[Acute tubulointerstitial nephritis following adenovirus and respiratory syncytial virus infection]. / Néphrite tubulo-interstitielle aiguë au cours d'une virose respiratoire à adénovirus et virus respiratoire syncytial.

Acute tubulointerstitial nephritis (TIN) is responsible for nearly 10% of acute renal failure (ARF) cases in children. It is mostly drug-induced, but in a few cases viruses are involved, probably by an indirect mechanism. An immune-competent 13-month-old boy was admitted to the intensive care unit for severe ARF with anuria in a context of fever, cough, and rhinorrhea lasting 1 week. The kidney biopsy performed early brought out tubulointerstitial damage with mild infiltrate of lymphocytes, without any signs of necrosis. There were no virus inclusion bodies, no interstitial hemorrhage, and no glomerular or vascular damage. Other causes of TIN were excluded: there was no biological argument for an immunological, immune, or drug-induced cause. Adenovirus (ADV) and respiratory syncytial virus (RSV) were positive in respiratory multiplex polymerase chain reaction (PCR) in nasal aspirate but not in blood, urine, and renal tissue. The patient underwent dialysis for 10 days but the response to corticosteroid therapy was quickly observed within 48 h. The mechanism of TIN associated with virus infection is unknown. However, it may be immune-mediated to be able to link severe renal dysfunction and ADV and/or RSV invasion of the respiratory tract.

Hepatitis B virus Dane particles bind to human plasma apolipoprotein H.

Human apolipoprotein H (apo H) was found to bind specifically to hepatitis B surface antigen (HBsAg) from hepatitis B virus (HBV)-infected individuals. We used recombinant HBsAg proteins to analyze HBV domains recognized by apo H. We showed that the myristylated pre-S1 domain of HBsAg strongly interacted with apo H. This binding involved phospholipid components of the HBV envelope because their removal by detergent prevented apo H-HBsAg interaction. The opposite effects of iron and zinc metal ions on binding suggest that the oxidation of phospholipids also affects apo H-HBsAg interaction. After fractionation of viral particles on a sucrose gradient, and their addition to microtiter plates coated with apo H or anti-HBsAg, we observed that the maximal anti-HBsAg capture activity corresponded to a sucrose concentration of 36%, whereas the maximal apo H capture activity corresponded to a concentration of 39%. Electron microscopy and polymerase chain reaction (PCR) Southern blot studies of these fractions showed that the fraction with maximal apo H binding predominantly contained full Dane particles. Finally, we studied apo H-HBsAg binding relative to the presence of hepatitis B virus markers and observed that apo H binding activity for HBsAg was higher in sera from patients in the active virus replication phase.

Change in transaminases in hepatitis C virus- and HIV-coinfected patients after highly active antiretroviral therapy: differences between complete and partial virologic responders?

Patients with HIV and hepatitis C virus (HCV) coinfection have more severe hepatitis-related disease than do patients with HCV infection alone. Highly active antiretroviral therapy (HAART) with protease inhibitor appears to restore pathogen-specific immune responses, especially in patients with persistent undetectable HIV viral load. To evaluate the potent impact of immune restoration induced by HAART on the course of HCV-related disease, HCV viremia and levels of transaminases were compared between two groups of patients: 10 HIV/HCV-coinfected patients with persistently undetectable HIV viremia (group A) and 12 HIV/HCV-coinfected patients with persistent detectable HIV viremia. No difference was detected in HCV viral load in either group. An increase in transaminases was found only in patients with persistent undetectable HIV viral load, which was correlated with the increase in CD8+ T cells. This may suggest that the restoration of CD8+ T cell cytotoxicity could lead to an enhancement of hepatitis C-related disease in HCV/HIV-coinfected patients receiving HAART.

Effectiveness of a manual disinfection procedure in eliminating hepatitis C virus from experimentally contaminated endoscopes.

BACKGROUND: Transmission of hepatitis C virus (HCV) through endoscopy has been reported, but the implications as a public health concern remain controversial. This study investigated the degree to which a thorough manual cleaning-washing-disinfection procedure can decontaminate all channels of a flexible submersible endoscope experimentally contaminated with HCV. METHODS: To assess the accuracy of the method currently in use, the initial investigation focused on sampling effectiveness. Nine endoscopes were contaminated with high-titer HCV-positive plasma and flushed with 150 mL of sampling solution (distilled water) before disinfection. To assess the effectiveness of the disinfection procedure, the following sequence was performed on another 10 endoscopes: inoculation, disinfection, and sampling. After concentration residual viruses were detected by means of RNA amplification with commercial assays. RESULTS: The study showed that sampling alone can reduce viral titer to one-fourth its original value. Within the limits of this method, HCV RNA was never detected by means of polymerase chain reaction after disinfection, whereas all internal amplification controls were positive. This reduction to less than 1/100,000 of original titer exceeds the criterion expected for the virucidal activity of disinfectants. CONCLUSIONS: The results of this in vitro experiment provided evidence that patient-to-patient endoscopic transmission HCV can be reduced, if not eliminated, with the current mechanical cleaning-washing-disinfection procedure.

HCV-Infection in blood donors: association between anti-HCV core IgM antibodies and serum HCV RNA.

Among 47 blood donors tested positive with HCV EIA 2.0 Abbott, 27 (57.4%) also reacted with four ¿third-generation' EIAs. The presence of anti-HCV antibodies was confirmed with 3 different immunoblot assays in 16 of 27 sera (34.0%) while 10 samples (21.3%) had indeterminate profile with antibodies usually directed against structural core antigen. Anti-HCV core IgM response was found in 12 of 47 sera (25.5%) and HCV viremia detected by the polymerase chain reaction (PCR) procedure was observed in 15 samples (31.9%). A comparative study of the different markers confirmed a good correlation between a strong antibody response in EIAs and immunoblot assays and the presence of HCV RNA in the serum; only 2 immunoblot indeterminate samples were PCR positive. An association was observed between IgM antibodies against "core' epitopes and HCV RNA carriage: all IgM-positive sera were found positive by PCR. However, the direct detection of viral genome remains the best method for identifying HCV carriers in the blood donor population.

Quantitative detection of hepatitis B virus DNA in serum using chemiluminescence: comparison with radioactive solution hybridization assay.

A quantitative, non-radioactive hybrid capture HBV DNA assay (Digene Diagnostics), which uses an efficient solution hybridization procedure coupled to a sensitive chemiluminescent signal amplification system, was compared with the quantitative, radioactive solution hybridization assay (Genostics, Abbott Laboratories), in hepatitis B virus carriers, particularly in those undergoing antiviral therapy. The qualitative reproducibility of the chemiluminescent method, tested on 30 sera, was acceptable, with a reproducibility rate of 93.3%. A comparison of this hybrid capture HBV DNA assay with the radioactive test on 113 sera obtained from 48 patients (39 HBsAg-positive patients) gave a sensitivity of 87.2%, a specificity of 100% and an agreement between the two tests of 89.4% (101 sera including 82 HBV DNA positive and 19 negative samples). Changes in HBV DNA levels measured by the two assays showed a good correlation with each other during interferon therapy. However, the hybrid capture values were higher than the radioactive assay values, with the ratio of the two values being variable in the same patient during the course of treatment. The Genostics assay therefore seems to be a more accurate procedure for evaluating changes in viral replication, particularly at high HBV DNA levels. However, the hybrid capture method is faster and has the advantage of being a non-radioactive procedure. This chemiluminescent assay is easy to perform as a routine diagnostic procedure and may be a useful alternative to the radioactive solution hybridization method.

High prevalence of hepatitis C virus RNA in the supernatant and the cryoprecipitate of patients with essential and secondary type II mixed cryoglobulinemia.

Detection of hepatitis C virus RNA by polymerase chain reaction was performed in 26 patients with type II mixed cryoglobulinemia, and compared with anti-HCV antibody detection. The patients were divided into two groups according to etiology: 15 had essential type II mixed cryoglobulinemia and 11 had secondary type II mixed cryoglobulinemia. In the essential type II mixed cryoglobulinemia group, the prevalence of hepatitis C virus RNA detected by polymerase chain reaction was 60% in the supernatant and 93% in the cryoprecipitate. In the secondary type II mixed cryoglobulinemia group the prevalence of hepatitis C virus RNA was 45% in the supernatant and 55% in the cryoprecipitate. The differences between the two groups were not statistically significant. In both patient groups, detection of hepatitis C virus RNA in the cryoprecipitate was the most sensitive test for hepatitis C virus infection. These results suggest that hepatitis C virus might be involved in the origin of mixed cryoglobulinemia.

[The role of Mycoplasma pneumoniae in acute pneumopathies in children]. / Rôle de Mycoplasma pneumoniae dans les pneumopathies aiguës de l'enfant.

Among 199 cases of bronchopulmonary infection in children observed over a 2-year period, 22 cases (11%) were due to Mycoplasma pneumoniae. The diagnosis was based upon the complement fixation test on whole serum in half of the children and the research of specific IgM by complement fixation test on fractioned serum and/or indirect immunofluorescence on the others. The mean age of children with Mycoplasma pneumoniae was 6 years. The clinical and radiographic appearance of the affection was non specific, often similar to pneumococcal pneumonia.

[Acute encephalopathy following acquired rubella. Apropos of 6 cases]. / Encéphalopathie aiguë au décours d'une infection rubéolique acquise. A propos de six observations.

The authors report 6 cases of acute encephalopathy during the course of primary rubella infection. The mean age of the patients was 7 years and 6 months. Clinical features included, 3 days after an inconstant exanthema, seizures, coma and hyperthermia. The diagnosis of rubella was confirmed by a high rate of antibodies in serum with presence of IgM fraction. Five children recovered fully, one patient remained epileptic. The authors discuss the problems of diagnosis, the nosological position and the treatment of non-congenital rubella encephalitis.

[Epstein-Barr virus encephalitis. Apropos of a case in a child]. / Encéphalite à virus d'Epstein-Barr. A propos d'un cas chez l'enfant.

Encephalitic illnesses with Epstein-Barr virus (EBV) only represent a small percentage of the causes of viral encephalitis. Clinical symptoms are not specific. Biological standards tests carry few elements of direction, only serologic test of infectious mononucleosis confirms the diagnostic of recent EBV infection. Previous observation shows that the initial study can present similarities with herpes simplex encephalitis, which forces the immediate start of treatment by Acyclovir.

[Study of the fibrin degradation products in the synovial fluid of rheumatological diseases (author's transl)]. / Etude des produits de dégradation de la fibrine dans le liquide synovial pathologique.

FDP were studied in the synovial fluid of 23 patients with various rheumatological diseases. The levels, measured by the passive hemagglutination inhibition technique (Merskey technique), showed variable values, but were always found to be present. On half the cases a number of these molecules could be eliminated by a high dose of thrombin. Using three immune sera (anti-fibrinogen, anti-D, anti-E), immunoelectrophoresis revealed in half the cases one central nonmigrating arc and another with cathodic migration. This differs from results using FDP obtained by the digestion of fibrinogen by plasmin, but is, however, analagous with those obtained in vitro by the action of proteases of leukocyte origin. These results suggest that the intense fibrinogen catabolism within the pathological joints results from the action of proteolytic enzymes other than plasmin.