sIL-2R and NSE were measured in 24 patients with small cell carcinoma (SCC) of the lung, in 25 patients with non small cell carcinoma (NSCC) and in 20 controls matched for age, sex and smoking habits. Significantly elevated values of sIL-2R and NSE were found in the SCC group (mean ± SEM: 2103 ± 314.4 U/ml and 44.5 ± 7.3 ng/ml repsectively), compared to those in the NSCC group (1079 ± 104.5 U/ml and 3.64 ± 0.8 ng/ml, p < 10-7 respectively) and to controls (561 ± 44.6 U/ml and 1.7 ± 0.3 ng/ml p < 10-5). In the SCC group, 83.3% of sIL-2R and 87.5% of NSE values were above cut-off (900 U/ml and 10 ng/ml respectively), while in the NSCC group, 48% of sIL-2R and only 8% of NSE values were above cut-off. In the controls, all values of both parameters were below cut-off. The results suggest that sIL-2R and NSE in concurrent measurements may help in decision making as regards treatment and prognosis.

The authors conclude that serum levels of sIL-2R and β2M may play a role in the early diagnosis and identification of patients with chronic rejection.