Enhanced detection of anti-tissue antibody by anti-immunoglobulin bound glucose oxidase

An immunohistochemical procedure, using glucose oxidase (GO) linked to anti-immunoglobulin serum, has been adapted to detect anti-tissue antibody to smooth muscle, parietal cells, and mitochondria. With this procedure antibody to smooth muscle was detected in a high percentage of normal sera. Anti-tissue antibodies were frequently detected in sera of patients clinically suspected of having an autoimmune disease when an immunofluorescence (IF) test to detect the antibodies was negative. The glucose oxidase immunohistochemical procedure to detect anti-tissue antibodies is feasible and highly sensitive, and produces permanent results. The clinical usefulness of this procedure will have to be carefully evaluated. The detection of anti-tissue antibody in normal sera may indicate that such antibody is normally present in low concentration and that it may possibly have physiologic functions.     

Failure to induce tolerance to rat tissue antigens

Rats subjected to an intensive injection schedule from birth for 5 weeks with rat liver antigen failed to show immunological tolerance with respect to the production of heat-labile and heat-stable high molecular weight antibody when challenged with liver antigen or carbon tetrachloride.

It is suggested that particulate subcellular components of the animals' own tissues, like foreign particulate antigens, may not readily induce tolerance and that this may explain the finding of anti-tissue antibodies in various human diseases particularly following tissue breakdown.

     

Difference between bacterial and food antigens in mucosal immunogenicity.

The mucosa-associated lymphoid tissue may deviate from its systemic counterpart in being able to discriminate between microbial and nonmicrobial antigens. To study this, the systemic and mucosal antibody responses to bacterial and food antigens were followed in parallel in female rats during two pregnancies and lactation periods. Germfree rats were monocolonized with an Escherichia coli O6K13H1 strain, and their diet was switched to pellets containing large amounts of ovalbumin and beta-lactoglobulin. Antibodies against O6 lipopolysaccharide already appeared in serum and bile 1 week after colonization, and those against type 1 fimbriae appeared a few weeks later. Serum immunoglobulin G antibodies against the E. coli enzyme beta-galactosidase were found in moderate titers in all rats after 16 weeks of exposure. In contrast, few rats had detectable antibody levels against the dietary proteins ovalbumin and beta-lactoglobulin in serum or bile even after 16 weeks of exposure. In the milk, antibodies against E. coli beta-galactosidase and type 1 fimbriae reached the highest titers, while moderate titers were found against the food antigens and against O6 lipopolysaccharide. The difference in immune reactivity against bacterial versus dietary antigens was not likely due to insufficient amounts of the latter reaching lymphoid tissue, since (i) uptake studies indicated that ovalbumin was more efficiently taken up than endotoxin and (ii) the same difference in antigenicity between ovalbumin and E. coli was seen after immunization directly into Peyer's patches. We therefore suggest that a prerequisite for a strong mucosal antibody response is that the antigen be encountered by the gut-associated lymphoid tissue within microorganisms capable of stimulating antigen presentation.     

Multiple-antigen slide test for detection of immunoglobulin M antibodies in newborn and infant sera by immunofluorescence.

A microimmunofluorescence test was evaluated for use in measuring immunoglobulin M (IgM) antibodies in infant sera to five of the agents implicated in congenital and neonatal disease. Pen point dots of Toxoplasma gondii, cytomegalovirus, rubella virus, herpes simplex virus, and chlamydial cell culture antigens were applied to each circle of eight-circle printed slides. These multiple-antigen slides greatly facilitated the screening of 607 sera from infants and 117 sera from mothers for the presence of IgM antibody to these agents. Forty sera could be examined microscopically in approximately 30 min. All sera reacting with one or more antigens were tested for rheumatoid factor by the latex method, absorbed with glutaraldehyde-cross-linked human IgG, and retested for the presence of IgM antibody. IgM antibody to cytomegalovirus was demonstrated in sera from four newborns, but IgM antibody to rubella virus could not be detected until 21 days after birth, although rubella virus was isolated from sera from five younger infants. This may indicate that rubella IgM levels in many congenitally infected newborns are too low to be measured by the immunofluorescence method. Five percent of the sera from infants in this study possessed demonstrable IgM antibody to one of the antigens.     

Anti-tissue antibodies and immunoglobulin levels in relation to HLA and other markers in Icelandic families.

Studies of 521 sera from the Icelandic cousin marriage project were made to assess the incidence of various anti-tissue antibodies and the levels of immunoglobulins, as these were considered to be useful markers of the humoral immune response. Comparisons were made between these parameters and the HLA-A and B antigens, the blood groups, the immunoglobulin allotypes (Gm, Km and Am), the properdin factor (Bf), and other markers. These investigations offered another approach to the study of the sites of action of immune response genes in man. Because the immune response may be expected to differ for each individual and depend at least in part, on the degree of exposure to different antigens, no absolute correlation was expected. There was, however, a marked association between certain IgG anti-tissue antibodies and HLA antigens. This was most marked for HLA-A10, B18 and b27, but not for HLA-A1 or B8. The comparison of immunoglobulin levels with HLA antigens, was less striking, although HLA-A2 appeared to be associated with low levels of IgE. There were also some associations between immunoglobulin levels and ABO blood groups.     

ANTI-TISSUE ANTIBODIES AND IMMUNOGLOBULIN LEVELS IN RELATION TO HLA AND OTHER MARKERS IN ICELANDIC FAMILIES

Studies of 521 sera from the Icelandic cousin marriage project were made to assess the incidence of various anti-tissue antibodies and the levels of immunoglobulins, as these were considered to be useful markers of the humoral immune response. Comparisons were made between these parameters and the HLA-A and B antigens, the blood groups, the immunoglobulin allotypes (Gm, Km and Am), the properdin factor (Bf), and other markers. These investigations offered another approach to the study of the sites of action of immune response genes in man. Because the immune response may be expected to differ for each individual and depend at least in part, on the degree of exposure to different antigens, no absolute correlation was expected. There was, however, a marked association between certain IgG anti-tissue antibodies and HLA antigens. This was most marked for HLA-A10, B18 and B27, but not for HLA-A1 or B8. The comparison of immunoglobulin levels with HLA antigens, was less striking, although HLA-A2 appeared to be associated with low levels of IgE. There were also some associations between immunoglobulin levels and ABO blood groups.     

Anti-tissue transglutaminase, anti-endomysium and anti-R1-reticulin autoantibodies-the antibody trinity of coeliac disease.

Anti-tissue transglutaminase has been recently described as the predominant autoantigen in coeliac disease. We purified serum anti-tissue transglutaminase antibodies from three patients with coeliac disease by column chromatography and eluted tissue section-bound R1-anti-reticulin antibodies from sections of rat tissue for two of these. Lastly, we generated seven mouse MoAbs to guinea pig tissue transglutaminase. Each preparation was examined for anti-tissue transglutaminase, anti-endomysium, anti-R1 reticulin and anti-gliadin antibodies. Column-purified patient antibodies and 2/7 mouse MoAbs gave characteristic anti-endomysium/anti-R1 reticulin reactivity on rat, monkey and human tissue. All positive sera gave indistinguishable patterns of immunofluorescence on rat liver, kidney and stomach, monkey oesophagus, and human umbilical cord. Anti-R1-reticulin eluted from sections showed anti-tissue transglutaminase reactivity in 2/2 cases, but 0/2 showed anti-gliadin reactivity. In both, tissue section-eluted anti-R1 reticulin gave endomysial staining on monkey oesophagus. None of the mouse monoclonals, or any of the purified patient's anti-tissue transglutaminase or anti-R1-reticulin antibody showed any reactivity with gliadin. These data confirm tissue transglutaminase as the predominant autoantigen in coeliac disease and suggest that both anti-endomysium and anti-R1 reticulin reactivities seen in coeliac disease arise due to an immune response to tissue transglutaminase. Rigorous immunoabsorption was sufficient to abrogate reactivity in the tissue transglutaminase ELISA, but failed to completely absorb anti-endomysium and anti-reticulin activity. The possibility remains that some of the anti-endomysium and anti-reticulin activity was directed against antigens other than tissue transglutaminase.     

Immunogenicity and protection in small-animal models with controlled-release tetanus toxoid microparticles as a single-dose vaccine.

Tetanus toxoid (TT) was encapsulated in microparticles prepared from polylactide-co-glycolide polymers by a solvent-evaporation technique. Combinations of small- and large-sized microparticles with controlled-release characteristics were used to immunize Sprague-Dawley rats, and the antibody responses were monitored for 1 year. For comparison, control groups of rats were immunized at 0, 1, and 2 months with TT adsorbed to alum. The antibody responses generated by the TT entrapped in microparticles were comparable to those generated by TT adsorbed to alum in control groups from 32 weeks onwards. Microparticles with a single entrapped antigen (TT) induced better antibody responses than microparticles with two antigens (TT and diphtheria toxoid) entrapped simultaneously. A combination vaccine consisting of TT adsorbed to alum and also entrapped in microparticles gave the best antibody responses. In an inhibition assay designed to determine the relative levels of binding of antisera to the antigens, the sera from the microparticle- and the alum-immunized animals showed comparable levels of binding. In addition, in a passive-challenge study with mice, TT adsorbed to alum and TT entrapped in microparticles provided equal levels of protection against a lethal challenge with tetanus toxin. An intradermal-challenge study was also performed with rabbits, which showed similar levels of protection in sera from alum- and microparticle-immunized animals at 4, 12, and 32 weeks after immunization.     

Type-specific protection of neonatal rats from lethal group B streptococcal infection by immune sera obtained from human volunteers vaccinated with type III-specific polysaccharide.

Sera obtained from human volunteers at 6 weeks after vaccination with highly purified type III polysaccharide antigen prepared from a group B Streptococcus, strain M732, were found to protect neonatal rats from otherwise lethal infection by the homologous strain. The specific antibody content of the sera, expressed in micrograms of antibody protein per milliliter, was determined by an enzyme-linked immunosorbent assay in conjunction with quantitative precipitin analysis. For two sera studied in detail, the protective dose of antibody for 50% of the animals was 0.4 micrograms. Immune serum obtained from a volunteer who received type II polysaccharide vaccine was not protective against type III infection. Absorption of anti-type III serum by quantitative precipitation of antibodies with type III polysaccharide completely removed the passive protective activity of the serum. The results show that antibodies induced in humans by purified type II polysaccharide give serotype-specific protection in an animal model of neonatal infection.     

Developmental expression of autoimmune target antigens during organogenesis.

A common factor existing among autoimmune target antigens was sought in association with their developmental expression during organogenesis. Autoimmunity against a certain organ was experimentally induced in rats by deliberate immunization with whole tissue extract of the respective organ. Histopathological changes in a target organ of the immunized rats were recorded, and tissue specificity of the raised autoantibodies was immunohistologically examined with tissue sections of normal adult rats. These immune sera were also reacted with tissue sections of a target organ in each stage of organogenesis, and the time of first expression of the target antigen was determined for each immune serum. As a result, induced autoantibodies were directed only to a limited number of tissue antigens, such as thyroid follicular antigens [gestation day 17 (17 GD)], salivary ductal antigens (18 GD), anterior pituitary antigens (21 GD), gastric parietal cell antigens (22 GD), neural myelin antigens (2 days after birth), retinal photo-receptor cell antigens (3 days after birth) and testicular germ cell antigens (4 weeks after birth). They were first expressed on the day indicated in parentheses. Comparing with the development of the immune system, which was monitored by demonstrating CD4- and/or CD8-positive cells in the developing thymus and spleen, a common feature of these potential autoimmune target antigens was found to be that they were expressed either in parallel with, or after, but never before, the development of the immune system. This observation might suggest why only a limited number of self antigens can be autoimmune target antigens among the enormously large number of antigen determinants existing in the whole extract of each organ.     

Immunoblot analyses of Candida albicans-associated antigens and antibodies in human sera.

We tested 10 patient sera for the presence of immunoglobulin G (IgG) antibodies to Candida albicans and for C. albicans antigens by immunoblot analysis (i.e., electrotransfer blot radioimmunoassay) (G. E. Smith and M. D. Summers, J. Virol. 39:125-137, 1981). We evaluated sera from two patients at risk for candidiasis, five patients with systemic candidiasis documented by culture, and two patients who had experienced transient candidemia. Both the specificity and the relative amount of IgG antibodies to C. albicans in each serum sample were readily visualized by this technique, as was the absence of antibody from serum of neonatal and immunocompromised patients. No antibody species appeared to be uniquely associated with candidiasis patients (i.e., each antibody species present in the candidiasis patient was also present in sera of normal individuals or "at-risk" patients). IgG from rabbits immunized with whole cells or with a cytoplasmic fraction of C. albicans was used to detect C. albicans antigens in patient sera. Although several antigens were detected in the sera from patients with candidiasis, the same antigens were also detected in sera from patients at risk and in normal human serum. No antigens were detected in human serum when preimmune rabbit sera were used. These results suggest that the antigens detected by the rabbit antisera were human serum proteins that cross-reacted with C. albicans antigens. These findings may have important implications in studies of both the pathobiology of C. albicans and the serodiagnosis of candidiasis.     

The role of antibody affinity and titre in immunity to Schistosoma mansoni following vaccination with highly irradiated cercariae.

Sera from rabbits and rats vaccinated with highly irradiated cercariae of Schistosoma mansoni (VRabS, VRatS) were found to be of substantially higher affinity than sera from CBA mice vaccinated four times (4 X CVMS), single sex sera (SSS) or chronic infection sera (CIS). In contrast, VRabS and SSS appeared to possess the highest titres of antibody, followed by CIS and VRatS, with 4 X CVMS displaying the lowest titre. Two mouse strains selectively bred for high-affinity (HA) or low-affinity (LA) antibody following vaccination were tested for their ability to resist a challenge infection. LA mice, which produce high titres of low-affinity antibody, manifested significantly more resistance than HA mice, which produce low titres of high-affinity antibody. Immunoprecipitation studies demonstrated that sera from vaccinated LA mice (LVMS) recognized 125I-labelled schistosomular surface antigens more intensely than sera from vaccinated HA mice (HVMS). However, peritoneal macrophages from HA and LA mice in the presence of HVMS, LVMS or 4 X CVMS, and naive macrophages activated in vitro with interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS) mediated comparable levels of schistosomula killing in vitro. The experiments described here provide evidence that the titre of antibody rather than its affinity may be a more critical factor in the development of optimal immunity to S. mansoni.     

The mode of action of treatment by IgG of haemolytic anaemia induced by an anti-erythrocyte monoclonal antibody

Tolerization of pathogenic antigens is one of the experimental strategies that has been proposed to prevent autoimmune disease. We have investigated here whether neonatal intraperitoneal infection of Lewis rats with Mycobacterium bovis-BCG has any effect on the expression of adjuvant arthritis (AA), an autoimmune disease that is produced by immunization of the rats with dead mycobacteria in mineral oil (i.e. Freund's complete adjuvant (FCA)). We found that neonatal infection with 10⁸ viable BCG bacilli rendered all Lewis rats resistant to the expression of AA after FCA immunization. This BCG-induced protection from reactive arthritis was not seen in Lewis rats infected with smaller inocula (10⁶ BCG bacilli) or if the infection was performed after the neonatal period (e.g. at 3 weeks of age). Neonatal administration of 65-kD mycobacterial heat shock protein (hsp65, a key antigen in the etiopathogenesis of AA) failed to protect Lewis rats from AA; injection of lactoferrin (an autoantigen that may be involved in the physiopathology of autoimmune arthritis) to newborn Lewis rats decreased the severity of AA observed after FCA immunization of the animals. Western blotting revealed that Lewis rats that had acquired resistance to AA also showed changes in their repertoire of antibody specificities; among these alterations was decreased anti-hsp65 reactivity. We conclude that neonatal infection with BCG, but not hsp65 injection, renders Lewis rats resistant to AA and that the phenomenon is associated with change in the repertoire of specificities of circulating antibodies.     

Reactivity of IgE in humanSchistosoma mansoni sera toS. mansoni antigens

Sera fromSchistosoma mansoni-infected human patients were tested for total IgE levels and specific IgE and IgG antibodies toS. mansoni adult worm, cercaria, and egg antigen by ELISA. Of 50 sera, 28 were investigated by enzyme-linked crossed immunoelectrophoresis (ELCIE) to detect IgE reactivity to individual adult worm extract components. All sera showed increased total IgE levels. Specific IgE antibody levels to the different antigens varied; they were significantly correlated with each other but independent from total IgE. No correlation was found between specific IgG and any of the IgE antibody levels. Testing of the 28 individual sera by ELCIE revealed heterogeneous patterns. Seven sera were found to be non-reactive: three reacted with one precipitate, and the others reacted with between two and nine precipitates. However, in no case were identical patterns recognized, although four antigens reacted with about 80% of the sera. The number of bands detected by the individual sera depended neither on the levels of total IgE nor on those of specific IgE.Supported by the Bundesministerium für Forschung und Technologie der Bundesrepublik Deutschland (grant PTB 8324)     

Radioimmunoassay and opsonic antibody responses to pneumococcal capsular polysaccharide vaccine in serum and ascitic fluid of cirrhotic patients.

Pneumococcal capsular polysaccharide vaccine was administered to 19 cirrhotic patients and to 25 control subjects. Radioimmunoassay antibody concentration and opsonic titers (OT) were measured in sera and ascites collected before and 3 to 4 weeks after inoculation. The geometric mean antibody concentrations in prevaccination sera from the cirrhotic patients were significantly increased to types 3, 4, 7F, 8, 9N, and 12F antigens, and in postinoculation sera their geometric mean antibody concentration was increased to types 3, 9N, and 12F antigens. OT to Streptococcus pneumoniae type 3 correlated with the radioimmunoassay antibody concentration in postinoculation sera. Of 14 cirrhotic subjects, 3 had OT of greater than or equal to 4 in prevaccination sera, and the highest OT and radioimmunoassay antibody concentration were observed in postinoculation specimens from this group. Antibody and OT against S. pneumoniae type 3 were also observed in ascitic specimens. These data suggest that cirrhotic subjects respond to pneumococcal capsular polysaccharide with antibodies in both serum and ascitic fluid. However, the protective efficacy of this antibody response must be assessed by larger prospective studies.     

Sera with high levels of anti-smooth muscle and anti-mitochondrial antibodies frequently bind to cytoskeleton proteins.

Using ELISA methods, 54 sera from chronic active hepatitis (CAH) patients displaying high levels of anti-smooth muscle antibodies (SMA) and 18 sera from primary biliary cirrhosis (PBC) patients with high levels of anti-M2 antibodies were examined for the presence of high antibody levels against actin, tubulin, myosin, tropomyosin, troponin, vimentin and desmin. Our results showed that: (i) in CAH with high SMA activity, increased antibody levels were found in 51.9% of sera for actin, 31.5% for myosin, 35.2% for tubulin, 34.0% for tropomyosin, 11.3% for troponin, 22.6% for vimentin and 43.4% for desmin, compared with natural antibody levels in 21 normal sera; (ii) Similar high levels of these antibodies were found in the case of PBC; (iii) in most cases, sera simultaneously bound to several antigens of the panel; and (iv) approximately 26% of the CAH sera were found to be negative with the seven antigens examined while 22% were reacted with a cytoskeleton protein (CP) other than actin. These results indicate that current opinion associating SMA with anti-actin activity in CAH is confirmed for only 50% of cases and that although a good correlation between SMA and anti-CP antibodies can be obtained, there is still a significant percentage of SMA for which the putative antigen recognized needs to be determined.     

Studies on Active Immunization with Self Antigens

Newborn BALB/c mice were repeatedly injected either with syngeneic (BALB/c) or xenogeneic (bovine) myosin, albumin, or actin in sterile physiological saline. The serum antibody response was evaluated by enzyme immunoassay 1 and 2 months after birth and after two booster injections. At 1 month, higher antibody titres were found in the sera of mice injected with syngeneic than with xenogeneic antigens. At 2 months and after boosting, anti-syngeneic actin antibodies were present in equal or higher amounts, anti-syngeneic albumin antibodies were not detected, and anti-syngeneic myosin antibodies were considerably decreased. Antibodies produced after booster injections of syngeneic actin were found to be highly specific and to belong mainly to the IgG isotype. These results suggest that newborn mice are better able than adult mice to respond to stimulation with self antigens, and that administration of self proteins during neonatal life may lead to the induction of immunological memory. They also indicate that one of the primary functions of the immune system in newborn mice is the recognition of self antigens.     

Diagnosis of hepatitis A infection: Comparative specificity of IgM capture assays using antigens derived from tissue cultures and marmoset faeces

Hepatitis A virus (HAV) antigens from two tissue culture sources were compared with that from the faeces of infected marmosets to determine whether the former were satisfactory substitutes. Sera from 313 healthy blood donors and 417 patients with various clinical conditions were tested for IgM class antibody to HAV (anti-HAV IgM) using an IgM antibody capture assay (MACRIA) with each of the 3 antigens.Forty-eight specimens, all from cases of acute hepatitis, were positive in MACRIA with all 3 antigens. Only 2 of the 313 blood donors' sera reacted at all. These reactions were weak and did not arise with all antigens. Weakly reactive specimens were also found in 3 out of the 13 clinical categories. Overall 12 weak reactions arose with the faecal antigen and 8 and 7 with the two tissue culture antigens. Rheumatoid factor (RhF) was detected in 8 of the weakly reactive specimens and these had significantly higher titres of anti-HAV than sera known to contain RhF that were unreactive in MACRIA.It is concluded that tissue culture derived HAV antigen should replace that from primates on the grounds of quality, economy and convenience: also that non-specific activity in HAV MACRIA is usually due to a combination of RhF and high anti-HAV titres, but is infrequently strong enough to cause reactions interpreted as positive.     

Serum antibody and cellular responses in LEW and F344 rats after immunization with Mycoplasma pulmonis antigens

Mycoplasma pulmonis causes a chronic respiratory disease in rats which is more severe in LEW than in F344 rats. This study compared the ability of each of these rat strains to produce specific immune responses to M. pulmonis antigens. By an enzyme-linked immunosorbent assay, LEW rats were found to produce approximately 10 times lower levels of specific immunoglobulin G (IgG) after immunization with M. pulmonis antigens than F344 rats, while no significant difference was found in the levels of IgM. The difference in IgG levels was due to much greater levels of specific IgG2b (about 50 times) in F344 rats; no differences were found in other subclasses. Nonimmune LEW rats were found to have as much total IgG2b in their sera as unimmunized F344 rats by a single radial immunodiffusion test; thus, the difference was not due to the inability of LEW rats to produce IgG2b. In contrast to the antibody response to M. pulmonis antigens, anti-keyhole limpet hemocyanin IgG responses in LEW and F344 rats were similar, but F344 rats produced significantly more (about 21 times) IgG2b than was found in M. pulmonis responses. Antisera from F344 rats recognized several additional M. pulmonis antigens than antisera from LEW rats; however, this could not explain the differences in the level of IgG2b in LEW and F344 rats. In vitro stimulation of splenic lymphocytes with M. pulmonis antigens from immunized F344 rats produced much greater proliferative responses than in LEW and nonimmune F344 cells. Thus, the susceptible rat strain LEW produced lower cellular and humoral immune responses to M. pulmonis antigens than the resistant rat strain F344 after immunization.     

Serum antibody response to the superficial and released components of Helicobacter pylori.

Superficial and released components were extracted from six selected Helicobacter pylori strains. The protein and antigenic profiles of these extracts were representative of the profiles found most frequently among the clinical strains and included major peptidic fractions at 19, 23.5, 57, 68, 76, 118, and 132 kDa and major antigens at 68, 57, and 23.5 kDa. Immuno-cross-reactions were seen with a hyperimmune rabbit serum to Campylobacter fetus but not with sera to Campylobacter jejuni or Salmonella spp. An antigenic preparation was obtained by pooling equivalent quantities of each extract, and the antigenic preparation was used to study the antibody responses of sera from 65 French patients and 127 Tunisian patients. By enzyme-linked immunosorbent assay, we observed that the sera from French and Tunisian patients clustered into two populations, defined as antibody positive (72 patients) and antibody negative (120 patients). The antibody-positive patients were more frequently infected with H. pylori (P < 0.01) and were more frequently affected with gastritis (P = 0.05). However, no correlation between antibody levels and clinical signs of dyspepsia was noticed. The proportions of antibody-positive patients were similar in France and Tunisia. Antibody-positive and antibody-negative sera were studied by western blot (immunoblot) analysis. The antibody-positive sera revealed an average of 7.7 antigenic bands, whereas the antibody-negative sera revealed an average of 2.4 antigenic bands (P < 0.01). The antigens between 15 and 40 kDa and greater than 66 kDa were specifically recognized by the antibody-positive sera, although in this molecular size range the antibody profiles of these sera exhibited a fairly high degree of diversity. We conclude that the superficial and released components from H. pylori contain a variety of bacterial immunogens and may be useful in antigenic preparations for the serodiagnosis of H. pylori infections. Moreover, a group of antigens in combination appears to be useful for discriminating antibody-positive and antibody-negative patients.