Schmeer N
Zentralbl Bakteriol Mikrobiol Hyg A. 1985 Feb;259(1):20-34.
By application of IgG1-, IgG2-, and IgM-specific conjugates in an enzyme-linked immunosorbent assay (ELISA), dominance of IgG1 in natural Q-fever infections of cattle could be demonstrated. In contrast, vaccination with an inactivated Q-fever vaccine predominantly induced IgG2 antibodies. Complement fixing activity was detected in positive sera (inactivated at 56 degrees C) in the IgG1 fraction only. Therefore, with serum samples containing exclusively IgM (10%), or IgG2 (4%), a serodiagnosis could be achieved only by ELISA. Furthermore, it could be shown that IgG2 and IgM may suppress fixation of complement by IgG1 antibodies, thus resulting in incomplete inhibition of hemolysis and even reduction of CF-titers. So, sera with low CF-titers may give incorrect negative results in the CF-test. Applying the ELISA with L-chain-specific conjugates, such problems could be avoided. For evaluation of the early and later stages of infection or the status of vaccination, IgM, IgG1-, and IgG2-specific conjugates were used. In comparison to sera, only 73% of corresponding milk samples were positive in the IgG1-ELISA. However, for seroepidemiological purposes testing of bulk milk samples by ELISA may be feasible.
通过在酶联免疫吸附测定（ELISA）中应用IgG1、IgG2和IgM特异性结合物，可以证明在牛的自然Q热感染中IgG1占主导地位。相比之下，用灭活的Q热疫苗接种主要诱导产生IgG2抗体。仅在IgG1组分的阳性血清（56℃灭活）中检测到补体结合活性。因此，对于仅含有IgM（10%）或IgG2（4%）的血清样本，只能通过ELISA进行血清学诊断。此外，可以证明IgG2和IgM可能会抑制IgG1抗体的补体结合，从而导致溶血抑制不完全甚至补体结合试验（CF）滴度降低。所以，CF滴度低的血清在CF试验中可能会给出错误的阴性结果。应用L链特异性结合物的ELISA可以避免此类问题。为了评估感染的早期和后期阶段或疫苗接种状况，使用了IgM、IgG1和IgG2特异性结合物。与血清相比，相应的乳样在IgG1-ELISA中只有73%呈阳性。然而，对于血清流行病学目的，通过ELISA检测乳样可能是可行的。
