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Human phospholipase B-precursor (PLB-P) is a newly identified and purified protein from human neutrophils. The precise function of PLB-P in vivo is not yet known. Its existence in neutrophils and the enzymatic activity against phospholipids imply a role in the defence against invading microorganisms and in the generation of lipid mediators of inflammation. We describe here the generation of specific antibodies against PLB-P, the tissue localizations of PLB-P and the establishment of an accurate, specific, and reproducible radioimmunoassay (RIA). A survey of normal and malignant tissues showed strong immunostaining of PLB-P in neuronal and myeloid cells and in adrenal glands. Elevated levels were found in sera of patients with influenza A infection i.e. > 1 mu g/L and in gut fluids of patients with inflammatory bowel disease i.e. > 20 mu g/L. The levels correlated to markets of neutrophil activation, suggesting a neutrophil origin of PLB-P in these conditions. The antibodies and the assay will be useful in the future basic and clinical investigations of PLB-P.

Background Sensitivity to food antigens has been postulated as a contributing factor to the pathogenesis of IgA nephropathy (IgAN) Methods In this study we used a recently developed mucosal patch technique to evaluate rectal mucosal sensitivity to soy and cow's milk (CM) proteins in IgAN patients (n = 28) compared to healthy subjects (n = 18) The rectal mucosal production of nitric oxide (NO) and release of myeloperoxidase (M PO) and eosinophil cationic protein (ECP) were measured Serum samples were analyzed for IgA and IgG antibodies to a-lactalbumin, P-lactoglobulin, casein and soy Results 14 of 28 (14/28) patients experienced a rectal mucosal reaction, measured by increased NO and/or MPO levels, upon rectal challenge with soy and/or cow's milk proteins The levels of IgG antibodies to a-lactalbumin, beta-lactoglobulin and casein were significantly higher in CM sensitive as compared with non-sensitive IgAN patients, whereas the mean serum levels of IgA antibodies were similar No differences were seen in serum levels of IgA or IgG antibodies to soy Conclusion It is concluded that approximately half of our IgAN patients have a rectal mucosal sensitivity to soy or CM, and that an immune reactivity against antigens may be involved in the pathogenesis of IgAN in this subgroup of patients

BACKGROUND AND AIMS: To elucidate the dynamics of nitric oxide (NO) production induced by rectal gluten challenge and the relation between NO production and mucosal granulocyte activation. Subjects and METHODS: Release of rectal NO was measured in 13 patients with coeliac disease and in 18 controls before and after rectal wheat gluten challenge. Rectal gas was collected with a rectal balloon using a newly developed instrument/technique, the "mucosal patch technique". The instrument allows simultaneous measurements of concentrations of granulocyte mediators in the rectal mucosa. We measured myeloperoxidase (MPO), eosinophil cationic protein (ECP), and histamine. For comparison, we made similar measurements after corn (maize) gluten challenge. RESULTS: In all coeliac patients rectal NO concentration increased after gluten challenge and reached a peak after 15 hours (mean 9464 (SEM 2393) parts per billion (ppb); range 250-24982). The maximum MPO and ECP increase occurred five hours after challenge. A correlation was found between mucosal MPO and NO production at 15 hours. Six of the patients showed an increase in NO production 15 hours after rectal corn gluten challenge but this was much smaller than after gluten challenge. No increases were seen in the control group after either challenge. CONCLUSION: Mucosal activation of neutrophils and eosinophils precedes pronounced enhancement of mucosal NO production after rectal wheat gluten challenge in patients with coeliac disease. Some of our coeliac patients displayed signs of an inflammatory reaction, as measured by NO and granulocyte markers, after rectal corn gluten challenge.