Serrano-Lorenzo, PabloCoya, Olga NLópez-Jimenez, AnaBlázquez, AlbertoDelmiro, AitorLucia, AlejandroArenas, JoaquínMartín, Miguel ACOVID-19 ’12 Octubre’ Hospital Clinical Biochemistry Study Group2025-01-072025-01-072021-04-212352-5517https://hdl.handle.net/10668/25375We aimed to determine whether the plasma profile of lactate dehydrogenase (LDH) isoenzymes is altered in patients with COVID-19, and whether this is attributable to a specific release of LDH-3, the main LDH isoenzyme expressed in lungs. We collected fresh plasma aliquots from 17 patients (LDH range, 281-822 U/L) and seven controls (LDH ​ Despite the expected higher total LDH activity levels in patients (p ​ ​0.05). We found no correlation between total plasma LDH activity and the in-gel relative activities of the different LDH isoenzymes, including LDH-3. Likewise, there was no correlation between LDH-3 and various routine haematological and serum parameters that have been previously reported to be altered in COVID-19 (such as lymphocyte count, albumin, alanine and aspartate aminotransferase, creatinine, C-reactive protein, or ferritin). Our findings suggest that elevation of plasma LDH activity in patients with COVID-19 is not associated to a specific release of LDH-3 into the bloodstream, and do not support the use of LDH as a specific biomarker for lung affectation in patients with COVID-19.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/COVID-19LDH isoenzymesLactate dehydrogenaseSARS-CoV-2research article33898686open access10.1016/j.plabm.2021.e00226PMC8058053https://doi.org/10.1016/j.plabm.2021.e00226https://pmc.ncbi.nlm.nih.gov/articles/PMC8058053/pdf