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We described a Hepatitis B surface antigen (HBsAg) subtyping method based on a commercial enzyme immunoassay (EIA) for detection of HBsAg in which the procedure was modified to include the use of monoclonal antibodies with restricted anti-HBs specificities. This method, which was able to classify HBsAg as: ayw1, ayw2, ayw3, ayw3* (intermediate between ayw3 and ayw4), ayw4, ayr, adw2, adw4 and adr, was compared to counter electrophoresis procedure (CEP) by testing HBsAg positive sera from blood donors included in a prospective national epidemiological survey. Among the 256 HBsAg positive samples tested with both techniques, 111 (43.3%) could not be subtyped with CEP vs 10 (3.9%) with our modified EIA. This difference was related to the serum HBsAg concentration which must be greater than 3000 ng/mL and 100 ng/mL for CEP and EIA, respectively. The results obtained from 145 sera with both methods were concordant. Seventeen out of 18 samples partially classified as ay with CEP were completely determined with EIA. This reliable procedure, derived from commercially available reagents, can be easily used in several applications such as large epidemiologic studies and as a substitute for nucleotide sequencing genotyping which is not adapted for large-scale screening and not applicable on samples from nonviremic hepatitis B virus (HBV) carriers.

BACKGROUND: Exposure to GB virus type C/HGV (GBV-C/HGV) could be determined by detection either of RNA by RT-PCR or of antibodies of the envelope protein E2. STUDY DESIGN AND METHODS: The aim of the study was to determine the proportion of the GBV-C/HGV markers of infection in a blood donor population infected with HCV and to identify GBV-C/HGV routes of transmission that are associated with HCV genotypes and risk factors. RESULTS: Among 306 HCV RNA-positive blood donors, the proportion of GBV-C/HGV RNA-positive donors and anti-E2-positive donors was 19.3 percent (95% CI = 15.0-24.2%) and 42.1 percent (95% CI = 36.6-47.9%), respectively. Exposure to GBV-C/HGV (RNA or anti-E2) was significantly associated with the risk factor of IV drug use. There was a trend toward association with HCV subtypes 1a and 3a, probably because these HCV subtypes are the most frequent in IV drug users. No correlation was observed between ALT elevation and the presence of GBV-C/HGV RNA. CONCLUSION: In persons with HCV infection, IV drug use seems to be a major route of GBV-C/HGV transmission. Precautions taken to avoid HCV infection will probably also decrease GBV-C/HGV transmission.

Resume Dans une population de 75 hemodialyses, I'ARN du virus de l'hepatite C (ARN-VHC) a ete recherche par polymerase chain reaction (PCR). Pour chaque patient le statut en anticorps anti-VHC a ete determine par ELISA et par RIBA-2 en cas de resultat positif. Le taux des transaminases a ete determine chaque mois au cours de l'annee precedant la fin de l'etude. Soixante patients avaient des resultats serologiques sur les 4 dernieres annees et parmi eux 39 ont eu une recherche de viremie VHC par PCR au cours des 2 dernieres annees sur au moins 4 prelevements. Les neuf patients anti-VHC negatifs etaient negatifs par PCR. Sur 7 patients presentant un profil RIBA-2 indetermine, 3 etaient positifs par PCR (1/1 avec un anticorps anti-C33c isole et 2/6 avec un anticorps anti-C22-3 isole). Parmi les 59 patients positifs par RIBA-2, 57 etaient viremiques pour le virus de l'hepatite C. Sur les 2 patients negatifs, l'un etait devenu negatif par PCR apres un traitement par interferon. Sur les 38 patients sans infection aigue, etudies par PCR sur 5 prelevements successifs, 11 ont ete trouves ARN-VHC negatifs (dont 7 anti-VHC negatifs et 3 « indetermines ) et 23 ARN-VHC positif sur tous les echantillons ; une viremie intermittente a ete observee chez 4 autres patients. La probabilite d'infection par le VHC augmente en fonction de la duree de dialyse et du nombre de transfusions recues. Le taux des ALAT etait correle a la viremie VHC. Les resultats obtenus montraient une bonne correlation entre la presence des anticorps anti-VHC et la positivite en ARN-VHC (97 %).

The aim of this study is the evaluation of the main kits used for the HBs Ag screening in French blood donors. Eight ELISA or RIA kits were evaluated. The specificity was assessed by testing samples from unselected blood donors. Repeatedly reactive sera were confirmed by a neutralisation test using an anti-HBs polyclonal antibody. The specificity expressed by the false positive reactions was lower than 0.1% for the ELISA and RIA kits. Sensitivity was assessed by the study of a panel of 16 HBs Ag specimens (ad and ay subtypes) with titres ranging from 0.05 to 1.80 ng/ml; all were tested in duplicate. Differences in sensitivity were observed according to the kits and procedures used. Some kits have a better sensitivity than RIA which is no longer the most sensitive technique. Such a study and a permanent control of each lot of HBs Ag commercial kit allow an improvement of reagents quality.

Background. HCV genotyping was performed to identify the source of HCV infection in haemodialysed patients. Methods. Specimens from 48 HCV-infected patients treated in the same dialysis unit were genotyped by line probe assay (LiPA). Results. Thirty-seven patients (77 %) were infected by genotype 1b. Only four of the 48 patients were never transfused and three of them had genotype 1b. In two of the three genotype 1b-infected patients, seroconversion was observed during the follow-up, suggesting a nosocomial HCV infection. Ten of the 44 transfused patients were infected with genotypes other than 1b. Blood products were very probably the source of infection in these patients. The 34 other patients (77.3%) were infected with genotype 1b and retrospective analysis failed to identify nosocomial and transfusional origin. Eight of the 11 patients with genotypes different from 1b were found in the 16 patients who were more than 55 years old. Only three of the eight originated from France. Conclusion. Blood transfusions and nosocomial infections were the main causes of HCV transmission in haemodialysed patients. Both screening of blood donors and aseptic measures in haemodialysis units may prevent HCV transmission.

Samples from 128 haemodialysed patients were tested by anti-HCV 2nd- and 3rd-generation assays from Ortho: 53 were positive by ELISA 2.0 and 54 (42%) by ELISA 3.0. The 54 anti-HCV-positive patients were tested by RIBA-2 and RIBA-3 and by PCR for the detection of HCV-RNA: 46 of the 47 patients (98%) reactive by RIBA-2 and 48 of the 51 patients (94%) reactive by RIBA-3 were HCV-RNA positive. Three patients with RIBA-3 indeterminate results were HCV-RNA negative. Among the 74 anti-HCV negative patients, 29 were tested by PCR with negative results. Two distinct episodes of hepatitis C have been observed in two patients during the follow-up and 44 of the 50 patients (88%) known positive for anti-HCV since at least 1989 were still viraemic in 1993. A very high correlation was found between anti-HCV antibodies reactive by RIBA and the presence of HCV-RNA. A lack of protection after a resolved infection and a high frequency of chronic disease have been observed as well as a reinfection or a reactivation of the infection in two patients.

Natural interleukin-2 at low dose has been reported to overcome the non-responsiveness of patients with chronic uraemia to hepatitis B vaccine. Therefore, we revaccinated 52 previous such non-responders (24 on maintenance dialysis) with 20 micrograms of recombinant preS2-containing hepatitis B vaccine with human recombinant interleukin-2 (1 MU) or placebo (randomly allocated). Seroconversion rates (74 vs 80%, respectively) and proportion of patients who elicited anti-HBs titres of 10 mlU/mL or more (56 vs 68%) were similar in both groups. Our results do not confirm local injection of interleukin-2 as an effective immunoadjuvant to hepatitis B vaccine in uraemic patients.

BACKGROUND: The results obtained in sequential specimens from recently infected subjects generally provide the best means of comparing the sensitivity of assays. STUDY DESIGN AND METHODS: The sensitivity of second- and third-generation assays for antibody to hepatitis C virus (HCV) was compared on sequential specimens, generally collected at monthly intervals from 45 patients undergoing hemodialysis who seroconverted for HCV between 1980 and 1990. RESULTS: Fifteen patients (33%) were positive earlier in the third-generation enzyme-linked immunosorbent assay (ELISA), with a mean difference of 17 days (range, 7–30) between the last negative and the first positive specimens. At the first rise in alanine aminotransferase, and at its peak, 63 and 91 percent of the patients, respectively, were anti-HCV positive in the third-generation ELISA. Third-generation recombinant immunoblot assay (RIBA) reacted at the same time as third-generation ELISA. Of the first specimens that were positive in second-generation ELISA, 44 percent reacted and 56 percent were indeterminate in third-generation RIBA, while 10 percent reacted, 72 percent were indeterminate, and 18 percent did not react in second-generation RIBA. From the beginning to the end of the follow-up, antibody to c33c was the most prevalent, followed in descending order by antibody to c22-3, antibody to c100-3, and antibody to NS5: 56, 54, 26, and 18 percent, respectively, at time 0, and 100, 86, 83, and 31 percent, respectively, 12 months later. CONCLUSION: Third-generation assays (both ELISA and RIBA) were more sensitive than second-generation assays in the diagnosis of HCV infection, in that positive results were obtained earlier and a higher proportion of specimens were confirmed positive in RIBA testing

A new anti-B19 IgM ELIS A was developed taking advantage of antibody-capture with biotinylated fusion protein as antigen. Specificity was examined using serum IgM antibody positive for rubella, hepatitis B core antigen, cytomegalovirus and Epstein-Barr virus as well as with sera positive for rheumatoid factors or antinuclear antibodies. The specificity was found to be 96%. Of one hundred serum samples compared using the new ELISA or the standard MACRIA tests for the presence of B19 IgM, 88 gave the same results. Fifty-three were negative and 35 were positive. Six sera were ELISA-negative MACRIA-positive, and six MACRIAnegative ELISA-positive. Thus, the ELISA gave 90% agreement with MACRIA. In a clinical study with 725 sera from suspected B19 infections, 161 (22%) were found positive by ELISA. The positive sera were from patients suffering from arthritis (35%), rash (35%), acute or chronic erythroblastopenia (21%), pancytopenia (5%), vascular purpura (2%) and lymphadenopathy (2%). A series of serum specimens obtained from two-B19 infected individuals were also studied. The IgM antibody became undetectable after four months.

Resume Deux cas de viremie a parvovirus ont ete observes en 1972 grâce a l'electroimmunodiffusion lors des recherches systematiques de l'Ag HBs chez les donneurs de sang. Ce virus fut appele « Antigene Aurillacdu nom de la ville ou le premier cas francais avait ete observe. A Londres, un virus mis en evidence dans les memes circonstances en 1975, s'est revele etre identique a l'Antigene Aurillac. Ces auteurs londoniens l'ont appele « serum parvovirus-like virus(SPLV) ou parvovirus B 19. Depuis 1972, 16 autres cas ont ete observes au CNTS. Sur ce total de 18 cas, 11 etaient des donneurs de sang, 4 du personnel hospitalier et 3 des patients. Un serum tardif obtenu chez 13 de ces 18 sujets a montre une seroconversion chez tous a l'exception d'un patient atteint d'un lymphome de Burkitt. Cette seroconversion a pu etre observee en quelques jours. Des anticorps anti-Aurillac sont decelables par EID chez 25,3 % des donneurs de sang. Une etude en immunomicroscopie electronique de l'une de ces viremies a montre des particules d'environ 20 nm de diametre. La densite de ce virus en chlorure de cesium etait de 1,38. Dix des 15 adultes sains ont pu etre interroges : 7 n'avaient presente aucun symptome, 1 avait eu une fievre a 39° pendant une journee et 2 avaient presente un erytheme (ainsi que 3 sujets en contact avec ces 2 personnes). Ces cas sont discutes et compares a la litterature anglo-saxonne qui montre que ce virus serait l'agent responsable de la 5e maladie ou erythema infectiosum, et de crises aplasiques au cours de syndromes hemolytiques chroniques. Il serait susceptible de contaminer les fractions coagulantes.

A vaccine against hepatitis B surface antigen (Institut Pasteur Production) was assessed in 138 haemodialysis patients in a placebo-controlled randomised double-blind trial. In an interim analysis, hepatitis B infections were observed in 21% of the vaccine group and 45% of the placebo group (p less than 0.02). 2 of the infections in the vaccine group and 12 of the infections in the placebo group occurred after the third injection. 60% of the vaccine recipients had an immune response. 4 months after the first injection the mean titre of anti-HBs was 120 mlU/ml.

We report the human parvovirus (HPV) infection cases diagnosed in 1984 and 1985 in the virological laboratory of C.N.T.S. Detection of viral antigen and total anti-HPV antibodies was performed by electroimmunodiffusion, and specific IgM by antibody-capture-radioimmunoassay. Seven viraemias were found in 38,730 sera sent for detection of hepatitis A and B markers. Twenty-two observations of aplastic crisis are described, with underlying haemolytic anaemias in 21 cases. HPV infection was serologically proven in 4 cases out of 22 rubeolelike illness, and, in 17 cases out of 17 erythema infectiosum (fifth disease). Four cases of vascular purpura (one of which was Schonlein-Henoch purpura) were studied, and HPV antigen was isolated in 2 cases. An observation of arthropathies in a young adult is described. Finally, 2 spontaneous abortions were simultaneous to an HPV infection. Our study allows us to underline the following points: HPV is the principal (but not exclusive) agent of the aplastic crisis in chronic haemolytic anaemias; these acute erythroblastopenias can reveal an unknown haemolytic anaemia, in particular in hereditary spherocytosis; the polymorphism of the clinical expression of HPV infection is important. Some viraemias are asymptomatic, while others are accompanied by vascular purpura, or atypic erythema; HPV has never been isolated in the fifth disease. Nonetheless bringing out of specific IgM and association of HPV infection linked manifestations in a same patient or in a same family shows its responsibility in the fifth disease; HPV responsibility in spontaneous abortions and fetal malformations remains to be demonstrated.

Resume Les immunoglobulines polyvalentes a usage intraveineux (GVP) sont obtenues par fractionnement a l'ethanol de plasma humain, selon une methode faisant intervenir des traces de pepsine a pH 4 et eliminant ainsi toute activite dite anticomplementaire. Tous les tests analytiques sont conformes aux normes officielles, et il est presente les resultats de controles elargis concernant les specificites et activites, la repartition des sous-classes d'immunoglobulines, la demi-vie biologique et le pouvoir opsonisant. Depuis leur mise a disponibilite officielle aux cliniciens le 1er juillet 1983, pres de 15 000 unites therapeutiques contenant 2,5 g d'immunoglobulines ont ete utilisees sans qu'aucun accident ne soit signale. Par ailleurs, plusieurs experimentations cliniques multicentriques sont en cours, chez l'adulte et chez l'enfant. Les resultats disponibles confirment que la tolerance est excellente et que l'activite, dans les indications connues et bien codifiees, est celle qui est attendue.

A vaccine against hepatitis B surface antigen (Institut Pasteur Production) was assessed in staff members from forty-eight French haemodialysis units where the risk of hepatitis B was high. Of 318 subjects who completed the protocol, 164 received three monthly injections of vaccine and 154 received corresponding injections of placebo. Hepatitis B infection was observed in 3.6% of the vaccine group and 12.3% of the placebo group (p less than 0.005). The 6 infections in the vaccine group all arose within 63 days from the first injections, whereas the 19 in the placebo group arose throughout the 12 months of follow-up. The rate of side-effects after injection did not differ in the two groups. 94% of the vaccine recipients had an immune response ( greater than 10 mIU/ml in at least 5 successive specimens). 4 months after the first injection the mean + or - 2 SE peak level of anti-HBs was 2433 + or - 1077 mIU/ml.

Traditional preventive measures against virus B hepatitis (SH, MS-2), new measures based on the detection of the Australia (Au) antigen, and some recent attempts at active and passive immunization against Au antigen will be discussed. Traditional Preventive Measures Traditional preventive measures are directed toward reducing contamination. Whole blood, red blood cell, and platelet concentrates, and especially plasma and certain derivatives of plasma, such as fibrinogen and cryoconcentrates are potential sources of contamination. Human plasma fraction (PPSB) 1 appears to be less susceptible to contamination than other preparations among prothrombin complex and factor IX concentrates. The size of the pool is important for plasma and derivatives. Equipment for injection should be disposable. Needles, scalpels, if reused, and dental instruments should be sterilized with prolonged boiling or autoclaving. Sodium hypochloride, β-propiolactone, and ultraviolet light are usually used for disinfection. Crowding and poor sanitary conditions favor contamination since virus B may be transmitted