The MDRD equation may mask decline of glomerular filtration rate in Fabry patients with normal or nearly normal kidney function.

AIMS: The renal prognosis in Fabry disease is better when enzyme replacement therapy (ERT) is initiated before glomerular filtration rate (GFR) deteriorates. Current studies evaluating kidney function in Fabry disease are mainly based on the MDRD equation. The aim of this cross sectional study was to compare estimated and measured GFR in adult Fabry patients with normal or near normal kidney function.

METHODS

Iohexol GFR (mGFR) was compared to estimated GFR (eGFR) (MDRD, Cockcroft-Gault and Counahan-Barratt equations) in 8 male and 13 female Fabry patients with minimal albuminuria and mean mGFR of 94 ml/min/1.73 m2 for both genders.

RESULTS

A significant overestimation of eGFR-MDRD by 24 ml/min/1.73 m2 was seen in male Fabry patients. The performance of the MDRD equation was similar to mGFR in female Fabry patients. GFR was significantly overestimated by the Cockcroft-Gault equation, whilst Counahan-Barratt equation gave results in agreement with mGFR for both male and female Fabry patients.

CONCLUSIONS

Overestimation of eGFR-MDRD in Fabry patients with CKD stage 1 - 2 and minimal albuminuria may prevent recognition of early progressive renal failure and delayed ERT initiation may be the consequence. Exact GFR markers should be part of the routine evaluation of GFR in Fabry patients.