Predictive value of megakaryocytes in bone marrow for therapeutic response of severe thrombocytopenia in patients with systemic lupus erythematosus

Abstract

Objective To explore the value of bone marrow megakaryocyte counts in predicting clinical response of thrombocytopenia (TP) in systemic lupus erythematosus (SLE) patients. Methods Thirty-one patients of SLE with severe TP (platelet ≤50×109/L) from Peking Union Medical College Hospital during 2007 to 2014 with appreciable bone marrow aspiration results were retrospectively analyzed. Their therapeutic responses were stratified and the correlation with clinical and laboratory findings including the megakaryocyte counts in bone marrow were evaluated with logistic multivariate regression. Results Totally fifteen patients obtained complete response (CR), eight patients obtained partial response (PR) and eight no response (NR). Megakaryocyte counts in bone marrow were (101±26)/slide, (156±48)/slide and (34±15)/slide respectively with statistically significant difference (χ2=6.632, P=0.036). Those NR patients had less megakaryocytes in their bone marrow compared with those with clinical response (CR + PR) (Z=-2.438, P=0.015). By ROC curve method, we found 20/slide might be a good cutoff of megakaryocyte counts in bone marrow for determining the therapeutic response of immunotherapy with a sensitivity of 91% and a specificity of 63% and a AUC (area under the curve) of 0.793. Those with 20/slide or less megakaryocytes in bone marrows only had a clinical effective response rate of 29% verse a response rate of 88% in those with more megakaryocytes in bone marrow. Conclusion Megakaryocyte counts in bone marrow may provide predictive value for therapeutic response of severe TP in SLE patients. Those patients with equal or less than 20/slide megakaryocytes in their bone marrow tend to have poor therapeutic response. Key words: Lupus erythematosus, systemi; Thrombocytopenia; Megakaryocyte