Cyclosporine lymphocyte maximum level: a new alternative for cyclosporine monitoring in kidney transplantation.

Objectives: To determine the relationship between clinical outcome, lymphocyte count (LC), and cyclosporine (CsA) lymphocyte maximum level (LT(m)L) in kidney transplant recipients.

Materials And Methods: CsA LT(m)L was determined in patients with biopsy-proven graft dysfunction and in patients with normal graft function. Clinical outcome was compared according to CsA LT(m)L, dosage, blood trough (C(0)) and maximum (C(max)) levels, hematocrit level, and LC.

Results: Rejecting patients had significantly lower LT(m)L than did those with normal graft function (27 -/+ 11 pg/Lc vs 71 -/+ 79 pg/Lc; P < 0.01) and similar LTmL to those with nephrotoxicity (27 -/+ 8 pg/Lc). Patients with normal graft function exhibited significantly lower LC (0.001292 -/+ 696 x 10(9)/L) and serum creatinine levels (88.4 -/+ 35 micromol/L) when compared with rejecting patients (0.001717 -/+ 364 x 10(9)/L, 132.6 -/+ 8.8 micromol/L) and those with nephrotoxicity (0.001884 -/+ 582 x 10(9)/L, 123.7 -/+ 8.8 micromol/L) (P < 0.03, P < 0.001). No significant difference was observed among the 3 groups with regard to CsA dosage, C(0), C(max), mycophenolate mofetil (MMF) dosage, and mycophenolic acid (MPA) plasma levels. CsA LT(m)L closely correlated in an exponential (R(2) = 0.98) and linear (R(2) = 0.35) fashion with LC and hematocrit level, respectively. Conversely, CsA C(max) failed to correlate with C(0) and these 2 latter parameters. Weak correlations were observed between CsA C(max) and its corresponding LT(m)L.

Conclusions: CsA LT(m)L appears to correlate better than CsA C(max) with rejection-free outcome and LC. An increase in hematocrit appears to have an adverse effect on CsA lymphocyte binding. CsA LT(m)L may offer a new alternative for CsA monitoring in kidney transplantation.