Peripheral blood mononuclear cells in patients with nonleukemic cutaneous T-cell lymphoma. Reduced proliferation and preferential secretion of a T helper-2-like cytokine pattern on stimulation.

BACKGROUND AND DESIGN: Since patients with cutaneous T-cell lymphoma (CTCL) demonstrate several immunologic abnormalities such as elevated serum immunoglobulin levels or reduced natural killer cell activity, we analyzed functional properties of the peripheral blood mononuclear cells in patients with nonleukemic CTCL and healthy donors.

RESULTS: After priming with phytohemagglutinin for 3 days, a reduced proliferation in the presence of interleukin 2 and interleukin 4 was found. Limiting dilution technique revealed a diminished number of peripheral blood mononuclear cells from patients with CTCL that were capable of proliferating on interleukin 2 but not on interleukin 4 stimulation. Phytohemagglutinin induced a significantly higher release of interleukin 4 (mean +/- SD, 196 +/- 149.8 pg/mL [n = 19] vs 76.4 +/- 16.4 pg/mL [n = 248]) and a significantly lower secretion of interferon-gamma (24.9 +/- 30.7 U/mL [n = 17] vs 47.5 +/- 43.5 U/mL [n = 18]) in the peripheral blood mononuclear cells of patients with CTCL compared with the peripheral blood mononuclear cells of healthy donors (P < or = .02, U test).

CONCLUSION: These functional characteristics can be explained by an imbalanced T helper-1/T helper-2 system and allow speculations concerning clinical features such as elevated immunoglobulin serum levels and reduced cytotoxic activity in patients with CTCL.