Memory T cell subsets in B cell non-Hodgkin's lymphomas.

Memory T cells were quantitated by three color flow cytometry in cell suspensions from biopsy specimens of 34 B cell non-Hodgkin's lymphomas (NHL) and 10 benign lymphoid hyperplasias (BLH). CD3+CD45R0-CD45RA+ (naive), CD3+CD45R0+CDRA- (memory) and total CD3+ T cells were compared in BLH, low grade (LG), intermediate (IG) and high grade (HG) B cell NHL. Mean percentage +/- s.e. of CD45R0 + T cells for BLH, LG, IG and HG NHL were: 14.7 +/- 3.8, 11.2 +/- 3.5, 28.9 +/- 7.5 and 45 +/- 15, respectively. Mean percentage +/- s.e. of CD45RA+ T cells were: 10.2 +/- 2.6, 7.1 +/- 2.3, 5.4 +/- 1.4 and 3.5 +/- 1.2, respectively. Mean percentage +/- s.e. of total CD3+ T cells were: 42.5 +/- 11, 22.4 +/- 7.5, 39.3 +/- 10.1 and 62.7 +/- 22.2, respectively. Memory and total T cells progressively increased from LG toward IG and HG NHL while naive T cells simultaneously decreased. Although the differences in naive T cells were non-significant, the differences in memory T cells were significant between LG and IG and LG and HG NHL (both p < .0100). We previously reported an increase in activated-cytotoxic T cells in IG -HG B cell NHL. We now report that this subset of lymphocytes has also acquired memory function. Future studies should determine if in vitro expansion and adoptive transfer of this subset of T cells results in tumor cytolysis.