[Marrow megakaryocyte count as a response predictor of severe thrombocytopenia in patients with primary Sjögren syndrome].

Abstract

Objective: To explore the predictive factors for determining the therapeutic response and prognosis of severe thrombocytopenia (TP) in patients with primary Sjögren syndrome(pSS). Method: Patients with pSS and severe TP (platelet count ≤ 50×10(9)/L) admitted between 2010 to 2016 at Peking Union Medical College Hospital were classified according to their therapeutic response and analyzed retrospectively. The response parameters and clinical data including bone marrow aspiration results and laboratory findings were collected. Result: Thirty patients were finally analyzed, including twenty with appreciable bone marrow aspiration results. Fourteen and 7 patients achieved a complete response (CR) and a partial response (PR) respectively, other 9 patients with no response (NR). The megakaryocyte counts in bone marrow (BM-MK) counts per slide in each group were 13.0 (9.2,23.5) in CR patients, 7.0 (7.0,20.0) in PR patients, and 5.0 (1.0,6.0) in NR patients. BM-MK counts in patients with clinical response (CR+PR) were significantly higher than those with NR (P=0.006). A receiver-operation characteristic analysis revealed a cutoff value of BM-MK counts at 6.5 per slide stratifying patients by different responses with a sensitivity of 13/14, a specificity of 6/7, and area under the curve of 0.879. Univariate analysis indicated a better prognosis as BM-MK counts>6.5 per slide. Conclusion: BM-MK count could be a predictive factor of response in patients with pSS and severe TP. Patients with BM-MK counts≤6.5 per slide represent worse platelet improvement..