The pathophysiology of glandular dysfunction in Sjögren's syndrome (SS) has not been fully elucidated. Previously, we reported the presence of autoantibodies to AQP-5 in patients with SS, which was associated with a low resting salivary flow. The purpose of this study was to investigate the presence of anti-AQP1 autoantibodies. To detect anti-AQP1 autoantibodies, cell-based indirect immunofluorescence assay was developed using MDCK cells that overexpressed human AQP1. By screening 112 SS and 52 control sera, anti-AQP1 autoantibodies were detected in 27.7% of the SS but in none of the control sera. Interestingly, the sera that were positive for anti-AQP1 autoantibodies also contained anti-AQP5 autoantibodies in the previous study. Different from anti-AQP5 autoantibodies, the presence of anti-AQP1 autoantibodies was not associated with the salivary flow rate. Although anti-AQP1 autoantibodies are not useful as a diagnostic marker, the presence of autoantibodies to AQP1 may be an obstacle to AQP1 gene therapy for SS.

中文翻译：

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原发性干燥综合征患者血清中水通道蛋白1自身抗体的检测

干燥综合征 (SS) 腺功能障碍的病理生理学尚未完全阐明。以前，我们报道了 SS 患者存在 AQP-5 自身抗体，这与低静息唾液流量有关。本研究的目的是调查抗 AQP1 自身抗体的存在。为了检测抗 AQP1 自身抗体，使用过表达人 AQP1 的 MDCK 细胞开发了基于细胞的间接免疫荧光测定。通过筛选 112 份 SS 和 52 份对照血清，在 27.7% 的 SS 中检测到抗 AQP1 自身抗体，但在对照血清中均未检测到。有趣的是，在之前的研究中，抗 AQP1 自身抗体阳性的血清也含有抗 AQP5 自身抗体。与抗 A​​QP5 自身抗体不同，抗 AQP1 自身抗体的存在与唾液流速无关。尽管抗 AQP1 自身抗体不能用作诊断标志物，但 AQP1 自身抗体的存在可能是 AQP1 基因治疗 SS 的障碍。