title: C2 deficient systemic lupus erythematosus: its association with anti-Ro (SSA) antibodies.
abstract: C2 deficiency is the most common complement component deficiency. While individuals with C2 deficiency may be completely normal, a lupus erythematosus-like disease process has developed in some. A 28-year-old woman had a chronic photodermatitis, arthralgias, and mesangial lupus nephritis, She has C2 deficiency associated with an HLA-Dw2 transplantation antigen. Her serum has shown antibodies to the macromolecule Ro (the A antigen in Sjögren's syndrome), while failing to demonstrate antinuclear antibodies in routine laboratory determinations.
mesh_terms: D000328:Adult; D000941:Antigens / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D001324:Autoantigens; D003175:Complement C2 / Q000172:deficiency* / Q000235:genetics; D005260:Female; D015802:HLA-DR2 Antigen; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D008297:Male; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D012859:Sjogren's Syndrome / Q000276:immunology*; D000099207:SS-A Antigen
chemical_list: D000941:Antigens; D001323:Autoantibodies; D001324:Autoantigens; D003175:Complement C2; D015802:HLA-DR2 Antigen; D000949:Histocompatibility Antigens Class II; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human