Multiple organ infection and the pathogenesis of SARS

TLDR

The pathogenesis of SARS remains poorly understood despite over 8,000 infections and 700 deaths worldwide. The study proposes a comprehensive theory of SARS pathogenesis emphasizing immune response and lung damage. The authors examined 18 autopsies, 22 confirmed patients’ white blood cells at various disease stages, and T‑cell counts from 65 confirmed and 35 misdiagnosed cases to investigate SARS infection. SARS viral particles were detected in multiple cell types across organs, showing the virus infects diverse cells and that immune cells and pulmonary epithelium are primary injury sites.

Abstract

After >8,000 infections and >700 deaths worldwide, the pathogenesis of the new infectious disease, severe acute respiratory syndrome (SARS), remains poorly understood. We investigated 18 autopsies of patients who had suspected SARS; 8 cases were confirmed as SARS. We evaluated white blood cells from 22 confirmed SARS patients at various stages of the disease. T lymphocyte counts in 65 confirmed and 35 misdiagnosed SARS cases also were analyzed retrospectively. SARS viral particles and genomic sequence were detected in a large number of circulating lymphocytes, monocytes, and lymphoid tissues, as well as in the epithelial cells of the respiratory tract, the mucosa of the intestine, the epithelium of the renal distal tubules, the neurons of the brain, and macrophages in different organs. SARS virus seemed to be capable of infecting multiple cell types in several organs; immune cells and pulmonary epithelium were identified as the main sites of injury. A comprehensive theory of pathogenesis is proposed for SARS with immune and lung damage as key features.