Collagenous colitis and rheumatoid arthritis: is there a connection?

Background

Collagenous colitis (CC), discovered by the Swedish pathologist Claes Lindström in 1976 [1], is characterised clinically by chronic watery diarrhoea, and a macroscopic normal colonic mucosa, where characteristic changes are found microscopically. CC is most prevalent in middle-aged women and has frequently been associated with connective tissue diseases, including rheumatoid arthritis (RA) [2].

Objectives

To confirm the occurrence of RA in a large series of CC, and to search for distinguishing clinical features and possible clues to the connection.

Method

Retrospective chart review and follow-up examination of patients a large referral center.

Results

A registry of CC at the Örebro University Hospital contains 163 patients [3]. Sixteen of these patients had a previous diagnosis of RA. Fifty-three of the patients were residents of the immediate catchment area, and among them eight patients with RA have been identified, all women. The onset of RA preceded that of CC in seven out of eight patients by between 1 and 34 years. In the remaining case, CC started 14 years before RA. Radiographic erosions were present in six out of eight patients, rheumatoid factor in three out of eight patients, and seven out of eight patients fulfilled the ACR criteria for RA. Four out of eight patients had first-degree relatives with RA. Four out of eight patients had extra-articular manifestations, and three out of eight patients had monoclonal IgG components in the blood. Three out of eight patients had Sicca syndrome or full-blown Sjögren's syndrome.

Conclusions

We confirm the occurrence of RA in at least 10% of a large series of CC, usually present before the onset of CC. This is further evidence for a real correlation rather than mere coincidence. We were not able to find any distinguishing features of RA, but it is suggested that familial RA and extra-articular manifestations are common. RA as such, or remedies used to treat RA, may contribute to the pathogenesis of CC