Chronic graft-versus-host disease (GVHD) is thought to result from abnormalities of several cytokine regulations in vivo. We analyzed interleukin-5 (IL-5) production by peripheral lymphocytes in a patient showing hypereosinophilia associated with chronic GVHD after allogeneic bone marrow transplantation. IL-5 production by activated T-lymphocytes which are known to play a major role in chronic GVHD was upregulated when stimulated by PMA+ionomycin. Therefore, hypereosinophilia observed in our patient may be correlated with IL-5 production in donor T-lymphocytes.
