Coronavirus disease 2019 in a patient with pulmonary fibrosis and emphysema: An autopsy report.

Various diseases (e.g., hypertension and diabetes) are risk factors for the exacerbation of coronavirus 2019 (COVID-19). Patients with chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) tend to develop severe COVID-19. Patients with severe COVID-19 present with acute respiratory distress syndrome (ARDS), and many COVID-19-related ARDS survivors eventually develop fibrosis. However, the appropriate management of patients with COVID-19 and ILD and post-COVID-19 ILD remains unclear. Thus, a better understanding of the pathology that exacerbates COVID-19 in patients with ILD is needed. We report the autopsy results of a patient with COVID-19 and combined pulmonary fibrosis and emphysema, whose lung organization and fibrosis progressed after the acute phase of infection. Histopathological findings suggest that fatal pulmonary fibrosis persists after the negative conversion of SARS-CoV-2. Elucidating the cause of death by autopsy may help determine therapeutic strategies in patients with COVID-19 and ILD. Vaccination and early administration of anti-inflammatory drugs or antifibrotic agents may be crucial for preventing disease progression and fatal lung fibrosis. This report aims to clarify the histopathological features of COVID-19 in patients with ILD via autopsy and discuss treatment strategies.

Insight of diagnostic performance using B-cell epitope antigens derived from triple P44-related proteins of Anaplasma phagocytophilum.

Human granulocytic anaplasmosis (HGA) is caused by Anaplasma phagocytophilum. Indirect immunofluorescence assay (IFA) is generally used for HGA serodiagnosis. A. phagocytophilum immunodominant P44 major outer membrane proteins are encoded by p44/msp2 multigene family, responsible for IFA reactivity. However, because multiple P44-related proteins may involve immunoreactivity in IFA, the available diagnostic antigens remain obscure. In this study, we identified 12 B-cell epitopes on triple P44-related proteins using peptide array that reacted with 4 HGA patients' sera. Then, peptide spot immunoassay using 14 synthetic peptides derived from those 12 epitopes as antigens was applied for the detection of antibody to A. phagocytophilum from patients with fever of unknown origin. The sensitivities and diagnostic efficiencies of this immunoassay were higher than those of Western blot analysis using 3 recombinant proteins previously developed. Thus, the immunoassay using our epitope-derived antigens, which has higher diagnostic performances, may have significant benefit for HGA serodiagnosis.