Surface immunoglobulin restriction in B-non Hodgkin's lymphomas in cell suspension and on frozen tissue sections

The diagnostic relevance of different tests for detection of surface immunoglobulin on tumour cells of B-type non-Hodgkin's lymphomas (B-NHL) was investigated by comparison of the direct antiglobulin rosetting reaction (DARR) in suspension with two-colour direct immunofluorescence (DIF) on frozen tissue sections. In benign lymph nodes (n = 27) the kappa/lambda ratio by DARR test ranged from 0.9 to 2.8. Tested by suspension and frozen tissue analysis, light chain restriction was found in 24 and 27 of 31 cases of B-NHL, respectively. Heavy chain restriction was found in half of the cases (14 of 26) studied in suspension and in almost all (28 of 31) tested on sections. In 9 cases DARR tests showed restriction of more than one Ig class on tumour cells, which was infrequent (2 of 28) in frozen section analysis. Although both tests appeared valuable for routine diagnostic purposes, we found the DIF analysis on tissue sections somewhat more discriminative, especially in detection of heavy chain restriction in B-NHL.