Objective: To analyze the clinical characteristics of adult patients with phytosterolemia presenting with thrombocytopenia as the initial manifestation. Methods: A retrospective analysis was conducted on eight adult patients with phytosterolemia who visited Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, from December 2020 to December 2023. Results: ① The participants consisted of 2 (25%) male and 6 (75%) female patients, with a median age at diagnosis of 55 years (range: 29-66 years). The median duration from the discovery of thrombocytopenia to diagnosis was 10 years (range: 0.2-50 years). ② Compared with the normal control group (30 healthy adult volunteers) and the immune thrombocytopenia (ITP) control group (20 patients with ITP), patients with phytosterolemia exhibited significantly higher mean platelet volume and large platelet ratio. Peripheral blood smears revealed that the mean platelet diameter and the proportion of large platelets (diameter> 4 μm) were significantly higher in patients with phytosterolemia than those in the normal and ITP control groups (P<0.01). ③ After a low-plant-sterol diet and ezetimibe treatment, five patients demonstrated decreased serum sitosterol and campesterol levels, increased hemoglobin concentration and platelet counts, and reduced platelet volume. Conclusion: Adult-onset phytosterolemia presenting with thrombocytopenia as the initial manifestation is prone to misdiagnosis. The presence of hemolytic anemia, splenomegaly, increased large platelets and schistocytes on peripheral blood smears, and xanthomas are crucial diagnostic indicators. Restricting dietary plant sterol intake and using ezetimibe to inhibit sterol absorption effectively lowers serum plant sterol levels and improves hematological abnormalities.
目的： 分析以血小板减少为首发临床表现的成人植物固醇血症患者的临床特征。 方法： 对2020年12月至2023年12月在华中科技大学同济医学院附属协和医院就诊的8例成人植物固醇血症患者进行回顾性分析。 结果： ①8例植物固醇血症患者中男2例（25%）、女6例（75%），中位诊断年龄55（29~66）岁。发现血小板减少到确诊的中位病程为10（0.2~50）年。②8例患者的平均血小板体积（MPV）和大血小板比例（LPR）明显高于健康对照组（30例成人志愿者）和原发免疫性血小板减少症（ITP）患者（20例），外周血涂片平均血小板直径（MPD）和大血小板（直径>4 μm）比例明显高于健康对照和ITP对照组（P<0.01）。③5例患者接受低植物固醇饮食和依折麦布治疗，血中谷固醇和菜油固醇含量下降，血红蛋白和血小板计数上升，血小板体积下降。 结论： 以血小板减少为首发临床表现的成人植物固醇血症易被误诊；伴溶血性贫血、脾脏肿大，外周血涂片见巨大血小板和口形红细胞增多以及脂黄瘤是诊断该病的重要依据。限制饮食中植物固醇摄入和接受依折麦布治疗可有效降低血中植物固醇含量，改善血液系统异常。.
Keywords: ABCG5 and ABCG8 gene mutations; Ezetimibe; Mean platelet volume; Phytosterolemia.