A comprehensive testing algorithm for the diagnosis of Fabry disease in males and females
A comprehensive testing algorithm for the diagnosis of Fabry disease in males and females
复制标题
DOI：
10.1016/j.ymgme.2020.04.006
复制
发表时间：
2020-07-01
影响因子：
3.8
通讯作者：
Young, Sarah P.
中科院分区：
文献类型：
--
作者：
Stiles, Ashlee R.;Zhang, Haoyue;Young, Sarah P.
目的：由于临床异质性和缺乏疾病意识，患者（尤其是女性）对法布里病的成功诊断经常被延迟或漏诊。我们介绍了我们在高危人群中检测法布里病的经验，并讨论了血液中 α-半乳糖苷酶 A (α-Gal A) 酶活性、血浆溶血三糖神经酰胺 (lyso-Gb(3)) 生物标志物和 GLA 基因测序作为男性和女性法布里病诊断测试的相对敏感性。方法：通过酶分析、生物标志物分析和GLA 测序。所有三种测定均使用单管 EDTA 血液进行。使用荧光测定法测定干燥血斑中的 α-Gal A 活性，通过 UPLC-MS/MS 测定血浆 lyso-Gb3，并通过桑格测序测定 GLA 分析。 结果：从 94 名男性和 200 名女性获得外周血样本，其中 29% 的男性和 22% 的女性有法布里病阳性家族史。在 87 名 (30%) 患者（50 名男性，37 名女性）中发现了可能的致病性或致病性变异，证实了法布里病的诊断。在其余患者中，根据正常酶活性（男性）或正常 lyso-Gb(3) 和阴性测序结果（女性），确定 178 名 (61%) 患者未受影响。 29 名 (10%) 患者发现 VUS。血浆lyso-Gb(3)的阳性和阴性预测值在男性中分别为100%和97%，在女性中分别为100%和99%。相比之下，α-Gal A 活性检测的男性为 84% 和 100%，女性为 58% 和 50%。结论：血浆 lyso-Gb(3) 对男性和女性法布里病具有较高的敏感性和特异性，并在基因测序结果阴性或不确定时提供支持性诊断信息。干血斑 (DBS) 中的 α-Gal A 活性对男性法布里病具有较高的敏感性，但特异性较低，因为并非所有 α-Gal A 活性低的男性都被证实患有法布里病。因此，基因测序和血浆 lyso-Gb(3) 的反应对于男性疾病的确认非常有用。对于女性，我们发现由 GLA 测序和血浆 lyso-Gb(3) 分析组成的第一层测试提供了最大的敏感性和特异性。酶测试对女性的敏感性较低，因此作为一级测试的用处较小。在分子检测和血浆 lyso-Gb(3) 分析无法提供信息且体外酶活性较低的情况下，女性酶分析作为二级检测仍然可能有所帮助。总结：优先考虑具有高特异性和敏感性的检测的性别特异性检测算法提供了识别法布里病个体的有效方法。
Purpose: Successful diagnosis of Fabry disease is often delayed or missed in patients, especially females, due to clinical heterogeneity and a lack of disease awareness. We present our experience testing for Fabry disease in high risk populations and discuss the relative sensitivities of alpha-galactosidase A (alpha-Gal A) enzyme activity in blood, plasma lyso-globotriaosylceramide (lyso-Gb(3)) biomarker, and GLA gene sequencing as diagnostic tests for Fabry disease in both males and females.Methods: Patients with a clinical suspicion of Fabry disease were evaluated with enzyme analysis, biomarker analysis, and GLA sequencing. All three assays were performed from a single tube of EDTA blood. alpha-Gal A activity was determined in dried blood spots using a fluorometric assay, plasma lyso-Gb3 by UPLC-MS/MS, and GLA analysis by Sanger sequencing.Results: Peripheral blood samples were received from 94 males and 200 females, of which 29% of males and 22% of females had a positive family history of Fabry disease. A likely pathogenic or pathogenic variant was identified in 87 (30%) patients (50 males, 37 females), confirming a diagnosis of Fabry disease. Of the remaining patients, 178 (61%) were determined to be unaffected based on normal enzyme activity (males) or normal lyso-Gb(3) and negative sequencing results (females). A VUS was identified in 29 (10%) patients. The positive and negative predictive value of plasma lyso-Gb(3) was 100% and 97% in males and 100% and 99% in females, respectively. This compares with 84% and 100% in males, and 58% and 50% in females for alpha-Gal A activity testing, respectively.Conclusions: Plasma lyso-Gb(3) has high sensitivity and specificity for Fabry disease in males and females, and provides supportive diagnostic information when gene sequencing results are negative or inconclusive. alpha-Gal A activity in dried blood spots (DBS) has high sensitivity, but lower specificity for Fabry disease in males, as not all males with low alpha-Gal A activities were confirmed to have Fabry disease. Therefore, reflexing to gene sequencing and plasma lyso-Gb(3) is useful for disease confirmation in males. For females, we found that first tier testing consisting of GLA sequencing and plasma lyso-Gb(3) analysis provided the greatest sensitivity and specificity. Enzyme testing has lower sensitivity in females and is therefore less useful as a first-tier test. Enzyme analysis in females may still be helpful as a second-tier test in cases where molecular testing and plasma lyso-Gb(3) analysis are uninformative and in vitro enzyme activity is low.Summary: Sex-specific testing algorithms that prioritize tests with high specificity and sensitivity offer an effective means of identifying individuals with Fabry disease.