Changing pattern of chronic renal failure and renal replacement therapy in children and adolescents: a 20-year single centre study

Characteristics and survival of young adults who started renal replacement therapy during childhood

BACKGROUND

Little is known about the group of children on renal replacement therapy (RRT) who reach the age of 18 years and are transferred from paediatric to adult nephrology services. The aim of this study was to describe patient demographics, primary renal diseases, treatment history and determine the risk factors for mortality of these young adults who started RRT in childhood.

METHODS

We included 1777 young adults who had started RRT during childhood and turned 18 between 1985 and 2004 from nine European renal registries submitting data to the ERA-EDTA Registry. The chi-square test was used to test differences between patient groups and Cox regression analysis to examine patient survival.

RESULTS

Young adults who began RRT during childhood increased the total number of adult patients starting RRT by 1.5% per annum. The annual number of children on RRT turning 18, per million persons (Pmarp) reaching the age of 18 years, increased between 1985 and 2004 from 71 to 116. Over time, there was an increase in the percentage of young adults who started RRT at a very young age, a greater number of children with hypoplasia/dysplasia and cystic kidneys and more young adults who started RRT with peritoneal dialysis or pre-emptive transplantation. The unadjusted 5-year patient survival from the 18th birthday was 95.1% (95% CI 93.9-96.0). The average life expectancy was 63 years for young adults with a functioning graft and 38 years for those remaining on dialysis.

CONCLUSIONS

The number Pmarp of young adults on RRT has increased over time. Their characteristics and treatment history changed. Their survival prospects are good; however, transplant recipients have an expected remaining lifetime that is at least twice as high as for young adults on dialysis.

Chronic renal failure in Kuwaiti children: an eight-year experience

Over an 8-year period (January 1996 to December 2003), a total of 171 patients below the age of 15 years were diagnosed with chronic renal failure. The mean incidence rate of CRF in Kuwaiti children was found to be 38.2 per million children per year, with a peak incidence of 55 per million children per year. While the mean age at diagnosis was 33+/-12 months (range: 1 month to 15 years), the male:female ratio was 2.7:1. Etiological factors for chronic renal failure included congenital urological malformation (61.9%), chronic glomerulopathies (5.2%), hereditary nephropathies (21%), multi-system disease (0.5%), chronic pyelonephritis (without VUR) (4.6%), tumors (0.6%), ischemic renal disease (1.1%) and unknown etiology (1.7%). Thirty percent of patients reached end-stage renal disease within a mean of 18 months following diagnosis. The overall mortality before reaching ESRD was reported to be 4%. Kuwait has one of the highest incidence and prevalence rates of CRF in children. It is likely that genetic and hereditary factors are the cause of these high rates.

Renal replacement therapy in children: data from 12 registries in Europe

In June 2000 the ERA-EDTA Registry office moved to Amsterdam and started collecting core data on renal replacement therapy (RRT) entirely through national and regional registries. This paper reports the pediatric data from 12 registries. The analysis comprised 3,184 patients aged less than 20 years and starting RRT between 1980 and the end of 2000. The incidence of RRT rose from 7.1 per million of age-related population (pmarp) in the 1980-1984 cohort to 9.9 pmarp in the 1985-1989 cohort, and remained stable thereafter. The prevalence increased from 22.9 pmarp in 1980 to 62.1 in 2000. Hemodialysis was the commonest form of treatment at the start of dialysis, but peritoneal dialysis gained popularity during the late 1980s. Pre-emptive transplantation accounted for 18% of the first treatment modality in the 1995-2000 cohort. The relative risk of death of patients starting dialysis in the period 1995-2000 was reduced by 36% [adjusted hazard ratio (AHR) 0.64 [95% confidence interval (CI) 0.41-1.00] and that of those receiving a first allograft by 42% [AHR 0.58 (95% CI 0.34-1.00)], compared with patients in the period 1980-1984. The prevalence of RRT in children has continued to rise, while its incidence has been stable for about 15 years. Patient survival has improved in both dialysis patients and transplant recipients. The development of this pediatric registry will form the basis for more-detailed and focused studies in the future.

Cardiac disease in young adult patients with end-stage renal disease since childhood: a Dutch cohort study

BACKGROUND

Cardiovascular disease is the most important cause of death in patients with pediatric end-stage renal disease (ESRD). Yet, few data exist on cardiac function in these patients. We assessed the extent of cardiac abnormality and analyzed its association with potential determinants in young adult patients with pediatric ESRD in a long-term follow-up study.

METHODS

All Dutch living adult patients with ESRD onset at age of 0 to 14 years between 1972 and 1992 were invited for echocardiography and blood pressure assessment. Special attention was paid to evidence of left ventricular hypertrophy (LVH), diastolic dysfunction, and aortic valve calcification. We collected data on determinants by review of all medical charts.

RESULTS

Of all the 187 living patients, 140 participated in the study. Of those, 110 patients had received a transplant and 30 patients were on dialysis. Mean age was 29.2 (20.7 to 41.8) years. Left ventricular mass index (LVMI) exceeded 150 g/m2 in 47% of all male patients and 120 g/m2 in 39% of all female patients, both consistent with LVH. Diastolic dysfunction, defined as an early over atrial transmitral blood flow velocity (E/A ratio) <1, was found in 18 (13%) patients; 27 (19%) had aortic valve calcification. Multiple regression analysis revealed the following: a high LVMI was associated with a current high blood pressure (beta=0.46, P < 0.001) and male gender (beta=0.21, P=0.009), a low E/A ratio with aging (beta=-0.28, P < 0.001) and a glomerular filtration rate (GFR) <25 mL/min/1.73 m2 (beta=-0.29, P < 0.001), and aortic valve calcification with prolonged peritoneal dialysis (beta=0.36, P < 0.001).

CONCLUSION

Young adult patients with pediatric ESRD are at risk for LVH caused by hypertension and for aortic valve calcification. Diastolic function decreases with age and is enhanced by a current low GFR. Prolonged peritoneal dialysis may enhance aortic valve calcification.

Mortality and causes of death of end-stage renal disease in children: a Dutch cohort study

BACKGROUND

To establish mortality rates, causes of death, and determinants of mortality in children with end-stage renal disease (ESRD), we performed a national long-term follow up study.

METHODS

Mortality rate was determined in all Dutch patients with onset of ESRD at ages 0 to 14 years in the period between 1972 and 1992. Causes of death and mortality determinants were investigated in all patients of this cohort who were born before 1979. Data were derived from the Dutch Registry for patients on renal replacement therapy (RRT), medical charts and National Health Database.

RESULTS

Of all 381 patients 85 had died. The overall mortality rate (MR) was 1.57/100 patient-years, and the standardized mortality rate (SMR) was 31.0. The MR for patients 0 to 5 and 6 to 10 years old at onset of ESRD decreased from, respectively, 7.0 (range 0-14.9) to 3.9 (1.2-6.7) and 4.3 (1.1-7.5) to 1.6 (0.3-2.8) between the periods 1972-1981 and 1982-1992. The mortality hazard ratio of relatively long standing dialysis and of long standing hypertension were, respectively, 7.2 (4.4-11.8) and 3.1 (2.1-4.6), of cyclosporine-introduction in transplanted patients 0.3 (0.1-0.4). Overall cerebrovascular accidents (24%) and infections (21%) were the most common causes of death; after 10 years of RRT cardiac death (7/21) was most prevalent. Cardiovascular death was most prominent in dialysis as well as transplanted patients.

CONCLUSION

Survival in children with ESRD has increased over the last 20 years, but the SMR remains high. Early transplantation and a more vigorous approach toward hypertension and infection may be mandatory in order to further reduce mortality.

The impact of dialysis and transplantation on children

Effective methods to treat end stage renal disease (ESRD) in children have become available in the United States during the last 3 decades. Since the United States Congress created the Medicare ESRD Program in 1972, most children with ESRD have the option of Medicare insurance. Medicare expenditures for children with ESRD range from $14,000 for transplant recipients to $43,000 for dialysis patients per year. The tremendous expense of ESRD treatment has led to research to determine which treatment options are associated with the best health outcomes and the best value (quality/cost) for the money spent treating ESRD. The National Kidney Foundation's Dialysis Outcomes Quality Initiative recommends the use of quality of life and health status measures to gauge the impact of renal replacement therapy on quality of life in the ESRD population. In adult patients with renal failure, several generic and disease-specific quality of life measures have been validated and tested for reliability. In contrast, little research using validated and reliable health status measures has been performed in pediatric patients to measure the impact of ESRD. This article summarizes existing literature on how we currently measure the impact of dialysis and transplantation on children, discusses existing health status measures for children and adolescents, and describes how these measures might be used to improve our care of patients and long-term outcomes for children with kidney failure.

Mortality trends in pediatric patients with chronic renal failure

Mortality trends were analyzed in 441 children and adolescents with chronic renal failure (CRF) observed over a 24-year period before and after institution of renal replacement therapy (RRT). A total of 93 patients died. Overall mortality rate (MR) per 100 patient years decreased from 6.6 in 1969-1978 to 2.5 in 1979-1988 and increased slightly to 2.9 in 1989-1992. The fall involved all four modes of treatment: conservative, hemodialysis (HD), continuous peritoneal dialysis (CPD), and transplantation (TX). From 1979-1988 to 1989-1992 MR on conservative and on dialysis treatment changed only slightly and was similar on HD and CPD. An alarming rise in MR was noted after TX in 1989-1992, mainly due to malignant tumors. In 44 patients who died on conservative treatment, the reasons for non-acceptance for RRT were analyzed: in 22 multi-morbidity was the main reason, usually because of a congenital neurological disorder. Some patients died from advanced uremia or unexpected events after the decision to institute RRT. Our experience demonstrates a persistent mortality in pediatric patients with CRF, which in recent years is primarily ascribed to congenital multi-morbid conditions which make RRT unfeasible, infections on dialysis treatment, and malignancies after TX.