Correlation between hypophosphatemia and the severity of Corona Virus Disease 2019 patients

Xiaobo Xue; Jing Ma; Yuxia Zhao; Aibin Zhao; Xiaohong Liu; Wei Guo; Fang Yan; Zhixin Wang; Yanqing Guo; Mengbai Fan

The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.27.20040816 doi: medRxiv preprint Pathological anatomy of a patient with COVID-19 revealed that the patient's lymphocytes were over-activated, and the highly pro-inflammatory CCR4 + CCR6 + Th17 cells increased, which partially explained the severe immune damage to the lung of neocoronary pneumonia 17 . In this study, 85% of patients with severe/critical type had lymphocyte absolute value lower than the reference range, and the lymphocyte level of patients with severe/critical type was lower than that of patients with normal patients. Studies have shown that the immune function of elderly patients with severe pneumonia is significantly lower than that of their healthy peers, while the immune function of patients with hypophosphatemia is lower and generally in the state of immunosuppression. Studies have found that serum phosphorus in elderly patients with severe pneumonia is positively correlated with the ratio of CD4+ / CD8+ 18 . Our study also showed that there was a positive correlation between the absolute value of lymphocyte and the level of serum phosphorus, so the timely treatment with phosphorus supplementation for severe patients with low phosphorus may improve their immune level and promote their recovery. The decrease of blood phosphorus level in clinical practice is commonly seen in chronic diseases such as fasting, malnutrition, parenteral nutrition 19 , metabolic or respiratory alkalosis, diabetic ketoacidosis, alcoholism, chronic alcohol withdrawal, and inadequate phosphorus intake without timely supplementation [20] [21] . Most of the severe/critical COVID-19 patients mentioned in our study were middle-aged, with an overweight BMI and few underlying diseases, and a decrease in blood phosphorus levels was detected 1-10 days after admission. It is more likely that novel coronavirus invades human body, causing a strong stress response and the release of inflammatory factors. On the one hand, gastrointestinal function decline or gastrointestinal mucosal cell integrity and barrier function is impaired, resulting in a reduction in phosphorus intake from food. On the other hand, stress response leads to increased secretion of epinephrine, glucagon, etc., and severely reduced utilization of intracellular phosphorus, leading to the migration of a large amount of phosphorus into the cell to participate in energy metabolism 22 . In addition to following the treatment of COVID-19 (trial version fifth), we also treated patients with hypophosphatemia with phosphorus supplementation. With the recovery of the disease and the transformation of the viral nucleic acid, the blood phosphorus level and the absolute value of lymphocytes in the majority of severe/critical patients returned to normal. In this process, is it caused by exogenous supplement or redistribution of phosphorus inside All rights reserved. No reuse allowed without permission. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.