tacrolimus and teriflunomide

Polyoma BK virus produces an aggressively destructive nephropathy in approximately 3% to 8% of renal allografts, is associated with graft loss within one year in 35% to 67% of those infected and there is no therapy of proven efficacy. Leflunomide is an immune suppressive drug with anti viral activity in vitro and in animals.. We treated twenty-six patients with biopsy proven NK virus nephropathy (BKN) with either leflunomide alone (n=17) or leflunomide plus a course of cidofovir (n=9) and followed them for six to forty months. Leflunomide was dosed to a targeted blood level of active metabolite, A77 1726, of 50 microg/ml to 100 microg/ml (150 microM to 300 microM). Response to treatment was gauged by serial determinations of viral load in blood and urine (PCR), serum creatinine, and repeat allograft biopsy.. In the 22 patients consistently sustaining the targeted blood levels of active drug, blood and urine viral load levels uniformly decreased over time (P<.001). Mean serum creatinine levels stabilized over the first six months of treatment, and with 12 months or more of follow-up in 16 patients the mean serum creatinine has not changed significantly from base line. Four patients who did not consistently have blood levels of active drug (A77 1726) above 40 microg/ml did not clear the virus until these levels were attained or cidofovir was added.. Leflunomide inhibits Polyoma virus replication in vitro and closely monitored leflunomide therapy with specifically targeted blood levels appears to be a safe and effective treatment for Polyoma BK nephropathy.

Topics: Aniline Compounds; BK Virus; Blood; Cells, Cultured; Creatinine; Crotonates; Female; Humans; Hydroxybutyrates; Immunosuppressive Agents; Isoxazoles; Kidney; Kidney Transplantation; Leflunomide; Male; Middle Aged; Nitriles; Polyomavirus Infections; Renal Insufficiency; Tacrolimus; Toluidines; Urine; Virus Replication

We have optimized assays to measure mitogen-stimulated rat lymphocyte activation in whole blood and have used these assays to quantitate the potencies of immunosuppressive drugs with different mechanisms of action. To define the optimal conditions for measuring T cell functions in whole blood, the effects of different concentrations of mitogens that activate T cells through calcium-dependent and -independent pathways were measured over time. Proliferation was measured by tritium-labeled thymidine ([3H]-TdR) incorporation and by flow cytometric analysis of proliferating cell nuclear antigen (PCNA)/DNA content. Furthermore, we detected the increases in percent expression of cell-surface activation antigens (CD25, CD134, CD71, CD11a and CD54). Concanavalin A (Con A) stimulated maximum lymphocyte proliferation and expression of T cell surface activations by 72-96 h, which was 48 h later than stimulation by phorbol 12-myristate 13-acetate (PMA) plus anti-CD28 monoclonal antibody (mAb) or PMA plus ionomycin (IONO). Addition of sirolimus, tacrolimus, cyclosporine or the active metabolite of leflunomide, A77 1726, to mitogen-stimulated whole blood produced drug concentration-dependent inhibitions of lymphocyte proliferation and expression of cell surface activation antigen expression. From these data, we determined drug potencies (inhibitory concentration of 50%, IC(50)) and drug concentrations causing maximum inhibition of T cell functions (I(max)). We developed simple and reproducible assays to measure different lymphocyte functions in whole blood cultures. These assays were used to investigate the mechanisms of different immunosuppressive drugs. These methods can be exploited to measure T cell functions in blood collected from subjects treated with immunosuppressants in vivo.

Topics: Aniline Compounds; Animals; Blood; Calcium; CD28 Antigens; Concanavalin A; Crotonates; Cyclosporine; Flow Cytometry; Hydroxybutyrates; Immunosuppressive Agents; Ionomycin; Kinetics; Lymphocyte Activation; Male; Mitogens; Nitriles; Rats; Rats, Inbred Lew; Sirolimus; T-Lymphocytes; Tacrolimus; Tetradecanoylphorbol Acetate; Toluidines