SESSION TITLE: Monday Fellow Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: Solid organ transplants (SOT) are increasing worldwide so there is a growing number of patients living with chronic immunosuppression. Due to operative advances, opportunistic infections are one of the main issues facing these patients. We had a complicated case of Histoplasmosis after SOT that was further convoluted by immune reconstitution inflammatory syndrome (IRIS). CASE PRESENTATION: 41-year-old woman with type 1 diabetes mellitus and end-stage renal disease received pancreas kidney transplant. Months later she had developed fevers to 40 degrees C, malaise, cough, exertional dyspnea, and arthralgias. Initial evaluation noted pancytopenia and negative chest x-ray. Workup for infectious source was unrevealing. Then oxygen saturations decreased marginally and CT chest showed groundglass opacities, patchy consolidation, centrilobular nodules, and necrotic mediastinal lymphadenopathy. Bronchoalveolar lavage smear, culture, and cytology all revealed Histoplasma capsulatum. She was given itraconazole with rapid improvement in oxygen saturation, fever curve, and symptoms. Insurance issues arose after discharge and she was without antifungals for several days. Then despite resuming itraconazole for several days, she had recurrence of her prior symptoms, plus headache and disequilibrium. On repeat presentation she was hypotensive and there was concern for meningitis, so empiric antimicrobials and antifungals were initiated, immunosuppressants were held, and lumbar puncture was obtained. CSF was not consistent with meningitis so amphotericin was continued alone. Despite amphotericin for known Histoplasmosis, she continued to spike fevers and her oxygen requirements climbed from 21% to 100%. Extensive infectious workup only revealed CSF culture and resected lymph node both positive for Histoplasma. She was started on steroids for IRIS with rapid improvement in symptoms, fever curve, and oxygen requirements. She was discharged on room air. DISCUSSION: IRIS is a shift towards inflammatory state and paradoxical worsening with known infection or unmasking of hidden infections upon changes in a patient’s immune system. It is well-recognized in patients with HIV starting antiretroviral therapy, however there are reports in HIV-uninfected patients. Post-transplant IRIS is believed due to the proinflammatory state that comes from both the withdrawal of iatrogenic immunosuppressive agents and the employment of antimicrobial therapy. Risk factors include higher levels of immunosuppressive therapy and disseminated infection. CONCLUSIONS: Our patient developed post-SOT disseminated Histoplasmosis, complicated by non-HIV IRIS. This provides a reminder of the importance of differential diagnoses and multi-disciplinary care for complex patients, as inflammatory responses after transplantation are altered due to immunosuppression and may represent a wide array of pathologies. Reference #1: Alhyraba, M, et al. "A Multicenter Study of Histoplasmosis and Blastomycosis After Solid Organ Transplantation.” Transplant Infectious Disease : an Official Journal of the Transplantation Society, vol. 14, no. 1, 2012, pp. 17-23. [PMID:21749587] Reference #2: Kauffman, Carol A.. "Diagnosis of Histoplasmosis in Immunosuppressed Patients.” Current Opinion in Infectious Diseases, vol. 21, no. 4, 2008, pp. 421-5. [PMID:18594296] Reference #3: Sun H-Y, Singh N. “Opportunistic Infection-Associated Immune Reconstitution Syndrome in Transplant Recipients.” Clinical Infectious Diseases. 2011;53(2):168-176. https://doi.org/10.1093/cid/cir276. DISCLOSURES: No relevant relationships by Emily Amin, source=Web Response No relevant relationships by Galyna Clous, source=Web Response No relevant relationships by Rachel Quaney, source=Web Response