The tumor-associated shift in immunoglobulin G1/G2 is expressed at the messenger RNA level of peripheral blood B lymphocytes in patients with gynecologic malignancies

BACKGROUND. Previously, it could be demonstrated that human patients with m alignant diseases of various tissues exhibited characteristic and highly si gnificant changes in the serum patterns of immunoglobulin (Ig)G subclasses, consisting of a decrease in IgG1 and an increase in IgG2 relative to total IgG. The aim of the current study was to determine whether this phenomenon was detectable at the level of IgG-producing B lymphocytes. METHODS. Using a competitive reverse transcriptase polymerase chain reactio n specific to IgG1 and IgG2, the gene expression of these 2 IgG subclasses in peripheral B cells from 10 patients with carcinomas of various sites wit hin the female reproductive tract and 10 healthy controls was quantitativel y determined, in parallel with the concentrations of the respective serum p roteins. RESULTS. Absolute levels of IgG subclass messenger ribonucleic acid (mRNA) showed a slight but not significant decrease in IgG1 and an increase in IgG 2 in patients with gynecologic malignancies. However, the ratio of IgG1 to IgG2 expression showed a highly significant (P < 0.001) decrease in tumor p atients compared with healthy controls, and corresponded to the change in t he ratio of IgG1 to IgG2 serum proteins. CONCLUSIONS. These data suggest that the shifts in the serum patterns of Ig G1 and IgG2 observed in patients with gynecologic malignancies are due to i rregular biosynthesis of these IgG subclasses at the B-cell level. (C) 2000 American Cancer Society.