Human Polyomavirus 7 and WU Polyomavirus-Associated Lymphocytic Bronchitis/Bronchiolitis in Native and Allograft Lung Biopsies From Immunocompromised Patients: Report of 3 Cases and Review of Literature

Abstract

Abstract Human polyomavirus (PyV) family comprised 13 DNA viruses, which cause subclinical infection in more than 90% of the general population. However, significant disease including cancer is mainly observed in immunosuppressed patients. Few studies have investigated the detection of PyV in the respiratory tract. In this report, 3 transbronchial biopsies showed viral inclusions on histologic examination and were evaluated for anti-SV40 large T antigen (SV40 T Ag) by immunohistochemistry (IHC), in situ hybridization, and viral genome sequencing by polymerase chain reaction. Patients 1 and 2 were immunosuppressed lung transplant recipients. Patient 1 presented with diffuse pruritic rash and respiratory failure, and patient 2 with PyV viremia. Patient 3 had chronic lymphocytic leukemia/small lymphocytic lymphoma and presented with cough and shortness of breath. Histologic examination of all 3 lung biopsies were similar and revealed predominantly bronchial epithelial cells with enlarged nuclei, smudgy chromatin quality, and lymphocytic bronchitis/bronchiolitis with a patchy alveolar septal mononuclear infiltrate. SV40 large T antigen IHC was positive in all cases, whereas in situ hybridization for BK and JC virus was negative. Polymerase chain reaction sequencing identified PyV7 in case 1 and WUPyV in cases 2 and 3. We describe for the first time that PyV7 and WUPyV may be associated with lymphocytic bronchitis/bronchiolitis in the lungs of immunosuppressed individuals. It is important to be cognizant of the cross-reactivity of SV40 T Ag IHC with other types of PyV and equally essential to distinguish PyV bronchitis from other viral pathogens.