ESPN 50th Annual Meeting

ESPN 2017


 
Clinical manifestations of systemic oxalosis in Primary Hyperoxaluria type 1: when do which clinical manifestations occur
SANDER F. GARRELFS 1 MICHIEL J.S. OOSTERVELD 1 SALLY-ANNE HULTON 2 MARIO DE MARCHI 3 PIERRE COCHAT 4 BERND HOPPE 5 JAAP W. GROOTHOFF 1

1- DEPARTMENT OF PEDIATRIC NEPHROLOGY, EMMA CHILDREN’S HOSPITAL, ACADEMIC MEDICAL CENTER, UNIVERSITY OF AMSTERDAM, AMSTERDAM, THE NETHERLANDS
2- DEPARTMENT OF NEPHROLOGY, BIRMINGHAM CHILDREN’S HOSPITAL NHS TRUST, BIRMINGHAM, UK
3- MEDICAL GENETICS UNIT, SAN LUIGI UNIVERSITY HOSPITAL, ORBASSANO, TORINO, ITALY
4- DEPARTMENT OF PEDIATRIC NEPHROLOGY, HOSPICES CIVILS DE LYON AND UNIVERSITY DE LYON, LYON, FRANCE
5- DEPARTMENT OF PEDIATRIC NEPHROLOGY, CHILDREN’S HOSPITAL OF THE UNIVERSITY OF BONN, BONN, GERMANY
 
Introduction:

Description of the manifestations of systemic oxalosis in a large European cohort of patients with Primary Hyperoxaluria type 1 (PH1) and analysis of eGFR, plasma oxalate and other potential clinical thresholds for the occurrence of systemic oxalosis.

Material and methods:

Review of all PH1 patients registered in the OxalEurope database, which now includes more than 900 PH patients. We have performed a sub analysis of patients in whom data of sufficient detail was obtained. A more comprehensive dataset will be available in the near future.

Results:

Of the 132 included patients, 51 (38.6%) were found to have at least one manifestation of systemic oxalosis. Bone disorders represented the most frequent manifestation (18.9% (25/132) at diagnosis and cumulatively 30.3% (40/132) at follow up), followed by cardiac (3.8%, 15.2%), cutaneous- and vascular (3.8%, 15.4%), ophthalmologic (7.6%, 12.9%), neurological (4.5%, 8.3%) amongst other manifestations. We found 31 different combinations of symptoms. The majority of manifestations (94%, 48/51) were found in patients with an eGFR <15 ml/min/1.73m2. PH patients were not routinely screened; e.g. 26.5% had not undergone any ophthalmologic evaluation. We report the first patient with manifestations of oxalosis, an eGFR above 50 ml/min/1.73m2 and plasma oxalate level below 30 µmol/l.

Conclusions:

This study highlights the heterogeneity of systemic oxalosis. The high number of reported systemic manifestations of oxalosis might be an underestimate due to the large number of non-systematically screened asymptomatic patients. Evidence of systemic oxalosis in a patient with moderate CKD warrants attention. Our results challenge the current assumption that systemic deposition of oxalate starts when the plasma oxalate level is > 30 µmol/l and the eGFR < 40 ml/min/1.73m2. Therefore, we stress the value of annual screening for systemic oxalosis in PH1 patients with CKD2+.