Characteristics and Outcomes of Children with Primary Oxalosis Requiring Renal Replacement Therapy

Abstract

SummaryBackground and objectives Primary hyperoxaluria (PH) as a cause of ESRD in children is believed to have poor outcomes. Data on management and outcomes of these children remain scarce.Design, setting, participants, & measurements This study included patients aged ,19 years who started renal replacement therapy (RRT) between 1979 and 2009 from 31 countries providing data to a large European registry.Results Of 9247 incident patients receiving RRT, 100 patients had PH. PH children were significantly younger than non-PH children at the start of RRT. The median age at RRT of PH children decreased from 9.8 years in 1979-1989 to 1.5 years in 2000-2009. Survival was 86%, 79%, and 76% among PH patients at 1, 3, and 5 years after the start of RRT, compared with 97%, 94%, and 92% in non-PH patients, resulting in a three-fold increased risk of death over non-PH patients. PH and non-PH patient survival improved over time. Sixty-eight PH children received a first kidney (n=13) or liver-kidney transplantation (n=55). Although the comparison was hampered by the lower number of kidney transplantations primarily derived from the earlier era of RRT, kidney graft survival in PH patients was 82%, 79%, and 76% at 1, 3, and 5 years for liver-kidney transplantation and 46%, 28%, and 14% at 1, 3, and 5 years for kidney transplantation alone, compared with 95%, 90%, and 85% in non-PH patients. ConclusionsThe outcomes of PH children with ESRD are still poorer than in non-PH children but have substantially improved over time.

Combined liver and kidney transplantation in children

“…In the large European registry, the kidney graft survival rate in PH1 patients was 82, 79, and 76 % at 1, 3, and 5 years, respectively, for CLKT. These percentages are still about 10 % lower than those observed in patients with isolated KT for reasons other than PH1 [23]. Due to the oxalate load, the recovery of renal function is often delayed in PH1 patients [29].…”

“…Better survival following CLKT for PH1 has been attributed to early diagnosis, short time on dialysis, and good condition of the patient (less complications of oxalosis) before the operation. In two recent registry reports, kidney graft survival rates in PH1 patients were 79 and 84 %, respectively, at 3 years [23,27].…”

“…Early and aggressive conservative management, including high fluid intake, oxalate crystallization inhibitors, and pyridoxine, may preserve renal function and delay the development of ESRD [22]. Infantile PH1, which nowadays represents almost half of the cases, however, often progresses rapidly, and ESRD is reached before the age of 2-3 years [23]. The most recent recommendations for the diagnostics and management of PH1 were published in 2012 by the OxalEurope Study Group (Table 2) [24].…”

Primary and secondary hyperoxaluria: Understanding the enigma

“…At least 1% of the ESRD seen in the pediatric population is attributable to PH1 in European and Japanese studies [48,49] . It is more frequently seen in Kuwaiti and Tunisian populations where consanguineous marriages are practiced [50,51] .…”

“…Isolated kidney transplantation may be the procedure of choice for adult patients who are sensitive to pyridoxine [96] . However, in isolated renal transplant, allograft survival rates have been reported to be inferior in patients with primary hyperoxaluria compared to patients who received renal transplant for a non PH1 cause of ESRD [48] . Thus, caution should be exercised while advocating this approach.…”