University of Arizona College of Medicine Phoenix, AZ
Anam Omer, MD1, Adriana Gaidici, MD2, Rashmi Kumar, MD1; 1University of Arizona College of Medicine, Phoenix, AZ; 2Banner University Medical Center, Phoenix, AZ
Introduction: Mycobacterium avium complex (MAC) colitis is a rare complication of immunosuppression in solid organ transplant (SOT) recipients. Here, we describe a case of disseminated MAC infection with colitis following simultaneous pancreas-kidney (SPK) transplantation.
Methods: A 54-year-old female was admitted to the hospital with a two-month history of watery diarrhea, intermittent nausea and unintentional weight loss of 40-pounds. She was recently discharged after a prolonged hospital stay for management of acute diarrhea and was diagnosed with recurrent Clostridium difficile Infection (CDI) that required multiple courses of fidaxomicin as she was intolerant to vancomycin. Past medial history included SPK transplant 4 years ago complicated by allograft rejection, CMV viremia and recurrent CDI. Her immunosuppressive regimen included mycophenolic acid, sirolimus, prednisone, and tacrolimus with therapeutic range drug levels. Laboratory examination was remarkable for leukopenia of 1.7 x 109/L with absolute neutrophil count (ANC) of 1300 cells/µL and otherwise normal chemistries. Initial infectious work-up unremarkable including CMV PCR, BK Virus PCR, C diff toxin and antigen and infectious stool studies. Computed tomography showed mild esophageal thickening without any colitis. Colonoscopy showed few patchy erosions dispersed throughout the colon. Histologic examination of random colon biopsies revealed poorly formed granulomas that stained positively for acid fast bacilli (AFB). Esophagogastroduodenoscopy was unremarkable except LA grade D esophagitis and biopsies were obtained from the duodenum. Interestingly, these duodenal biopsies also showed granulomas that stained positive for AFB. AFB culture performed on all specimens was positive for MAC. MAC was also isolated from urine and stool cultures that were reported later. Patient was started antimicrobial therapy with ethambutol, rifampin, and azithromycin guided by infectious disease specialist with resolution of diarrhea and weight gain. Discussion: MAC infections are well established in acquired immunodeficiency virus infection, but remain rarely reported in SOT recipients. Moreover, disseminated MAC presenting as diarrhea is even more uncommon. The causes of diarrhea are exhaustive in patients on immunosuppression and hence it is important to keep MAC in the differential as its diagnosis is challenging and requires tissue sampling with culture and gene sequencing. Antimicrobials provide effective treatment and eradication.
Disclosures: Anam Omer indicated no relevant financial relationships. Adriana Gaidici indicated no relevant financial relationships. Rashmi Kumar indicated no relevant financial relationships.