误诊为干燥综合征的Gitelman综合征一例

Gitelman syndrome misdiagnosed as Sjögren’s syndrome:a case report

该文报道1例38岁女性患者,反复低钾血症伴碱性尿、尿钾升高,多次查抗核抗体及抗干燥综合征A(SSA)抗体阳性,外院曾疑诊为干燥综合征合并Ⅰ型远端肾小管酸中毒。但患者无明显口干、眼干表现,进一步检查非刺激唾液流率、角膜荧光染色、Schirmer泪液分泌试验及唇腺活组织检查结果均为阴性,故不支持干燥综合征的诊断;患者的代谢性碱中毒、低血氯、低血镁、低尿钙表现,不支持远端肾小管酸中毒的诊断。患者的低镁血症严重,出现Trousseau征,最终通过基因检测而确诊Gitelman综合征。该例患者的诊治过程提示,对于反复低钾血症伴抗SSA抗体阳性的患者,临床医师应根据酸碱失衡及电解质紊乱类型进行鉴别诊断,而非过于关注自身抗体和干燥综合征,以免被特异性不高的抗核抗体和抗SSA抗体误导。

This article reported a 38-year-old female patient who was misdiagnosed as Sjögren’s syndrome complicated with type I distal renal tubular acidosis(dRTA)due to recurrent hypokalemia,alkaline urine,elevated urinary potassium,positive antinuclear body(ANA),and positive anti-SSA antibody.The diagnosis of Sjögren’s syndrome was then excluded because the patient had no obvious dry mouth or dry eyes,and the results of unstimulating saliva flow rate,corneal fluorescence staining,Schirmer secretion test,or labial gland biopsy were all negative.The clinical manifestations,such as metabolic alkalosis,hypochloremia,hypomagnesemia and low urinary calcium,could not support the diagnosis of dRTA.The patient presented with severe hypomagnesemia and a Trousseau sign,then Gitelman syndrome was finally confirmed based on genetic testing.Therefore,the diagnosis and treatment of this case prompted that for patients with recurrent hypokalemia and positive anti-SSA antibody,clinicians should make differential diagnosis based on the acid-base imbalance and the electrolyte disturbance at first,instead of paying too much attention to autoantibodies and Sjögren’s syndrome,to avoid being misled by the ANA and anti-SSA antibody.