Abstract：
BACKGROUND: A score to predict the association between unexplained osteoporosis and an underlying systemic Mastocytosis (SM) is lacking.
OBJECTIVE: This study aimed at identifying criteria able to predict the diagnosis of SM without skin involvement and provide an indication for bone marrow (BM) assessment.
METHODS: We included 139 adult patients with unexplained osteoporosis and suspected SM. After BM evaluation, 63 patients (45.3 %) were diagnosed with SM, while the remaining 76 patients (54.7 %) negative for clonal mast cell (MC) disorders, constituted our control group. Univariate and multivariate analysis identified three independent predictive factors: age (<54 years: +1 point, >64 years: -1 point), serum basal tryptase (sBT) levels >19 ng/mL (+2 points) and vertebral fractures (+2 points).
RESULTS: These variables were used to build the OSTEO-score, able to predict the diagnosis of SM before BM assessment with a sensitivity of 73.5 % and a specificity of 67.1 %. Patients with a score < 3 had a lower probability of having SM compared to patients with a score ≥ 3 (28.5 % and 71.4 %, respectively, p < 0.0001). When sBT levels were corrected for the presence of hereditary alpha-tryptasemia (HαT) using the BST calculater (https://bst-calculater.niaid.nih.gov/) recently published [1,2], the sensitivity of ΗαT-adjusted OSTEO-score increased to 87.8 %, and the specificity reached 76.1 %. Also, the positive predictive value of a score ≥ 3 increased to 85.2 %.
CONCLUSIONS: Further studies are needed to validate these results and characterize the role of tryptase genotyping in patients with unexplained osteoporosis in reducing the risk of misdiagnosing patients with SM. Our proposed scoring model allows the identification of patients with the highest probability of having SM, avoiding unnecessary BM studies.
OBJECTIVE: This study aimed at identifying criteria able to predict the diagnosis of SM without skin involvement and provide an indication for bone marrow (BM) assessment.
METHODS: We included 139 adult patients with unexplained osteoporosis and suspected SM. After BM evaluation, 63 patients (45.3 %) were diagnosed with SM, while the remaining 76 patients (54.7 %) negative for clonal mast cell (MC) disorders, constituted our control group. Univariate and multivariate analysis identified three independent predictive factors: age (<54 years: +1 point, >64 years: -1 point), serum basal tryptase (sBT) levels >19 ng/mL (+2 points) and vertebral fractures (+2 points).
RESULTS: These variables were used to build the OSTEO-score, able to predict the diagnosis of SM before BM assessment with a sensitivity of 73.5 % and a specificity of 67.1 %. Patients with a score < 3 had a lower probability of having SM compared to patients with a score ≥ 3 (28.5 % and 71.4 %, respectively, p < 0.0001). When sBT levels were corrected for the presence of hereditary alpha-tryptasemia (HαT) using the BST calculater (https://bst-calculater.niaid.nih.gov/) recently published [1,2], the sensitivity of ΗαT-adjusted OSTEO-score increased to 87.8 %, and the specificity reached 76.1 %. Also, the positive predictive value of a score ≥ 3 increased to 85.2 %.
CONCLUSIONS: Further studies are needed to validate these results and characterize the role of tryptase genotyping in patients with unexplained osteoporosis in reducing the risk of misdiagnosing patients with SM. Our proposed scoring model allows the identification of patients with the highest probability of having SM, avoiding unnecessary BM studies.
摘要：
背景：缺乏预测无法解释的骨质疏松症与潜在的系统性肥大细胞增多症（SM）之间关联的评分。
目的：本研究旨在确定能够预测无皮肤受累的SM的诊断标准，并为骨髓（BM）评估提供指征。
方法：我们纳入了139名不明原因骨质疏松症和疑似SM的成年患者。BM评估后，63例（45.3%）被诊断为SM，而其余76例患者（54.7%）为克隆性肥大细胞（MC）疾病阴性，构成了我们的对照组。单变量和多变量分析确定了三个独立的预测因素：年龄（<54岁：+1分，>64年：-1分），血清基础类胰蛋白酶（sBT）水平>19ng/mL（2分）和椎骨骨折（2分）。
结果：这些变量用于构建OSTEO评分，能够在BM评估前预测SM的诊断，敏感性为73.5%，特异性为67.1%。与评分≥3的患者相比，评分<3的患者患SM的概率较低（28.5%和71.4%，分别,p<0.0001)。当使用BST计算器（https：//bst-calculater）校正sBT水平是否存在遗传性α-色氨酸血症（HαT）时。niaid.nih.gov/)最近出版(Chovanec等人,2023年；里昂等人。,2022[1,2]),HαT调整的OSTEO评分的敏感性增加到87.8%，特异性达到76.1%。此外，≥3分的阳性预测值增加至85.2%.
结论：需要进一步的研究来验证这些结果，并描述类胰蛋白酶基因分型在无法解释的骨质疏松症患者中的作用，以降低误诊SM患者的风险。我们提出的评分模型允许识别患有SM的概率最高的患者，避免不必要的BM研究。
目的：本研究旨在确定能够预测无皮肤受累的SM的诊断标准，并为骨髓（BM）评估提供指征。
方法：我们纳入了139名不明原因骨质疏松症和疑似SM的成年患者。BM评估后，63例（45.3%）被诊断为SM，而其余76例患者（54.7%）为克隆性肥大细胞（MC）疾病阴性，构成了我们的对照组。单变量和多变量分析确定了三个独立的预测因素：年龄（<54岁：+1分，>64年：-1分），血清基础类胰蛋白酶（sBT）水平>19ng/mL（2分）和椎骨骨折（2分）。
结果：这些变量用于构建OSTEO评分，能够在BM评估前预测SM的诊断，敏感性为73.5%，特异性为67.1%。与评分≥3的患者相比，评分<3的患者患SM的概率较低（28.5%和71.4%，分别,p<0.0001)。当使用BST计算器（https：//bst-calculater）校正sBT水平是否存在遗传性α-色氨酸血症（HαT）时。niaid.nih.gov/)最近出版(Chovanec等人,2023年；里昂等人。,2022[1,2]),HαT调整的OSTEO评分的敏感性增加到87.8%，特异性达到76.1%。此外，≥3分的阳性预测值增加至85.2%.
结论：需要进一步的研究来验证这些结果，并描述类胰蛋白酶基因分型在无法解释的骨质疏松症患者中的作用，以降低误诊SM患者的风险。我们提出的评分模型允许识别患有SM的概率最高的患者，避免不必要的BM研究。
