High level of lactate dehydrogenase and ischaemia-reperfusion injury regulate the multiple organ dysfunction in patients with COVID-19

Multiple organ damage has been observed in patients with COVID-19, but the exact pathway is not known. Vital organs of the human body may get affected after replication of SARS-CoV-2, including the lungs, heart, kidneys, liver and brain. It triggers severe inflammation and impairs the function of two or more organ systems. Ischaemia-reperfusion (IR) injury is a phenomenon that can have disastrous effects on the human body. In this study, we analysed the laboratory data of 7052 hospitalised patients with COVID-19 including lactate dehydrogenase (LDH). A total of 66.4% patients were men and 33.6% were women, which indicated gender difference as a prominent factor to be considered. Our data showed high levels of inflammation and elevated markers of tissue injury from multiple organs C reactive protein, white blood cell count, alanine transaminase, aspartate aminotransferase and LDH. The number of red blood cells, haemoglobin concentration and haematocrit were lower than normal which indicated a reduction in oxygen supply and anaemia. On the basis of these results, we proposed a model linking IR injury to multiple organ damage by SARS-CoV-2. COVID-19 may cause a reduction in oxygen towards an organ, which leads to IR injury.