SOS Immunology and Allergology Laboratory Unit, Department of Laboratory Medicine, Azienda Usl Toscana Centro, S. Giovanni di Dio Hospital, Florence, Italy.
Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
Immunol Res. 2018 Feb;66(1):74-78. doi: 10.1007/s12026-017-8974-3.
Immunofluorescence on HEp2-cells is the standard diagnostic assay for the detection of anti-nuclear antibodies (ANA). Cytoplasmic speckled patterns are a common finding, and are associated with various antibodies, including anti-synthetase antibodies. However, classic ENA testing generally identifies only anti-Jo-1. Moreover, anti-synthetase syndrome is increasingly recognized as a pleomorphic entity, possibly presenting as isolated arthritis or interstitial lung disease. Sera referred for routine ANA testing were selected on the basis of the presence of a fine dense speckled cytoplasmic pattern (254 samples) and compared to control sera with negative cytoplasm (239 samples). All 493 samples were tested with a commercial synthetase profile dot-blot (D TEK - Alphadia-Alifax) including anti-Jo1, anti-PL7, anti-PL12, anti-EJ, anti-OJ, anti-KS, anti-ZO, anti-HA, anti-SRP, and anti-Ribosome P0. Retrospective clinical data was searched for positive patients. Dot-blot identified 18/254 (7.1%) positive sera in the samples with a cytoplasmic fluorescence pattern and 4/239 (1.7%) in the control group (χ2 = 8.4627; p = 0.003625). Blot intensity was more intense in samples with concordant cytoplasmic staining (cytoplasmic negative 27 ± 12.4; cytoplasmic positive 53.9 27 ± 27.7; p = 0.0027). In the positive samples, 8/18 had a highly compatible diagnosis (myositis, interstitial lung disease, arthritis), 7/18 an uncharacterized connective tissue disease, and 3 a diagnosis not associated with the presence of anti-synthetase antibodies. We evaluated the performance of a dot-blot assay for anti-cytoplasmic antibodies in a serologic cohort presenting a cytoplasmic speckled pattern found during routine ANA testing. This algorithm enabled the identification of a significant quota of patients with rare anti-synthetase antibodies and an incomplete or atypical clinical picture. Reflex testing strategies of speckled cytoplasmic patterns with multiplex assays containing cytoplasm-specific antigens, as opposed to standard ENA testing, may yield important data and for this reason should be implemented in routine ANA testing.
免疫荧光法在 HEp2 细胞上是检测抗核抗体 (ANA) 的标准诊断检测方法。细胞质斑点模式是一种常见的发现，与各种抗体相关，包括抗合成酶抗体。然而，经典的 ENA 检测通常只能识别抗 Jo-1。此外，抗合成酶综合征越来越被认为是一种多形实体，可能表现为孤立性关节炎或间质性肺病。根据存在细而密集的细胞质斑点模式（254 份样本）选择用于常规 ANA 检测的血清，并与细胞质阴性的对照血清（239 份样本）进行比较。所有 493 份样本均使用商业合成酶谱点印迹（D TEK - Alphadia-Alifax）进行检测，包括抗 Jo1、抗 PL7、抗 PL12、抗 EJ、抗 OJ、抗 KS、抗 ZO、抗 HA、抗 SRP 和抗核糖体 P0。回顾性搜索了阳性患者的临床数据。在具有细胞质荧光模式的样本中，斑点印迹法在 254 份样本中鉴定出 18/254（7.1%）阳性血清，在对照组中 4/239（1.7%）（χ2=8.4627；p=0.003625）。在具有一致性细胞质染色的样本中，印迹强度更强（细胞质阴性 27±12.4；细胞质阳性 53.9±27.7；p=0.0027）。在阳性样本中，8/18 具有高度相容的诊断（肌炎、间质性肺病、关节炎），7/18 为特征不明的结缔组织疾病，3 例与抗合成酶抗体无关。我们评估了在常规 ANA 检测中发现的细胞质斑点模式的血清学队列中，细胞质斑点印迹法检测细胞质抗体的性能。该算法能够鉴定出具有罕见抗合成酶抗体和不完整或非典型临床表现的患者的重要比例。与标准 ENA 检测相比，使用包含细胞质特异性抗原的多重检测进行细胞质斑点模式的反射性检测策略可能会产生重要数据，因此应在常规 ANA 检测中实施。
