Effect of Virus Inactivation by Heating on Routine Clinical Laboratory Indicators in Serum

Highly infectious viruses such as SARS-CoV-2, MERS-CoV, and Ebola virus represent a threat to clinical laboratory workers. We aimed to investigate how virus inactivation by heating at 60°C for 1 hour affects routine clinical laboratory indicators.

Each collected serum sample was separated into two aliquots, and various indicators were measured in first aliquot after inactivation by heating at 60°C for 1 hour and in the second after room-temperature incubation for 1 hour.

Serological test results for 36 indicators remained mostly unaffected by heat inactivation, with a mean estimated bias of < 10%. By contrast, the results for alanine transaminase, pseudocholinesterase, creatine kinase, lactate dehydrogenase, cardiac troponin I, and myoglobin were affected by heat inactivation, with the mean esti-mated bias here being > 20%, which was further increased in the case of the results for alkaline phosphatase, lipase, and creatine kinase isoenzyme MB. Immunological serological measurements showed good agreement according to Kappa consistency checks after heat inactivation of serum. The results for alanine transaminase, pseudocholinesterase, creatine kinase, lactate dehydrogenase, cardiac troponin I, and myoglobin were significantly correlated (r > 0.95) after heat inactivation, and after correction by using a regression equation, the results for the indicators still retained a clinical reference value.

Inactivation by heating at 60°C for 1 hour exerts no marked effect on numerous routine biochemical and immunological indicators in serum, but the detection values for certain items are significantly decreased. Our method could serve as reference strategy for routine serological diagnostics in patients with suspected or confirmed infection with highly pathogenic viruses.