Plasma Soluble Interleukin 2 Receptor Levels in Patients with Malignant Lymphoma are Correlated with Disease Activity but not Cellular Immunosuppression

Abstract

Studies of peripheral blood lymphocytes (PBL) and plasma from patients with malignant lymphoma [Hodgkin's disease (HD) and non Hodgkin's lymphoma (NHL)] show that plasma soluble interleukin 2 receptor (sIL2R) levels are closely linked with disease status (normal volunteers (n = 15) 402 ± 158u/ml; patients with Hodgkin's disease in remission (n = 4) 525 ± 195 u/ml or with active disease (n = 11) 3026 ± 1602 u/ml (p < 0.001); patients with non Hodgkin's lymphoma in remission (n = 6) 462 ± 202 u/ml, active disease (n=15) 2713 ± 1755 u/ml, (p < 0.001)) but no correlation between sIL2R and the inhibition of interleukin 2 (IL2) generated cytotoxicity for the cell line K.562. In only 1 of 15 patient plasma samples studied was there a dose dependent inhibition of IL2 generated cell killing. In a further patient, IL2 generated K562 killing was inhibited at all doses (500-3000 brmp units/ml); treatment of this plasma with anti-Interleukin 4 (αIL4) had no effect on the potent inhibitory activity of the plasma. Plasma sIL2R levels were markedly elevated in patients receiving IL2 in vivo (pre treatment 520 ± 170iu/ml, during treatment 5578 ± 2564iu/ml, p = 0.05). The aetiology of immunosuppression in patients with lymphoma appears to be multi-factorial; although sIL2R correlates with disease activity it does not appear to directly mediate immunosuppression in most patients with malignant lymphoma.

Key Words:

• Soluble interleukin 2 receptor (sIL2R)
• interleukin 2 (IL2)
• in vitro cytotoxicity
• Malignant lymphoma (ML)