[Chediak-Higashi syndrome. Study of lymphocyte transformation stimulated by phytohemaglutinin (PHA)]

The reactivity to PHA stimulation of peripheral blood lymphocytes from a child with a Chediak-Higashi syndrome was studied. Lymphocyte transformation was assayed by tritiated-thymidine incorporation. Patient lymphocytes reacted to much lower concentrations of PHA than normal controls. With an optimal dose of PHA the peak of thymidine uptake occurred on day 2 of incubation instead of day 4 as observed in normals.