rapid decrease in viral load (n = 4) to no response (n = 3) with some late response slowly decreasing viremia (n = 3). In 2 cases MBV was used as secondary prophylaxis. No clear parameter emerged as a clinical surrogate for nonresponse to MBV. These results contrast with the lack of efficacy in phase III trials of MBV prophylaxis among stem cell recipients, which were possibly due to low doses or inadequate timing of drug initiation in the study. Additional clinical and surrogate laboratory markers are needed to determine antiviral responses to guide MBV use. Dosage ranging studies might benefit future MBV use.

Optimization of in situ hybridization for detection of viral genomes in cultured cells on 96-microwell plates: a cytomegalovirus model.

In situ hybridization (ISH) for identification of infectious replicative cytomegalovirus (CMV) in cell culture microplates (96 microwells) infected by clinical specimens was tested by using a biotin-labeled DNA probe and an avidin-alkaline phosphatase conjugate. A total of 395 specimens were examined by using ISH and a monoclonal antibody (MAb) specific for an early antigen of CMV. Of 47 specimens that gave a positive signal for CMV by ISH, 33 were confirmed virus positive by MAb staining. Of 141 blood samples tested, 4.96% were positive by ISH, and 0.7% were positive by the MAb technique. ISH shows 40% more sensitivity than MAb staining. This technique should be widely applicable for the specific identification of viral isolates (e.g., herpesvirus, myxovirus, paramyxovirus, and enterovirus) in cell culture 96-microwell microplates, thereby making it feasible to screen a larger number of samples than is possible with classical methods using conventional culture tubes, shell vials, or 24-well plates.