Measurement of intracellular interferon-gamma and interleukin-4 in whole blood T lymphocytes from patients with systemic lupus erythematosus

Abstract

Contradictory data are available about the dominance of T-helper 1 (T H1), or T-helper 2 (T H2) cytokines in systemic lupus erythematosus (SLE). Therefore, intracellular interferon-gamma (IFN-γ) and interleukin-4 (IL-4) production of T lymphocytes was measured in whole blood of healthy donors and active and inactive SLE patients by flow cytometry. The percentage of IFN-γ and IL-4 positive cells was low (<1%) in unstimulated samples of the healthy controls, while that of IFN-γ and IL-4 positive cells in the stimulated cells was 25.2±10.6% and 0.6±1.5%, respectively. No significant difference was found between SLE patients and healthy controls and between active and inactive patients in these parameters either in the unstimulatad or in the stimulated samples. One patient with severe disease had as high as 11.8% IL-4 positive cells and 12.5% IFN-γ positive cells in the stimulated samples, but after the initiation of intensive corticosteroid and cytostatic therapy, the percentage of IL-4 positive T cells decreased (4.76%) while that of IFN-γ positive T cells increased (47.91%). We conclude that the intracellular IL-4 and IFN-γ expression of T lymphocytes does not differ markedly between SLE patients and healthy controls, with the possible exception of severe disease, when marked IL-4 overproduction may exist beside low IFN-γ production. Furthermore, corticosteroid and cytostatic therapy might normalize this altered IFN-γ/IL-4 ratio.