Pneumocystis Jirovecii Pneumonia in Immunocompetent Japanese Male

Abstract

SESSION TITLE: Unusual Pulmonary Infections SESSION TYPE: Global Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Pneumocystis jiroveci pneumonia (PCP) is a common opportunistic infection in acquired immune deficiency syndrome (AIDS) patients. The risk factors are low CD4+ lymphocyte count (in HIV patients), underlying malignancies, organ transplantation or immunosuppressive medications. PCP without those risk factors is extremely rare. We herein report a case of PCP in an immunocompetent patient. CASE PRESENTATION: A 37-year-old Japanese male presented with a non-productive cough for two weeks. He had a history of intracerebral hemorrhage at the age of two. He had never smoked and drunk alcoholic beverages. Initial vital signs were almost unremarkable other than low oxygen saturation (93% in room air). Physical examinations were unremarkable. Chest radiograph revealed a diffuse airspace consolidation on the both lungs. Chest computed tomography (CT) scan revealed bilateral airspace consolidation, ground-glass opacity, and traction bronchiectasis on the upper lobes. Laboratory tests were remarkable for the elevated white blood cell (8,850/mm3), lactate dehydrogenase (425 U/l), C-reactive protein (9.18 mg/dl), KL-6 (2,940 U/ml), and decreased total protein (5.3 g/dl) and albumin (2.1 g/dl). Serum rheumatoid factor and anti-nuclear antibody were negative. Serum levels of immunoglobulin A, G and M were within normal range. Sputum and blood culture did not yield any organisms, and the patient underwent bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB). The cytological analysis of BAL fluid (BALF) was unremarkable, and routine cultures of BALF were negative. TBLB sample from the right upper lobe revealed alveolar septal thickening by chronic inflammatory cells infiltration with collagen-type fibrosis. From these results, the patient was diagnosed with acute exacerbation of chronic fibrosing interstitial pneumonia, and received intravenous levofloxacin with corticosteroid pulse therapy followed by a prednisolone maintenance therapy. On the 5th day of the treatment, his respiratory condition worsened and cyclophosphamide (500 mg/body) was added intravenously. On the same day, the additional laboratory examination revealed an elevated serum β-D glucan level (104.3 pg/ml), and voriconazole and sulfamethoxazole trimethoprim were started. The additional HIV antibody test was negative. Despite the anti-fungal therapy, he died on the 12th day due to respiratory failure. Autopsy revealed alveolar spaces filled with foamy amorphous material composed of abundant numbers of cystic forms of Pnemocystis jirovecii and cell debris, and also inflammatory reaction with hyaline membranes. Retrospectively, Gomori-Grocott’s methenamine silver-nitrate staining of the BALF and TBLB samples obtained on the admission day revealed a little amount of cystic forms of Pneumocystis jirovecii, therefore, it was thought that he had been PCP from the admission day. DISCUSSION: PCP in patients without underlying immunosuppressive diseases is exclusively rare, and to our best knowledge, only 19 cases have been reported to date. In Cano’s case series, two patients had previous or simultaneous infection by another microorganisms, and they speculated that a transitory alteration in the immunocompetency condition due to a previous or concomitant infection of PCP might develop. However, our patient did not show the evidence of infection other than Pneumocystis jirovecii. In our patient, we finally suspected PCP from the resistance immunosuppressive therapy and the elevated β-D glucan level, and it is thought that we should perform the Gomori-Grocott’s methenamine silver-nitrate staining of BALF, retrospectively. CONCLUSIONS: We experienced a case of PCP without any underlying risk factors. Although this condition is exclusively rare, but it may be necessary to perform serum β-D glucan assay and Gomori-Grocott’s methenamine silver-nitrate staining of BALF in patients with diffuse ground-glass opacity, regardless of immune status. Reference #1: Palella Jr FJ, Delaney KM, Moorman AC, et al. Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. New England Journal of Medicine. 1998;338(13):853-60. Reference #2: Jacobs JL, Libby DM, Winters RA, et al. A cluster of Pneumocystis carinii pneumonia in adults without predisposing illnesses. New England Journal of Medicine. 1991;324(4):246-50. Reference #3: Koshy G, Koshy JM, John M, Deodhar D. Pneumocystis jirovecii pneumonia in an immunocompetent host. Annals of Tropical Medicine and Public Health. 2015;8(4):122. DISCLOSURE: The following authors have nothing to disclose: Masanobu Okahisa, Kazunori Tobino No Product/Research Disclosure Information