Care of the kidney transplant recipient. Vigilant monitoring creates the best outcome

Kidney transplant recipients require careful follow-up in both the early (< 6 months) and late posttransplant periods. Monitoring should focus on graft function and the most common complications of immunosuppression therapy. Infections, especially CMV infection, require particular attention in the first few months after transplantation, when immunosuppression is most intense. In both the early and the late posttransplant periods, an emphasis should be placed on intensive management of CVD risk factors (e.g., hypertension, hyperlipidemia, cigarette smoking). Screening for malignancies known to occur with a high incidence after transplantation is also important. With the improved short-term survival rates brought about by new, potent immunosuppressive agents, emphasis has now shifted to the prevention and treatment of posttransplant complications in kidney transplant recipients. A heightened awareness of these complications, along with a cooperative effort between primary care physicians and transplant programs, offers the best hope for further improvement in outcomes after kidney transplantation.

A thirty percent chronic decline in inverse serum creatinine is an excellent predictor of late renal allograft failure

We previously reported that the percentage of change in inverse serum creatinine (Delta1/Cr) was the best of several time-dependent serum creatinine-derived predictors of renal allograft failure in patients not administered cyclosporine (CsA). To further validate the utility of Delta1/Cr, we collected creatinine levels (mean, 90.7 +/- 45.2 creatinine measurements) in 100 patients treated for 6.7 +/- 5.9 years with CsA. We also validated Delta1/Cr using a limited creatinine-sampling strategy, then performed multivariate Cox proportional hazards analysis of 1,663 transplantations. A time-dependent covariate determined by the date of first chronic decline (excluding creatinine levels from periods of acute rejection) in Delta1/Cr to less than -30% of baseline similarly was predictive of graft failure in 101 patients treated without CsA (relative risk, 5.04; 95% confidence interval, 2.18 to 11.6; P = 0.0002) and 100 patients treated with CsA (relative risk, 5.02; 95% confidence interval, 2.50 to 10.1; P < 0.0001). A limited creatinine-sampling strategy (measured at 1 week, 1, 3, 6, 12, 18, 24, and 36 months, and each year thereafter) reduced the ability of Delta1/Cr less than -30% to predict graft failure. In 1,663 patients, Delta1/Cr less than -30% first occurred a median of 1.0 years posttransplantation (n = 792 of 1,663 patients) and 3.0 years before graft failure (n = 478 of 897 patients with graft failure). In a multivariate model (n = 1,663) that included baseline function, acute rejection, and other covariates, Delta1/Cr less than -30% was a strong independent predictor of graft failure (relative risk, 2.56; 95% confidence interval, 2.12 to 3.09; P < 0.0001). Thus, Delta1/Cr less than -30% is an excellent predictor of graft failure that is similarly predictive in patients treated with and without CsA. A limited sampling strategy for creatinine diminishes, but does not negate, the usefulness of Delta1/Cr less than -30%.

Defining the risk of elective cyclosporine withdrawal in stable kidney transplant recipients

Although it is known that elective cyclosporine (CsA) withdrawal increases the risk for acute rejection, few studies have been large enough to identify risk factors for acute rejection after CsA withdrawal. We examined risk factors for acute rejection in 464 kidney transplant recipients who underwent elective CsA withdrawal. The incidence of acute rejection within 6 months of CsA withdrawal was 20/141 (14.2%) in the period January 1986 to May 1989, but only 14/323 (4.5%) since May 1989 (p = 0.0002). Among those transplanted since May 1989, the incidence was 5/20 (25%) for those with both 2 HLA-B and 2 HLA-DR mismatches, compared with only 9/298 (3.0%) for those with fewer mismatches (p < 0.0001). In Cox proportional hazards analysis, risk factors for acute rejection within 6 months, or at any time after elective CsA withdrawal, were date of transplant January 1986 to May 1989 (compared with more recently May 1989 to March 1999), younger age, obesity, as well as B and DR mismatches. Recipient race (83% were white), acute rejection during the first year before withdrawal (31%), mycophenolate mofetil (17%), and other variables failed to predict postwithdrawal acute rejection. We concluded that avoiding CsA withdrawal in the relatively small number of recipients with both 2 HLA-B and 2 HLA-DR mismatches could further reduce our already low incidence of acute rejection following elective CsA withdrawal.

Comparing methods for monitoring serum creatinine to predict late renal allograft failure

Few studies have systematically investigated what changes in chronic renal allograft function best predict subsequent graft failure, when these changes occur, and whether they occur soon enough to allow possible intervention. We collected serum creatinine values (mean, 183 +/- 75 values/patient) measured over a maximum follow-up of 22 years in 101 consecutive renal transplant recipients (excluding creatinine levels from periods of acute rejection). We determined the dates of first decline in inverse creatinine (Delta1/Cr; < -20%, -30%, -40%, -50%, and -70%), declines in estimated creatinine clearance (CCr; <55, 45, 35, 25, and 15 mL/min), and declines in measured slope of 1/Cr over time. We used time-dependent covariates in Cox proportional hazards analyses to determine the relative effect of each renal function parameter on outcomes while adjusting for other risk factors. The best predictor of subsequent graft failure was Delta1/Cr. Delta1/Cr less than -40% first occurred at a median of 1.28 years after transplantation in 73 patients, and 67 patients went on to have graft failure a median of 3.28 years after Delta1/Cr less than -40%. The independent relative risk for graft failure attributable to Delta1/Cr less than -40% was 5.91 (95% confidence interval, 3.25 to 10.8; P < 0.0001). A decline in CCr, eg, less than 45 mL/min, also was a strong predictor of subsequent graft failure. Conversely, declines in allograft function estimated from slopes of 1/Cr were poor predictors of graft failure. In analysis limited to patients followed up for 2.5 years or less, Delta1/Cr continued to predict graft failure, suggesting that Delta1/Cr will be a useful predictor in populations with shorter follow-up. If confirmed in other populations, eg, patients treated with calcineurin inhibitors, this simple marker of chronic allograft dysfunction may prove to be a practical tool for defining patients at high risk for late graft failure.

Dyslipidemia and its management after renal transplantation

Dyslipidemias are common after renal transplantation. Most common are elevations in total and low-density lipoprotein cholesterol. Causes of dyslipidemia are usually multiple, but include immunosuppression (especially prednisone, cyclosporine and sirolimus), graft dysfunction (reduced glomerular filtration rate and proteinuria), and genetic predisposition. There is a growing amount of evidence suggesting that dyslipidemias contribute to the very high incidence of cardiovascular disease after transplantation. Less well established is whether the associations between dyslipidemias and graft dysfunction are due to a causal role of lipid abnormalities on renal injury. In any case, hypercholesterolemia, and especially increases in low density lipoprotein cholesterol, should be treated using guidelines established for patients in the general population.