Renal involvement in hypocomplementaemic urticarial vasculitis syndrome: a report of three paediatric cases

To describe the diagnosis and management of renal disease in three paediatric cases of hypocomplementaemic urticarial vasculitis syndrome (HUVS).

Three children who were diagnosed with HUVS and developed abnormalities of renal function during the disease course are described.

Urinary findings were heterogeneous: all the patients developed persistent microhaematuria, which was isolated in patient 1, associated with mild proteinuria in patient 2 and with nephrotic syndrome in patient 3. Renal biopsies were performed in all the patients: patients 1 and 2, who had normal levels of serum autoantibodies, shared a full-house IF (C3, C1q and Ig deposits), compatible with an SLE-like disease; patient 3 showed negative staining for IgG and IgM, but developed positive anti-dsDNA without fulfilling criteria for the diagnosis of SLE.

Renal involvement in HUVS is probably more frequent and more severe than in adults and may appear later. Isolated microhaematuria can be the only sign of subclinical renal involvement: its role should not be underestimated and a renal biopsy should be considered. Previous observations of rapidly progressive nephritis and consequent end-stage renal disease in children suggest the need for prompt diagnosis and treatment of renal involvement.