Chronic liver disease increases the risk of linezolid-related thrombocytopenia in methicillin-resistant Staphylococcus aureus-infected patients after digestive surgery

Linezolid is an effective antibiotic for treatment of infections caused by resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). However, thrombocytopenia has been reported in a certain proportion of patients receiving linezolid treatment. We investigated the risk factors for linezolid-related thrombocytopenia in MRSA-infected patients after digestive surgery. Forty-three patients who were treated with linezolid for postoperative MRSA infection were enrolled. We compared the characteristics of the patients who developed thrombocytopenia during linezolid therapy with those of the patients who did not. Thrombocytopenia was defined as a platelet ratio (post/pre-treatment with linezolid) of <0.7. Twenty-one (48.8%) patients developed thrombocytopenia. In univariate analysis, long treatment duration, high pre-treatment levels of total-bilirubin and transaminases, and the coexistence of chronic liver disease (CLD) were found to be significant risk factors for development of thrombocytopenia. Other factors, for example pre-treatment platelet count, serum creatinine and albumin levels, and previous hepatic resection were not associated with thrombocytopenia. In the multivariate regression analysis, only CLD remained as an independent factor associated with thrombocytopenia. In addition, thrombocytopenia was more common among patients with indocyanine green retention at 15 min (ICG-R15) of more than 10% than in those with an ICG-R15 of 10% or less. Our results suggest that patients with CLD are at high risk of developing linezolid-related thrombocytopenia. Therefore, they should be targeted for more intense platelet count monitoring during linezolid therapy.