Comparative study of three commerical preparations for the detection of Australia antigen]

2,944 sera from blood donors (420 of them being new donors) were tested in four techniques: Counterelectrophoresis (CEP) and three commercial tests: Ausria II, Auscell and Hepanosticon. Over 10 HBs Ag detected by RIA, 8 were evidenced by the Auscell test and 6 by the Hepanosticon Test. False positive results (approximately 3%) represent a disadvantage to the reverse hemagglutination method; this rate increased considerably in a group of 386 patients sera also tested. The authors conclude that the results obtained with the reverse hemagglutination technique are nearing those of RIA.     

Application of a reversed passive hemagglutination test to the detection of HBs antigen]

In this report we present an evaluation of the sensitivity, specificity and ability to detect HBs Ag carriers of a new reversed passive hemagglutination test, using immunochemically purified chimpanzee anti HBs bound to stabilized human erythrocytes. The method was shown to have a sensitivity equal (within one two fold dilution) to that of the Ausria I 125 ratio immuno assay, and in a double blind comparison detected essentially the same number of Hbs Ag containing specimens among volunteer blood donors. The method therefore provides an economical method for the third generation testing of blood donors. The methodology which has been described incorporates a definitive specificity test in which serum drawn before and after immunization of chimpanzees with purified HBs Ag is compared for its ability to neutralize the hemagglutination reaction. The use of serum from the same animal for this purpose avoids the theoretical possibility that antiglobulin antibodies directed at subclass determinants such as Gm of Inv could be differentially inhibited due to possible subclass differences in the blocking sera employed. A reliable test for specificity of HBs Ag screening results is essential to avoid false notification of donors that they are carriers of hepatitis B virus.     

Hepatitis C Virus Infection-Associated Markers in Sera from Blood Donors in Surabaya,Indonesia

Among 2,233 sera obtained from volunteer blood donors, 259 (11.6%) showed elevated alanine aminotransferase (ALT) levels. A second-generation enzyme-linked immunosorbent assay (ELISA) revealed that 23 (8.9%) of the 259 sera were positive for antibodies against hepatitis C virus (HCV), whereas only 9 (1.4%) of 646 sera randomly collected from blood donors with normal ALT levels were positive (P<0.001). The overall prevalence of anti-HCV antibodies among blood donors was estimated to be 2.3%. HCV RNA was detected in 19 (83%) of the 23 anti-HCV-positive sera with elevated ALT levels, and 8 (89%) of the 9 sera with normal ALT levels. Among the anti-HCV-positive sera, IgM anti-HCV was detected in 5 (22%) of 23 sera with elevated ALT levels and in 2 (22%) of 9 sera with normal ALT levels. All of the IgM anti-HCV-positive sera were positive for HCV RNA, irrespective of ALT levels.     

乙肝病毒表面抗原和抗体双阳性者中病毒S区基因序列分析

为了解乙肝病毒 (HBV)表面抗原和抗体双阳性患者中病毒的基因型及其HVBS区是否有变异。用放射免疫试剂检测HBsAg阳性样品中的抗 HBs抗体 ,用聚合酶链反应法检测双阳性样品中的HBVDNA ,然后对阳性样品进行克隆和基因序列分析 ,并将所得序列与HBV不同基因型的代表株进行比较分析。结果显示 389例HBsAg阳性样品中有 10例为抗HBs抗体阳性 ;该 10例双阳性样品中有 5例为HBVDNA阳性 ;序列分析显示该 5株HBV均为B基因型 ,其中 4株为adw亚型 ,1株为adr亚型 ;其中有 2株在S区的“a”决定簇的氨基酸发生了变异     

Serum beta 2 microglobulin in adult myeloid acute leukemias

Serum beta 2 microglobulin levels, measured by radioimmunoassay (Phadebas test), were found increased in acute myeloid leukemias at diagnosis. Serum beta 2 microglobulin levels were significantly higher in patients with monocytic leukemias (13 patients, M4-M5 FAB classification) than in those with other cytological types (18 patients). Beta 2 microglobulin levels at diagnosis were correlated with serum lysozyme levels, but they were not correlated with blood blast counts, serum LDH and ferritin levels. 195 serum beta 2 microglobulin measurements were made serially in 30 patients with acute myeloid leukemias in first remission. Compared to values at diagnosis, beta 2 microglobulin levels in remission were significantly decreased. Out of 30 patients in remission 12 had increased serum beta 2 microglobulin levels (greater than 3 mg/l). Serial measurements were not predictive for relapses.     

HBs antigen in the blood donors of Calvados. Epidemiologic study and surveillance of the patients

175 Chronic HBs Ag carriers have been discovered in the blood donors of the Calvados blood transfusion center from 1971 to 1979. 72 of them (41%) gave their consent for a clinical and biological study at the end of 1979, after receiving a convocation letter. This work had two aims: - to study the epidemiological factors in this population. - to evaluate the clinical and biological consequences of persistent antigenemia. 1. Epidemiological Study. Most results agree with the literature (higher prevalence in male, age, stay in endemic countries) but some results disagree for several reasons: our donors are all volunteers, HBs Ag prevalence is low in our region, most of the patients are caucasian and with life conditions and habits which may explain some particularities in contagion. Furthermore, the relative number of blood donors found every year as chronic HBs Ag carriers, does not increase in our country. 2. The Clinical and Biological follow-up of 62 HBs Ag carriers (alcoholics excluded) was carried out for 4,3 years on average. No patients developed clinical and biological features of chronic liver disease. After a mean term follow-up, we conclude that the asymptomatic HBs Ag carriers state seems not to be of bad prognostic. Since long term complications cannot be excluded, the follow-up of these patients must be maintained.     

Occurrence of non-A, non-B post-transfusion hepatitis in heart surgery. Prospective study on the value of the determination of serum alanine aminotransferase and detection of anti-HBc antibodies in blood donors

We studied a group of 64 patients undergoing cardiac surgery for the occurrence of post-transfusion hepatitis during a follow-up period of 5 months. They received blood units (packed red cells in saline-adenine-glucose medium and/or fresh frozen plasma exclusively) from 447 volunteer donors. Post-transfusion hepatitis was identified in 5 patients: 1 patient had cytomegalovirus hepatitis and the remaining 4 cases were defined, by exclusion, as non-A, non-B hepatitis (with prevalence and incidence rates of 80% and 6.25% respectively). We found no statistically significant differences between the numbers of transfused blood product units in patients who developed non-A, non-B hepatitis as compared to those who did not. Our analysis of the predictive effectiveness of alanine aminotransferase and anti-HBc antibodies screening in blood donors to prevent non-A, non-B post-transfusion hepatitis led to the following conclusions: we failed to confirm the association between anti-HBc in blood donors and enhanced risk of non-A, non-B hepatitis in recipients since no case developed among patients receiving blood products from anti-HBc positive donors. So, 20 donors (4.5%) would have been discarded without any reduction of the incidence of non-A, non-B hepatitis. we could not confirm nor exclude the possibility that screening donor blood for elevated alanine aminotransferase levels would have reduced the number of non-A, non-B hepatitis in recipients.     

Seroprevalence of Hepatitis B virus infection among an Afro-descendant community in Brazil

Furnas dos Dionísios is an Afro-Brazilian black community whose descendants were mainly fugitive slaves that established themselves in the State of Mato Grosso do Sul (MS), Brazil. The population is comprised mainly of low socioeconomic individuals who are engaged in agricultural activities. The objective of this study was to investigate the prevalence of hepatitis B (HB) and its correlation with epidemiological data obtained from the community. The studied population totaled 260 individuals with ages varying from 1 to 79 years (median 20). One hundred thirty-three (51.2%) were females and 127 (48.8%) were males. A high prevalence for anti-HBc was observed (42.7%), with present infection detected in 9.2% of the subjects who were also HB surface antigens (HBs Ag) positive; 27.3% were anti-HBc and anti-HBs reactive, and 6.2% had anti-HBc as only marker. The prevalence for anti-HBc was proportional to age, reaching its highest peak in age categories greater than 50. No serological marker was detected in children under the age of 2 years, however anti-HBc was present in 12 subjects with ages between 2 and 14 years, of these 8 (7.4%) were HBsAg positive. Among individuals over the age of 15 years, 99 were anti-HBc reactive, of these 16 (10.5%) were also HBsAg positive, thus suggesting an increased prevalence of HBV carriers among children and adolescents. The risk factors observed in this community that were significantly associated with anti-HBc positivity were age (over 20 years) and having an anti-HBc positive mother. Both HBeAg and anti-HBe were detected in 44.4% of the samples tested. HBsAg subtypes found in the studied population were adw2 (77.7%) and ayw2 (23.3%). While intrafamilial transmission was most likely responsible for HBV infection among children, other routes such as sexual contact might be considered for individuals with ages over 15 years.     

Blood transfusion and hepatitis: still a threat?

The incidence of post-transfusion hepatitis (PTH) in recipients of blood products is reviewed. PTH was observed in 10%-12% of recipients of blood products in the United States, 2%-4% in northern Europe and 15%-20% in southern Europe. All studies indicate that 80%-90% of all PTH cases are attributed to non-A/non-B. At least 40% of the patients with PTH non-A/non-B will develop chronic hepatitis or cirrhosis. No specific tests for the detection of the non-A/non-B agent(s) exist. However, several independent studies indicate that part of the donors carrying the infectious non-A/non-B agent have increased levels of alanine amino transferase (ALT). When donors are excluded with elevated ALT values, it is estimated that about 30% of the PTH non-A/non-B cases would be prevented. Some studies indicate that anti-hepatitis B core (anti-HBc) positive donors may carry an increased risk to transmit the non-A/non-B agent, but more recent studies do not confirm this. There is hope that a specific non-A/non-B test will be developed soon.     

Detection of Lewis(a) antigen in sera of ovarian carcinoma patients by MOv2-MOv8 double-determinant radioimmunoassay

The monoclonal antibodies MOv2 and MOv8, raised against ovarian carcinoma, were found to be directed against two non-crossreacting epitopes expressed on the same molecule. Immunochemical analysis of the MOv8 recognized epitope showed that the Le(a) oligosaccharide, or commercial anti-Le(a) MAb, but not the anti-Le(b) MAb, prevented Ov8 binding to the reference target cell line (SW626), indicating that it is carried by the Le(a) antigen. Since we previously reported that MOv2 also recognises the Le(a) antigen, these data suggest that Mov8 and Mov2 were directed against different epitopes on the same oligosaccharide chain. Bearing in mind the knowledge of the biochemical nature of the monoclonal antibody recognized epitopes (CaMOv2 and CaMOv8), the presence of the circulating molecules recognized by them was analyzed by double determinant immunoradiometric assay (DDIRMA) in 103 sera from ovarian carcinoma patients. Patients with clinical evidence of the disease (ED) with MOv2 and MOv8 reactive and negative tumors had sera reactivity in 67% and 19% respectively. Also, 26% of the patients with no clinical evidence of disease (NED) had positive sera. When we investigated the relationship between MOv2-MOv8 DDIRMA sera positivity and red blood cells (RBC) Lewis phenotype, a strong correlation was found between the Le(a)+ phenotype and DDIRMA sera reactivity in healthy donors (6/6) and in ovarian carcinoma patients (9/10) whatever their clinical condition. No Le(a)- healthy donors gave evidence of MOv2-MOv8 reactive sera. In contrast, 33% and 57% of the sera from ED carcinoma patients with respectively Lea-b+ and Lea-b- phenotype were positive.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of Passive Hemagglutination, Solid-Phase Radioimmunoassay, and Immunoelectroosmophoresis for the Detection of Hepatitis B Antigen

Sensitivity and specificity of passive hemagglutination (RCA), solid phase radioimmunoassay (RIA), and immunoelectroosmophoresis (IEOP) were compared under experimental and clinical conditions. In dilution experiments with sera containing hepatitis B antigen (HB Ag) of known subtypes, the sensitivity for an ad subtype serum was RIA (1), RCA (1/2), IEOP (1/256) and for an ay subtype serum RCA (1), RIA (1/8), IEOP (1/128). An evaluation of the National Institutes of Health, Division of Biologics Standards test panel number 2 demonstrated HB Ag in 34 of 60 samples by RIA, in 33 by RCA, and in 25 by IEOP. HB Ag was detected in 57.5% of 200 outpatients with a tentative diagnosis of hepatitis by RIA, in 54% by RCA, and in 42.5% by IEOP. In 1,661 volunteer blood donors, 13 (0.78%) were "positive" for HB Ag by RIA, 11 (0.66%) by RCA, and 3 (0.18%) by IEOP. However, absorption experiments indicated that at least six of the above RIA positive and five of the RCA positive sera exhibited nonspecific positive reactions.     

Suitability of yeast- and Escherichia coli-expressed hepatitis B virus core antigen derivatives for detection of anti-HBc antibodies in human sera

Antibody to hepatitis B virus core antigen (anti-HBc) is one of the most important serological markers during hepatitis B virus (HBV) infection. The quality of the hepatitis B virus core antigen (HBcAg; diagnostic antigen) is crucial to the accuracy of anti-HBc detection. In an attempt to explore the suitability of recombinant HBcAg (rHBcAg) for diagnostic purposes, HBcAg was expressed in Escherichia coli (E. coli) and Pichia pastoris (P. pastoris) and evaluated for the detection of anti-HBc. The expression level of the recombinant protein satisfied the criteria for large-scale biologic production. P. pastoris- and E. coli-derived rHBcAg were purified with gel filtration followed by sucrose gradient (reagents A and C) or with a monoclonal anti-HBc antibody binding (reagents B and D) and were utilized to detect anti-HBc in competitive inhibition enzyme-linked immunosorbent assay (ELISA) format. The ELISA using P. pastoris-derived rHBcAg had a higher specificity and sensitivity than that using E.coli-derived rHBcAg to detect the anti-HBc standard panel. Serum specimens were collected from HBV-infected patients and healthy individuals (voluntary blood donors). Anti-HBc was detected in those specimens using P. pastoris- and E. coli-derived rHBcAg. The positive rate of anti-HBc detection in HBV-infected patients' sera was 100% with reagents A and B, 96.4% with reagent C, and 93.6% with reagent D. The negative rate in healthy control sera was 100% with reagents A and B, 97.0% with reagent C, and 99.7% with reagent D. These data indicate that P. pastoris-derived rHBcAg is superior to E.coli-derived rHBcAg for the detection of anti-HBc using the diagnostic ELISA.     

Screening for Chagas disease by immunoenzymology: comparison of ELISA with immunofluorescence and indirect hemagglutination in 976 blood donors

The efficiency of an immunoenzymatic technique (ELISA) for the systematic research of Chagas' disease in blood donors was compared with one of 2 well-known methods, indirect haemagglutination (IHA) and indirect fluoro immuno assay (IFA). For the ELISA technique two different antigenic extracts from epimastigote culture forms of T. cruzi, were used for sensitizing the polystyrene plates: a crude extract (Ag R) and a delipidized one (Ag B). Firstly the authors tested these 3 techniques in 5 control groups: sera from Chagas' disease, negative control sera, sera from visceral leishmaniasis, african trypanosomiasis and finally monoclonal gammapathies, the high levels of blood proteins being a possible cause of false positives. Secondly the screening of Chagas' disease was performed in the same way in 976 blood donors from Recife, Brazil. In the case of the Ag-R extract used in the ELISA technique a high cross-reactivity was found with visceral leishmaniasis sera, along a risk of false positives with gammapathic ones. The sensitivity of this technique was found to be high (3,3 +/- 1 p. cent of positive blood donors) and a very good correlation was found with the reference techniques, IFA and IHA, the sensitivity of which is lower (2,3 +/- 1 and 1,7 +/- p. cent). The use of a delipidized antigenic extract (Ag B) for the ELISA technique is not suitable, in spite of an apparent higher specificity: indeed, the positives rate is high (11,5 +/- 0,2 p. cent), but the correlation is very weak or non existent in the case of IHA or IFA. In conclusion, the ELISA technique using a crude extract of T. cruzi appears to be a very convenient method for screening blood donors with Chagas' disease, the lack of specificity due to leishmaniasis or monoclonal blood proteins not posing any real problem to blood banking.     

Prevalence of hepatitis B viral markers in Vietnamese blood donors

Serum samples were assayed using radioimmunoassay in 573 Vietnamese blood donors living in Hano? (North Viet Nam). 66 (11.5%) subjects were HBsAg-positive. Of these 66 HBsAg carriers, 17 (25,8%) were positive for hepatitis B e antigen (HBeAg) and 43 (65.1%) for antibody to HBeAg (anti-HBe). 22 (3.8%) subjects were positive for antibody to hepatitis B core antigen (anti-HBc) alone. 402 (70.2%) subjects were positive for antibody to HBsAg (anti-HBs). This anti-HBs percentage increased with age. Only 83 (14.5%) subjects were negative for all hepatitis B viral (HBV) markers. This no HBV markers percentage decreased with age. The chi 2 test showed a non significant difference for frequencies of HBsAg, anti-HBc alone, anti-HBs but a significant one for frequencies of no HBV markers in men and women.     

Subclass distribution of antigen-specific IgA antibodies in normal donors and individuals with homozygous C alpha 1 or C alpha 2 gene deletions

To analyze the subclass restriction of Ag-specific IgA, sera and saliva from healthy blood donors and from IgA class or subclass deficient individuals were studied. The latter included donors with or without C alpha 1 or C alpha 2 gene deletions. Monoclonal human IgA1 and a genetically engineered IgA2 antibody, normal human serum and colostrum IgA were used as standards to estimate serum and saliva levels of Ag-specific antibodies. In normal individuals, there was a strong IgA1 preference of naturally acquired antibodies in serum against both polysaccharide Ag (PPS 6A, PPS 23, pneumococcal C-polysaccharide, and LPS from Escherichia coli) and protein Ag (Staphylococcus aureus alpha-toxin and HSV). Specific IgA2 in serum against the tested Ag were frequently not measurable. In contrast, most of the individuals with homozygous C alpha 1 gene deletions displayed substantial amounts of specific IgA2 against protein as well as polysaccharide Ag. The median levels of specific IgA in serum against protein Ag were approximately one-third as compared to normal individuals and one-fifth, or less, against polysaccharide Ag. Normal serum levels of IgA against the tested Ag, restricted to the IgA1 subclass, were noted in two individuals with IgA2 deficiency, one of whom carried a homozygous C alpha 2 gene deletion. Median values of specific IgA, against the tested Ag S. aureus alpha-toxin, HSV, and pneumococcal C-poly-saccharide, from normal healthy donors were approximately four to eight times higher in serum as compared to saliva. Individuals with homozygous C alpha 1 gene deletions displayed increased levels of the various specific IgA2 antibodies in saliva. In conclusion, the individuals with homozygous C alpha 1 gene deletions displayed decreased median levels of specific IgA antibodies in serum despite normal levels of total IgA. Normal levels of both specific IgA and total IgA in saliva were found.     

Comparative study on subtypes of hepatitis B surface antigen (HBs Ag) in two regions of southern Japan, Okinawa and Kumamoto. Prevalence and unusual subtypes

A total of 209 hepatitis B surface antigen (HBs Ag)-positive sera from two possibly ethnologically different regions of southern Japan, Okinawa and Kumamoto, were subtyped by counterelectrophoresis using monospecific antisera to a, d, y, w, and r antigenic determinants. There was a marked difference in the prevalence of the w and r determinants in the two regions; the frequency of the HBs Ag/adr subtype was 95% in Kumamoto and 47% in Okinawa, suggesting that HBs Ag subtypes may be one of the markers reflecting an ethnological difference between the peoples of the two regions. Seven and three serum specimens in Okinawa and Kumamoto respectively showed unusual HBs Ag subtypes: four carried adwr (two specimens), aywr, or adyw determinants, five had only a, and the remaining one carried ar.     

Use of monoclonal antibodies in the assay of hepatitis B core antigen and antibody

Hybridoma cells secreting antibody against hepatitis B core antigen (HBc Ag) were prepared. BALB/c mice were immunized with 0.2 ml of purified HBc Ag, and their spleen cells were fused with mouse myeloma (P3U1) cells by means of polyethylene glycol 1000. Activities of antibodies against HBc Ag (anti-HBc) were tested by the immune adherence hemagglutination (IAHA) and reverse passive hemagglutination inhibition (RPHI) techniques. Hybridoma cells found to contain antibodies accounted for 26.5% by IAHA and 52.1% by RPHI, respectively. Among 32 monoclonal anti-HBc antibodies, 18 were found to be positive by both IAHA and RPHI, and the remaining 14 positive by RPHI only. After cloning, they were injected intraperitoneally into ascitic mice. The highest anti-HBc activity with an IAHA titer of 1:4 X 10(6) and with an RPHI titer of 1:1 X 10(5) was detected in this ascitic fluid. Enzyme immunoassay (EIA) and RPHI with monoclonal antibody containing the highest anti-HBc activity were developed. All the sera in which anti-HBc was detected by IAHA and RPHI with polyclonal antibody were positive in EIA. RPHI titers obtained with monoclonal antibody were in good agreement with usual IAHA and RPHI titers obtained with polyclonal antibody. These results indicate that monoclonal antibody can be used in the HBc Ag and anti-HBc assay system.     

Anti-cetuximab IgE ELISA for identification of patients at a high risk of cetuximab-induced anaphylaxis

Cetuximab, a chimeric mouse-human IgG1 monoclonal antibody against the epidermal growth factor receptor, has proven effective in the treatment of metastatic colorectal cancer and squamous cell carcinoma of the head and neck. However, a high incidence of immediate hypersensitivity reactions (HSR) to cetuximab after the first infusion has been observed. We have developed a test for identification of patients likely to show treatment-related HSR to cetuximab. An enzyme-linked immunosorbent assay (ELISA) for detecting anti-cetuximab IgEs was developed and tested on serum samples collected from cancer patients before start of cetuximab treatment, and from healthy blood donors. Similar levels of anti-cetuximab IgE were detected in pre-treatment patient sera (24/92, 26.1%) and sera from healthy blood donors (33/117, 28.2%). HSR were observed in 14 out of the 92 patients (15.2%), and 8 of these (57.1%) were grade 3-4. Anti-cetuximab IgEs were detected in 7/8 of the patients (87.5%) with severe HSRs as compared with 14/78 patients (17.9%) with no HSR (p=0.0002). Predictive value of the anti-cetuximab IgE test for HSR events of grades 3-4 was calculated using Receiver Operating Characteristics analysis. With a cut-off value of 29 arbitrary units for the anti-cetuximab IgE, the ELISA test showed a sensitivity of 87.5%, specificity of 82.1%, positive predictive value of 33.3% and negative predictive value of 98.5%. Anti-cetuximab IgE ELISA detection could be a valuable tool to help the physician anticipate an anaphylaxis episode following cetuximab infusion and opt for a suitable alternative treatment.     

e antigen in acute hepatitis B.

To examine the association between e antigen and hepatitis-B surface antigen (HBs Ag) we studied 90 inpatients with acute viral hepatitis type B. e Antigen was present in 24 of the patients; these patients had detectable levels of HBs Ag for significantly longer than the 66 with no e antigen in their serum. The HBs Ag subtypes D (adw) and Y (ayw) were similarly distributed among patients with e antigen and among those without, and no differences in the results of biochemical liver function tests were observed between the two groups during the acute phase of illness. Three of the five patients who developed clinical and histological signs of chronic liver disease were positive for e antigen, a finding which supports the hypothesis that e antigen has a prognostic value in hepatitis B.