A Case of COVID19 Followed by PCP Pneumonia in an Immunocompromised Host

Abstract

Here we present a case of a middle-aged female with extensive past cardiac history, on methotrexate, who presented with respiratory failure. The case illustrates the complicated diagnostic struggles that clinicians have encountered during the pandemic and provokes the possibility of COVID19 as a potential risk factor for PCP pneumonia. A 62-year-old female presented to a New York City Hospital in July 2020 with hypoxic respiratory failure. She had a past medical history of coronary artery disease s/p stent and CABG, rheumatoid arthritis on methotrexate, hypertension, hyperlipidemia, diabetes mellitus, and chronic kidney disease. She was s/p a two month course of antibiotics for sternal wound infection. At presentation, her SpO2 was 75% on room air. She endorsed worsening shortness of breath for 3 weeks. Admission labs were significant for GFR=20, elevated LFTs 2-3xULN, CRP=19.2, troponin=0.5, BNP=45,000 and ANC=1.1. Chest x-ray demonstrated perihilar infiltrates sparing the left upper lobe. She was placed on bipap. COVID19 nasal swab was negative, antibodies were positive. She was intially treated for CHF exaccerbation. During the course of admission, she developed worsening hypoxemia requiring intubation and shock requiring vasopressors. She underwent bronchoscopy with BAL, which revealed lymphocyte count of 42% suspicious for methotrexate toxicity. Steroids were initiated for the treatment of both potential COVID19 and methotrexate toxicity. She developed progressive white out leading to pneumothoraces requiring chest tube insertion. The patient expired. Culture from BAL eventually grew PCP. This patient's case was extremely challenging and introduces thought-provoking questions regarding cooccurrence of PCP and COVID19. There have been a few case reports of PCP coinfection with COVID19. These infections can have significant overlap in terms of the initial imaging and symptoms (bilateral ground glass opacities associated with progressive hypoxemia over weeks). Bronchoscopy is useful for confirming PCP amidst this diagnostic challenge. There has been speculation that lymphopenia associated with COVID19 may result in susceptibility to PCP. PCP infections have commonly been associated with lymphopenia (low CD4) in HIV patients. Most viral infections can predispose patients to fungal and bacterial super-infection. This case raises the question of whether PCP prophylaxis may be considered in patients with COVID19 and other risk factors for development of PCP, such as immunosuppression.