title: Erosive arthritis in systemic lupus erythematosus: analysis of a distinct clinical and serological subset.
abstract: Erosive arthritis (EA) in systemic lupus erythematosus (SLE) can be debilitating and deforming with uncertain factors for risk, although antibodies to the A2 hnRNP core protein, known as anti-RA33, have been associated with EA. Two hundred patients under long-term follow-up for SLE were evaluated for EA and associated clinical and serological abnormalities. In addition, sera were tested in a masked fashion for anti-RA33 antibodies in a total of 60 patients: 10 with EA and 50 age-, sex- and ethnically matched controls. Ten of 200 (5%) patients with SLE, mainly non-white women, had EA. There were trends for increased renal involvement (P = 0.06), Sjögren's syndrome (P = 0.07) and Raynaud's phenomenon (P = 0.03) in patients with EA compared to those without EA. Rheumatoid factor (RF) was increased in patients with EA (P < 0.02), as were antibodies to double-stranded DNA (P < 0.05), Sm (P < 0.01) and La/SS-B (P < 0.001). Anti-RA33 antibodies were present in 70% with EA compared to 28% without EA (P < 0.05). RF correlated with anti-RA33 antibodies in patients with EA, but not with the presence of anti-RA33 alone. Thus, anti-RA33 antibodies may identify those patients with SLE who are at risk for EA, and an association with RF suggests a common immune response or pathological mechanism in autoimmune erosive joint disease.
authors.affiliation: Department of Medicine, University College London.
authors.forename: M
authors.initials: M
authors.lastname: Richter Cohen
authors.forename: G
authors.initials: G
authors.lastname: Steiner
authors.forename: J S
authors.initials: JS
authors.lastname: Smolen
authors.forename: D A
authors.initials: DA
authors.lastname: Isenberg
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood*; D001168:Arthritis / Q000208:ethnology / Q000276:immunology* / Q000401:mortality*; D044466:Asian People; D001324:Autoantigens / Q000276:immunology; D044383:Black People; D005260:Female; D006367:HeLa Cells; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000208:ethnology / Q000276:immunology* / Q000401:mortality*; D008297:Male; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000276:immunology; D012307:Risk Factors; D044465:White People; D000097585:SS-B Antigen; D000099207:SS-A Antigen
chemical_list: D000974:Antibodies, Antinuclear; D001324:Autoantigens; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000097585:SS-B Antigen; D000099207:SS-A Antigen; C116006:RO60 protein, human; C439768:hnRNP A2