血清-腹水白蛋白梯度在腹水病因鉴别诊断中的价值

Value of Serum Ascitic Albumin Gradient in Differential Diagnosis of Ascitic Etiologies

背景:血清-腹水白蛋白梯度(SAAG)是间接反映门静脉压力的指标。目的:探讨SAAG和其他实验室指标在腹水病因鉴别诊断中的价值。方法:回顾性分析以腹水待查入院的122例患者的病史,按出院诊断分为门静脉高压相关疾病组(68例)和非门静脉高压相关疾病组(54例);以同一天测定的血清白蛋白浓度和腹水白蛋白浓度计算SAAG,比较两组SAAG与诊断的关系。结果:门静脉高压相关疾病组的SAAG(18.5g/L±5.3g/L)显著高于非门静脉高压相关疾病组(7.0g/L±3.1g/L)(P<0.001)。以SAAG≥11g/L为界限值,诊断门静脉高压相关性腹水的敏感性为95.6%,特异性为98.1%,准确性为96.7%,阳性预期值98.5%,阴性预期值94.6%。结论:SAAG虽不能直接对腹水的病因做出诊断,但却能为进一步检查腹水病因提出方向。高SAAG腹水大都与门静脉高压有关,而低SAAG腹水患者,在排除结核性腹膜炎和自身免疫性疾病后,应尽力排查恶性肿瘤。

Background： Serum-ascitic albumin gradient （SAAG） is an indirect parameter reflecting the portal vein pressure. Aims： To evaluate the diagnostic value and reliability of SAAG and other laboratory tests in patients with ascites. Methods： Case records of 122 patients with ascites were reviewed retrospectively. The patients were divided into 2 groups, the group associated with portal hypertension （68 patients） and the group without portal hypertension （54 patients）. The SAAG were calculated using the serum and ascitic albumin levels on the same day. Results： The mean level and standard deviation of SAAG of the group associated with portal hypertension and the group without portal hypertension was 18.5 g/L±5.3 g/L, and 7.0 g/L±3.1 g/L, respectively （P〈0.001）. Using SAAG≥ 11 g/L as the cut-off value, the diagnostic sensitivity for ascites associated with portal hypertension was 95.6%, diagnostic specificity was 98.1%, diagnostic accuracy 96.7%, positive predictive value 98.5%, negative predictive value 94.6%. Conclusions： Although the SAAG cannot make a diagnosis of the etiologies of ascites, it is useful for directing further evaluation. High SAAG is related to high portal venous pressure. If tuberculous peritonitis and autoimmune disease can be eliminated, the patients with low SAAG suggest the presence of probable malignant tumor requiring further investigation.