Role of interleukin‐2 and interleukin‐6 in the mitogen responsiveness of T cells from patients with ‘common‐variable’ hypogammaglobulinaemia
We have assessed the ability of interleukin‐2 (IL‐2) and interleukin‐6 (IL‐6) to augment the proliferative response of T lymphocytes from ‘common‐variable’ hypogammaglobulinaemia (CVH) patients and from normal controls, to the mitogens phytohaemagglutinin (PHA) and OKT3. We show that with cells from the control group and from those patients whose T cells respond to PHA within the control range, both IL‐2 and IL‐6 will significantly augment the response to OKT3. However, in those patients with a T cell defect in which the PHA response is below the control range, neither IL‐2 nor IL‐6 could restore the PHA or OKT3 response to normal. Responses to IL‐2 or IL‐6 alone were always in or above the control range.