Immunoglobulin class and subclass distribution of antibodies reactive with the immunodominant antigen of Actinobacillus actinomycetemcomitans serotype b

The aims of this study were to determine the immunodominant antigens of Actinobacillus actinomycetemcomitans serotype b (Aab) for the different immunoglobulin (Ig) classes and subclasses and to determine the relative levels of these different Igs in serum. Seropositive early-onset periodontitis patients were sampled, and the Ig classes IgG, IgA, and IgM and subclasses IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2 were studied. Reactivity with Aab antigens was assessed by using the Western blot (immunoblot) in limiting dilution analysis and radioimmunoassay with sera from 13 early-onset periodontitis subjects. A smeared antigen in the upper portion of the immunoblots, typical of high-molecular-weight LPS, was immunodominant for IgG, IgA, IgM, IgG1, IgG2, IgG3, IgA1, and IgA2. This smeared antigen was present in every patient for all of these Igs at the endpoint. A few additional antigens were also present at the endpoint in some patients, but none were present in more than half of the subjects. The distribution of antibody titers by Ig classes reactive with the Aab immunodominant antigen was IgG > IgA > IgM. The distribution of antibody titers by IgG subclass was IgG2 > IgG1 approximately IgG3. Further quantitation by radioimmunoassay revealed that the mean concentration of IgG2 (65.7 micrograms/ml) was significantly greater than that of IgG1 (8.8 micrograms/ml). The IgA subclass distribution was IgA1 > IgA2, with IgA1 apparently being second only to IgG2. Therefore, the Aab antigen eliciting the highest antibody level in virtually all Ig classes and subclasses appeared to be lipopolysaccharide, and IgG2 was markedly elevated over all other serum Ig classes or subclasses reactive with Aab.     

Perceived benefits of and barriers to exercise and stage of exercise adoption in young adults

Antibodies to a wide spectrum of infectious agents belonging to the IgA, IgM and IgG isotypes are thought to be one of the protective factors in human milk. Cow milk-fed newborns are at an increased risk of infections as well as of allergic diseases and of necrotising enterocolitis. A reasonable approach would be to add to the milk formula fed to them the immunoglobulins present in human milk. We developed a pasteurised immunoglobulin preparation from pooled donor plasma ('Orabulin') containing 75% IgG, 18% IgA and 6% IgM for feeding to high-risk bottle-fed babies. Its molecular composition was studied by HPLC and by SDS-PAGE. The levels of IgA, IgG and IgM antibodies in Orabulin were compared to these in the immunoglobulin fraction of human colostrum and an enrichment was found. It is suggested that the presence of a standardised amount of human IgM in an immunoglobulin preparation intended for feeding to newborns may bring an additional advantage because of the high opsonising and virus-neutralising activity of the antibodies of this isotype.     

Heat-aggregated IgA prepared from patients with IgA nephropathy increases calcium mobilization and superoxide production of human neutrophils in vitro

IgA nephropathy, characterized by predominant mesangial IgA deposition, is the commonest glomerulonephritis worldwide. It is envisaged that circulating IgA plays a primary role in the glomerular injury of IgA nephropathy. In this study, we examined the pathophysiologic effect of IgA and IgG isolated from IgA nephritic patients on the signal transduction and oxidative metabolism of human neutrophils. Heat-aggregated forms, monomers, and F(ab')2 fragments of IgA and IgG were prepared from sera of 11 IgA nephritic patients and 11 healthy controls. Signal transduction was studied by measuring calcium mobilization and oxidative metabolism by measuring superoxide production. Different forms of IgA and IgG from patients with IgA nephropathy did not induce a significant increase in calcium mobilization directly. Nonetheless, neutrophils preincubated with heat-aggregated IgA or IgG from IgA nephritic patients demonstrated a significant rise in calcium mobilization upon subsequent stimulation by a chemotactic peptide, FMet-Leu-Phe (FMLP). Heat-aggregated IgA or IgG pretreatment of neutrophils increased FMLP-induced calcium mobilization in a dose-dependent manner. Aggregated IgA or IgG prepared by heat aggregation from IgA nephritic patients induced a significantly greater superoxide production from neutrophils than immunoglobulins from healthy controls. Similarly, heat-aggregated IgA and IgG induced superoxide production in a dose-dependent manner. Our data suggest that heat-aggregated forms of IgA and IgG exert an upregulatory effect on signal transduction and oxidative metabolism in human neutrophils. These findings indirectly support the view that neutrophils could be activated in IgA nephropathy and may potentially be participating in the inflammatory process of glomerular and interstitial injury.     

IgG2 associated hypergammaglobulinaemia in some Nigerians with HIV infection

Concentrations of immunoglobulins (IgA, IgG and IgM) were measured in Nigerians with (HIV) infection. Considerable elevations up to two-fold the reference values were observed for IgG and IgM in the patient group as a whole but elevations in IgA concentration were least marked albeit significantly different from the healthy subjects. Elevation of a particular isotype was not always concomitant with elevation of the other major classes in the same patient. Overall, these elevations were observed in both symptomatic and asymptomatic infected subjects. Further analysis of IgG hyperglobulinemia showed that increases in this major class may be due to increased IgG2 subclass concentrations. It is suggested that elevation of IgG2 subclass in Nigerians with HIV infection and not IgG1 or IgG3 may be due to genetic and environmental factors rather than variation in the strain of the virus.     

Evaluation of two nonculture antigen tests and three serotests for detection of anti-chlamydial antibodies in the diagnosis of ocular chlamydial infections

BACKGROUND: Diagnosis of chlamydial conjuctivitis is difficult in chronic diseases because chlamydial elementary bodies are mostly undetectable in conjunctival scrapings by cell culture. We therefore compared two nonculture antigen tests and three different serotests for anti-chlamydial antibodies with McCoy cell culture, the "gold standard" of chlamydial diagnosis. Conjunctival scrapings and serum samples of 93 patients attending the outpatient eye clinic in Graz because of chronic follicular conjunctivitis were tested. METHODS: A total of 558 conjunctival scrapings and 93 serum samples were investigated. Chlamydial antigen detection was done by McCoy cell culture, polymerase chain reaction (PCR; Amplicor, Roche), and direct immunofluorescence assay (DFA; Microtrak, Syva). Antichlamydial IgA and IgG antibodies in the sera were detected by an immunoperoxidase assay (IPAzyme, Savyon) and two different enzyme-linked immunosorbent assays (SeroELISA, Savyon and rELISA, medac). RESULTS: Cell culture and PCR yielded identical results. The positivity rate for chlamydial conjunctivitis was 8.6% (8 of 93 patients). PCR proved most sensitive and most specific. IPAzyme was 75% sensitive for IgA and 100% for IgG; SeroELISA and rELISA were less sensitive. IPAzyme was 81% specific for IgA and 47.3% for IgG. SeroELISA and rELISA were less specific for IgA, but more specific for IgG. Post-test likelihood of disease was greatest in IPAzyme. CONCLUSIONS: PCR proved to be a good alternative to cell culture; DFA is useful for quick diagnosis. Genus-specific serotests cannot compete with chlamydial antigen detection. They differ in sensitivity and specificity because of the antigen type they present. They are still of only supportive value in cases where chlamydial antigen detection is not possible. Recently introduced species-specific antibody tests should be of greater value.     

Cytochrome system of myocardial mitochondria in patients with mitral valve insufficiency

A determination was made of the immunoglobulin G, M and A concentration in the blood serum of women suffering from dysentery and other acute intestinal diseases, those who sustained the disease and healthy persons (259 in all). Probability of detection of low IgA concentrations in the patients was 7-12 times greater during the first days of the disease than in healthy persons; IgG And IgM levels in the patients who sustained the disease and in healthy individuals showed no significant difference. Possible relationship between the synthesis of the secretory IgA in the intestine and the blood serum IgA level was discussed; however, a conclusion on a possibility of detection of persons most susceptible to dysentery and other acute intestinal diseases by the low serum IgA level could be made only after further investigations.     

Gliadin-specific and cow''s milk protein-specific IgA in human milk

The presence of gliadin-specific IgA and IgG antibodies in colostrum and serum of 140 newly delivered mothers was assessed by enzyme-linked immunosorbent assay. In addition, cow's milk protein (CMP)-specific IgA was determined in the colostrum samples. From 14 of the mothers longitudinal milk samples were obtained after 1 and 2 months of lactation and from 12 mothers after 3 months. Gliadin-specific IgA was found in 97.1% and gliadin-specific IgG in 9.3% of the colostrum samples. Gliadin-specific IgA was detected in mature samples but at significantly lower levels after 1, 2, and 3 months of lactation (p less than 0.01) as compared with colostrum. Gliadin-specific IgA was found in 2.8% of the serum samples and gliadin-specific IgG in 40%; however, the levels of both isotypes were low. CMP-specific IgA was found in 78.1% of the colostrum samples. It is concluded that IgA antibodies to two common food proteins are frequently found in human milk and that food-specific IgA present in milk may play a role in adapting the infant's immune reactions to food antigens in the gut.     

Characteristics of IgA anti-HIV antibodies in plasma from patients with HIV infection

The concentration of total IgA and the specificity and molecular size of IgA anti-human immunodeficiency virus (HIV) type-1 antibodies in plasma obtained from individuals at different stages of HIV infection were analyzed. The concentration of total IgA in the plasma was not decreased even in the late stage of HIV infection, in contrast with those of total IgG and IgM. The IgA anti-HIV antibodies differed to the IgG anti-HIV antibodies in their specificity as determined by Western blotting. The IgA antibodies mainly bind to Env glycoproteins. The IgA anti-HIV antibodies in plasma were detected between IgG and IgM by gel filtration, suggesting the presence of polymeric IgA anti-HIV antibodies. These results indicate that the production of non-specific IgA in plasma is enhanced by unknown mechanisms in every stages of HIV infection, and suggest that IgA anti-HIV antibodies in plasma which are possibly polymeric and have unique specificity may play an important role in HIV infection.     

Economic analysis of a comprehensive quality assurance program

The cervical mucus of 31 patients with normal and 16 patients with abnormal cervical cytology was investigated at each stage of the menstrual cycle for immunoglobulin IgG, IgA and IgM. IgG and IgA were present in every mucus sample, while IgM was only occasionally found in trace amounts. IgG and IgA increased towards the last week of the menstrual cycle, the increase being in general more marked for IgA. Patients with abnormal cervical cytology showed increased IgG and, more strikingly, IgA concentrations in their cervical mucus, but there was no correlation between the IgG and IgA concentrations at any stage of the menstrual cycle. Whereas in patients with normal cervical cytology the IgG and IgA concentrations correlated throughout the menstrual cycle.     

Occurrence of anti-C1q antibodies in IgA nephropathy

BACKGROUND: The pathogenic mechanisms and the antigens involved in the establishment and progress of IgA nephropathy are unknown. As antibodies against C1q have been reported to correlate with SLE nephritis, we analysed the occurrence of these antibodies in IgA nephropathy in order to investigate the possibility of pathogenetic similarities in these renal disorders. METHODS: The occurrence of IgA- and IgG anti-C1q antibodies (anti-C1q) were determined by ELISA in patients with IgA nephropathy (n = 36) and SLE nephritis (n = 37), diseases both known to be associated with circulating immune complexes. Levels of these antibodies were also determined in two other glomerular diseases, i.e. idiopathic membranous glomerulonephritis (n = 7) and minimal change disease (n = 2), in which circulating immune complexes are usually not present, and in 40 healthy controls. RESULTS: IgA anti-C1q was observed in increased titres in 11/36 of the patients with IgA nephropathy, in 2/37 of the patients with SLE nephritis (both with proliferative disease) and in 1/9 of the patients with membranous and minimal change disease (P < 0.001). Increased titres of IgG anti-C1q were observed in 1/36 of the patients with IgA nephropathy, in 17/37 of the patients with SLE nephritis and in 0/9 of the patients with membranous and minimal change disease (P < 0.001). There were no correlations between the levels of anti-C1q antibodies and clinical parameters such as degree of proteinuria, haematuria, or renal function. Nor was there any correlation to the concentration of C3a and the terminal complement complex (TCC) in patients with IgA nephropathy. CONCLUSIONS: The occurrence of anti-C1q antibodies in both IgA nephropathy and SLE nephritis, albeit of different predominating isotypes, indicates the possibility of a similar pathogenic mechanism involved in these renal disorders. The occurrence of IgA anti-C1q antibodies in patients with IgA nephropathy has to our knowledge not previously been reported.     

Development of humoral immunity system of the small bowel

The study was performed in 24 children aged 2 months to 6 years, without intestinal or immunological diseases. Intestinal biopsies were obtained by a Crosby's capsule, pediatric size. The number of immunoglobulin forming cells of lamina propria was measured by planimetry. Under 12 months of age there are increased levels of IgM forming cells and a low IgA forming cells/IgM forming cells quotient, but over 1 year the difference disappears. This suggests that the maturity process is very rapid. There are no correlation between serum IgA, IgM, and IgG levels and its respective forming cells number of lamina propria. It seems to support that the participation of intestinal lymphoid tissue in serum pool of immunoglobulin is very poor and that systemic and intestinal immunity maturation are completely independent.     

Immunoglobulin A response in murine schistosomiasis: stimulatory role of egg antigens

The immunoglobulin G (IgG) and IgA antibody responses to different Schistosoma mansoni antigens have been determined in chronically infected mice as well as in unisexually infected animals. With a panel of enzyme-linked immunosorbent assays (ELISAs), soluble antigens from furcocercariae, adult worms, and eggs were probed with sera collected at 3-week intervals. Bisexually infected animals developed significant IgG and IgA antibody responses to the antigens tested, which increased after egg deposition. In unisexual infections no significant differences were recorded in the IgG antibody profile for furocercaria and adult worm antigens, whereas the IgA antibody response was impaired. Both the IgA and IgG antibody responses toward egg antigens were reduced compared with those in a bisexual infection. Furthermore, a specific mucosal IgA antibody response was observed only in the bisexually infected animals. Histological analysis performed on bisexually infected mice led to the observation of eggs and granulomatous lesions within the Peyer's patch follicles, which are essential sites for the induction of mucosal immunity in the intestine. These data suggest a relationship between egg deposition and the induction of the IgA antibody response toward schistosomes.     

The use of exhaled carbon monoxide for the diagnosis of carbon monoxide poisoning. A case report

Antigliadin antibodies (AGA) mark celiac disease, but AGA are also encountered in IgA-nephritis, psoriasis, sickle-cell anemia, hepatic disorders, juvenile rheumatoid arthritis, autoimmune thyroidism and in persons who occupationally contact great amounts of wheat. AGA IgA and/or IgG were registered in 19 of 60 subjects (51 adults and 9 children) with various immunomediated diseases without symptoms of celiac disease: in 4 cases of chronic active hepatitis, in 2 of 4 cases of chronic persistent hepatitis, in 4 of 16 cases of rheumatoid arthritis, in 3 of 19 cases of IgA-deficiency, in 1 of 8 cases of SLE, in 2 cases of postvaccine reaction, in all the single cases of juvenile rheumatoid arthritis, focal scleroderma, macroglobulinemia. IgA only occurred in in 6 patients, IgG- in 6 patients, both IgA and IgG in 7 patients. The most pronounced positive reaction to AGA was recorded in 8-year-old girl with juvenile rheumatoid arthritis. The emergence of AGA in immunomediated diseases may be attributed to the response to food protein in pathological conditions and is often unrelated closely with celiac disease.     

Interleukin-6 and small intestinal luminal immunoglobulins

Our aim was to determine the relationships between interleukin-6 and immunoglobulin levels within small intestinal luminal secretions. Twenty adult subjects with small intestinal bacterial overgrowth (N = 13), irritable bowel syndrome (N = 4), and nonulcer dyspepsia (N = 3) underwent endoscopic aspiration of secretions from the small intestinal mucosal surface for assessment of IL-6, IgA1, IgA2, IgM, IgG1, IgG2, IgG3, and IgG4 concentrations. Serum immunoglobulin concentrations and small intestinal histology were also determined. IgA2 and IgG3 were the predominant IgA and IgG subclasses in luminal secretions in 19/20 (95%) and 20/20 (100%) subjects, respectively. IgA1 and IgG1 predominated in serum in all subjects. No subject had villous atrophy. Luminal IL-6 concentrations correlated significantly with luminal IgA2, IgM, and IgG3 concentrations but not with IgA1 or any other IgG subclass levels. Conversely, luminal IL-6 or immunoglobulin concentrations did not correlate significantly with levels of any immunoglobulin isotype in serum. These observations suggest that important relationships exist between local IL-6 and IgA2, IgM, and IgG3 responses in human small intestinal luminal secretions. Local investigation is mandatory when assessing intestinal immune activity.     

Overexpression of c-myc induces apoptosis at the prophase of meiosis of rat primary spermatocytes

Serum samples from 36 cervical carcinoma patients, 33 patients with high-grade squamous intraepithelial lesions, and 31 cytologically normal women were tested by enzyme-linked immunosorbent assay (ELISA) using human papilloma virus type 6 (HPV 6) and HPV 16 virus-like particles as antigens. Forty serum specimens from 1-year-old children were used to assign cutoff points. When serum samples from the subjects infected with HPV 16 were tested in an HPV 16 ELISA detecting immunoglobulin A (IgA), IgG, and IgM binding, 61% showed IgA, 44% showed IgG, and 39% showed IgM reactivity. Of HPV 6- or 11- or HPV 18-infected subjects. fewer than 17% showed IgA or IgG responses and 33% showed IgM reactivity. In contrast, 13% showed IgA, 10% showed IgG, and 16% showed IgM reactivity in the HPV DNA-negative controls. The results suggest that the IgA and IgG responses are HPV 16 specific and the IgM response is cross-reactive to different HPV types. On the other hand, the serological responses to HPV 6 did not differ in the patient and control groups. The percentages of patients positive for both IgA and IgG antibodies were significantly higher in the groups with high-grade squamous intraepithelial lesions (12% [4 of 33]; P = 0.04) and cancer (17% [6 of 36]; P = 0.02) than in the healty women (0% [0 of 31]), and the percentages for either IgA or IgG were higher for the cancer group (47% [17 of 36]; P = 0.01) than in the normal group (19% [6 of 31]). Most sera positive for IgA and IgG in the patient groups showed higher titers than those in the normal group. All these results suggest that high IgA and IgG responses are good indicators for estimating HPV 16 infection.     

Subglottic hemangioma as the cause of laryngostenosis in young children

The amount of plasma cells synthesizing different class immunoglobulins in the gallbladder wall in 9 practically healthy people and in 19 patients with different forms of cholecystitis was studied by a complex of histological, histochemical and immunofluorescent methods. It was established that catarrhal cholecystitis was accompanied by activated production of immunoglobulins of all classes by plasmocytes of the gallbladder wall. In patients with destructive forms of cholecystitis the level of secretory immunoglobulin A was substantially decreased as well as the amount of plasmocytes synthesizing IgA. The amount of immunocytes producing IgM and IgG became disproportionally greater, there appeared immune IgM complexes and IgG and IgG in the wall of blood vessels and perivascular stroma. The author considers that local immune reactions play an important role in protection of the gallbladder mucosa and pathomorphogenesis of cholecystitis.     

Comparison of anaesthetic and non-anaesthetic effects on depolarization-evoked glutamate and GABA release from mouse cerebrocortical slices

The aim of the study was to investigate whether patients with Aspergillus-induced lung disease can be monitored by immunoblot analysis to detect antibodies to Aspergillus fumigatus (Af). Immunoblotting was performed by incubating 57 longitudinally collected sera from 13 patients on nitrocellulose sheets, blotted with Af antigen, separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Bound antibodies were demonstrated by peroxidase-labelled antihuman immunoglobulins (Ig)G and IgA antiserum and diaminobenzidine plus H2O2 as substrate. The immunoblot patterns were related to the patients' clinical status and time. Each patient had a characteristic immunoblot pattern that varied with time. There was a relationship between disease activity or clinical response and changes in immunoblot antibody patterns: a rise in anti-Af IgG and IgA antibodies was seen in sera collected during active disease, compared with before active disease, and a significant decline in anti-Af IgG and IgA was demonstrated in sera collected during recovery, compared with during active disease. Only in the acute stage of allergic bronchopulmonary aspergillosis were IgA antibodies against Af antigens of <20,000 Da demonstrated. Immunoblot analysis can be used to monitor the disease activity and the responses to treatment of patients with Aspergillus-induced lung diseases. Changes in specific immunoglobulin A may be more informative than specific immunoglobulin G.     

Role of sarcoplasmic reticulum in the contractile dysfunction during myocardial ischaemia and reperfusion

The aim of our study was to analyze HIV-specific humoral immunity in the intestinal mucosa at different stages of HIV infection in comparison with serum and saliva. Duodenal biopsy specimens from 30 AIDS patients and 9 HIV-infected patients without AIDS were cultured for 48 hours. Culture supernatants, as well as simultaneously obtained serum and saliva samples, were adjusted to the same immunoglobulin concentrations and tested for HIV-specific IgG and IgA by Western blot. The HIV antigen pattern differed clearly between IgA and IgG but was similar for each isotype independent of its origin (i.e., serum, saliva, or biopsy specimen supernatants). Short-term cultured duodenal biopsy specimens from HIV-infected patients at all stages produced predominantly IgG, which was broadly reactive with HIV antigens. Lower titers of HIV-specific IgA, which recognized few antigens, were found, mostly the glycoprotein gp160. At later stages of the disease compared with earlier stages, the reaction pattern of mucosal IgA from saliva and biopsy supernatants was even more restricted; secretory component was frequently absent. The abnormal predominance of HIV-specific IgG over IgA in mucosal secretions may result from abnormal antibody production in the mucosa rather than from serum leakage. Mucosal inflammation induced by HIV-IgG immune complexes and insufficient immune exclusion by secretory IgA may not only lead to increased mucosal HIV replication but may also contribute to gastrointestinal disease in HIV-infected patients.     

Detection of circulating antigen-antibody complexes by their inhibitory effect on the agglutination of IgG-coated particles by rheumatioid factor of Clq

The agglutination of Ig-coated particles by human RF or Clq can be inhibited by Ig aggregates or AgAb complexes. The effect of Ig class was studied by means of agarose-linked human monoclonal Igs. RF was inhibited by all subclasses of IgG and IgA but not by IgM, whereas Clq reacted with IgM, IgG3 and IgG1. Heat-aggregated IgG3 was fractionated by gel-filtration on Ultrogel. Inhibition was restricted to certain fractions of aggregates, viz (IgG3) approximately 7 and (IgG3) approximately 21 for RF, and (IgG3) approximately 10, (IgG3) approximately 14 and (IgG3) approximately 27 for Clq. In a precipitin curve experiment, it was found that RF was inhibited by soluble complexes over an extended range of AgAb ratios, the inactivation of Clq being limited to complexes with 2-5 times antigen excess. Inhibiting factors were found in patients with various diseases and, at low titres, in 22% of healthy people. In 27% of patients' sera, the inhibitors were demonstrable by Clq only after removal of endogenous RF by adsorption on insolubilized IgG. In several patients endogenous agglutinating activity and direct inhibitory activity tended to alternate during the course of the disease. Sera from various patients were also filtrated on Ultrogel and the elution was monitored by immunoassay of IgA, IgM and IgG, as well as by the two inhibition tests. The inhibiting factors were distributed over several peaks which only partially coincided with the elution profiles of IgG and IgM.     

Evidence against colonic mucosa colonisation by Helicobacter pylori. Lack of a specific antibody response in homogenates of rectal endoscopic biopsies

Aim of this study is to provide indirect evidence that human colonic mucosa harbour Helicobacter pylori. The antibody response of IgG and IgA class against Helicobacter pylori was examined in autologous homogenate of gastric and rectal endoscopic biopsies from 26 patients and in rectal samples of a further 36. All had a documented (histology and/or serology) Helicobacter pylori status. Helicobacter pylori specific IgG and IgA were measured by an in-house ELISA. In Helicobacter pylori positive patients having both gastric and rectal homogenate, mean level of Helicobacter pylori IgG and IgA was higher in gastric than in rectal samples (0.810 +/- 0.668 optical density vs 0.329 +/- 0.509 optical density for IgG, p = 0.007 and 0.660 +/- 0.477 vs 0.116 +/- 0.229 for IgA, p < 0.001, respectively). In each patient, level of the two isotypes was clearly higher in gastric than in autologous rectal sample. In the overall study population, mean level of Helicobacter pylori IgG in rectal homogenate was not significantly (p = 0.16) different between Helicobacter pylori positive (48/62, 77%, 0.243 +/- 0.388 optical density) and negative (14/62, 23%; 0.095 +/- 0.088) patients. In same material, levels of Helicobacter pylori IgA were very low and undetectable either in Helicobacter pylori positive or negative patients. Although Helicobacter pylori IgG are detectable in rectal homogenates of Helicobacter pylori positive patients, present data suggest that these antibodies may not be local in origin but rather reflect circulating response. These observations do not support the view that large bowel mucosa is colonised by Helicobacter pylori.