RADICAL TREATMENT FOR BLASTOMYCOSIS FOLLOWING FAILED LIPOSOMAL AMPHOTERICIN

Abstract

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pulmonary blastomycosis is a respiratory disease that is caused by the fungus Blastomyces, most commonly through inhalation of the fungal spores. Infected individuals typically show symptoms 3 weeks to 3 months after inhalation of these spores. About 50% of patients with pulmonary blastomycosis are asymptomatic. Individuals with severe blastomycosis are initially treated with intravenous antifungal therapy with Amphotericin followed by long-term itraconazole maintenance therapy. CASE PRESENTATION: We present the case of an immunocompetent young male who was diagnosed with pulmonary Blastomyces dermatitidis and had poor clinical response to 10 days of liposomal Amphotericin B (L-AmB). Due to persistent hypoxia and hypoxemia, the patient was endotracheally intubated and extracorporeal membrane oxygenation (ECMO) was initiated. Due to the poor response to L-AmB, L-AmB was discontinued in favor of continuous infusion of amphotericin B deoxycholate (AmB-d). Additionally, the patient was started on a short course of corticosteroids. With the combination of these treatments, the patient had significant clinical improvement. The patient was taken off ECMO on day 9 and extubated on day 12 after the initiation of AmB-d. DISCUSSION: Literature review yielded limited information regarding treating blastomycosis with a continuous AmB-d infusion. To our knowledge, this is the third case reported in the literature of the use of continuous AmB-d infusion for the treatment of severe blastomycosis. ARDS due to blastomycosis has a mortality of up to 80% with the standard of treatment in such severe cases being liposomal amphotericin. Given that ECMO and AmB-d infusion were started concurrently, it is unclear if the significant improvement was due to the decrease in burden on the respiratory system by ECMO or due to AmB-d infusion demonstrating higher effectiveness compared to liposomal amphotericin B, or a combination of both. A case reported by Branick, K et al. discusses a patient on ECMO treated with L-AmB without improvement until AmB-d continuous infusion was started. Even though they attributed the treatment failure to clogging of the ECMO circuit by L-AmB, their belief was that ECMO is not an effective means to treat Blastomycosis and therefore, believed that the patient improvement was solely due to AmB-d infusion. CONCLUSIONS: While L-AmB is considered first line treatment for blastomycosis, the mortality remains high in those with ARDS associated with blastomycosis. This case demonstrates the importance of considering AmB-d in patients with severe blastomycosis who may have poor response to L-AmB. ECMO and steroids were also included in the patient's treatment plan which may have contributed to the patient's improvement. In a disease process with such high mortality rates, the need for continued evaluation of treatment options is crucial given the limited treatment options currently available. REFERENCE #1: Branick K, Taylor MJ, Trump MW, Wall GC. Apparent interference with extracorporeal membrane oxygenation by liposomal amphotericin B in a patient with disseminated blastomycosis receiving continuous renal replacement therapy. Am J Health Syst Pharm. 2019;76(11):810-813. REFERENCE #2: Meyer KC, McManus EJ, Maki DG. Overwhelming pulmonary blastomycosis associated with the adult respiratory distress syndrome. N Engl J Med. 1993;329(17):1231-1236. REFERENCE #3: Lahm T, Neese S, Thornburg AT, Ober MD, Sarosi GA, Hage CA. Corticosteroids for blastomycosis-induced ARDS: a report of two patients and review of the literature. Chest. 2008;133(6):1478-1480. DISCLOSURES: No relevant relationships by Christopher Chew, source=Web Response No relevant relationships by Henry Ogbuagu, source=Web Response No relevant relationships by Dhaval Patel, source=Web Response No relevant relationships by Nikhilesh Thapa, source=Web Response No relevant relationships by Merin Varghese, source=Web Response