Heparin-induced thrombocytopenia is associated with mortality in critical COVID-19 (preprint)



Sixty-one critical COVID-19 patients admitted to the intensive care unit (ICU) and 93 severe non-ICU patients at Huoshenshan Hospital (Wuhan, China) were included in this study. Medical records, including demographic, platelet counts, heparin-involved treatments, heparin-induced thrombocytopenia-(HIT) related laboratory tests, and fatal outcomes of COVID-19 patients were analyzed and compared between survivors and nonsurvivors.


Sixty-one critical COVID-19 patients treated in ICU included 15 survivors and 46 nonsurvivors. Forty-one percent of them (25/61) had severe thrombocytopenia, with a platelet count (PLT) less than 50×109/L, of whom 76% (19/25) had a platelet decrease of >50% compared to baseline; 96% of these patients (24/25) had a fatal outcome. Among the 46 nonsurvivors, 52.2% (24/46) had severe thrombocytopenia, compared to 6.7% (1/15) among survivors.


Continuous renal replacement therapy (CRRT) [induced] a significant decrease in platelet count in 81.3% of critical CRRT patients (13/16), resulting in a fatal outcome.

Editor’s note: if this preprint is accepted for publication, the publisher will likely suggest that the conclusion above should be softened to ‘associated with’ rather than ‘resulting in’.

In addition, a high level of anti-heparin-PF4 antibodies, a marker of HIT, was observed in most ICU patients. Surprisingly, HIT occurred not only in patients with heparin exposure, such as in CRRT, but also in heparin-naive patients, suggesting that spontaneous HIT may occur in COVID-19.


Anti-heparin-PF4 antibodies are induced in critical COVID-19 patients, resulting in a progressive platelet decrease. Exposure to a high dose of heparin may trigger further severe thrombocytopenia with a fatal outcome. An alternative anticoagulant other than heparin should be used to treat COVID-19 patients in critical condition.

SOURCE: bioRxiv

Editor’s note: Sodium citrate is a circuit anticoagulant often used in CRRT; its use might reduce the incidence of HIT. ‘Preprints’ are released prior to publication, and in many cases, prior to peer review.

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