A Tool to Early Predict Severe 2019-Novel Coronavirus Pneumonia (COVID-19) : A Multicenter Study using the Risk Nomogram in Wuhan and Guangdong, China

Jiao Gong; Jingyi Ou; Xueping Qiu; Yusheng Jie; Yaqiong Chen; Lianxiong Yuan; Jing Cao; Mingkai Tan; Wenxiong Xu; Fang Zheng; Yaling Shi; Bo Hu

The increased RDW in COVID-19 patients may be due to the increased turnover of erythrocytes: 1) Pro-inflammatory states may be responsible for insufficient erythropoiesis with structural and functional alteration of RBC, such as decreased deformability leading to more rapid clearing of RBC. 2) Plasma cytokines such as interleukin 1 (IL-1) and tumor necrosis factor-α (TNF-α) could not only attenuate the renal erythropoietin (EPO) production, but also blunt the erythroid progenitor response to EPO. In addition, INF-γ contributes to apoptosis of the erythroid progenitors and decrease the EPO receptor expression 17 . 3) RBC are dynamic reservoirs of cytokines 18 . Decreased deformability of RBC in severe illness leads to RBC lysis and release of intracellular contents into the circulation 19 , including some inflammatory cytokines. This positive feedback could greatly promote the apparent shortened RBC survival and ultimately more morphological variations in cell sizes (i.e., elevated RDW), increased inflammatory response, and lead to severe illness. RDW can be regarded as an index of enhanced patient fragility and higher vulnerability to adverse outcomes 20 . The elevated RDW may explain fatigue experienced by All rights reserved. No reuse allowed without permission. author/funder, who has granted medRxiv a license to display the preprint in perpetuity.