[The role of immune system in development of structural changes in colonic mucosa in diverticulosis]

To determine the role of immune response with production of auto- and heterologous antibodies (Ab) in development of the pathological process and in structural changes in colon mucosa (CM) in diverticulosis (Dv).

Of 219 Dv patients, 39 were newly diagnosed with x-ray-detected signs of previous inflammation (group 1), 180 had earlier detected Dv which was confirmed and endoscopic examination detected inflammation (group 2). The comparison group consisted of 25 patients with irritable colon syndrome. The immune status was assessed by concentration of immunoglobulins (Ig), auto- and heterologous Ab. Antibodies to catalytic cytoplasmic antigens to proteinase-3, myeloperoxidase, bactericide protein BPI, tissue transglutaminase (tTG) and antiglycanic Ab were detected with solid-phase enzyme immunoassay.

IgA and IgG levels in group 2 were significantly higher than in group 1 and in the controls. Elevation of both IgA and IgG levels reflects activation of B-cell immunity. Group 2 patients had a higher level of Ab to endogenic peptides Saccharomyces cerevisiae (ASCA) of class IgG and IgA than group 1 and controls. The level of Ab to tissue molecules was elevated: antibodies to tTG IgG were detected in both groups--in group 2 twice more often than in group 1, while Ab to BPI--in 27% cases in group 1 and in 97%--in group 2. IgG Ab to antigens associated with phagocytic cells were detected in group 2, while Ab in group 1 were positive in single cases.

Activation of immune response with a high concentration of IgA and IgG, Ab to tissue antigens (BPI, tTG) and IgGAb to catalytic antigens is characteristic of chronic course of Dv. Morphological changes in CM reflect different severity of inflammation-dystrophic process.