Serum CD25 levels during interleukin-2 therapy: dose dependence and correlations with clinical toxicity and lymphocyte surface sCD25 expression.

Using an enzyme-linked immunosorbent assay (ELISA), we have measured serum levels of a soluble form of the p55 subunit of the interleukin-2 receptor complex, soluble CD25 (sCD25), at regular intervals in the sera of 51 pediatric and adult cancer patients receiving recombinant human interleukin-2 (IL-2). The IL-2 was administered in repetitive weekly cycles alone or in combination with lymphokine-activated killer (LAK) cells. Levels of CD25 correlated with clinical toxicities reflected by nadir blood pressures, percentages of weight gained, and minimum Karnofsky performances during IL-2 therapy. Coadministration of autologous in vitro activated LAK cells together with IL-2 did not significantly affect the pattern of sCD25 release relative to administration of IL-2 alone. Examination of sCD25 release in response to different doses of IL-2 revealed a statistically significant dose effect of IL-2 on the sCD25 levels in patient sera. In addition, the level of sCD25 in patient sera also correlated strongly with expression of CD25 on the surface of peripheral blood lymphocytes (PBL) obtained from patients following IL-2 therapy. These studies demonstrate the utility of the sCD25 ELISA as a clinical tool for monitoring patients on treatment regimens that include IL-2.

Use of subcutaneous terbutaline to reverse peripheral ischemia.

Four cases are presented, one involving extravasation of a dopamine and dobutamine solution in the arm and three involving accidental digital injection of epinephrine into the thumb. In three cases, local infiltration of terbutaline resulted in dramatic reversal of vasospasm and ischemia. In the remaining case the use of terbutaline resulted in minor clinical improvement. These are the first reported cases involving the successful treatment of peripheral ischemia with subcutaneous terbutaline. This experience suggests that terbutaline may be an effective alternative for treatment of peripheral ischemia when phentolamine is not available.