[Hepatitis A seroprevalence in HIV-infected patients]. / Séroprévalence de l'hépatite A chez des patients infectés par le VIH.

OBJECTIVE: The authors had for aim to prospectively study the hepatitis A seroprevalence of an HIV-infected population, followed-up in an outpatient clinic (CISIH Strasbourg). DESIGN: Blood tests were performed on all patients from September 2003 to March 2004 to screen for hepatitis A (total antibodies with Elisa). RESULTS: The overall seroprevalence was 219/514 (56.6%), similar in male and female patients. It increased with age, especially in European patients (P = 0.003). The seroprevalence was lower in European subjects: 46.3% (while it reached 100% in sub-Saharan Africans), the prevalence was similar whatever the HIV risk group (46% in homosexual as well as in heterosexual patients, 44% in intravenous drug users). Hepatitis B or C co-infection did not increase the seroprevalence of hepatitis A. The hepatitis A seroprevalence was similar in various CD4 T cell count categories. CONCLUSIONS: Our results stress the utility of hepatitis A serology in HIV-infected patients (more than 50% of European patients are non immune), and the importance of assessing hepatitis A vaccination.

[Evaluation of two commercial enzyme immunoassays for diagnosis of hepatitis C in the conditions of a virology laboratory]. / Evaluation de deux trousses commerciales EIA pour le diagnostic de l'hépatite C dans les conditions d'un laboratoire de virologie.

BACKGROUND: Most studies which evaluate antibody detection assays are conducted on blood donors specimens, i.e healthy individuals. Sera collected in patients, vs healthy individuals, can make serological tests difficult because of possible non specific reactions interfering with serological tests. The aim of this work was to compare the specificity and the sensitivity of two commercial automated assays for the detection of hepatitis C virus antibody, Monolisa anti-HCV Plus on the Evolis automate (Biorad) and Axsym anti-HCV 3.0 (Abbott). PATIENTS AND METHOD: The prospective study of specificity included 2020 routine serum samples sent to our virology laboratory. The sensitivity was established with eight commercially available HCV seroconversion panels. RESULTS: The Monolisa and the Axsym assays showed a specificity of 99.64 and 99.12%, respectively. Of 49 specimens from eight commercially available HCV seroconversion panels, the number of positive results was 21 and 24 for the two tests, respectively. CONCLUSION: A statistical analysis of specificity and sensitivity results proved no significant difference between the two tests. Nevertheless, the Monolisa kits could be preferred for its more homogeneous sensitivity than the Axsym test and for its apparent better specificity. The final choice of a kit should also take into account the easiness to perform and an optimal integration in the usual practice of the concerned laboratory.

[Immunoblot in the serological diagnosis of hepatitis C virus infection]. / Intérêt de l'immunoblot dans l'évaluation du statut sérologique vis-à-vis de l'hépatite C.

The objective of the study was to assess three immunoblot assays, the Deciscan HCV Plus, the Riba and the Inno-Lia, on 44 discordant samples with three EIA kits. These immunoblots were considered as confirmation reagents. A result was considered as a false positive by anti-HCV antibody assay if the three immunoblots were negative or if two immunoblots were negative with the third being indeterminate and a negative virological genomic diagnosis observed on all the samples. The result was positive if at least two immunoblots out of three were positive. Thus, 34 samples were considered as false positive and ten samples were excluded because it was impossible to conclude between true or false positive result. The 44 discordant results were never confirmed as positive by the use immunoblot or PCR. The three immunoblots were negative for half of the samples and two immunoblots and one indeterminate were observed for 77% of the samples. The false positive results by the Monolisa assay were more often found indeterminate with the Deciscan assay than with the other immunoblots. That was also checked for Vitros/Riba pair. One of the explanations could be the use of common antigens for the reagents from the same manufacturer. The Inno-Lia test is the most specific immunoblot according to the results obtained in our study.

Increasing the number of hepatitis B vaccine injections augments anti-HBs response rate in HIV-infected patients. Effects on HIV-1 viral load.

Preventing hepatitis B by vaccination is essential in HIV-infected patients (higher progression rate of HBV infection to chronicity, lower rate of serum HBe Ag loss). However, it has been shown a decreased anti-HBs response in these individuals after a standard vaccination (3 doses of 20 micrograms). Thus, we tested the hypothesis that doubling the number of hepatitis B vaccine injections might increase anti-HBs response rate. HIV-infected patients with CD4 > 200/microliter, who were on stable antiretroviral treatment, as well as seronegative for HBV markers, and who have never been vaccinated against HBV, were given 3 intramuscular injections of Genhevac B 20 micrograms at 1 month intervals. Initial non responders were given 3 additional monthly injections. Anti-HBs titer was followed. We also evaluated the effects on HIV-1 viral load. Twenty patients with a median CD4 cell count of 470/microliter were enrolled. The response rate after three 20 micrograms injections was 55% (11/20), lower in individuals with CD4 between 200 and 500/microliter (4/12 = 33.3%), compared to patients with CD4 above 500/microliter (7/8 = 87.5%, P = 0.02). Among 9 initial non-responders, only 2 did not respond to 3 additional doses; thus, the overall response rate was 90% (18/20). Geometric mean titers of anti-HBs were 133 IU/l and 77.5 IU/l, after 3 and 6 Genhevac doses, respectively (P = 0.38). One year later, only 10/17 (58.8%) patients had protective anti-HBs. Five patients experienced a significant viral load increase, transient in 3 cases. These preliminary results suggest that doubling the number of hepatitis B vaccinations in HIV-infected patients might significantly improve anti-HBs response rate; however, close monitoring of anti-HBs is necessary because of its short-lived persistence. The effects on HIV-1 viral load are limited.

[Retrospective study of the value of the RIBA-3 test in 68 patients with discordant serologies with regard to hepatitis C obtained with third generation ELISA tests. Is there still a value in RIBA-3?]. / Etude rétrospective de l'intérêt du test RIBA-3 pour 68 cas de sérologies discordantes vis-à-vis du virus de l'hépatite C obtenues avec des tests ELISA de 3e génération. Reste-t-il un intérêt au RIBA-3?

The aim of the present study is to evaluate the ability of RIBA-3 to resolve cases with controversial ELISA results, since modifications have been introduced by the manufacturer in July 1997 to analyse immunoblot patterns. Sera from 68 patients are studied: 49 controversial cases Ortho/Murex, 17 Ortho/Abbott and 2 cases tested by the three ELISA kits. Indeterminate patterns by ELISA assays remain unresolved in 65% of the samples. RIBA analysis performed in patients with controversial results Ortho/Murex seems to reveal a lack in sensitivity of the Murex kit, but does not show differences in the specificity between these two immunoassays. The RIBA patterns among the samples with Ortho/Abbott controversial results do not demonstrate any discrepancy in the sensitivity of these ELISA tests but it appears that Ortho could be less specific. Our data need to be further confirmed by the analysis of more samples. At last, when the ELISA result is included in the grayzone, the RIBA pattern is generally indeterminate and it is negative in other cases. Finally, the controversial ELISA results, that are mainly found in patients with severe immunosuppression, remain indeterminate depending on the RIBA test. Moreover, the immunoblot is less sensitive and more expensive than any other HCV ELISA test, so there is no convenience to use it for confirmation of a preliminary positive or indeterminate screening.

[Prenatal diagnosis of viral infections. A two year study in Strasbourg]. / Diagnostic prénatal des infections virales. Bilan de deux années d'activité à Strasbourg.

We report here the results of a 2-year study on the prenatal diagnosis of viral infections in Strasbourg. This screening was carried out by virus isolation, by PCR assay, or by detection of IgM fetal antibody for 98 pregnant women at risk of transmitting one of the viruses that causes fetal disease such as parvovirus B19 (B19), Herpesviruses [cytomegalovirus (CMV), varicella-zoster virus, herpes simplex virus] and rubella virus. A viral etiology was proven in 7 out 98 cases: PCR applied to B19 DNA detection was positive in 5 amniotic fluids (AF), 2 fetal serums and one ascitic liquid. The diagnosis of 2 cases of CMV infection was obtained by both PCR and virus isolation in AF from twins fetuses. The detection of specific IgM in maternal serum or fetal serum is useful to achieve the diagnosis but serological tests on other samples have no efficiency. No virus was found in any other specimen, but the genome of Toxoplasma gondii was detected by PCR in 1 of 17 AF samples analyzed at the Institut de Parasitologie. These findings show that PCR assay is a sensitive method for the positive diagnosis of intrauterine infection and promises to careful follow-up of the pregnancy.

[A case report of post-rubella myelitis in an adult]. / A propos d'un cas de myélite post-rubéolique chez l'adulte.

Neurological complications following rubella are only rarely encountered. We report a case of isolated myelitis. A 44-year-old healthy female suffered from an erythematous macular rash which rapidly cleared. However, the following days, dysuria initiated hospitalization. On admission, she was febrile but alert and in normal mental status. General physical examination was quite unremarkable. Four days later, she suffered from acute urinary retention, fecal retention and vaginal hypoesthesia. Routine laboratory data, chest skull and spinal column X-rays were unremarkable. The sterile cerebrospinal fluid contained 30 lymphocytes/mm3, 0.48 g/ml of protein but normal amount of glucose. Rubella antibody titers showed a significant elevation and specific IgM were detected by immunocapture. Improvement was rapid and recovery was uneventful except a mild vaginal hypoesthesia that persisted 5 weeks later. Diffuse myelitis occurring shortly after rubella vaccination have also been described. The immunopathological mechanisms by which involvement of the nervous system occurs is far from clear. Little is known about the pathogenesis of post-vaccination myelitis and although the mecanism of sensitization and the specific neural antigens are not known, post-infectious and post-vaccinal myelitis are thought to share a common pathogenic basis.

Enterovirus infections in neonates. A retrospective study of 21 cases.

OBJECTIVES: The aim of this study was to define the major features of enterovirus infections in the neonatal period based on our own experience. METHODS: Epidemiology, clinical manifestations and laboratory investigations concerning 21 neonates having experienced a Coxsackie B or an Echovirus infection between 1987 and 1991, were retrospectively reviewed. Aetiological diagnosis was made by classical viral isolation and/or by evidencing Coxsackie B-specific IgM antibodies with an immunocapture enzyme immunoassay. RESULTS: In 13 neonates the infection occurred between June and September. The onset of clinical signs ranged from day 1 to day 25 after birth with two separate periods: before 7 days of age, suggesting a perinatal transmission of the virus, or beyond this date, more likely connected with a postnatal transmission. Clinical manifestations included hyperthermia, gastroenteritis, meningitis, encephalitis, pneumonia and myocarditis, with a diphasic pattern in 6 cases. Most of the neonates improved gradually and developed normally. The Coxsackie B-specific IgM assay was the most rapid method whereas viral isolation, even though it took more time, was the most sensitive technique to establish the aetiological diagnosis in neonates. CONCLUSIONS: Enterovirus infections in neonates are difficult to diagnose and to differentiate from bacterial infections. A viral-like illness in the environment of the neonate allows the clinician to anticipate the clinical signs and a possibly fatal disease. Identification of the causal virus should be performed by both viral isolation and search for specific IgM antibodies. Treatment and prophylaxis are so far disappointing.