1728. A Retrospective Analysis of 49 Cases of Histoplasmosis in Inflammatory Bowel Disease Patients on Tumor Necrosis Factor-α Antagonists

Background Tumor necrosis factor (TNF)-α antagonist therapy has revolutionized the practice of management of inflammatory bowel disease (IBD); however, these medications carry a boxed warning from the Food and Drug Administration for risk of serious infection. We aimed to study the invasive fungal infection, histoplasmosis, in the setting of TNF-α antagonist therapy. Methods We performed a retrospective review of patients with IBD receiving TNF-α antagonist therapy who developed histoplasmosis during the time period January 2001–May 2018 at the Mayo Clinic, Rochester, MN. The medical records of patients were reviewed for demographics, medications, symptoms, diagnosis, treatment, and outcomes including mortality. IBD was diagnosed by biopsy, radiographic, or endoscopic evidence of disease. Results We identified 49 patients (age range 19–74; median 44 years) with a confirmed diagnosis of histoplasmosis while receiving a TNF-α antagonist. 73.5% of cases were classified as disseminated. Median time from starting TNF-α antagonist to histoplasmosis diagnosis was 2.1 years. Liposomal amphotericin B was given in 17 cases as the initial treatment. Itraconazole was given to all 49 patients. Initial treatment was split evenly between inpatient (49%) and outpatient (51%) locations with 6 patients (12%) requiring ICU-level care. Median length of stay was 9.5 days. The total length of treatment for all antifungals was 38.4 weeks, with 20.4% of patients developing documented antifungal side effects. TNF-α antagonist was continued in 9 patients (18.4%) and another 10 patients resumed TNF-α antagonist. Half of those who resumed TNF-α antagonists were on antifungal therapy. There was one histoplasmosis recurrence while off TNF-α antagonist, and three deaths (6%). Conclusion Histoplasmosis outcomes in IBD patients on TNF-α antagonists were mostly favorable; however, approximately half required hospitalization. Many patients were young with few co-morbidities, and over one-third were able to continue or resume TNF-α antagonists without documented recurrence of histoplasmosis. Practitioners should be vigilant for histoplasmosis infections in this patient population who reside in histoplasma-endemic regions. Disclosures All authors: No reported disclosures.