RT Journal Article T1 Plasma LDH: A specific biomarker for lung affectation in COVID-19? A1 Serrano-Lorenzo, Pablo A1 Coya, Olga N A1 López-Jimenez, Ana A1 Blázquez, Alberto A1 Delmiro, Aitor A1 Lucia, Alejandro A1 Arenas, Joaquín A1 Martín, Miguel A A1 COVID-19 ’12 Octubre’ Hospital Clinical Biochemistry Study Group, K1 COVID-19 K1 LDH isoenzymes K1 Lactate dehydrogenase K1 SARS-CoV-2 AB We 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. SN 2352-5517 YR 2021 FD 2021-04-21 LK https://hdl.handle.net/10668/25375 UL https://hdl.handle.net/10668/25375 LA en DS RISalud RD Apr 4, 2025