本研究旨在探讨血小板增多症的脊柱关节炎（SpA）患者的临床、实验室和放射学特征，探索SpA患者血小板增多的危险因素，评估抗肿瘤坏死因子-α（抗TNF-α）治疗对SpA患者血小板计数的影响。共纳入145名SpA患者，其中76名患者无血小板增多，69名患者有血小板增多，其中38名接受了抗TNF-α治疗。进行Logistic回归分析，以探究与血小板增多相关的危险因素。收集了血小板增多组在第0周、第6周和第12周接受抗TNF-α治疗的患者的血小板计数，并与接受传统治疗组进行比较。血小板增多组臀部受累比例（60.86% vs 36.84%, p = 0.004）、巴思可弯曲性脊柱炎疾病活动指数评分（4.24 ± 0.55 vs 3.69 ± 0.67，p < 0.001）、红细胞沉降率（62.22 ± 41.97 mm/hour vs 27.00 ± 25.93 mm/hour，p < 0.001）、C-反应蛋白（53.45 ± 47.45 mg/L vs 18.91 ± 31.09 mg/L，p < 0.001）、纤维蛋白原（5.77 ± 1.48 g/L vs 4.01 ± 1.32 g/L，P < 0.001）、白细胞（8.15 ± 1.90 × 109/L vs 6.85 ± 2.39 × 109/L，p < 0.001）和中性粒细胞（5.08 ± 1.55 × 109/L vs 4.01 ± 2.04 × 109/L，p = 0.001）较高，而血红蛋白和白蛋白较非血小板增多组低（122.88 ± 17.25 g/L vs 131.51 ± 16.03 g/L，p = 0.002；37.19 ± 4.73 g/L vs 39.67 ± 3.99 g/L，p = 0.001）。多元Logistic回归分析表明，SpA患者中较高的白细胞（OR，1.644；95% CI，1.045-2.587；P = 0.032）和纤维蛋白原（OR，2.169；95% CI，1.237-3.804；P = 0.007）与血小板增多独立相关。血小板增多组接受抗TNF-α治疗的患者在第6周和第12周的血小板计数与第0周相比降低得更多（225.05 ± 60.58 × 109/L vs 368.26 ± 54.34 × 109/L，p < 0.001；201.26 ± 51.48 × 109/L vs 368.26 ± 54.34 × 109/L，p < 0.001），与传统治疗组相比（第6周，225.05 ± 60.58 × 109/L vs 370.00 ± 74.05 × 109/L，p < 0.001；第12周，201.26 ± 51.48 × 109/L vs 303.13 ± 71.49 × 109/L，p < 0.001）。 SpA患者中具有血小板增多较高的臀部受累比例和疾病活动。SpA患者的较高白细胞和纤维蛋白原是血小板增多的潜在风险因素。与传统治疗相比，抗TNF-α治疗可以更有效和迅速地降低SpA患者血小板计数。©2023.作者。

This study aimed to investigate the clinical and laboratory as well as radiological features of spondyloarthritis (SpA) patients with thrombocytosis and to explore risk factor for thrombocytosis in SpA patients and to assess the effect of antitumor necrosis factor-α (anti-TNF-α) therapy on platelet count in SpA patients with thrombocytosis.A total of 145 patients with SpA were included in this study, and non-thrombocytosis was identified in 76 patients while thrombocytosis was found in 69 patients, 38 out of the 69 patients received anti-TNF-α therapy. Logistic regression analysis was performed to investigate risk factors that associated with thrombocytosis. The platelet count of patients in the thrombocytosis group treated with anti-TNF-α therapy on week 0, week 6 and week 12 were collected and compared with conventional therapy group.The proportion of hip involvement (60.86% vs 36.84%, p = 0.004), bath ankylosing spondylitis disease activity index score (4.24 ± 0.55 vs 3.69 ± 0.67, p < 0.001), erythrocyte sedimentation rate (62.22 ± 41.97 mm/hour vs 27.00 ± 25.93 mm/hour, p < 0.001), C-reactive protein (53.45 ± 47.45 mg/L vs 18.91 ± 31.09 mg/L, p < 0.001), fibrinogen (5.77 ± 1.48 g/L vs 4.01 ± 1.32 g/L, P < 0.001), white blood cells (8.15 ± 1.90 × 109/L vs 6.85 ± 2.39 × 109/L, p < 0.001) and neutrophils (5.08 ± 1.55 × 109/L vs 4.01 ± 2.04 × 109/L, p = 0.001) are higher in thrombocytosis group, but hemoglobin and albumin are lower compared to non-thrombocytosis group (122.88 ± 17.25 g/L vs 131.51 ± 16.03 g/L, p = 0.002; 37.19 ± 4.73 g/L vs 39.67 ± 3.99 g/L, p = 0.001, respectively). Multivariable logistic regression analysis indicated that higher white blood cells (OR, 1.644; 95% CI, 1.045-2.587; P = 0.032) and fibrinogen (OR, 2.169; 95% CI, 1.237-3.804; P = 0.007) were independently associated with thrombocytosis in SpA patients. The platelet count in the thrombocytosis group treated with anti-TNF-α therapy on week 6 and week 12 were statistically lower than week 0 (225.05 ± 60.58 × 109/L vs 368.26 ± 54.34 × 109/L, p < 0.001; 201.26 ± 51.48 × 109/L vs 368.26 ± 54.34 × 109/L, p < 0.001) and conventional therapy (week 6, 225.05 ± 60.58 × 109/L vs 370.00 ± 74.05 × 109/L, p < 0.001; week 12, 201.26 ± 51.48 × 109/L vs 303.13 ± 71.49 × 109/L, p < 0.001).SpA patients with thrombocytosis have a higher proportion of hip involvement and disease activity compared to non-thrombocytosis SpA patients. The potential risk factors for thrombocytosis in SPA patients were higher white blood cells and fibrinogen. Anti-TNF-α therapy can reduce the increased platelets more effectively and rapidly than conventional treatments in SpA patients with thrombocytosis.© 2023. The Author(s).