Abnormal Ultrastructure Features on Type II Pneumocytes of COVID-19 Patients with Aplastic Anemia

Aplastic anemia is a rare and severe hematological condition marked by reduced cellularity in the bone marrow and the presence of pancytopenia. Type II pneumocytes—essential for lung function and repair—play a crucial role in pulmonary pathology. Recent studies have identified notable ultrastructural changes in these cells associated with aplastic anemia, particularly in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In patients with aplastic anemia type II pneumocytes display abnormalities in the size and number of lamellar bodies, along with occasional mitochondrial enlargement. Notably, coronavirus disease 2019 (COVID-19) patients with aplastic anemia display both normal and abnormally enlarged lamellar bodies, with giant lamellar bodies ranging from 2.0 to 4.0 μm in size and covering an area of 3.0 to 5.0 μm. However, the number of these giant structures per cell remains low. This chapter highlights the ultrastructural alterations observed in type II pneumocytes of COVID-19 patients with aplastic anemia, offering potential insights into lung involvement during infections. A diagram illustrates SARS-CoV-2 infection in aplastic anemia patients, alveolar changes, virus interaction with pneumocytes, and ultrastructural features. It details the virus internalization process. https://www.w3.org/1999/xlink" content-type="colour" xlink:href=" https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003748908/550bc977-6f4b-4545-82bf-2735acee8d94/content/fig17_504_1_C.jpg "/>