Haemolysis index conundrum in a COVID-19 patient
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Updated: Jun 25, 2026

Measuring the 50% Haemolytic Complement CH50 Activity of Serum
Published on: March 29, 2010
Chong Qin Michael Zhao1, Jordan Steinberg2, Dennise Otero Espinal3
1Pathology and Laboratory Medicine, Northwell Health North Shore University Hospital, Manhasset, New York, USA.
In this study, we report a preanalytical challenge noted in our laboratory on plasma samples from a critically ill COVID-19 patient treated with hydroxychloroquine. This is significant because, in critically ill COVID-19 patients on hydroxychloroquine, plasma samples can have a high measured haemolysis index in the absence of haemolysis, with the impact on reporting the results for potassium and other analytes.
In this study, we report a preanalytical challenge noted in our laboratory on plasma samples from a critically ill COVID-19 patient treated with hydroxychloroquine. This is significant because, in critically ill COVID-19 patients on hydroxychloroquine, plasma samples can have a high measured haemolysis index in the absence of haemolysis, with the impact on reporting the results for potassium and other analytes.
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