Podocyturia in paediatric patients with Fabry disease.

INTRODUCTION

Fabry disease (FD) is a hereditary disorder caused by a deficiency of α-galactosidase A enzyme activity. The transmission of the disorder is linked to the X chromosome.

OBJECTIVES

The objectives of the study were: 1. To quantify the presence of podocytes in paediatric patients with FD and compare them with the value of the measured podocyturia in healthy controls. 2. To determine whether a greater podocyturia is related to the onset of pathological albuminuria in patients with FD. 3. To determine the risk factors associated with pathological albuminuria.

METHODS

We performed an analytical, observational study of Fabry and control subjects, which were separated into 2groups in accordance with the absence of the disease (control group) or the presence of the disease (Fabry group).

RESULTS

We studied 31 patients, 11 with FD and 20 controls, with a mean age of 11.6 years. The difference between the mean time elapsed from the diagnosis of FD to the measurement of podocyturia (40 months) and the onset of pathological albuminuria (34 months) was not significant (p=0.09). Podocytes were identified by staining for the presence of synaptopodin and the mean quantitative differences between both podocyturias were statistically significant (p=0.001). Albuminuria was physiological in 4 of the patients with FD and the relative risk to develop pathological albuminuria according to podocyturia was 1.1 in the control group and 3.9 in the Fabry group, with a coefficient of correlation between podocyturia and albuminuria in the Fabry group of 0.8354. Finally, the 2 risk factors associated with the development of pathological albuminuria were podocyturia (OR: 14) and being aged over 10 years (OR: 18). We found no significant risk with regard to glomerular filtrate renal (GFR) (OR: 0.5) or gender (OR: 1.3). The mean GFR remained within normal values.

CONCLUSION

The detection of podocyturia in paediatric patients with FD could be used as an early marker of renal damage, preceding and proportional to the occurrence of pathological albuminuria.