Sustained clinical response to infliximab in refractory Cronkhite-Canada syndrome.

A 59-year-old man with refractory Cronkhite-Canada syndrome (CCS) had poor clinical response to high-dose intravenous steroids, azathioprine, total parenteral nutrition and best supportive care. He remained highly symptomatic with abdominal pain, diarrhoea, recurrent sepsis and profound weight loss. Infliximab induction was given as rescue therapy, with marked clinical improvement observed within 3 weeks. This allowed steroid taper. Within 12 months of infliximab therapy, he achieved complete clinical remission and returned to his baseline weight and a full oral diet. Sequential endoscopies observed significant regression of previous marked gastrointestinal polyposis, including histological remission on colonic biopsies at 3.5 and 5 years of treatment. He currently remains in remission following 6 years of combination therapy with 5 mg/kg 8 weekly infliximab and azathioprine, and there is ongoing discussion with regard to the benefits and risks of therapy de-escalation. This case demonstrates the effectiveness of infliximab in inducing and maintaining remission in refractory CCS.

Activation of the mucosal immune system in irritable bowel syndrome.

BACKGROUND & AIMS: A role for the mucosal immune system in the pathogenesis of irritable bowel syndrome is suggested by its association with intestinal infections. METHODS: To investigate this, we performed histologic and immunohistologic studies on colonoscopic biopsy specimens from 77 patients with symptoms satisfying the Rome criteria and 28 asymptomatic control patients. RESULTS: Histologic assessment of biopsy specimens from symptomatic patients indicated 3 different groups. The first (38 of 77) had normal conventional histology; however, immunohistology showed increased intraepithelial lymphocytes (median, 1.8-fold; range, 1.74-1.86), lamina propria CD3(+) cells (2-fold; range, 1.55-2.91), and CD25(+) cells (6.5-fold; range, 4.98-8.13) compared with asymptomatic controls. The second group (31 of 77) had nonspecific microscopic inflammation and on immunohistology showed similar increases in lymphocyte populations (not significant vs. the uninflamed group) as well as increased numbers of neutrophil leukocytes and mast cells (P < 0.0001 vs. controls and the uninflamed group). The third group (8 of 77) fulfilled histologic and immunohistologic criteria for classic lymphocytic colitis. CONCLUSIONS: Examination of colonoscopic biopsy specimens from patients meeting the Rome criteria for a clinical diagnosis of irritable bowel syndrome showed subgroups with normal and abnormal conventional histology. All groups showed increased numbers of activated immunocompetent cells in the intestinal mucosa on quantitative immunohistology, implicating the mucosal immune system in pathogenesis.