P-ANCA Associates With The New-onset SLE And Interstitial Lung Disease

ObjectiveTo study the diagnostic value of antineutrophil cytoplasmic antibodies (ANCA) on interstitial lung disease (ILD), and the relationship between ANCA and the disease activity in new-onset systemic lupus erythematosus.Methods1,Selection of patients106 female and 1 male patients with SLE as defined were recruited from in-patients at the Department of Rheumatology and Immunology of the First Affiliated Hospital of China Medical University, who never accept treatment for SLE, and first visited the hospital. The mean age of the patients is 37.5±9.8 years(range from 16 to 60 years).2,Diagnostic CriteriaThe patients were diagnosed as SLE by the 1997 revised American College of Rheumatology (ACR) criteria. For all the patients, chest radiography and lung high-resolution computed tomography (HRCT) were done to help evaluating the severity of ILD. The characteristic changes included lobular thickening, irregular linear shadow (hint of early mild disease), ground-glass appearance (showing acute inflammation), honeycomb lung (showing irreversible fibrosis). Tuberculosis, virus, bacterial infection were excluded by the specialists of Infectious department and Radiology department.3,Methods For all the patients, clinical and laboratory variables assessed, including anti ds-DNA antibody; anti-nuclear antibody; immunoglobulin levels (IgM, IgG, IgA); serum levels of C3/C4; complete blood cell count and routine urinalysis. ANCA was determined by indirect immunofluorescence (ⅡF).4,Statistical methodsAll data were analyzed using SPSS 13.0 software. Chi-square test and odd ratios were used to assess difference between the two groups. In all instances, p< 0.05 was considered significant.Results1,45 of 107(42%) patients, showed ANCA was positive(all were P-ANCA except one were c-ANCA).2,Compared with ANCA-negative patients, the ANCA-positive patients had significantly higher incidence of renal involvement, anemia, Reynaud's phenomena, decreased serum complement3, complement4 and elevated ESR, (all p< 0.05).3,In 45 ANCA-positive cases,25 patients were accompanied with ILD(55.6%). Whereas In the 62 ANCA-negative patients, only 15 patients had ILD(24.2%).ConclusionsThe positive ANCA in new-onset SLE may be related to higher frequency of ILD,also,ANCA may facilitate assessment of for the disease activity of new-onset SLE. As the number of patients included in this study was limited, future studies in larger numbers of cases are required.