We have read with interest the letter by Dr D'Ambriosio et al., which highlights the possible underestimation of chronic kidney disease in patients with hereditary transthyretin amyloidosis (ATTR).
In a series of 19 patients with neurological or mixed phenotype of ATTR, D'Ambriosio et al. showed that the combined creatinine–cystatin C equation revealed a more altered estimated glomerular filtration rate than creatinine-based equations. This difference could be related to the decreased muscular mass of patients with symptomatic ATTR, with lower serum creatinine despite altered glomerular filtration.
We are in agreement with this analysis, and we have now implemented in our centres the systematic measurement of serum cystatin C, in addition to serum creatinine, to estimate glomerular filtration rate based on the creatinine-cystatin equation. Our work has also encouraged cardiologists and neurologists to assess annually proteinuria and microalbuminuria in patients followed-up for hereditary ATTR amyloidosis.
In addition to providing an effective evaluation of kidney function, this annual kidney assessment will accurately assess the kidney response to the different therapeutic strategies in hereditary ATTR.
Contributor Information
Justine Solignac, Centre de Néphrologie et Transplantation Rénale, Hôpital de la Conception, Assistance Publique–Hôpitaux de Marseille, Marseille, France.
Noémie Jourde-Chiche, Centre de Néphrologie et Transplantation Rénale, Hôpital de la Conception, Assistance Publique–Hôpitaux de Marseille, Marseille, France.
CONFLICT OF INTEREST STATEMENT
None declared.