Clinical characteristics of sitosterolemic children with xanthomas as the first manifestation. Clinical characteristics of sitosterolemic children with xanthomas as the first manifestation

Background: Sitosterolemia (STSL) is an extremely rare genetic disease. Xanthomas as the first symptom is frequently misinterpreted as familial hypercholesterolemia (FH) in children. Inappropriate treatment may deteriorate the condition. Objectives: The goal of this study was to summarize the clinical characteristics of children with STSL who had xanthomas as their first symptom and to provide clues for early clinical diagnosis. Methods: We summarized the clinical characteristics of STSL patients, and investigated the differences between the STSL and FH groups, as well as the diagnostic value of STSL. Results: Two tertiary pediatric endocrinology departments contributed ten STSL cases. Five of the patients (50%) experienced mild anemia, whereas two (20%) had vascular complications. The xanthomas displayed comparable morphologies to the FH group. There were ten cases of homozygous FH with xanthomas as the predominant symptom, but no anemic patients. While serum cholesterol (Chol) and low density lipoprotein cholesterol (LDL-c) levels were significantly higher (p values of 0.002 and 0.003, respectively), MPV levels and anemia proportions were significantly lower (the p values were 0.009 and 0.033, respectively) than in the STSL group. The AUC values of Chol, LDL-c, MPV, and anemia for the diagnosis of STSL were 0.910, 0.890, 0.869, and 0.750, respectively. Chol15.41 mmol/L, LDL-c13.22 mmol/L, MPV9.05 fl, or anemia present were the best thresholds for diagnosing STSL. Conclusions: The morphologies of STSL xanthomas vary. When xanthomas were the initial symptom of a child with Chol15.41 mmol/L, LDL-c13.22 mmol/L, MPV9.05 fl, or anemia, the clinical diagnosis of STSL was most likely made.

背景：谷固醇血症（Sitosterolemia, STSL）是一种极为罕见的遗传性疾病。儿童患者若以黄瘤为首发症状，其病情常被误诊为家族性高胆固醇血症（familial hypercholesterolemia, FH），不当治疗可能导致病情恶化。
研究目的：本研究旨在总结以黄瘤为首发症状的谷固醇血症患儿的临床特征，为早期临床诊断提供参考依据。
研究方法：本研究梳理了谷固醇血症患者的临床特征，对比分析了谷固醇血症组与家族性高胆固醇血症（FH）组的临床差异，并评估了谷固醇血症的诊断价值。
研究结果：两家三级儿童内分泌专科共纳入10例谷固醇血症病例。其中5例患者（50%）伴发轻度贫血，2例（20%）发生血管并发症。谷固醇血症患者的黄瘤形态学特征与FH组无显著差异。本研究同时纳入10例以黄瘤为主要症状的纯合子FH病例作为对照，该组无贫血患者。与FH组相比，谷固醇血症组的血清总胆固醇（Chol）及低密度脂蛋白胆固醇（LDL-c）水平显著升高（对应p值分别为0.002和0.003），而平均血小板体积（Mean Platelet Volume, MPV）及贫血发生率显著降低（对应p值分别为0.009和0.033）。用于诊断谷固醇血症的总胆固醇、低密度脂蛋白胆固醇、平均血小板体积及贫血的受试者工作特征曲线下面积（Area Under the Curve, AUC）分别为0.910、0.890、0.869和0.750。诊断谷固醇血症的最佳截断值为：总胆固醇≥15.41 mmol/L、低密度脂蛋白胆固醇≥13.22 mmol/L、平均血小板体积≤9.05 fl，或伴发贫血。
研究结论：谷固醇血症患者的黄瘤形态存在异质性。当儿童以黄瘤为首发症状，且满足总胆固醇≥15.41 mmol/L、低密度脂蛋白胆固醇≥13.22 mmol/L、平均血小板体积≤9.05 fl，或伴发贫血时，临床可高度怀疑为谷固醇血症。