[Renal amyloidosis revealing a cryopyrin associated periodic syndrome]

Cryopyrin associated periodic syndrome is a rare auto inflammatory disease including three clinical entities with a common genetic cause. Among these three entities, Muckle-Wells syndrome is described as an intermediate phenotype associated with a progressive sensorineural hearing loss and AA amyloidosis. The present case reports a renal AA amyloidosis associated with an IgA nephropathy, revealing a Muckle-Wells syndrome.

The case is reported of a 38-years-old patient who presented a renal failure revealed concomitantly with a macroscopic hematuria exploration. Urological investigations were performed with negative results. The patient had no particular background except urticarial rashes, unlabeled inflammatory rheumatism and a grandmother's amyloidosis. Renal biopsy revealed glomerular, vascular and interstitial AA amyloidosis associated to an IgA nephropathy. This amyloidosis was known to be a part of Muckle-Wells syndrome, and a NLRP3 gene study confirmed the diagnosis.

Cryopyrin associated periodic syndrome is a rare disease and the clinical diagnosis suspicion need genetic confirmation. AA amyloidosis is known to happen in Muckle-Wells syndrome. Other occasional renal impairments are described in this syndrome whereas the IgA nephropathy association remains poorly characterized.