Predictive effects of IgA and IgG combination to assess pulmonary exudation progression in COVID‐19 patients

Xue, Mingshan; Zhang, Teng; Hu, Haisheng; Huang, Zhifeng; Zhen, Yingjie; Liang, Yueting; Zeng, Yifeng; Jin, Tengchuan; Zhou, Luqian; Zhang, Xiaohua Douglas; Sun, Baoqing

Our study intended to longitudinally explore the prediction effect of IgA on pulmonary exudation progression in COVID‐19 patients. The serum IgA was tested with chemiluminescence method. Autoregressive moving average (ARMA) model was used to extrapolate the IgA levels before hospital admission. The positive rate of IgA and IgG in our cohort was 97% and 79.0%. The IgA was peaked in 10‐15 days after admission, and IgG was peaked at the time of admission time while HRCT and chest PA & LAT (posteroanterior oblique and lateral views) were peaked in 20‐25 days after admission. We found that the time difference between their peaks was about 10 days. Viral RNA detection results showed that the positive rate in sputum and feces were the highest. Blood gas analysis showed that deterioration of hypoxia with the enlargement of pulmonary exudation area. And alveolar‐arterial oxygen difference (A‐aDO(2)) and oxygenation index were correlated with IgA and IgG. The results of biopsy showed that the epithelium of lung was exfoliated and the mucosa was edematous. In severe COVID‐19 patients, the combination of IgA and IgG can predict the progress of pulmonary lesions and is closely related to hypoxemia and both also play an important defense role in invasion and destruction of bronchial and alveolar epithelium by SARS‐CoV‐2. This article is protected by copyright. All rights reserved.