Elevated concentration of soluble interleukin-2 receptors in serum of smokers and patients with lung cancer. Correlation with clinical activity.
Soluble interleukin-2 receptor (sIL-2R) levels in cigarette smokers and in patients with lung cancer were measured using an enzyme immunoassay. The rationale for our study was based on the fact that activation of T-cells is dependent upon the T-cell growth factor, interleukin-2, which may be regulated by its receptor, IL-2R. Measurements of circulating sIL-2R might be useful in the immune assessment of certain conditions. This study assessed elevated concentrations of circulating sIL-2R in smokers and in patients with lung cancer. The data show that healthy smokers, as a group, have an elevated level of sIL-2R compared with that in nonsmokers. Significantly higher than normal levels were found among light, moderate, and heavy smokers. Patients with lung cancer (squamous cell carcinoma [SSC] or adenocarcinoma [AC]) also have abnormally high sIL-2R levels. In the SCC group, the highest level of sIL-2R was among asymptomatic patients with well-differentiated tumors. Similarly, patients with SCC whose tumors were less than 3 cm in diameter had a significantly higher mean level of sIL-2R than did patients whose tumors exceeded 3 cm. The sIL-2R level in the SCC group also correlated with the tumor stage, with the highest level found among Stage I patients. In patients with SCC, but not in those with AC, the sIL-2R level was indicative of the extent of malignancy. These data support the concept that sIL-2R may be important in the pathogenesis of immune alterations associated with smoking and lung cancer.
Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston 02114.
L C
LC
Ginns
A
A
De Hoyos
M C
MC
Brown
B R
BR
Gaumond
D000230:Adenocarcinoma / Q000097:blood*; D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000097:blood*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D012907:Smoking / Q000097:blood*
D015375:Receptors, Interleukin-2