Cradock-Watson J E, Ridehalgh M K
J Hyg (Lond). 1976 Feb;76(1):109-23. doi: 10.1017/s0022172400055005.
The indirect immunofluorescent technique has been used to detect and titrate the specific immunoglobulins in serum specimens from 154 infants with confirmed or suspected congenital rubella. IgM antibody was stained more efficiently in sucrose density gradient fractions than in whole serum and was detected in this way in 27 out of 40 patients with confirmed congenital rubella at ages ranging from birth to 2 years. It was present in 48 out of 50 serum specimens during the first 6 months of life and in 11 out of 38 specimens obtained at ages between 6 1/2 months and 2 years. IgM antibody was therefore estimated to persist for about 6 months in the majority of cases and up to 2 years in a few individuals. IgM antibody was also detected by this method in 11 out of 114 infants with suspected but unconfirmed congenital rubella at ages up to 5 months. The total concentrations of IgM were above the normal range in nearly all sera taken from confirmed cases during the first 3 months of life and in half the specimens obtained between the ages of 3 and 6 months. IgG antibody was detected by fluorescent staining of whole serum in all patients with congenital rubella. Geometric mean titres increased during the first 3 months of life and then declined slowly. IgA antibody was not detected, except in two patients in whom traces were present at the age of 6 months, and the total concentrations of IgA were usually within normal limits. Fluorescent staining of fractions showed that the sedimentation characteristics of rubella IgG and IgM antibodies were the same in infants as in adults. The peak IgM fractions never contained IgG antibody, and the presence of specific IgM in these fractions could usually have been safely inferred from their HAI titres. Fluorescent staining, however, was more sensitive and frequently detected IgM antibody in fractions which had no definite HAI activity. Fluorescent staining of whole serum for IgM antibody was less distinct, and often unsuccessful, even in specimens in which specific IgM was detected in the fractions. The addition of IgG- to IgM-containing fractions caused depression of IgM staining and suggested that failure to detect IgM antibody in whole serum was partly due to competitive inhibition by specific IgG.
间接免疫荧光技术已用于检测和滴定154例确诊或疑似先天性风疹婴儿血清标本中的特异性免疫球蛋白。在蔗糖密度梯度分级分离物中，IgM抗体比在全血清中染色更有效，通过这种方法在40例确诊先天性风疹患者中的27例中检测到了IgM抗体，这些患者年龄从出生到2岁不等。在出生后头6个月的50份血清标本中有48份检测到IgM抗体，在6个半月至2岁之间采集的38份标本中有11份检测到IgM抗体。因此，估计大多数病例中IgM抗体持续约6个月，少数个体中可持续2年。在114例疑似但未确诊先天性风疹的婴儿中，有11例在5个月龄以下时也通过这种方法检测到了IgM抗体。几乎所有出生后头3个月确诊病例的血清以及3至6个月龄采集的一半标本中，IgM的总浓度均高于正常范围。通过对全血清进行荧光染色，在所有先天性风疹患者中均检测到了IgG抗体。几何平均滴度在出生后头3个月内升高，然后缓慢下降。除了2例在6个月龄时检测到微量IgA抗体的患者外，未检测到IgA抗体，IgA的总浓度通常在正常范围内。对分级分离物进行荧光染色显示，婴儿风疹IgG和IgM抗体的沉降特性与成人相同。IgM峰值分级分离物中从未含有IgG抗体，通常可以根据这些分级分离物的血凝抑制（HAI）滴度安全推断其中存在特异性IgM。然而，荧光染色更敏感，经常在没有明确HAI活性的分级分离物中检测到IgM抗体。对全血清进行IgM抗体荧光染色不太清晰，甚至在分级分离物中检测到特异性IgM的标本中也常常不成功。向含有IgM的分级分离物中添加IgG会导致IgM染色减弱，这表明在全血清中未能检测到IgM抗体部分是由于特异性IgG的竞争性抑制。
