Recently, a possible relationship between Kawasaki syndrome (KS) and superantigen has been discussed since the report of selective expansion of specific Vbeta family in the acute phase of KS. To further investigate the relationship between KS and superantigens, we examined 25 types of T-cell receptor Vbeta family repertoire in patients with KS using the reverse transcription polymerase chain reaction. This is the first attempt to examine all of 25 Vbeta families in KS. A non radioisotope method was used to quantify mRNA so that the experiment was safer, simpler, and faster. An expression index (EI) for each Vbeta was defined as: (the amount of each Vbeta mRNA)/(the sum of all Vbeta mRNA) x 100. Ten patients with KS and ten normal children were studied. The Vbeta9 and Vbeta15 of acute phase of KS showed both significantly lower mean EI and significantly higher frequency of a decreased EI value as compared with control children. Selective expansion of the Vbeta family in the patients with KS was not observed. Although highly increased EIs were observed in various Vbetas, their frequency was not statistically significant. The pattern of increased Vbetas did not show the specific pattern that indicates a particular superantigen.
Conclusion: In Kawasaki syndrome non-radioisotope method for analysing Vbeta mRNA is useful in cases where many samples have to be handled. The depletion of Vbeta9 and Vbeta15 or highly increased expression index in the acute phase of Kawasaki syndrome might suggest a relationship to superantigens.