Hypocomplementemic urticarial vasculitis or systemic lupus erythematosus?

The 2 patients presented here showed the typical signs of hypocomplementemi c urticarial vasculitis syndrome (HUVS), During follow-up, there was an inv erse correlation between anti-C1q autoantibody titer and C1q antigen concen tration in serum in both patients over a period of 2 years, The first patie nt had nephritis characterized by immune deposits in glomeruli and around t he tubules, The histological findings, C1q deposits, and presence of tubulo reticular inclusions in capillary endothelial cells suggested a disease pro cess identical to systemic lupus erythematosus (SLE), The second patient, a fter a lag phase of 2 years, fulfilled a fourth American College of Rheumat ology criteria for SLE when she developed anti-double-stranded DNA antibodi es. HUVS and SLE overlap, and the criteria for identifying HUVS as an entit y distinct from SLE are lacking. (C) 1999 by the National Kidney Foundation , Inc.