Surface IgG subclasses in human B cell lymphomas as revealed by monoclonal antibodies.

IgG subclass expression on cells from lymph node biopsies of 17 sIgG positive B cell lymphomas has been studied. Subclass specific monoclonal antibodies were used in an immunoradiometric assay. Ten were also tested by immunofluorescence using a biotin-avidin system. Thirteen of the lymphomas expressed IgG only, while four co-expressed other Ig isotypes. Morphological investigations revealed that 14 lymphomas originated from germinal centre cells. IgG1 was found to be dominant subclass in 10 lymphomas, IgG3 in seven, IgG2 in one, while none expressed IgG4. Multiple IgG subclasses could not be detected in any of the lymphomas tested.