A case series of Fabry diseases with CKD in Japan

Background It is well known that kidney injury is vital organ damage in Fabry disease (FD).

Renin–angiotensin system (RAS) inhibitors are known to reduce proteinuria in patients with chronic kidney disease (CKD) by dilating the glomerular export arteries and reducing intraglomerular pressure.

This improvement in intraglomerular pressure, although lowering the glomerular filtration rate, is thought to prevent renal damage and be renoprotective in the long term.

RAS inhibitors may be effective in FD patients with proteinuria to prevent the progression of kidney disease, however, the degree to which they are used in clinical practice is unknown.

Methods The J-CKD-DB-Ex is a comprehensive multicenter database that automatically extracts medical data on CKD patients.

J-CKD-DB-Ex contains data on 187,398 patients in five medical centers.

FD patients were identified by ICD-10.

Clinical data and prescriptions of FD patients between January 1 of 2014, and December 31 of 2020 were used for the analysis.

Results We identified 39 patients with FD from the J-CKD-DB-Ex including those with suspected FD.

We confirmed 22 patients as FD.

Half of the patients received RAS inhibitors.

RAS inhibitors tended to be used in CKD patients with more severe renal impairment.

Conclusions This case series revealed the actual clinical practice of FD patients with CKD.

In particular, we found cases in which patients had proteinuria, but were not treated with RAS inhibitors.

The database was shown to be useful in assessing the clinical patterns of patients with rare diseases.