No abstract

We studied 166 hospitalized male patients to determine the clinical importance of tolerance-test-determined "lactose intolerance," assumed to affect most of the world's adults. Abnormal lactose tolerance tests were found in 81% of 98 blacks, 12% of 59 whites of Scandinavian or Northwestern European extraction, and three of nine non-European whites. Seventy-two per cent of the "lactose-intolerant" subjects had previously realized that milk drinking could induce abdominal and bowel symptoms. Two hundred and forty milliliters of low-fat milk produced gaseousness or cramps in 59% of 44 "lactose-intolerant" men, and 68% were symptomatic with the equivalent amount of lactose. None of 18 "lactose-tolerant" men noted symptoms with milk or lactose. Refusal to drink 240 ml of low-fat milk served with meals correlated significantly with "lactose-intolerance": 31.4% versus 12.9% among "lactose-tolerant" patients. "Lactose intolerance" is common in adults and is a clinically relevant problem.

Lymphocytic colitis is a newly described chronic diarrheal disorder. Although its etiology is unknown, the possibility has been raised that autoimmunity may play a role in both lymphocytic and collagenous colitis, a similar clinicopathologic illness. The frequencies of HLA class I and class II antigens were examined in 24 white patients with lymphocytic colitis and in 47 white patients with collagenous colitis. Frequencies in these two disorders were compared to control white populations and to each other. An increased frequency of HLA-A1 was noted in 16 of 24 lymphocytic colitis patients (66.6%) compared with 1089 of 3942 controls (27.6%) (P less than 0.005; relative risk 5.2). Furthermore, HLA-A3 was found in decreased frequency in lymphocytic colitis patients: 0 of 24 (0%) compared with 1017 of 3942 controls (25.8%) (P less than 0.05; relative risk 0.0). Collagenous colitis patients had no significant deviation from control frequencies of HLA antigens. In lymphocytic colitis, there was no significant increase in B8 or DR3 antigens, which are found in linkage disequilibrium with A1 and associated with many autoimmune diseases. Moreover, the frequency of autoimmune-associated class I HLA antigens was not increased in lymphocytic colitis. Statistically significant differences existed between lymphocytic and collagenous colitis in HLA-A1, A3, Bw6, and B7 antigen frequencies. The HLA patterns noted previously in other gastrointestinal disorders, including ulcerative colitis and Crohn's disease, were not apparent in lymphocytic or collagenous colitis. HLA typing provides further evidence that lymphocytic colitis is a distinct form of chronic intestinal inflammatory disease associated with HLA class I phenotypes.