THE ERA OF HIV-NEGATIVE PNEUMOCYSTIS PNEUMONIA

ABSTRACT

SESSION TITLE Chest Infections in Immunocompromised Patients Case Posters SESSION TYPE Case Report Posters PRESENTED ON 10/17/2022 1215 pm - 0115 pm INTRODUCTION: Pneumocystis pneumonia (PCP) is a life-threatening opportunistic infection caused by Pneumocystis jirovecii. HIV-negative patients with PCP are primarily individuals receiving immunosuppressive therapy for other disease processes. In rare instances, PCP could be an initial manifestation of underlying defected or suppressed cell-mediated immunity that needs to be diagnosed to prevent morbidity and mortality. CASE PRESENTATION 75-year-old female with a history of hypertension and hypothyroidism presented to the emergency department for evaluation of cough, fever, and shortness of breath gradually worsening over the last few weeks. She received outpatient treatment with no improvement. She was vaccinated against covid-19. On presentation, the temperature was 103F, heart rate was 108 bpm, blood pressure was 163/93 mm Hg, and oxygen saturation was 86% on room air. Hemogram showed leukocytosis with left shift with elevated inflammatory markers. Chest X-ray revealed bilateral ground glass opacities. She was started on broad-spectrum antibiotics, but symptoms worsened over the next few days. CT chest showed diffuse bilateral ground glass opacities with prominent interstitial markings. BAL obtained from bilateral upper lobes was lymphocyte predominant with pneumocystis jirovecii diagnosed on Gomori methenamine silver (GMS) staining. She was started on PCP-directed antibiotics with intravenous glucocorticoids, and workup for an underlying immunodeficiency was started. Subsequent BATS biopsy revealed diffuse organizing alveolar damage, with possible associated acute interstitial pneumonia pattern. This could be a rare manifestation of PCP or a primary presentation in the appropriate clinical setting. Autoimmune panel, leukemia, and lymphoma panel came back negative. AFB smear, HIV, EBV, CMV, HTLV I/II also returned negative. The lymphocyte subset panel revealed a CD4 count of 205 and a subsequent count a few days later of 64 with decreased total IgG. The patient was treated with high dose steroids for an extended period along with treatment for PCP however continued to decline clinically. The patient and family eventually decided to pursue comfort care. DISCUSSION: The predisposition to PCP in patients is primarily due to a decrease in cell-mediated immunity regardless of HIV infection. In our patient, the etiology of idiopathic CD4+ T cell lymphocytopenia cannot be determined due to the lack of serial laboratory data measurement. One of the proposed etiologies of ICL is systemic persistent immune activation in the setting of exogenous mRNA, the current technology that is being widely used for vaccine development. CONCLUSIONS: In this era of biotechnology, with advancements in immunosuppressive therapy and mRNA-based vaccines, increased awareness around the potential immune system activation and potential downstream complications needs to be further highlighted to raise awareness among physicians. Reference #1 Li, Y., Ghannoum, M., Deng, C., Gao, Y., Zhu, H., Yu, X., & Lavergne, V. (2017). Pneumocystis pneumonia in patients with inflammatory or autoimmune diseases usefulness of lymphocyte subtyping. International Journal of Infectious Diseases, 57, 108-115. Reference #2 Pardi, N., Hogan, M. J., Porter, F. W., & Weissman, D. (2018). mRNA vaccines - a new era in vaccinology. Nature reviews. Drug discovery, 17(4), 261–279. https//doi.org/10.1038/nrd.2017.243 Reference #3 Vijayakumar, S., Viswanathan, S., & Aghoram, R. (2020). Idiopathic CD4 Lymphocytopenia Current Insights. ImmunoTargets and therapy, 9, 79–93. https//doi.org/10.2147/ITT.S214139 DISCLOSURES No relevant relationships by Santhosh Gheevarghese John No relevant relationships by Konstantin Golubykh No relevant relationships by Iuliia Kovalenko No relevant relationships by Maidah Malik No relevant relationships by Hafiz Muhammad Siddique Qurashi No relevant relationships by Taj Rahman No rel vant relationships by Tabinda Saleem