The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) presents an annual report for all transplants registered from January 1987 onwards. In this report we reviewed 6,534 renal transplants recorded for 5,958 patients who had entered the study by January 1999, and attempted to identify changes in practice patterns that had led to improved graft survival. There has been a steady decline in cadaver source transplants nationally and our accrual for 1996 and 1997 reflected this trend. There has also been a decrease in the number of infants and young children receiving a transplant in recent years. From a peak of 23.3% in the 1987-91 cohort, the current report shows that children under 6 yr of age now account for only 20.4% of all transplants. Changing disease patterns and rates of progression of disease have decreased the percentage of Caucasian children in the transplant registry, from 68.5% in the first 5 yr to 62.9% in the most recent cohort. Changing practice patterns have markedly reduced the use of cadaver donor (CD) kidneys (recovered from donors younger than 10 yr of age) from 35% in 1991 to 22% in the current report. Acute rejection patterns are identical for CD and living donor (LD) grafts for the first 2 weeks post-transplant. The comparative percentages on days 30 and 45 are 36% and 44% for CD, and 26% and 32% for LD recipients respectively. By the end of the first year post-transplant, 45% of LD and 60% CD recipients have had an acute rejection. There has been a marked improvement in our ability to reverse the initial episode of rejection; in 1987, 52% were completely reversed in LD recipients, and in 1997 61% were reversed. Rejection percentages continued to be lower in patients maintained on cyclosporin A (CsA) doses of > 6.4 mg/kg. One-, 3-, and 5-yr graft survival probabilities were 91%, 85%, and 80%, respectively, for LD recipients, and 83%, 73%, and 65% for CD recipients. Comparative 1- and 3-yr figures from 1987 to 1991 were 88% and 81% for LD and 74% and 63% for CD recipients. When short-term graft survival (1 yr) results were compared, a significant improvement was demonstrated from 71.7% in 1987/88 to 92.6% in 1998/1999 for CD transplants. Hence, changing practice patterns have gradually brought the short-term graft survival of CD transplants very close to that of LD transplants. The continuing decrease in the incidence of acute rejections in more recent years should translate into a further delay in the onset of chronic rejection, thus improving graft longevity.

End-stage renal disease (ESRD) is a major cause of morbidity in children. Besides its high cost to society, ESRD carries significant mortality. Chronic renal insufficiency (CRI) often precedes ESRD. Identifying factors that correlate with the rate of progression to ESRD is beneficial in the management of children with CRI. Since 1994 the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) has extended its registry to include children with CRI, defined as creatinine clearance (C Cr ) <75 ml/min per 1.73 m 2 . As of January 2001, our database registered 4,666 children (<20 years of age) with CRI. Data analysis showed that at least 40% of patients entered had congenital urological anomalies; 39% of patients were followed for at least 3 years. Follow-up data showed that 31% of all registered patients progressed to ESRD by the end of the reporting period. There was a correlation between CRI and several co-morbid clinical factors: low hematocrit, hypoalbuminemia, hypocalcemia, hyperphosphatemia, and hyperparathyroidism, and the rate of progression to ESRD. Primary clinical diagnosis and the age at entry into registry were additional factors that correlated with the rate of progression to ESRD. The main cause of hospitalization in this registry was infection, which accounted for 45% of hospital admissions. Growth delay measured by standard deviation score at baseline was -1.40 at the time of registration. Our data suggest potential areas of improved care that could impact the onset of ESRD.Keywords Chronic renal failure · Etiology · Treatment A. Tejani is deceased.

The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) presents an annual report for all transplants registered from January 1987 onwards. In this report we reviewed 6,534 renal transplants recorded for 5,958 patients who had entered the study by January 1999, and attempted to identify changes in practice patterns that had led to improved graft survival. There has been a steady decline in cadaver source transplants nationally and our accrual for 1996 and 1997 reflected this trend. There has also been a decrease in the number of infants and young children receiving a transplant in recent years. From a peak of 23.3% in the 1987-91 cohort, the current report shows that children under 6 yr of age now account for only 20.4% of all transplants. Changing disease patterns and rates of progression of disease have decreased the percentage of Caucasian children in the transplant registry, from 68.5% in the first 5 yr to 62.9% in the most recent cohort. Changing practice patterns have markedly reduced the use of cadaver donor (CD) kidneys (recovered from donors younger than 10 yr of age) from 35% in 1991 to 22% in the current report. Acute rejection patterns are identical for CD and living donor (LD) grafts for the first 2 weeks post-transplant. The comparative percentages on days 30 and 45 are 36% and 44% for CD, and 26% and 32% for LD recipients respectively. By the end of the first year post-transplant, 45% of LD and 60% CD recipients have had an acute rejection. There has been a marked improvement in our ability to reverse the initial episode of rejection; in 1987, 52% were completely reversed in LD recipients, and in 1997 61% were reversed. Rejection percentages continued to be lower in patients maintained on cyclosporin A (CsA) doses of > 6.4 mg/kg. One-, 3-, and 5-yr graft survival probabilities were 91%, 85%, and 80%, respectively, for LD recipients, and 83%, 73%, and 65% for CD recipients. Comparative 1- and 3-yr figures from 1987 to 1991 were 88% and 81% for LD and 74% and 63% for CD recipients. When short-term graft survival (1 yr) results were compared, a significant improvement was demonstrated from 71.7% in 1987/88 to 92.6% in 1998/1999 for CD transplants. Hence, changing practice patterns have gradually brought the short-term graft survival of CD transplants very close to that of LD transplants. The continuing decrease in the incidence of acute rejections in more recent years should translate into a further delay in the onset of chronic rejection, thus improving graft longevity.

This report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) covers the years 1987-1997, and analyses data on 3,133 cadaver donor (CD) transplants performed in 2,736 patients. There has been a steady decline in the number of CD transplants in children since 1996. Kidneys recovered from donors under 10 years of age accounted for 35% of all transplants in 1987, whereas by 1996 they comprised less than 20%. Caucasian children received 54% of CD transplants, whereas African-American children received 21%. Children under 6 years of age received 17% of CD transplants. Approximately half (46%) of the patients were induced with a T-cell antibody, and at 7 years post-transplant triple therapy is used in 70% of those with a functioning graft. Cyclosporin A is the primary immunosuppressant, with 92% of the patients being maintained on it at 5 years post-transplant. Among patients receiving a transplant in 1997, 11% were initiated with another calcineurin inhibitor, tacrolimus. At 15 days post-transplant 20% of the patients have had a rejection episode and by day 45, 46% have had an acute rejection. The probability of developing a rejection within the first year was reduced from 71% in 1987-1988 to 47% in 1995-1996.

Chronic rejection accounted for 32% of all graft losses in 7123 pediatric transplants. In a previous study acute, multiple acute and late acute rejections were risk factors for the development of chronic rejection. We postulated that the recent decrease in acute rejections would translate into a lower risk for chronic rejection among patients with recent transplants. We reviewed our data on patients transplanted from 1995 to 2000, and using multivariate analysis and a proportional hazards model developed risk factors for patients whose grafts had failed due to chronic rejection. A late initial rejection increased the risk of chronic rejection graft failure 3.6-fold (p ∞0.001), while a second rejection resulted in further increase of 4.2-fold (p ∞0.001). Recipients who received less than 5 mg/kg of cyclosporine at 30 days post-transplant had a relative risk (RR) of 1.9 (p Ω0.02). Patients transplanted from 1995 to 2000 had a significantly lower risk (RR Ω 0.54, p ∞0.001) of graft failure from chronic rejection than those who received their transplants earlier (1987-94). Since we were able to demonstrate that there is a decreased risk of chronic rejection graft failure in our study cohort, we would conclude that the goal of future transplants should be to minimize acute rejections.