Pretreatment, prediagnosis immunoglobulin, and alpha 1-antitrypsin levels in patients with bronchial carcinoma.

Sera from 148 patients suspected of having bronchial carcinoma were evaluated for concentrations of IgA, IgM, IgG, and alpha 1-antitrypsin (alpha 1-AT). Histologically, 137 tumor specimens obtained by bronchoscopy or surgical biopsy were diagnosed as squamous cell carcinoma (55%), adenocarcinoma (18%), undifferentiated small cell carcinoma (20%), or undifferentiated large cell carcinoma (7%). The tumor types of the remaining 11 patients were not identifiable from the records but were included as a separate group. Serum protein values were compared with those of a control group of 60 healthy adult volunteers. Regression analysis of age, race, and sex effects on the results of comparisons between test and control groups indicated that, with the possible exception of age and IgM, these three independent variables did not significantly influence the observations. Both serum IgA and alpha 1-AT were significantly elevated in all tumor groups when compared to the control levels. This was not the situation for serum IgG. Results for serum IgM were equivocal and depended on the statistical methods used. Although the serum immunoglobulin concentrations for the small cell carcinoma group were consistently lower than those for the other tumor cell types, no statistically significant difference existed between the five tumor groups in this regard.