Factors Affecting eGFR Slope of Renal Transplant Patients During the First 2 Years

In healthy individuals, glomerular filtration rate decreases by 1 mL/min/y after a peak level of 125.0 mL/min has been reached in adulthood. Any reduction greater than this is a progressive slope (slope more negative than -1 mL/min/y, stable [-1 to +1]), or an improvable slope if it shows more of an increase, that is, greater than +1.0 mL/min/y). The aim of the study was to determine the factors affecting estimated glomerular filtration rate (eGFR) slope during the first 2 years of renal transplant in patients with negative pretransplant panel-reactive antibody.

The characteristics of 59 renal transplant patients, such as age, sex, etiology, and 2 years of laboratory data, were collected retrospectively. For each patient, the eGFR decline rate (slope) (mL/min-1/1.73 m²-1/y-1) was determined by linear regression analysis using all calculated eGFR values over the study period.

Of 59 patients, 7 (11.8%) had a progressive slope, 22 (37.2%) had a stable slope, and 30 (50.8%) had an improvable slope. The first-year mean tacrolimus level was lower in patients with progressive slope than in the patients with stable slope and improvable slope (P < .022). The determinants of eGFR slope in multiple regression analysis were post-transplant hypertension (β = -0.393; P = .002) and the first-year mean tacrolimus level (β = 0.320; P = .01), whereas age, serum albumin, and 2-year mean tacrolimus level did not reach the level of significance.

Keeping tacrolimus levels high in the first year to prevent eGFR declining is important.