Major immunoglobulin ratios in carcinoma of the head and neck.

Serum immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) levels were determined on 245 patients with carcinoma of the head and neck and on 92 controls. Ratios of these levels were calculated for each subject. The patients with cancer demonstrated elevated serum IgA levels (P less than .0001) and elevated IgA/IgM and IgA/IgG ratios (P less than .05). No differences were noted when the IgM/IgG ratios were compared between the cancer and the control groups. These observations are offered as evidence that previously reported elevations of serum IgA levels in patients with carcinoma of the head and neck are not merely an index of nonspecific increased immunoglobulin production in these patients.