Hypocomplementemic urticarial vasculitis or systemic lupus erythematosus?
The 2 patients presented here showed the typical signs of hypocomplementemic urticarial vasculitis syndrome (HUVS). During follow-up, there was an inverse correlation between anti-C1q autoantibody titer and C1q antigen concentration in serum in both patients over a period of 2 years. The first patient had nephritis characterized by immune deposits in glomeruli and around the tubules. The histological findings, C1q deposits, and presence of tubuloreticular inclusions in capillary endothelial cells suggested a disease process identical to systemic lupus erythematosus (SLE). The second patient, after a lag phase of 2 years, fulfilled a fourth American College of Rheumatology criteria for SLE when she developed anti-double-stranded DNA antibodies. HUVS and SLE overlap, and the criteria for identifying HUVS as an entity distinct from SLE are lacking.
Trendelenburg
M
M
Laboratory of Immunonephrology and Clinic of Medicine B, University Hospital, Basel, Switzerland. trendelenbur@ubaclu.unibas.ch
Courvoisier
S
S
Späth
P J
PJ
Moll
S
S
Mihatsch
M
M
Itin
P
P
Schifferli
J A
JA
D000328:Adult; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D001706:Biopsy; D015922:Complement C1q / Q000172:deficiency* / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007678:Kidney Glomerulus / Q000276:immunology / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008181:Lupus Nephritis / Q000175:diagnosis / Q000276:immunology / Q000473:pathology; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
D015922:Complement C1q