Alterations of lymphocyte populations in lymph nodes but not in spleen during the latency period of adjuvant arthritis

The aim of this study was to analyze potential imbalances in lymphocyte pop ulations from regional lymph nodes (LN) and spleen occurring before the dev elopment of the outer inflammation of adjuvant arthritis (AA). Percentages and absolute numbers of CD5(+), CD4(+), CD8(+), Ig(+), I-A(+), NKR-P1(+) an d TCR gamma delta(+) cells were determined. No differences in percentages o f gamma delta T or NK cells were found either in LN or spleen, thus ruling out an important role of these minor subpopulations in these early stages o f AA. While no significant lymphocyte imbalances were observed in spleen, a n increase in the percentage of B lymphocytes was found in regional LN. Mor eover, a high proliferation of CD8(+) cells was observed when measuring abs olute numbers of LN lymphocytes, thus producing an imbalance in the CD4/CD8 ratio at very early stages of the inflammatory process. These findings sug gest a role for CD8+ and B lymphocytes in the latency period of AA at the L N level. Our results indicate a primary role for lymph nodes in initiating the inflammation of AA, whereas cells from the spleen probably play a secon dary role.