The susceptibility of exocrine and serum immunoglobulins and antibodies to proteolytic degradation was assessed. Colostral and duodenal fluid exocrine 11S IgA, monomeric serum IgA, and IgG were digested with trypsin, chymotrypsin, or duodenal fluid. Exocrine IgA was more resistant to digestion than were the serum immunoglobulins. Under conditions of the experiments, most of colostral IgA retain...

The hallmark of a mucosal immune response is the production of antigen-specific secretory IgA (S-IgA) antibodies in external secretions. S-IgA consists of ten polypeptides produced in two different cell lineages. The heavy and light chains in plasma cells assemble into IgA, which on association with J chain become polymerized, whereas secretory component (SC) is added during transport across th...

To investigate local humoral immunity in ulcerative colitis (UC), immunoglobulin (Ig) contents and net Ig production in vitro was assessed using organ cultures of colonic biopsies from 21 patients with quiescent disease and 11 controls. Ig was estimated by enzyme linked immunoassay (ELISA) for IgA, secretory IgA (sIgA), IgM, and IgG. In parallel, numbers of IgA plasma cells were estimated by in...

IgA pemphigus is a newly characterized group of autoimmune intraepidermal blistering diseases presenting as vesiculopustular eruptions with a predilection in axillary and groin areas. Immunopathologically, IgA deposition in the intercellular space of the epidermis is present in all cases of IgA pemphigus by direct immunofluorescence. However, unlike pemphigus vulgaris, IgA pemphigus carries a r...

The diagnosis of IgA-dominant post-infectious glomerulonephritis (PIGN) may be challenging, as it must be differentiated from that of active IgA nephropathy. Predominant clinicopathologic features of IgA-dominant PIGN substantially overlap with those of active IgA nephropathy. Here, we present a case of a 67-year-old woman with rapidly rising serum creatinine, proteinuria and severe hypertensio...

The resolution of primary and secondary chlamydial genital infection in immunoglobulin A (IgA)-deficient (IgA(-/-)) mice was not different from that in IgA(+/+) mice. Furthermore, depletion of either CD4(+) or CD8(+) T cells prior to reinfection of IgA(+/+) or (-/-) mice had limited impact on immunity to reinfection. Thus, although antibody contributes importantly to immunity to chlamydial geni...

BACKGROUND Immunoglobulin A (IgA) antibodies to tissue transglutaminase (tTG) are the serologic test of choice for diagnosing celiac disease (CD). Our aim was to determine if elevated IgA anti-tTG were associated with increased mortality risk. METHODS Stored serum samples of National Health and Nutrition Examination Survey (NHANES) III (1988-1992) were available for 6032 individuals aged 50 y...

OBJECTIVE Although the diagnostic utility of serum IgG antibodies to Helicobacter pylori (H. pylori) is well established, the usefulness of IgA-based tests is less well documented. The aim of this study was to evaluate two commercially available ELISAs, both for IgG and IgA. PATIENTS AND METHODS Rapid urease test and histology analysis were performed in 183 patients. A patient was considered ...

BACKGROUND Primary IgA nephropathy (IgAN) is associated with elevated levels of circulating IgA and is characterized by deposition of primarily IgA1 in the renal mesangium. It has not yet been clarified which mechanisms govern the deposition of IgA1 in the mesangium. One of the factors which may play a role in trapping of IgA in the mesangial area is the interaction of IgA with specific IgA rec...