Anti-neutrophil Cytoplasmic Antibodies (ANCA) Assosicted Dermatosis

Background:ANCA was a set of self-antibody which reaction with the neutrophil cytoplasmic. The occurrence of these antibodies in the sera of patients suffering from glomerulonephritis and vasculitis was reported by Davis et al. in 1982. In the primary systemic vasculitis ANCA was also detected by hall et al.in 1984. The association of these antibodies with Wegener's granulomatosis(WG) was described by Van der Woulde and colleagues in 1985 They also proved that the ANCA's special Fluorescence Graphics of patients serum is an activity sign of WG. There had two classical terms C-ANCA and P-ANCA described by indirect immunofluorescence (IIF) patterns on granulocyte substrates.Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA are the main antigen of C-ANCA and P-ANCA separately.In 1988.Falk et al proved that in systemic vasculitis and spontaneous NCGN, MPO is a major target antigen for ANCA-related. After 90 years, with improved detection technology, people have a deeper study of ANCA and found a variety of other ANCA antigens.Such as cathepsin G (CG), lactoferrin (LF), bactericidal permeability protein (BIP), human leukocyte elastase (HLE), lysosomal membrane glycoprotein (LY) and a enolase at al.of all the antigens PR3 and MPO is more well known than others. Anti-PR3 antibodies usually show a C-ANCA pattern on both ethanol-fixed and formalin-fixed granulocytes, whereas anti-MPO antibodies show a P-ANCApatternonethanol-fixed granulocytes and a C-ANCA pattern on formalin-fixed ones.PR3 is a molecular weight 29KD serine protease with positive charge.It present in neutrophil azurophilic granule. It can be planted in the glomerular basement membrane by charge effec.And can inhibit the lysosomal membrane. After PR3-ANCA and PR3 combination, on the one hand can be formed in the kidney of local immune complexes, activate complement, causing tissue damage;On the other hand, the lysosomal enzyme is inhibited, a variety of enzymes dissolve the cell itself, caused widespread severe and lasting Injury. Typical C-ANCA positive patients, almost all are PR3 specificity,70% showed generalized the WG,30% showed microscopic polyarteritis. MPO also positively charged, a molecular weight of 150KD, is one of the components of neutrophil particulate antigen witch consists of two heavy chains and two light chains.It can deposit in glomerular basement membrane, P-ANCA positive is often for MPO specificity, about 50% to 80% positive cases of activity under the microscope nodosa, about 25% for Wegener granulomatosis.Therefore ANCA is considered as systemic necrotizing vasculitis's mark serum antibodies and indicators of disease diagnosis and assessment of disease activity index which had a predictive value of the disease's remission and relapse. Wegener granulomatosis is one of the main representative. But in recent years, many other autoimmune diseases has been detected ANCA, such as systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis, scleroderma, etc.Now it is considered not only systemic vasculitis has significant correlation with the serum ANCA, but also autoimmune diseases and other diseases.Purpose:Analysis the Clinical features and mechanism of ANCA in ANCA-related skin diseases.Raise awareness and vigilance of these diseases. Further guidance to the clinical diagnosis and treatment.Method:119 cases of skin diseases examined ANCA between January 2009 to December 2010 at our hospital.With the Ilf and ELISA method. Combined with good sensitivity and specificity. It seems to be clear that the terms P-ANCA and C-ANCA should only be used in connectionwith IIF.Investigate what skin disease had a high positive rate.Summarize which organ were involvementResult:Cutaneous vasculitis in 47 cases,3 were positive accounting for 6.3%(Allergic vasculitis,1/12, allergic purpura 1/20, erythema nodosum 1/ 9, Behcet's disease 0/4, sweet disease 0/1, gangrene pustulosis 0/1).Allergic skin diseases in 37 cases,6 cases were positive, accounting for 16.2%(Contact dermatitis 0/1, eczema,1/11, urticaria,2/11, drug eruption 3/14). Connective tissue disease in 15 cases,6 cases were positive, accounting for 40%.1 case of psoriasis in 19 cases positive, ANCA-positive rate of 5.3%. Sneddon Wilkinson disease 1 case positive.ANCA-positive group, there are complications seen hypoproteinemia, pulmonary diseases, rheumatoid arthritis and cancer, etc.Lung was the mainly involvement organ.Other organs such as liver,kidneys has a low involvement rate.Conclusion:1. ANCA-positive cases, the male to female ratio was 1:7.5, female incidence was significantly higher than men.2. ANCA in connective tissue diseases, allergic skin diseases and skin vasculitis,the positive rates were 40%,16.2%,6.3%separately, suggesting that ANCA play an important role in these disease.3. ANCA associated small vessel vasculitis is common in China,specially in elderly.Usually had multiple organ involvement. So timely detected is necessary for correct treatment and improve the progonsis.