Impaired T-cell mitogen responses in some patients with thalassemia intermedia.

Ten thalassemia intermedia patients were tested for their mitogenic responses to phytohemagglutinin P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). Impaired responses to PHA and Con A were observed in patients with serum-iron levels higher than 200 microgram/dl. Responses within or slightly higher than those in the normal range were observed in patients with serum-iron lower than 200 microgram/dl. By contrast, no significant changes occurred in the majority of the responses to PWM.