Rowan B P, Smith A, Gleeson D, Hunt L P, Warnes T W
Liver Unit, University Department of Gastroenterology, Manchester Royal Infirmary.
Gut. 1994 Apr;35(4):542-6. doi: 10.1136/gut.35.4.542.
Hepatitis C virus antibody titres (anti-HCV) were measured in serum from 122 patients with autoimmune liver disease (96 with primary biliary cirrhosis and 26 with autoimmune chronic active hepatitis using three generations of enzyme immunoassay (EIA): first generation--Ortho, EIA1; second generation--Abbott, EIA2; and third generation--Murex, EIA3. Anti-HCV was below the positive cut-off level in all 26 autoimmune chronic active hepatitis patients for all tests, while seropositivity values in primary biliary cirrhosis were 31% (EIA1), 14% (EIA2), and 0% (EIA3). In primary biliary cirrhosis, anti-HCV values as measured by all three tests correlated positively with serum IgG concentrations, serum storage time, and a number of other indices of hepatic dysfunction. Multiple regression analysis showed that anti-HCV values were independently affected by both serum IgG and the length of storage time, although the magnitude of the effects varied between tests. When all three multiple regression models were applied to an extreme clinical example, however, EIA3 was least likely to give a false-positive result. The difference in test performance was emphasised further by examination of anti-HCV values in nine primary biliary cirrhosis patients (confirmed negative by recombinant immunoblot assay 2) in whom serial samples were tested (seven to 14 per patient, stored for one to 138 months). Apparent anti-HCV values (EIA1 and EIA2) increased with increasing serum storage time, but were unchanged when measured by EIA3. A similar pattern was evident in a limited study of five autoimmune chronic active hepatitis patients. As the second generation EIA is in widespread use and confirmatory testing is not always available, the effect of serum storage in addition to hyperglobulinaemia should be considered in the interpretation of positive results in auto immune and in other types of chronic liver disease.
采用三代酶免疫分析法（EIA）检测了122例自身免疫性肝病患者（96例原发性胆汁性肝硬化患者和26例自身免疫性慢性活动性肝炎患者）血清中的丙型肝炎病毒抗体滴度（抗-HCV）：第一代——Ortho公司的EIA1；第二代——雅培公司的EIA2；第三代——Murex公司的EIA3。在所有检测中，26例自身免疫性慢性活动性肝炎患者的抗-HCV均低于阳性临界值，而原发性胆汁性肝硬化患者的血清阳性率分别为31%（EIA1）、14%（EIA2）和0%（EIA3）。在原发性胆汁性肝硬化中，所有三项检测测得的抗-HCV值均与血清IgG浓度、血清储存时间以及其他一些肝功能障碍指标呈正相关。多元回归分析表明，抗-HCV值独立受到血清IgG和储存时间长短的影响，尽管不同检测的影响程度有所不同。然而，当将所有三个多元回归模型应用于一个极端临床实例时，EIA3产生假阳性结果的可能性最小。通过检测9例原发性胆汁性肝硬化患者（重组免疫印迹试验2确认阴性）的抗-HCV值（每位患者检测7至14份系列样本，储存1至138个月），进一步强调了检测性能的差异。明显的抗-HCV值（EIA1和EIA2）随血清储存时间的延长而升高，但用EIA3检测时则无变化。在一项对5例自身免疫性慢性活动性肝炎患者的有限研究中也观察到了类似模式。由于第二代EIA广泛应用且并非总能进行确证检测，因此在解释自身免疫性和其他类型慢性肝病的阳性结果时，除了高球蛋白血症外，还应考虑血清储存的影响。
