Peripheral follicular cytotoxic T -like cells in Kawasaki disease with coronary artery aneurysms: A case report

INTRODUCTION: Kawasaki disease (KD) is the leading cause of acquired heart abnormalities during childhood. The infiltration of CD8+ T cells plays an essential role in the formation of coronary aneurysms. Follicular cytotoxic T (Tfc) cells are a newly defined subset of CD8+ T cells that express CXC-chemokine receptor 5. The role of Tfc cells in KD is unclear. However, in this report, we present 2 KD children with sustained coronary artery aneurysms (CAA), and we found that their peripheral C-X-C Chemokine Receptor 5+ T cells contained quite amounts of CD4 negative cells. Importantly, these cells have never been reported in KD. PATIENTS CONCERNS: Case 1 was a 3-year-old boy with a complaint of continuous fever for 6 days and conjunctival injection for 3 days. Case 2 was a 6-month-old boy who was hospitalized because of persistent fever for 5 days, rashes and conjunctival injection for 1 day. DIAGNOSIS: Case 1 was diagnosed with KD according to typical symptoms and signs including fever over 5 days, conjunctival injection, rashes, swelling cervical lymph nodes and a strawberry tongue. Case 2 had atypical symptoms including persistent fever for 5 days, rashes and conjunctival injection, and he was diagnosed with KD based on the echocardiographic findings. INTERVENTION: Both the 2 patients received intravenous immunoglobulin and oral aspirin. Besides, case 1 was given the second infusion of intravenous immunoglobulin, intravenous prednisolone and low-molecular-weight heparin. OUTCOMES: The CAA of case 1 did not regress until the 12th month after disease onset. The CAA of patient 2 began to regress at the third month after disease onset. During the months from disease onset to the recent follow-up, no cardiovascular events had occurred. CONCLUSIONS: We speculate that Tfc cells may be associated with the formation of CAA. Further studies with larger sample size and functional analysis of these cells are needed.