Collagenous colitis : A study of epidemiology, etiology, clinical features and treatment

Sammanfattning: Collagenous colitis (CC) is characterised clinically by chronic watery diarrhoea and histopathologically by an increased submucosal collagen layer. An epidemiologic study of CC during 1984 to 1993 showed a female:male ratio of 9:1. The median age at diagnosis was 64 (28-78) years. The prevalence was 15.7/105 on December 31, 1993, and the mean annual incidence was 1.8/1()5 inhabitants. Age specific incidence showed a peak of 14.6/105 in females 70-79 years old, which approaches the incidence for ulcerative colitis in the same age group.Faecal stream diversion in 9 patients with severe, medically intractable CC induced histologic and clinical remission. This observation indicates that a noxious agent in the faecal stream constitutes an etiologic factor in CC. Faecal stream diversimi offers a treatment alternative in patients with severe CC who do not respond to medical treatment.Sera from 38 patients with CC and matched controls were analysed for specific autoantibodies, immunoglobulins and complement. The mean value of I gM was significantly increased in patients; 2.5 g!L compared to 1.4 gn ... in controls (p=0.002). ANA and pANCA occurred more frequently in patients, although the difference did not reach statistical significance. The result.;; of all other immunoglobulins, complement factors, and specific antiboctles were similar in patients and controls. The findingsof an increased IgM level in patients, might give some support to a hypothesis of autoimmunity in CC. The ANA- and pANCA positive patients could constitute a subpopulation among CC patients.Procollagen III propeptide (P-III-NP) is a product of collagen Ill metabolism. No significant difference between the serum level of P-III-NP in 38 patients (3.8±2.0 P-g!L) and 38 matched controls (3.7±1.3 ~g!L) was found, and P-III-NP did not correlate to clinical activity. There was a significant correlation, however, between P-III-NP and age in both patients and controls. The study showed that colonoscopy is still required to diagnose CC and cam~-9t be replaced, at present, by a simple blood test.A register of patients with CC was set up at the Örebro Medical Center Hospital. Twenty five Swedish hospitals contributed with patient records to this register which comprised of data from 163 patients. Data showed that CC usually followed a chronic intermittent benign course. The onset was sudden in up to 42% of the patients. The most common symptoms were chronic watery diarrhoea, sometimes nocturnal, abdominal pain and weight loss. Routine laboratory data were most often normaLEvaluation of the treatment showed a response rate of 59% for sulphasalazine, and 40% respectively SO% for olsalazine and mesalazine. Prednisolone was effective in about 80% of the patients, but the required dosage was often high, and the effect not sustained after withdrawal. Metronidazole, erythromycin and penicillin had response rates from 55% to 100%. Cholestyramine and loperamide offer treatmentalternatives of which about two thirds of the patients benefit.