Takayasu myocarditis mediated by cytotoxic T lymphocytes.

A 15-year-old Japanese man was referred for evaluation of heart failure. Conventional heart failure therapy had little effect, and severe left ventricular dysfunction as well as elevated erythrocyte sedimentation rate persisted. Magnetic resonance angiography showed aortic dilatation with wall thickening characteristic of Takayasu's arteritis. An endomyocardial biopsy specimen revealed infiltration of natural killer cells and gamma delta T lymphocytes, which play major roles in vascular injury of Takayasu's arteritis. Prednisolone administration provided great benefits to cardiac function. These findings suggest that autoimmune cytotoxic mechanisms similar to those in arterial tissue may contribute to cardiac impairment in Takayasu's arteritis.