Carriers of HBs antigen, anti-HIV antibodies and their association with blood donors in Brazzaville

Serum samples taken from 6,624 blood donors since 1984 to 1987, were tested for Hepatitis B virus surface antigen (HBs Ag) using a microhemagglutination assay and for anti-HIV antibodies by ELISA test. The mean carrier state of HBs Ag was 10.68% and that of anti-HIV antibodies was 6.99%. The association of HBs Ag and anti-HIV antibodies was discovered in 4.84% donors but without correlation for the period of the study.     

Serological HLA class I alleles in Senegalese blood donors detected HBs Ag positive

We analysed the HLA class I alleles in 96 blood donors HBs Ag positive compared with 93 healthy control individuals (HBs negative). The most frequent HLA-A, -B, -C alleles found were, A23 (33.6%); A2 (25%); A30 (25%); B8 (31.5%); B7 (16.3%); B58 (11.9%); B35 (11.9%); B49 (11.9%); B53 (10.8%); Cw7 (39.1%); Cw3 (36.9%); Cw4 (36.9%). Significant differences (P<0.001) were found between the blood donors and the controls for the following HLA alleles, A1; A23; B8 and Cw3. The detection of HBe antigen was positive in 26/84 blood donors. It was observed a significant difference (P<0.01; odds ratios (OR)=6.25) between positive and negative HBe antigens blood donors for HLA-A1 allele.     

Prevalence of HBs antigen in blood donors in the Bouaké regional centre of blood transfusion in 2001

A prospective cross-sectional study was conducted in the regional center of blood transfusion in Bouaké from December 1, 2001 to February 28, 2002. One thousand two hundred thirty one new blood donors were tested. HBs Antigen detection was made according to ELISA technique (Hepanostika HBs Ag Uni-Form II). HBs Antigen prevalence in blood donors in Bouaké was 12.5%. One hundred fifty four blood donors were tested positive and were divided into 131 males (85%) and 23 females (15%). Their average age was 27, 5 years old (18-65 years). HBs Antigen carriage rate was lower in females and students. They were mainly pupils (62%) and had risk factors of hepatitis B infection (intramuscular injection, multiple sexual partners, unsafe sex). HBs Antigen carriage rate in blood donors is high in Bouaké and justifies the systematic screening of this Antigen in any blood donor to reduce the transfusion risk. On the other hand, it is necessary to modify the blood collection strategy in order to make the most of the donation and to decrease the residual risk.     

Serial liver biopsies in blood donors with persistent HBs antigenaemia.

Initial liver biopsies from asymptomatic HBs antigen positive blood donors showed a range of histological abnormalities ranging from minor parenchymal lesions to cirrhosis. Twenty of these have now been followed up for periods of up to four years and during that time have had at least two liver biopsies. Throughout the period of study all the donors have remained carriers of HBs Ag, and there was no significant variation in the titers of antigen or the electron microscopic appearances of the serum in individual donors. The histological appearances of subsequent liver biopsies were not always the same as those seen initially, and while there appeared to be some improvement in three cases, there were nine in which the histological appearances were worse.     

Studies on natural cytotoxicity of human monocytes in viral hepatitis

Studies on natural cytotoxicity of peripheral blood monocytes were conducted in patients with acute viral hepatitis B, patients with chronic aggressive hepatitis etiopathogenically linked to viral hepatitis B, and in asymptomatic carriers of HBs antigen. In the majority of cases of viral hepatitis in the acute stage of the disease and in patients with chronic aggressive hepatitis a significant reduction in the examined function of monocytes was noted which became normalized during convalescence. Results obtained for HBs antigen carriers did not differ from those obtained for normal blood donors. The observations may indicate that restricted natural cytotoxicity of monocytes in the course of viral hepatitis B is related to liver injury. The disturbed monocyte natural cytotoxicity was becoming normal after in vitro incubation with thymic preparations (TFX, Thymex L).     

Comparative studies of human and animal sera containin g anti-HB-8 antibodies]

In a material of 768 sera obtained from blood donors and patients and 150 sera containing HBs antigen it was investigated whether the available animal sera (horse, swine, goat) with anti-HBs antibodies meet the requirements of diagnostic sera. It was found that none of these anti-HBs animal sera was better than the human serum used as yet. Only the specificity of horse anti-HBs antibodies was equal to the human serum, hence horse serum could be used for diagnostic purposes in routine investigations by the precipitation and complement fixation method. The swine and goat sera did not ensure detection of all HBs antigens which are detected using human or horse serum.     

乙型肝炎血源疫苗作体内免疫提高抗-HBs效价的研究

本文介绍了用乙型肝炎血源性疫苗进行人体内免疫提高人体抗-HBs效价的结果。21名正常献血员抗-HBs阳性志愿者分组进行不同免疫剂量的观察,结果表明提高志愿者的体内抗体效价,疫苗使用剂量以100μg/次为宜。抗-HBs效价免疫后一个月逐步上升,最高峰值维持一个月左右。本实验还证实曾接受过疫苗免疫的志愿者再次免疫后的各项反应优于未免疫的志愿者。此工作对制备抗-HBs人McAb寻找高效价抗-HBs血源提供了可靠依据。     

Screening for markers of infections transmitted by transfusions in the blood collected in France from 1996 to 1998]

From 1996 to 1998, a decrease in positive donation rates has been observed for HIV, HCV and HBs Ag in first-time donors, while these rates remained stable for HTLV. In repeat donors, the same decrease was observed for HCV and HBs Ag while the rates remained stable for HIV. No HTLV-positive donations from repeat donors were noted in 1998. About half of the HIV-positive repeat donors were regular donors (less than two years between the two donations), as well as 88% of HBV-infected repeat donors. Inversely, only 20% of HCV-positive repeat donors were regular donors. Anti-HBc antibodies have been found in 20% of HIV-infected donors, in 22% of HCV-infected donors, and were associated with HBs Ag in 99% of the cases. Elevated ALT was observed in 47% of donors with anti-HCV and in 10% of donors with HBs Ag. The major risk factors are at-risk sexual behavior for HIV and use of intravenous drugs and nosocomial infections for HCV. Being a native of an endemic country has been found to be the major risk for HBV. The major HTLV risk factor was directly or indirectly linked to the Caribbean area.     

Information carried by the DNA released by antigen-stimulated lymphocytes.

Both antigen-stimulated and non-stimulated human blood lymphocytes release in vitro a DNA-containing complex which is not the product of dying or disintegrating cells. Lymphocytes obtained from different PPD or HBs positive or negative donors were incubated with one of these antigens and the DNA released in the culture medium was tested for its information content using, successively, two cell-free systems. The ability of the resulting protein product to bind specifically to the stimulating antigen was examined by immunoadsorption chromatography. Results show that DNA excreted by stimulated lymphocytes was transcribed into an RNA which coded for an antigen-binding protein, whereas DNA released by unstimulated lymphocytes did not. The protein produced in this system, using as template the DNA released after cell stimulation, bound specifically to PPD or HBs Sepharose 4B coated columns, depending on the stimulating antigen and on the cell response to this antigen. After elution from the column the protein sedimented at 19S in a linear sucrose gradient.     

Prevalence of hepatitis B (Hbs Ag, Hbe Ag, DNA) and delta virus markers, in about 10,000 pregnant women in Limoges (France)

The risk of perinatal B virus transmission is well known, but is estimated in France on results obtained from blood donors or from urban populations. In the present study, the screening of HBs Ag was carried out during five years (1984-1988), within a sample population of pregnant women (french women: 8,364, immigrant women: 1,206) seen in the university hospital of Limoges. Positive sera for HBs Ag were also tested for the other markers of B virus including specific DNA, and markers of the delta virus. The total seroprevalence of HBs Ag among these women was 0.54%, and was significantly higher in the immigrant women group (2.57%) when compared to that of french women (0.25%). During the same period (1984-1988), the seroprevalence among females blood donor was 0.03%. Among the HBs Ag chronic carrier pregnant women (n = 52), 27% were HBe Ag positive and four of them (31%) had viral DNA in their serum. Viral DNA was found in three women who were HBe Ag negative. Thirteen per cent of the HBs Ag positive pregnant women were infected by the delta virus.     

Prévention du paludisme post-transfusionnel en zone d’endémie

BackgroundMalaria is a real public health problem in Africa; more than 300 million new cases and approximately two million deaths arise every year. In spite of the blood transfusion is a potential way of Plasmodium transmission, there is no consensus for measures to prevent post-transfusion malaria in endemic area. This work aimed at comparing some tools and to discuss various strategies to be implemented.Material and methodsThe study concerned 3001 blood donors recruited in seven blood transfusion centers in Senegal during two periods: dry season (June–July, 2003) and rainy season (October–November, 2003). We evaluated the efficiency of the selection questionnaire for the blood donors to exclude those who are potentially asymptomatic carriers of the Plasmodium. Every donation was screened for pLDH antigen and antibodies against Plasmodium by Elisa technique (DiaMed, Cressier sur Morat, Suisse), morphological tests was also performed, as well as the screening of HIV, HBs Ag, HCV Ab and syphilis.ResultsMedian age of blood donors was of 27.7 years. Anti-Plasmodium antibodies prevalence was 65.3% and pLDH antigen was of 0.53%, all positivity was confirmed by microscopy. The prevalence of the other infectious markers was 11.7% for HBs Ag; 0.83% for syphilis; 0.49% for HCV Ab and 0.46% for HIV Ab. The risk factors associated with an asymptomatic carrier of Plasmodium were: the rainy season, irregular character of the blood donations, high frequency of malaria attacks in the past, and absence of treatment during the last episode.ConclusionPlasmodium represents the third risk of blood transmitted infectious agents after hepatitis B virus, syphilis, and before HCV and HIV in Senegal. The medical questionnaire is not useful enough for asymptomatic carriers deferral, and we propose to introduce Plasmodium screening. The screening for Plasmodium pLDH by Elisa technique seems to be the best tool in endemic area and the strategy of systematic screening is the most suited in terms of blood transfusion safety.     

The Prevalence of Occult Hepatitis B Infection among the Blood Donors in a Tertiary Care Hospital,Puducherry

Occult hepatitis B infection (OBI) is a cause of concern while screening the blood donors to prevent transfusion-related transmission of infection. This study was conducted to assess the prevalence of OBI using total anti-HBc by ELISA and DNA detection by real time polymerase chain reaction (PCR). The samples included were negative for HBs Ag by ELISA. Out of 1102 samples tested, 156 were positive for total anti-hepatitis B core antigen and 52/156 by real-time PCR. Overall, the prevalence was found to be 4.71% (52/1102). The results indicate that nucleic acid-based testing should be an essential part of screening procedure to prevent missing of OBI.     

Le risque infectieux viral chez le polytransfusé : séroprévalence de sept agents viraux dans le centre tunisien

The aim of this study is to evaluate the prevalence of seven transfusion-transmitted viruses in polytransfused adults and children comparatively with a group of healthy control subjects. We studied 107 polytransfused patients (59 adults and 48 children) and 160 control subjects (100 blood donors and 60 children). Immunoenzymatic tests were used for detection of HBs antigen (HBs Ag), antibodies against hepatitis C Virus (anti-HCV), and human immunodeficiency virus (anti-HIV), and IgG antibodies against human cytomegalovirus (IgG anti-CMV), human parvovirus B19 (IgG anti-PB19), and hepatitis E virus (IgG anti-HEV). An immunofluorescent assay was performed for the detection of human herpesvirus 8 antibodies (anti-HHV8). Prevalence of HBs Ag, anti-HCV, anti-HIV, IgG anti-CMV, IgG anti-PB19, IgG anti-HEV, and anti-HHV8 in polytransfused group was 8.4, 4.7, 0, 86.9, 60.7, 28.9, and 47.6%, respectively, and 1.8, 0.6, 0, 86.2, 53.1, 10, and 12.5%, respectively, in the control group. The difference in prevalence between the two groups was statistically significant for HBs Ag (P = 0.01), anti-HCV (P = 0.03), IgG anti-HEV (P < 10(-4)), and IgG anti-HHV8 (P < 10(-4)). Categorization according to age showed that hepatitis B and C risk was limited in adult polytransfused group. HHV8 infection was higher in polytransfused subjects born before the use of leucocyte-depleted blood components. Our results corroborate literature data on the risk of HEV and HHV8 infection by blood transfusion. Hepatitis B vaccination and improvement in screening tests have an important role in reduction of hepatitis B and C risk in transfusion, especially in young polytransfused persons. However, a residual risk of transmitting viral infections persists, and efforts are needed to improve transfusion safety.     

Platelet aggregation by hepatitis B surface antigen-antibody complexes.

Platelet aggregation indicating antigen-antibody complex formation was observed when hepatitis B surface (HBs) antigen and antibody were mixed. Platelet aggregation titers were determined for serum specimens found positive by radioimmunoassay for either HBs antigen or HBs antibody. From these determinations, incidence of HBs antigen-antibody complexes was found to be higher in HBs antigen seraas than in HBs antibody sera. There was an inverse correlation between platelet aggregation titers and radioimmunoassay values that was statistically significant for HBs antigen sera but not for HBs antibody sera. The incidence of anti-complementary activity was twice as high for platelet aggregation-positive HBs antigen and antibody sera as for platelet aggregation-negative sera. HBs antigen sera that were positive by platelet aggregation exhibited nearly three times the incidence of anti-complementary activity as did HBs antibody sera. However, the low incidence of anti-complementary activity was distributed about equally between HBs antigen and antibody sera that were negative by platelet aggregation. Additional HBs antigen preincubated with HBs antigen-positive sera effectively inhibited platelet aggregation, whereas additional HBs antibody was somewhat less effective. On the other hand, preincubation of HBs antigen sera with anti-IgG serum effectively enhanced platelet aggregation, whereas preincubation of HBs antigen sera with HBs antibody did not.     

Molecular characterization of occult hepatitis B cases in Greek blood donors

The use of sensitive nucleic acid testing for hepatitis B virus in blood donors revealed a number of HBV DNA(+) cases among HBsAg(?) donors, a status known as occult HBV infection. The purpose of this study was the serological and molecular characterization of occult HBV infection in Greek blood donors. A prospective study was undertaken in order to identify occult HBV infection cases in blood donors. As part of the routine screening of blood donations in Greece, blood units were screened individually by a multiplex HIV‐1/HCV/HBV nucleic acid assay. Initially reactive samples were retested with discriminatory assays. HBV DNA(+)/HBsAg(?) samples were tested further for HBV serological markers and HBV DNA was quantified by real‐time PCR. Molecular characterization was performed by sequencing the envelope and polymerase genes of HBV. Preliminary screening revealed 21 occult cases with the following patterns: anti‐HBc only: 7 donors, anti‐HBc/anti‐HBs: 7 donors, anti‐HBc/anti‐HBe: 5 donors, anti‐HBc/anti‐HBs/anti‐HBe: 2 donors. In all cases, the HBV DNA load was <351 IU/ml. Sequencing was successful in 10 donors (classified within genotype D) revealing several amino acid substitutions related to diagnostic escape and antiviral resistance. HBsAg diagnostic failure and low viral replication in occult HBV infection carriers could possibly be attributed to multiple changes in envelope and polymerase regions, respectively. J. Med. Virol. 81:815–825, 2009. © 2009 Wiley‐Liss, Inc.     

Diagnosis of hepatitis B by dane particle associated DNA polymerase assay

We have studied prospectively 478 subjects exposed to hepatitis B virus and 20 pregnant women who developed HBs antigen during the last trimester of pregnancy. The results suggest that the DNA polymerase assay might be useful for the diagnosis of hepatitis B infection and that in confirmed cases of hepatitis, the enzyme might be detected in the absence of HBs antigen. HBe antigen appeared in 19% of those subjects who developed HBs and a positive correlation between HBe antigen and DNA polymerase was found in 40% of the cases positive for this antigen. The data presented also suggest that HBe antigenemia in pregnant women is not consistently associated with HBs infection in the babies born to them. However the children born to HBe positive mothers are at higher risk than those born to HBe negative mothers.     

Evaluation of hepatitis B virus markers for surrogate testing of hepatitis C]

To evaluate the surrogate markers of non-A, non-B hepatitis virus (es) carriage state, the relationship between antibody to hepatitis C virus (HCV) and antibody to HBc/HBs and liver enzyme (ALT) was sought in Saitama prefecture. Out of 36,642 blood donor samples, 410 (1.1%) samples were positive for anti-HCV. Anti-HCV was found in 1.79% of donors with anti-HBs and/or anti-HBc, which is 1.7 fold of the frequency found in donors (1.04%) negative for anti-HBc/HBs. In contrast to the reports from Europe or USA, a poor correlation of anti-HCV with the serological history of hepatitis B infection was observed. These results indicate that hepatitis B and hepatitis C were transmitted independently in the Japanese, which is more homogeneous socioeconomically than the European or American populations. On the other hand, anti-HCV prevalence was in close correlation to ALT level as observed in the USA and in Europe. As we predicted previously, ALT can be expected to reduce the incidence of post-transfusion non-A, non-B hepatitis, however, anti-HBc can not.     

The clinical examination for posttransfusion hepatitis

We studied viral hepatitis, type A, type B, type D and type non A non B. Type A hepatitis was diagnosed by the serological examination for IgM type anti-HA and total anti-HA. Several cases were negative for IgM type anti-HA within 2 weeks after the onset of type A hepatitis. Type B hepatitis was diagnosed by RIA for serum HBs antigen. Several cases of type B hepatitis were negative for serum HBs antigen but positive for IgM type anti-HBc, or hepatocytes were positive for HBs antigen. These cases had high titer of total anti-HBc. Type D hepatitis was diagnosed by RIA for anti-delta in serum and by PAP stain for delta antigen in hepatocytes. All cases of type D hepatitis were positive for anti-delta in their serum and positive for delta antigen in their hepatocytes, they were positive for HBs antigen. Incidence of HDV infection was 0.7% in HBV carrier. The incidence of non A non B hepatitis was 27.6% in 105 recipients and the incidence of its progression to the chronicity was 20.0%.     

The role of circulating hepatitis B antigen/antibody immune complexes in the pathogenesis of vascular and hepatic manifestations in polyarteritis nodosa

To investigate further the role of hepatitis B antigen (HBs Ag) and specific immune complexes in polyarteritis, sera from 55 histologically confirmed cases were tested for the presence of hepatitis B antigen-associated particles and hepatitis B-antibody (anti HBs) by solid phase radio-immunoassay, electron microscopy, and passive haemagglutination. Results of these findings have been correlated with the clinical course of the disease.HBs Ag was detected in 30 patients (54.5%) and anti HBs in 13/45 (28%). Subtyping in 20 patients revealed that 11 were Y and 9 D. Thirty-seven cases (69%) demonstrated either HBs Ag or anti HBs and 5/45 (11%) had both. Electron microscopic examination showed 20 nm spherical and tubular particles in sera of 20/27 patients with 42 nm particles in 11 cases and clumped particles in 12 (60%).No correlation was found between detection of immune complexes and liver disease whereas the presence of coexisting hepatitis B antigen and antibody or aggregated particles was restricted to cases of active vasculitis. Seroconversion or the presence of hepatitis B antibody alone was associated with improved prognosis. Circulating hepatitis B antigen antibody complexes may be responsible for vasculitis or polyarteritis but do not appear to be pathogenic for the liver.     

Interaction of hepatitis B surface antigen with serum albumin of various species on polystylene latex particles

Polystylene latex particles coated with serum albumin of various species, including non-primate serum albumin, were agglutinated by sera containing hepatitis B surface (HBs) antigen and hepatitis Be (HBe) antigen and by purified HBs antigen. Monomer and polymer albumin separated from human serum albumin preparations on latex particles were found to react with HBs antigen. Monomer from non-primate serum albumin preparations bound to latex particles was also found to have the ability to react with HBs antigen, but polymer of non-primate serum albumin did not. The mechanism of reaction between HBs antigen and the latex-bound serum albumin of various species is discussed.