CD8 T lymphocytes do not express cytotoxic proteins in coronary artery aneurysms in acute Kawasaki disease

Coronary arterial inflammation in acute Kawasaki disease (KD) is characterized by transmural infiltration of CD8 T lymphocytes, suggesting that CD8 T lymphocyte cytotoxic activity may be important in the pathogenesis of coronary arterial damage in acute KD. We performed immunohistochemistry for the cytotoxic proteins perforin and granzyme B on paraffin-embedded, formalin-fixed coronary artery aneurysm tissue from 6 children who died in the acute stage of KD. Neither perforin nor granzyme B was detected in the KD coronary aneurysm wall. We speculate that the etiologic agent of KD interferes with expression of these cytotoxic proteins by CD8 T lymphocytes, prolonging inflammation in the arterial wall and leading to coronary artery aneurysm formation.