Lack of Autoantibodies Against Related Proteins in Collagenous Colitis

The histological criteria for CC are a thickened sub-epithelial collagen layer (> 10 µm) in the extracellular matrix (ECM) of the mucosa, epithelial damage and presence of an inflammatory infiltrate in the lamina propria. CC shares many of the characteristics found in autoimmune diseases, but no autoantibodies have been identified. In CC, an imbalance in collagen turnover is evident.

Gastroenterologists at the Skåne University Hospital (Malmö, Sweden) included in a study, 66 women with CC. The mean age at inclusion was 60 years (range 31–74 years) and mean age at diagnosis was 55 years (range 28–69 years). The size of the control groups differed, but they were selected from the same cohort consisting of 100 healthy female blood donors. The mean age of the total control group was 41.7 years (range 19–69).

In-house enzyme-linked immunosorbent assays (ELISAs) were set up for analysis of anti-IgM and IgG antibodies against collagen type III (Col III and IV). Analyses of antibodies against matrix metalloproteinase-9 (MMP-9 and Tenascin-C (TNC) were conducted by in-house ELISAs and another in-house ELISA was set up for analysis of IgM and IgG antibodies against tissue inhibitors of metalloproteinase (TIMP-1). Anti-Saccharomyces cerevisiae antibodies (ASCA) IgG were analyzed by a fluorescent enzyme immunoassay method (FEIA) for which the reference value is set > 10 U/mL (Orgentec Diagnostika, Mainz, Germany). Thyroid peroxidase (TPO) antibodies were analyzed by a chemiluminescence enzyme immunological method (Siemens Healthcare GmbH, Erlangen, Germany).

The investigators reported that there was no difference in prevalence of these collage-associated autoantibodies between CC patients and controls. Sixteen patients expressed one type of autoantibody, whereas two patients expressed two different types. The mean disease duration was significantly lower in the subjects who expressed collagen-associated autoantibodies (3.7 years; range 1–14), compared to those who did not (6.4 years; range 1–22). The presence of autoantibodies against TPO and ASCA was slightly increased compared to controls, but not statistically significant. Increased levels of total IgE were equally present in the CC patients and the control group, and there was no correlation between total IgE-positivity and presence of any autoantibodies.

The authors concluded that no increased presence of the investigated antibodies could be found in the present study of CC. Neither could antibodies against ASCA or TPO, or elevated levels of IgE, be found. Consequently, no association was found between CC and these proteins, even though this may not be generalizable to other compounds in the collagen layer. The study was published on June 6, 2022 in the journal BMC Immunology.