The plot (and basement membrane) thickens: A case report of collagenous sprue associated with collagenous colitis

INTRODUCTION: Microscopic colitis is a common disease encountered in clinical practice that responds well to therapy. While comorbid celiac disease is common, collagenous sprue is rarely associated and has unique treatment considerations. We describe a case of a woman who presented initially with collagenous colitis that responded well to therapy but then developed additional symptoms and was ultimately found to have collagenous sprue. CASE DESCRIPTION/METHODS: An 82-year-old woman presented to GI clinic with a 10-pound abnormal weight loss, abdominal bloating, and loose stools. Basic chemistries, blood count, and celiac serologies were normal. Colonoscopy with random biopsies revealed collagenous colitis. Budesonidewas cost-prohibitive, so she was placed on colestipol and bismuth, and was doing well at five month follow up. At nine months, she developed upper abdominal post-prandial discomfort that did not respond to a trial of PPI, 20-pound abnormal weight loss, albumin of 2.9 g/dL (nl 4.0 g/dL), and a mild microcytic anemia. Upper endoscopy showed mucosal scalloping of the duodenal bulb and second portion. Biopsies showed increase in subepithelial collagen deposition and villous blunting, consistent with collagenous sprue. Serologies for celiac disease remained negative, and serologic evaluation also demonstrated normal serum protein electrophoresis, normal free light chains, negative anti enterocyte antibodies and negative anti goblet cell antibodies. The patient went on a gluten free diet and was also placed on azathioprine 0.5 mg/kg, which was titrated up to 1 mg/kg. At 11 months, her weight had stabilized and upper GI symptoms had resolved. DISCUSSION: Collagenous sprue is a rare disease of the small bowel characterized by pathologic collagen deposition in the basement membrane and villous blunting. Fewer than 100 cases have been reported since 1970. When patients do not respond to gluten elimination alone, options for immune suppression include budesonide, prednisone, immunomodulators, or biologic therapies. In our patient we chose to use an immunomodulator in combination with gluten free diet due to comorbid diabetes, cost of budesonide, and personal preference. Further study is needed to determine optimal therapy and duration. We report on this interesting clinical entity both to raise awareness of the condition and to remind clinicians of the need to look for alternative etiologies of new GI symptoms when a patient with microscopic colitis develops new and uncontrolled symptoms (Figure Presented).