Shift in the IgG subclass distribution in patients with lung cancer

Lung cancer patients have been reported to have generalized immune dysfunct ion of the cell-mediated immune response. In contrast, little is known abou t the humoral immune function in these patients. Therefore, we examined the IgG subclass distribution (IgG1-lgG4) in 67 lung cancer patients (23 adeno carcinoma, 29 squamous cell carcinoma, 15 small cell carcinoma), 13 patient s with inflammatory lung diseases, seven patients with pulmonary metastasis and 23 healthy controls using a commercial available ELISA. We found a sig nificant increase in the percentage of Ige I in adenocarcinoma, compared wi th squamous cell and small cell lung carcinoma (P < 0.05). Small cell lung cancer patients showed an increase in IgG2, IgG3 and IgG4 compared with all other groups (P < 0.05, respectively). IgG1/IgG2, IgG1/IgG3 and IG1/lgG4 r atios in adenocarcinoma were higher than in small cell lung cancer (P < 0.0 5). In the squamous cell carcinoma there was no difference in IgG subclass distribution compared to controls. Our study demonstrates that the differen t histological subtypes of lung carcinoma influence the IgG subclass distri bution. Whether this phenomenon is the result of a direct influence on B-ce ll activity by the tumor needs further investigation. (C) 1999 Elsevier Sci ence Ireland Ltd. All rights reserved.