Clinical value of measuring soluble interleukin-2 receptor in polymyalgia rheumatica.

Serum levels of soluble interleukin-2 receptor (sIL-2R) were measured in 15 patients with polymyalgia rheumatica (PMR) and followed prospectively for 11.5 months (range 2-22) and also in 22 patients with PMR treated with corticosteroids for a mean period of 47 months. The controls consisted of 21 patients in the same age range as the PMR patients, admitted to the hospital for various diseases, and of 40 healthy younger subjects. The initial sIL-2R values in the patients with newly diagnosed, untreated PMR were significantly higher than the values seen in the same patients after corticosteroid treatment for a median of 6 months and in PMR patients on corticosteroid treatment for more than a year (p < 0.005 and p < 0.05, respectively). However, while being significantly higher than the values in the normal controls, the sIL-2R values in PMR did not differ from the values seen in the hospital controls. Thus, this assay seems to be of little clinical value in the management of patients with PMR.