C294 - Abdominal Tuberculosis Mimicking Post-Transplant Lymphoproliferative Disorder in Cardiac Recipient

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Author Block: I. L. Ebong¹, M. Chrisant¹, K. Beddows¹, K. Hession¹, M. Foca², ¹Pediatric Cardiology, The Children's Hospital at Montefiore, New York, NY, ²Pediatric Infectious Diseases, The Children's Hospital at Montefiore, Bronx, NY
*Purpose: How to diagnose a challenging patient presentation: Post-transplant Lymphoproliferative Disorder (PTLD) vs Infection.
*Methods: We describe the course of a 22yo male who developed extrapulmonary Mycobacterium Tuberculosis (mTB) post Orthotopic Heart Transplant (OHT).
*Results: Patient was born in West Africa (WA), had OHT in the U.S. at age 15 for thrombotic complications of classic homocystinuria (HCU). Since OHT, he has been maintained on Tacrolimus (Tac) & Everolimus (Evr) for immunosuppression (IS), with intermittently elevated qEBV PCR. He had 1 episode of mild cellular rejection at 1mo post OHT, treated with IV Solumedrol; a 2^nd at 2.5 yrs post OHT treated with increased IS target level. He recently worked in a men’s shelter for 6mos. He presented to the ER with a 3wk history of abdominal pain, diarrhea, poor appetite, and weight loss, but denied fever or recent travel. CT abdomen showed ascites, thickening of the peritoneal surfaces, small bowel & colon, and mesenteric omental caking; findings concerning for PTLD vs infection. . He had elevated inflammatory markers (IM); plasma EBV qPCR was increased- 600 IU/mL; quantiferon negative x2; AFB negative x3. ALC was 1.0 k/µL. Remainder of testing was normal. Ascitic fluid had lymphocytic predominance and elevated total protein. Adenosine deaminase (ADA) was positive with negative AFB smear. CT of the chest and neck showed no evidence of PTLD or active mTB. Tac was held and Basiliximab was initiated as maintenance IS. Evr was continued with a target level of 3.5 ng/mL. He continued his home regimen for HCU. Colonoscopy and biopsy showed multiple ulcerations in the terminal ileum and non-necrotizing granulomas, pending culture for mTB. Tissue EBV level was markedly elevated at 332,000 IU/mg. Given the elevated ADA in ascitic fluid, granulomatous inflammation on colonic biopsy, and history of residence in WA, anti-TB therapy (RIPE regimen: rifampin, isoniazid, pyrazinamide, and ethambutol) was started. Following this, he improved with downtrending IM. Rifampin was switched to Rifabutin due to interaction with Tac. He was sent home after hospital day 25 with outpatient & NYS DOH follow up.
*Conclusions: The diagnosis of PTLD vs abdominal mTB in solid organ transplant recipients is challenging especially with elevated EBV PCR and chronic IS. Here, clinical improvement with RIPE therapy and a positive colonic culture confirmed extrapulmonary mTB. Prompt recognition and treatment are essential to prevent morbidity and mortality.