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Notes: One hundred and sixty-five infants were studied longitudinally from birth to 5 years of age. One hundred and twenty-three school-age children and 27 adults were examined cross-sectionally. Total salivary IgA levels and IgA antibodies against Escherichia coli O antigens were measured. Total IgA levels were low (〈20 mg/l) from birth to 4 years of age. At 5 years of age there was a dramatic increase in the total IgA level (geometric mean = 100.7 mg/l), after which the levels fell to values similar to those observed in adults (adult geometric mean = 53.2 mg/l). Low levels of IgA-specific E. coli antibodies were observed for the first 4 years of life (〈1.0 ELISA units). There was a gradual increase in specific antibodies between 5 and 9 years of age (geometric men at 9 years=4.66 ELISA units) to levels similar to those observed in adults (adult geometric mean=8.20 ELISA units). It is suggested that the patterns of development for these variables reflect a balance between antigenic exposure and immune control mechanisms.

Notes: During a prospective study of the ontogeny of the mucosal immune system using saliva, one subject acquired a selective IgA deficiency at 3 years 6 months of age. Prior to this time the infant had normal ontogeny patterns for salivary immunoglobulins and the salivary IgA was confirmed to be dimeric IgA containing secretory component. Two respiratory tract infections at 3 years 4 months and 3 years 5 months were reported prior to the collection of a saliva sample which was deficient in IgA. All subsequent saliva collections remained IgA deficient. Serum and saliva collected at 11 years of age confirmed persistent IgA deficiency. There was a family history of organ-specific autoimmune disease. The prospectively collected data indicate in this subject that the IgA deficiency was not congenital, but was acquired closely associated with two episodes of respiratory tract infections, against a genetic background of disturbed immune regulation.

Notes: Background The Pharmacia ImmunoCAP system (CAP) for assaying serum IgE specific antibodies was evaluated in a clinical setting against skin-prick test (SPT) perfonncd using Dome/Hollister-Steir allergen extracts. The five cotnmon inhalant allergens D. pteronyssinus. D. farinae, mould mix, grass mix and cat epithelium were tested concurrently by both methods in 167 children aged 7.5–12 years. The specific SPT for D. pteronyssinus and D. farinae were also tested against the CAP house dust mite (HDM) mix.Objective The purpose of the study was to determine the sensitivity and specificity of the Pharmacia ImmunoCAP system Tor detecting serum IgE specific antibodies to inhalant allergens in a clinical setting, using the SPT result as the ‘gold standard’.Methods The SPTs were performed using Dome/Hollister-Steir allergen extracts. The serum IgE specific antibodies were quantitated using the radioimmunoassay version of the Pharmacia ImmunoCAP system. A history of allergic disease was assessed using a validated questionnaire.Results SPT gave more positive reactions than CAP with the exception of cat epithelium. The concordance between SPT and CAP results was 91% over all the tests. The concordance with SPT was slightly higher for the specific CAP for D. pteronyssinus and D. farinae (93% and 95% respectively) than for the CAP HDM mix (86% and 90% respectively). There was a higher proportion of positive results for both SPT and CAP in the 115 children defined as having a history of allergic disease. Using SPT defined allergy as the gold standard, the sensitivity of the CAP system was 87% for the two specific house dust mites but was lower for cat epithelium (67%), mould mix (59%) and grass mix (46%). The sensitivity of the CAP system improved for D. pteronyssinus (96%) and the HDM mix (91%) when tested in subjects defined as having a history of allergy associated disease. The specificity of the CAP system showed less variation between allergens and ranged from 90–99%.Conclusion The results of this study of children aged 7.5–12 years demonstrate that, for the inhalent allergens tested, the Pharmacia ImmunoCAP system perfoms well in the setting of known allergic disease.

Notes: The role played by dietary chemical factors in the pathogenesis of chronic idiopathic urticaria (CIU) was assessed in seventy-six patients by challenge. Stable remission was first established by using an empirically established ‘exclusion diet’. A diet modified to exclude those chemicals giving a positive response to challenge was demonstrated to be of therapeutic value for time periods of up to 18 months. Re-testing twelve patients at 12 months indicated that most patients positive to salicylate or benzoate challenge retained this pattern of reactivity.

Notes: Recovery and identification in vitro of lymphocytes from gingival tissue was carried out for 20 patients with chronic marginal gingivitis. A combination of 90 min incubation in a collagenase-containing medium followed by mechanical disruption through a stainless-steel grid resulted in a mean yield of 2.42 × 105 (S. D. ± 1.26 × 105: n = 16) lymphocytes per 100 mg or tissue. When Ficoll density centrifugation was introduced into the recovery procedure, the mean lymphocyte yield dropped to 2. 15 × 104 (S. D. ± 0.99 × 104: n = 4) per 100 mg. Mean viability of recovered lymphocytes was 78% (S. D. ± 5%: n =16) and for Ficoll separation, 77% (S. D. ± 1%: n = 4). In cell suspensions obtained from 12 or the patients, T lymphocytes were identified by rosette formation with sheep erythrocytes, and B cells were quantitated using fluorescent identification of membrane immunoglobulin. Macrophages were identified on the basis of non-specific esterase characteristics. Tire predominant lymphocytes round were T cells, with a mean proportion of 53.9% (S. D. ± 5.6%); the mean proportion of B cells was 32.7% (S. D. ± 5.4%). Macrophages accounted for a mean of 7.7% (S. D. ± 2.8%) or the recovered lymphoid cells. The lymphocyte-plasma cell ratio in recovered cell suspensions was 7:1 compared with a ratio of 1.7:1 noted in histological sections.

Notes: Immunoglobulin production in vitro was investigated for lymphocytes recovered from gingival tissue of 16 patients with chronic marginal gingivitis. Recovered lymphocytes were maintained in culture for 7 days, and the presence of IgG, IgA, and IgM in culture supernatants quantitated using solid-phase radioimmunoassay. The production of IgG was assessed for 4 patients at days 1, 3, 5, and 7 whilst release of synthesized immunoglobulin due to repeated freeze-thawing was investigated immediately following cell recovery in 2 patients. The effect of adding pokeweed mitogen (PWM) to gingival cultures was assessed for 8 patients. The concentrations of immunoglobulins found in culture supernatants at 7 days were IgG, 6.6 μg/ml (SD ± 5.7); IgA, 0.8 μg/ml (SD ± 1.0); and IgM, 0.4 μg/ml (SD ± 0.2). Assessment of IgG production over 7 days showed that 56% of the IgG was present by 24 h, 80% by day 3, and 86% by day 5. The amounts of IgG found following repeated freeze-thawing accounted for 15% of the 7 day total in patient 1 and 38% in patient 2. Addition of PWM to gingival cell cultures at concentrations of 1/50 through to 1/400 had no stimulatory effect on immunoglobulin production. The results indicated that lymphocytes recovered from chronically inflamed gingival tissue secreted immunoglobulin progressively throughout a 7 day culture period. The findings also suggested that gingival B lymphocytes had been highly stimulated in vivo and were actively secreting immunoglobulin at the time of recovery from tissue.

Notes: Background : The performance of commercial Helicobacter pylori diagnostic kits developed for particular geographic regions has often been found to be of poor diagnostic value when applied to other regions, possibly because of infections being caused by different H. pylori strains in different regions.Aim : To evaluate the performance of an IgG2 anti-H. pylori enzyme-linked immunoassay test (Helirad Alert) for detection of H. pylori infection in both Australian and Hong Kong (Chinese) subjects.Methods : Serum samples were tested for H. pylori specific IgG2 and IgG antibodies by enzyme-linked immunoassay kits using identical antigen preparation in 168 Australian and 160 Hong Kong (Chinese) subjects diagnosed with dyspepsia.Results : Using a cut-off value determined by analysis of H. pylori-negative Australian samples, the sensitivity, specificity and accuracy of the IgG2 assay were 77.8, 97.4 and 91.1%, respectively, for the Australian samples and 96.3, 83.8 and 90% for Hong Kong samples. For the IgG assay, sensitivity, specificity and accuracy were 87.0, 99.1 and 95.2% for Australian samples and 97.5, 75 and 86.3% for Hong Kong samples respectively. Receiver-operating characteristic analysis showed better discrimination of H. pylori status when the IgG2 assay was applied to Hong Kong samples, while the IgG assay was better in the Australian samples.Conclusion : These data demonstrate that the Helirad Alert enzyme-linked immunoassay could provide a reliable method for screening H. pylori infection in both western and Chinese populations.

Notes: Saliva was collected from 57 infants aged ft weeks to 2.5 years and the molecular form of IgA was studied by centrifugation on sucrose density gradients. Two distinct populations were identified. Seventy-two per cent of the children had secretory IgA in their salivary secretions, while 28% had a molecular form corresponding to monomeric IgA. No samples with concurrent monomeric and secretory forms were detected. Monomeric IgA was not detected in any infant over 12 months of age. Secretory component was detected in all samples but was not associated with monomeric IgA. Forty-seven per cent of the samples contained IgA fragments of approximately 40,600 molecular weight. The presence of fragments dominated in the group of children with monomeric IgA. The presence of monomeric IgA in infant saliva did not result from degradation due to storage or proteolysis. The study demonstrated an apparent maturation sequence in the molecular form of IgA present in the salivary secretions of infants.