Pathological and immunohistochemical findings of lungs, heart, liver, and kidneys, and unexpected findings of fungi and parasites in lungs of deceased COVID-19 patients: A case series

Abstract

Objective: To define histopathologic and immunohistochemical features of the lungs, heart, liver, and kidneys in patients who died from coronavirus disease 2019 (COVID-19), and to determine the presence of SARS-CoV-2 in all tissues, as well as the presence of fungi and parasites in lung tissues. Methods: This retrospective case study was conducted in the intensive care units of Dokuz Eylül University Hospital, and patients (≥18 years) who died due to COVID-19 between October 2020 and April 2021 were included. The biopsy samples of the patient's lung, heart, liver, and kidney tissues were studied. Results: In the study, we enrolled 12 patients (mean age: 70 years; 50% male). Alveolar epithelial cell damage and diffuse alveolar damage were predominant in lung tissues. Lobular lymphocyte infiltration, centrilobular sinusoidal dilatation, and microvesicular steatosis in the liver, together with pigmented cast, non-isometric vacuolar degeneration, and capillary plugging in the kidneys, were commonly found among the patients. SARS-CoV-2 nucleocapsid protein antibodies were detected in three lung and two kidney tissues, and so did angiotensin-converting enzyme 2 receptor positivity in one lung and more than half of the kidney tissues. The RT-PCR tests were positive in three lungs and one kidney tissue. After DNA isolation from lung tissues, Pneumocystis jirovecii was detected in nine patients, Aspergillus fumigatus in two, Microsporidia in three, and Cryptosporidium in two. Conclusions: SARS-CoV-2 is a multisystemic disease. Fungi and parasites should be investigated in critically ill COVID-19 patients prescribed corticosteroids.