Donor factors influencing graft outcomes in live donor kidney transplantation.

Living donor renal allograft survival is superior to that achieved from deceased donors, although graft outcome is suboptimal in some of these patients. In an effort to identify the subset of patients at high risk for poor outcomes we studied donor risk factors in 248 living kidney donor-recipient pairs. Unadjusted donor (125)I-iothalamate GFR (iGFR), donor age more than 45 years, donor total cholesterol level less than 200 mg/dL, and donor systolic blood pressure (SBP) less than 120 mm Hg were correlated with allograft estimated glomerular filtration rate (eGFR), and incidence of acute rejection (AR), delayed graft function and/or graft loss at 2 years posttransplantation. Donor iGFR less than 110 mL/min (slope=-7.40, P<0.01), donors more than 45 years (slope=-8.76, P<0.01), donor total cholesterol levels more than 200 mg/dL (slope=-10.03, P<0.01), and SBP more than 120 mm Hg (slope=-5.60, P=0.03) were associated with lower eGFR. By multivariable linear regression analysis these variables remained independently associated with lower eGFR, and poorer outcomes. The increasing number of donor factors (age, iGFR, cholesterol, and blood pressure) was directly associated with worse posttransplant eGFR (P<0.01). In conclusion, our data suggest that routine assessment of living donor parameters could supplement the consideration of recipient characteristics in predicting posttransplant risk of graft injury/dysfunction.

Dosing intervals and hemoglobin control in patients with chronic kidney disease and anemia treated with epoetin alfa or darbepoetin alfa: a retrospective cohort study.

BACKGROUND: Anemia is a common complication of chronic kidney disease (CKD). The approved dosing interval for currently available erythropoiesis-stimulating agents (ESAs) is 2 to 3 times weekly for epoetin alfa (EPO) and every 1 to 2 weeks for darbepoetin alfa (DARB). However, clinicians sometimes use less frequent dosing in the interest of convenience. OBJECTIVES: This study investigated patterns of actual ESA use (doses and dosing intervals) and hemoglo- bin (Hb) control in adult outpatients with CKD not requiring dialysis at the Cleveland Clinic Foundation anemia clinic. The distribution of and variability in Hb levels in these patients were also examined. METHODS: The clinical charts and electronic records of adult outpatients with CKD who initiated ESA therapy before March 2005 were reviewed to identify the initial, dominant (used for the longest consecutive period), and final dosing intervals and mean weekly doses of EPO and DARB. Hb control was examined in terms of maximum deviations >12 g/dL and <11 g/dL, and the proportions of measurements outside these values. RESULTS: The analysis included data from 111 outpatients (mean [SD] age, 65.9 [14.4] years; 53.2% male; 66.7% white, 29.7% black, 2.7% other, 0.9% unknown ethnicity). Twenty-one patients received EPO only, 74 received DARB only, and 16 switched ESAs. The mean duration of follow-up was 20.5 months. The most common initial dosing intervals were qwk for EPO (66.7%) and q2wk for DARB (90.5%). The dominant dosing intervals were q2wk in 61.9% of EPO patients and q3wk in 62.3% of DARB patients. However, 80.0% of those who received EPO q2wk and 63.2% of those who received DARB q3wk eventually returned to their initial dosing intervals. The largest proportions of Hb mea- surements <11 g/dL occurred at dominant dosing intervals of qwk for EPO and q2wk for DARB (both, 46.0%; 11 and 26 patients, respectively), whereas the largest proportions of measurements >12 g/dL occurred with EPO dosed at q2wk (44.0%; 5 patients) and DARB dosed at >q4wk (62.0%; 5 patients). CONCLUSIONS: The patterns of ESA usage in adult outpatients with CKD at this center indicated that clinicians extended dosing intervals beyond those in the approved prescribing information. However, variations in Hb concentrations occurred during maintenance therapy administered at extended dosing intervals, resulting in the resumption of shorter dosing intervals in the majority of patients.

Differences in proteinuria and graft function in de novo sirolimus-based vs. calcineurin inhibitor-based immunosuppression in live donor kidney transplantation.

BACKGROUND: Calcineurin inhibitor(CNI)-free protocols using sirolimus (SRL) in kidney transplantation have proven effective, although reports have linked SRL to proteinuria. We sought to investigate this link and its impact on graft function. METHODS: We retrospectively analyzed 184 live donor kidney transplant recipients who exclusively received de novo CNI-based (n = 106) or SRL-based (n = 78) regimens. Estimated glomerular filtration rate (GFR) and semi-quantitative dipstick proteinuria measurements were obtained at one, six, 12, and 24 months and six and 12 months, respectively. RESULTS: SRL-treated patients had higher frequencies of proteinuria (> or =1+) at 6 months (40.8% vs. 21.4%, P = 0.006) and 12 months (37.8% vs. 18.4%, P = 0.004) than those treated with CNI. Independent predictors of proteinuria at 12 months were GFR at one month (OR 0.62 per 10 ml/min/1.73 m, P<0.001), delayed graft function (OR 11.5, P = 0.02), and a SRL-based regimen (OR 4.18, P=0.002). By univariable analysis, SRL vs. CNI patients had higher GFR at each point. SRL-treated patients without proteinuria had higher GFR at 12 months compared to CNI-treated patients with and without proteinuria (66 vs. 50 or 56 ml/min/1.73 m, P < 0.05). No difference in GFR was seen between SRL-treated patients with proteinuria vs. CNI-treated patients without proteinuria (57 vs. 56 ml/min/1.73 m, P > 0.05). Absence of proteinuria and a SRL-based regimen remained independently associated FS with higher GFR at 12 months by multivariable analyses. CONCLUSIONS: De novo SRL-based immunosuppression is associated with a higher frequency of semi-quantitative proteinuria, however, estimated graft function at 1 year posttransplant remains superior to that of CNI-treated patients. Nevertheless, the long-term implications of these findings need to be determined.

Performance of the Cockcroft-Gault and modification of diet in renal disease equations in estimating GFR in ill hospitalized patients.

BACKGROUND: Estimating glomerular filtration rate (GFR) in severely ill inpatients is clinically important for therapeutic interventions and prognosis, but notoriously difficult to do accurately. The Modification of Diet in Renal Disease (MDRD) equation and Cockcroft-Gault (CG) formula are widely used to estimate renal function in sick hospitalized patients; however, neither method has been validated in this setting. METHODS: Iodine 125-iothalamate clearances (iGFR) performed in 107 sick inpatients with renal dysfunction were compared with estimated GFRs (eGFRs) from the 6- and 4-variable MDRD (MDRD eGFR) and CG (CG eGFR) equations. RESULTS: Mean serum creatinine (SCr) level was 3.5 +/- 2.0 mg/dL (309 +/- 177 micromol/L), and mean iGFR was 17.1 +/- 17.9 mL/min/1.73 m2 (0.29 +/- 0.30 mL/s/1.73 m2). Six-variable MDRD eGFR was 22.5 +/- 17.4 mL/min/1.73 m2 (0.38 +/- 0.29 mL/s/1.73 m2), 4-variable MDRD eGFR was 23.9 +/- 16.3 mL/min/1.73 m2 (0.40 +/- 0.27 mL/s/1.73 m2), and CG eGFR was 26.0 +/- 17.1 mL/min/1.73 m2 (0.43 +/- 0.29 mL/s/1.73 m2). Blood urea nitrogen (BUN)/SCr ratios greater than 20 were seen in 58% of patients. Overall, the CG and MDRD equations overestimated iGFR, with poor agreement. Overestimation of at least 25% of measured iGFR was seen in 63%, 67%, and 70% of all inpatients when using the 6-variable MDRD, 4-variable MDRD, and CG equations, respectively. Accuracy of eGFR within 50% of measured iGFR was 55% for the 6-variable MDRD equation, 49% for the 4-variable MDRD equation, and 40% for the CG formula. The performance of both methods deteriorated further in patients with a BUN/SCr ratio greater than 20. CONCLUSION: Estimation equations are performed poorly compared with iGFR and are not reliable measures of actual level of function in sick hospitalized patients, especially those with a high BUN/SCr ratio. Although use of the 6-variable MDRD equation provides a better estimation of GFR, it still is unsuitable for clinical application in this population.