Cytological Characteristics of Bone Marrow in Sepsis-Associated Thrombocytopenia: A Retrospective Case-control Study

Objective: To compare the cytological characteristics of bone marrow cells in patients with sepsis with or without thrombocytopenia and their clinical significance. Methods: Ninety-one patients diagnosed with sepsis in the Department of General Practice, Sun Yat-sen Memorial Hospital of Sun Yat-sen University between February 2016 and December 2022 were retrospectively recruited in this study, and their clinical parameters, bone marrow smears and examination results, and blood routine examination results were collected. Patients were divided into thrombocytopenia (TP) group and non-thrombocytopenia (non-TP) group according to the count of peripheral blood platelets, the clinical parameters and the cytological characteristics of bone marrow cells were compared between two groups. Results: Hypoplasia of marrow was more frequent in TP group (26.5%, 13/49) compared to the non-TP group (4.8%, 2/42; P = 0.005) and the occurrence of reduced megakaryocyte or dysmaturity was more common in TP group (31/49, 63.3%) compared to that in the non-TP group (13/42, 31.0%; P = 0.002). The number of bone marrow megakaryocytes was positively correlated with the count of peripheral blood platelets in all patients (r = 0.2884, P = 0.0056) and the non-TP group (r = 0.3316, p = 0.0319), but there was no correlation in the TP group; Moreover, the hemoglobin level, the white blood cell, granulocyte, lymphocyte, and monocyte count were lower in TP group than those in non-TP group. Furthermore，a significant higher incidence of MODS was observed in TP group (29/49, 59.2%) compared to non-TP group (14/42, 33.3%; P = 0.014) and the mean SOFA scores in TP group were higher than that in non-TP group (9.69 ± 3.92 vs 7.83±3.87, P = 0.026). Conclusions: The decreased production of platelets, which is secondary to marrow cell failure, is an exact mechanism of sepsis-associatedthrombocytopenia. Thus, precautions and intervention should been taken early during the treatment.