S2176 Co-Occurrence of Two Rare Diseases: CMV Colitis in a Patient With Clozapine-Included Ischemic Colitis

Abstract

Introduction: CMV (Cytomegalovirus) colitis is a well-recognized disease in immunocompromised patients, however, there are case reports and series describing the disease in immunocompetent hosts. Given its rarity, its characteristics are yet to be well defined. We present a case of CMV colitis in an immunocompetent patient who likely had concomitant ischemic colitis from clozapine. Case Description/Methods: A 68-year-old female with PMH of Schizophrenia on Clozapine, chronic constipation presented to the emergency department with 1 day of bloody diarrhea and NBNB vomiting. On arrival, she was noted to be tachycardic and tachypneic with a physical exam revealing diffuse abdominal tenderness and hypoactive bowel sounds. Initial labs were notable with leukocytosis of 19 K/ul with bands. Serum lactate, renal function, and liver function tests were normal. Clozapine level was elevated at 1143 ng/dl. Computed Tomography Angiography of the abdomen showed severe colitis of the entire descending colon. Working diagnosis at that point was Infectious colitis, inflammatory colitic, and ischemic colitis. She completed 5 days of antibiotics despite negative Gastrointestinal panel PCR with some relief of symptoms. Colonoscopy planned on day 6 was postponed due to acute delirium, which required the initiation of a new anti-psychotic. Colonoscopy on day 28 showed a 10 cm area of non-bleeding ulcerated mucosa at the splenic flexure. Histopathology reports which became available 1 week later showed colonic mucosa with ulceration, granulation tissue, acute inflammation, and rare CMV-positive cells. HIV test which was then obtained was negative, and CMV DNA PCR was 52 IU/ml. She was subsequently started on Valgancyclovir and discharged without any acute events with a plan for a follow-up colonoscopic examination. Discussion: CMV is a common virus with positive serology in upwards of 2-thirds of the general population. However, it rarely manifests in immunocompetent hosts. CMV colitis in immunocompetent hosts has been described mostly as a superinfection in patients with primary gastrointestinal disorders. Destruction of colonic mucosa from the ischemic colitis caused by clozapine likely allowed for CMV to establish the infection in our patient. It is thought that the anticholinergic manifestation in the gastrointestinal tracts which causes constipation and luminal dilation leads to decreased capillary circulation. Treatment usually involves discontinuation of the drug and supportive care.