[Practical value of IgG index and IgG synthesis rate in multiple sclerosis]

IgG index and IgG synthesis rate were determined in 40 patients with multiple sclerosis (MS) (including 21 patients treated with corticosteroid), 20 patients with other neurological diseases (OND) and 22 normal controls, by Beckman Immunochemistry system II made in USA. The practical value of IgG index and IgG synthesis rate were evaluated by means of the method of clinical epidemiology. The results showed that in the diagnosis of MS the sensitivity, specificity and positive result likelihood ratio (PRLR) of IgG index were 63%, 65% and 1.80, respectively; those of IgG synthesis rate were 50%, 65% and 1.43, respectively. In the further observation, however, it was found that the sensitivity and PRLR were 84% and 2.4 in IgG index, 79% and 2.26 in IgG synthesis rate, after the influence of corticosteroid was excluded. In addition, in judging whether there was organic damage in central nervous system, the specificities and PRLRs of IgG index and IgG synthesis rate were 100% and infinitely great, respectively. The above results are discussed in this article.