Kimura M, Tatsumi K I, Tada H, Ikemoto M, Fukuda Y, Kaneko A, Kato M, Hidaka Y, Amino N
Department of Laboratory Medicine, Osaka University Medical School, Osaka 565-0871, Japan.
Clin Chem. 2000 Jan;46(1):112-7.
Arginase is an enzyme of the urea cycle, and one of the two isoenzymes is the liver-type enzyme. We examined serum autoantibodies to this liver-type enzyme in patients with hepatitis.
Antibodies to recombinant human liver-type arginase were measured by ELISA in 95 patients and 55 healthy controls.
The mean absorbance values in the ELISA assays of patients with definite autoimmune hepatitis (n = 11; P <0.0001), probable autoimmune hepatitis (n = 31; P <0.0001), and hepatitis C (HCV; n = 20; P <0.01) were significantly different from those of healthy controls, but the values in patients with hepatitis B (HBV; n = 23) and other autoimmune diseases (n = 10) were not significantly different from those of healthy controls. When the cutoff was fixed at the upper 95th percentile of the absorbance value in healthy controls, positive reactions were found in 18.2%, 32.3%, 20.0%, 13. 0%, and 10.0% of patients with definite autoimmune hepatitis, probable autoimmune hepatitis, HCV hepatitis, HBV hepatitis, and other autoimmune diseases, respectively. All of these positive reactions were abolished by inhibition of serum with recombinant antigen. The specificity and sensitivity of this ELISA were 96% and 29%, respectively. The intraassay and interassay coefficients of variation were 2.3-7.5% and 9.8-11%, respectively. There was no relationship between these antibodies and anti-nuclear, anti-smooth muscle, or anti-cytochrome P450IID6 antibodies.
The ELISA for anti-liver-type arginase autoantibody improved the detectability of autoimmune hepatitis when compared with established assays for liver-specific autoantibodies.
精氨酸酶是尿素循环中的一种酶，其两种同工酶之一为肝型酶。我们检测了肝炎患者血清中针对这种肝型酶的自身抗体。
采用酶联免疫吸附测定法（ELISA）检测95例患者和55名健康对照者血清中针对重组人肝型精氨酸酶的抗体。
确诊的自身免疫性肝炎患者（n = 11；P <0.0001）、可能的自身免疫性肝炎患者（n = 31；P <0.0001）和丙型肝炎（HCV；n = 20；P <0.01）在ELISA检测中的平均吸光度值与健康对照者相比有显著差异，但乙型肝炎（HBV；n = 23）患者和其他自身免疫性疾病患者（n = 10）的值与健康对照者无显著差异。当将临界值设定为健康对照者吸光度值的第95百分位数上限时，确诊的自身免疫性肝炎、可能的自身免疫性肝炎、HCV肝炎、HBV肝炎和其他自身免疫性疾病患者的阳性反应率分别为18.2%、32.3%、20.0%、13.0%和10.0%。所有这些阳性反应在用重组抗原抑制血清后均消失。该ELISA的特异性和敏感性分别为96%和29%。批内和批间变异系数分别为2.3 - 7.5%和9.8 - 11%。这些抗体与抗核抗体、抗平滑肌抗体或抗细胞色素P450IID6抗体之间无相关性。
与已有的肝脏特异性自身抗体检测方法相比，抗肝型精氨酸酶自身抗体的ELISA提高了自身免疫性肝炎的检测能力。
