Vitamin K1 and Vitamin K2 immunopharmacological effects on the peripheral lymphocytes of healthy subjects and dialysis patients, as estimated by the lymphocyte immunosuppressant sensitivity test.

WHAT IS KNOWN AND OBJECTIVE: Renal transplant recipients receive immunosuppressive therapy to prevent acute rejection. We evaluated the immunopharmacological efficacy of vitamin K1 (VK1) and vitamin K2 (VK2) on T-cell mitogen-activated-peripheral lymphocytes of dialysis patients and healthy subjects.

METHODS: The effects of VK1 and VK2 on the T-cell mitogen-stimulated proliferation of peripheral blood mononuclear cells (PBMCs) obtained from 12 healthy subjects and 12 dialysis patients were estimated. Seven cytokines produced from the activated PBMCs were measured by a BD Cytometric Beads Array kit. Regulatory T cells (Tregs) in PBMCs were analysed as CD4 + CD25 + FoxP3 +  lymphocytes by flow cytometry.

RESULTS: VK2 dose-dependently suppressed the concanavalin A-stimulated proliferation of PBMCs from healthy subjects and dialysis patients, whereas VK1 had no significant effect on the PBMC proliferation. VK1 and VK2 did not influence the production of most of the Th1/Th2/Th17 cytokines from the activated PBMCs of these subjects, although VK2 increased the IL-4 production from PBMCs of healthy subjects. The Treg percentages in the PBMCs of dialysis patients were markedly decreased compared to healthy PBMCs after the treatment with relatively low concentrations of VK2.

WHAT IS NEW AND CONCLUSION: The present data suggest that VK2 has immunosuppressive efficacy. VK2 may enhance the immunosuppressive efficacies of glucocorticoids while preventing osteoporosis caused by glucocorticoids.