Characterization of T Cell Repertoire Changes in Acute Kawasaki Disease By Jun Abe,* Brian L. Kotzm, ~11 Cody Melssner

Summary Kawasaki disease (KD) is an acute muhisystem vasculitis of unknown etiology that is associated with marked activation of T cells and monocyte/macrophages. Using a quantitative polymerase chain reaction (PCR) technique, we recently found that the acute phase of KD is associated with the expansion of T cells expressing the V/32 and V/38.1 gene segments. In the present work, we used a newly developed anti-V/32 monoclonal antibody (mAb) and studied a new group of KD patients to extend our previous PCR results. Immunofluorescence analysis confirmed that V/32-bearing T cells are selectively increased in patients with acute KD. The increase occurred primarily in the CD4 T cell subset. The percentages of V/32 + T cells as determined by mAb reactivity and flow cytometry correlated linearly with V/3 expression as quantitated by PCR. However, T cells from acute KD patients appeared to express proportionately higher levels of V/32 transcripts per cell as compared with healthy controls or convalescent KD patients. Sequence analysis of T cell receptor/3 chain genes of V/32 and V/38.1 expressing T cells from acute KD patients showed extensive junctional region diversity. These data showing polyclonal expansion of V/32 + and V/38 + T cells in acute KD provide additional insight into the immunopathogenesis of this disease.