S3377 Atypical Disseminated Mycobacterium Avium Complex: A Rare Case of Chronic Severe Diarrhea in a Patient with HIV

Introduction: The global use of highly active antiretroviral therapy (HAART) has led to a dramatic decline in the incidence of disseminated Mycobacterium Avium Complex (MAC) to ≤ 2 cases per 1000 person-years. We present a unique case of chronic diarrhea secondary to disseminated MAC which was initially thought to be cytomegalovirus(CMV) viremia. Case Description/Methods: A 41-year-old man with Human Immunodeficiency Virus(HIV)presents with progressively worsening loose, non-greasy, non-bloody, non-mucoid diarrhea for 6 weeks. Associated with recent 10-pound unintentional weight loss, and dyspnea. Outside records report splenectomy for a splenic rupture with tissue culture positive for acid-fast bacilli(AFB) non-Mycobacterium tuberculosis, non-MAC by PCR 3 months prior, started on therapy but reports nonadherence. Cachectic, hypotensive, tachycardic, tachypneic on exam. Labs showed hemoglobin 6.9 gm/dl, MCV 79.5 FL, platelets of 138,000/microL, pre-renal AKI with creatinine 1.36 mg/dl, lactic acid of 3.0mMol/L, and albumin of 2.1 gm/dl . WBC, bilirubin, ALT, AST, and ALP were normal. Extensive lab workup showed low CD4 count of 7 cells/uL, and high CMV PCR at 4,068 IU/mL. Qualitative fecal fat positive. Negative blood cultures, fungal culture, mycobacterial blood, and sputum cultures. Negative stool testing for Clostridium difficile, fecal leukocyte antigen, cryptosporidium, Giardia antigen, Salmonella, Shigella, Campylobacter species, ova and parasites. CT abdomen/pelvis showed a loculated fluid collection in the splenic bed that was drained with negative cultures. On EGD and colonoscopy, the duodenum and terminal ileum (TI) had petechial lesions which on pathologic examination revealed diffuse AFB and villous blunting in TI. Normal colonic biopsies. Biopsies were negative for CMV, celiac disease, and Whipple's disease. Diagnosed with disseminated atypical MAC(most likely M. kansasii) in the setting of HIV-AIDS. CMV viremia was thought to be an incidental finding without GI manifestations. Treatment for disseminated MAC with ethambutol, isoniazid, rifampin, azithromycin, pyridoxine, and for HIV with Dolutegravir & Truvada started. However, he deteriorated despite treatment and died from multi-organ failure 16 days later. (Figure) Discussion: Diarrhea, a common gastrointestinal symptom in AIDS, has many etiologies. DMAC is associated with higher morbidity and mortality. So physicians must be familiar with the causes and utilize endoscopic interventions as needed for effective diagnosis and treatment in AIDS patients.Figure 1.: Petechial lesions in the terminal ileum noted on endoscopy.