Development of enzyme-linked immunosorbent assay as a liver function test

建立了检测血清鸟氨酸氨基甲酰转移酶(OCT)蛋白的酶联免疫吸附试验(EL ISA)，并检测了各种肝病患者血清OCT的浓度。OCT浓度在肝性脑病、急性到慢性、急性肝炎急性期、慢性肝炎、肝硬变、肝细胞癌、原发性胆汁性肝硬变患者中显著升高，在脂肪肝患者中略有升高。慢性肝炎、肝硬变和肝细胞癌患者血清OCT蛋白水平高于正常值的比例较高(92-94%)。与天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)活性密切相关，与线粒体AST、谷氨酸脱氢酶、谷氨酰转肽酶呈中度相关。肝硬化组OCT/ALT明显高于慢性肝炎组(P<0.001)，肝细胞癌组OCT/ALT仍高于慢性肝炎组(P<0.05)。在两名“急性或慢性”患者中，入院后OCT浓度下降与AST或ALT活性相似或更快。在2例肝性脑病患者中，OCT浓度与AST、ALT活性变化相似。OCT-EL ISA系统有助于各种肝病的诊断和患者的随访，OCT/ALT比值可用于肝病的鉴别诊断。

We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for serum ornithine carbamoyltransferase (OCT) protein, and examined serum OCT concentrations in patients with various liver diseases. OCT concentrations were markedly elevated in cases of hepatic encephalopathy, "acute on chronic", and those with the acute phase of acute hepatitis, moderately in chronic hepatitis, Iiver cirrhosis, hepatocellular carcinoma, primary biliary cirrhosis, and slightly in those with a fatty Iiver. High percentages (92-94%) of patients with chronic hepatitis , liver cirrhosis and hepatocellular carcinoma had higher than normal concentration of serum OCT protein. There was a close correlation with aspartateaminotransferase (AST) and alanine aminotransferase (ALT) activities and moderate correlations with those of mitochondrial AST,glutamate dehydrogenase and g-glutamyl transpeptidase. The OCT/ALT ratio was higher in patients with liver cirrhosis than in those with chronic hepatitis (P<0.001), and was still higher in cases of hepatocellular carcinoma (P<0.05). In two patients with "acute on chronic", OCT concentrations decreased similarly with or more rapidly than AST or ALT activities after admission. In two patients with hepatic encephalopathy, the OCT concentrations changed similarly with AST and ALT activities. This OCT ELISA system will aid in diagnosing various liver diseases and for follow of the patients, and the OCT/ALTratio may serve for a differential diagnosis of liver diseases.