Chida K, Takase S
Department of Clinical Neurology, National Iwate Hospital.
Rinsho Shinkeigaku. 2000 Aug;40(8):791-6.
Substantial evidence obtained through polymerase chain reaction techniques strongly supports that reactivation of latently infected herpes simplex virus (HSV) in geniculate ganglia is the main cause of Bell's palsy. However, serum antibody titers to HSV rarely increase in patients with this disease. This discrepancy may result from the difficulty in detecting a small increase in antibody titers by conventional serological analysis. To detect such a small increase in antibody titer, we defined the significant increase in IgG antibody titers more precisely, and examined the association of HSV or varicella-zoster virus (VZV) with Bell's palsy. From 40 patients with Bell's palsy, paired sera were obtained within the 4th disease day and 2 weeks later. IgG antibodies to HSV, VZV, cytomegalovirus (CMV), or measles virus (MsV) were measured with solid-phase enzyme immunoassay (EIA). IgM antibodies were measured with captured EIA. Each antibody titer was expressed as an EIA-value, which was quantitatively measured by using a calibration curve prepared from the samples containing known titers to the virus in proportion to the logarithm of its titer. An EIA-value ratio (EVR) between paired sera and a corrected EVR was calculated according to the formulae: EVR = [EIA-value in the second serum]/[EIA-value in the first serum]; corrected EVR = [EVR to HSV, VZV or CMV]/[EVR to MsV]. The association with a virus was determined to be positive when the corrected EVR of the virus was beyond the normal range (the logarithmical mean +/- 3 SD of corrected EVRs among 24 healthy controls) while the corrected EVR of the other viruses were within it. Using the corrected EVR, 6 patients were positive: 4 for HSV, 2 for VZV. On the other hand, the conventional serological analysis, which confirms positivity by a 4-fold increase in IgG antibody titer or a demonstration of IgM antibody, disclosed only 2 positive patients (1 for HSV, 1 for VZV). EIA is a very sensitive method of detecting antibodies. Corrected EVRs can exclude a decrease in antibody titers induced by corticosteroids, which are generally used for therapy of Bell's palsy. Moreover, the normal range of corrected EVRs can be defined more precisely than in conventional serological analyses. Our results indicate that some sensitive analysis, such as the corrected EVR method, may make it possible to serologically detect the causative virus of Bell's palsy.
通过聚合酶链反应技术获得的大量证据有力地支持，膝状神经节中潜伏感染的单纯疱疹病毒（HSV）重新激活是贝尔麻痹的主要病因。然而，患有这种疾病的患者血清中针对HSV的抗体滴度很少升高。这种差异可能是由于传统血清学分析难以检测到抗体滴度的微小升高。为了检测这种抗体滴度的微小升高，我们更精确地定义了IgG抗体滴度的显著升高，并研究了HSV或水痘-带状疱疹病毒（VZV）与贝尔麻痹的关联。从40例贝尔麻痹患者中，在发病第4天内和2周后采集配对血清。用固相酶免疫测定法（EIA）检测针对HSV、VZV、巨细胞病毒（CMV）或麻疹病毒（MsV）的IgG抗体。用捕获EIA法检测IgM抗体。每种抗体滴度均表示为EIA值，通过使用由含有已知病毒滴度的样品制备的校准曲线，根据其滴度的对数进行定量测量。根据以下公式计算配对血清之间的EIA值比（EVR）和校正后的EVR：EVR = [第二份血清中的EIA值]/[第一份血清中的EIA值]；校正后的EVR = [针对HSV、VZV或CMV的EVR]/[针对MsV的EVR]。当病毒的校正后EVR超出正常范围（24名健康对照者校正后EVR的对数平均值±3个标准差），而其他病毒的校正后EVR在正常范围内时，判定与该病毒的关联为阳性。使用校正后的EVR，6例患者呈阳性：4例为HSV阳性，2例为VZV阳性。另一方面，通过IgG抗体滴度4倍升高或IgM抗体检测来确认阳性的传统血清学分析仅发现2例阳性患者（1例为HSV阳性，1例为VZV阳性）。EIA是一种检测抗体的非常灵敏的方法。校正后的EVR可以排除通常用于贝尔麻痹治疗的皮质类固醇引起的抗体滴度降低。此外，校正后EVR的正常范围比传统血清学分析能更精确地定义。我们的结果表明，一些灵敏的分析方法，如校正后的EVR方法，可能使血清学检测贝尔麻痹的致病病毒成为可能。
