ESPN 53rd Annual Meeting

ESPN 2021


 
Comparison of creatinine and cystatin C-based estimated GFR with respect to severity of spina bifida
EMIL DEN BAKKER 1 DEMI DE VRIES 1 CAROLA MCDONALD 1 DEWIE BAKKER 1 ERIC VAN DER HORST 1 AREND B├ľKENKAMP 1

1- AMSTERDAM UMC
 
Introduction:

Renal damage is a well-recognized complication of spina bifida. Paralysis of the lower extremities­­­­ results in diminished creatinine production and overestimation of GFR by creatinine-based equations. Cystatin C is produced by all nucleated cells and has been shown to be more accurate in spina bifida patients. As the neurological deficit in spina bifida varies with lesion height we aimed to define patients in whom cystatin C measurement is mandatory.

Material and methods:

Cross-sectional analysis of data collected during routine outpatient visits of 73 children with spina bifida (ΔeGFR study) and results of inulin clearance in 24 children. Comparison of the creatinine-based FASage and FASheight equations with the cystatin C-based FAScys equation. Analysis of ΔeGFRage (i.e. FASage-FAScys) and ΔeGFRheight in relation to lesion level, walking impairment and orthopaedic complications. In the clearance study, bias of FASage, FASheight and FAScys was related to lesion level and walking impairment.

Results:

 ΔeGFRage and ΔeGFRheight were directly related to lesion height and significantly higher than zero in lesions ≥L5, in complete wheelchair dependency, presence of scoliosis or contractures. By multivariate linear regression analysis, Both ΔeGFRage, and ΔeGFRheight were significantly related to complete wheelchair dependency and scoliosis/contractures, while lesion height ≥L3 was also related ΔeGFRage. Bias of FAScys was lower than bias of FASage and FASheight in patients with lesions ≥L5 and in fully wheelchair dependent patients.

Conclusions:

 FASage and FASheight overestimate GFR in spina bifida patients with a lesion ≥L5 who are completely wheelchair dependent or have scoliosis/contractures. In this subgroup, measurement of cystatin C is mandatory.