Clinical investigation of patients with positive antineutrophil cytoplasmic antibodies (ANCA) test for autoimmunity and vasculitis

Aim: Antineutrophil cytoplasmic antibodies (ANCA) autoantibodies target neutrophil and monocyte lysosomal granules. The objective of the study is to investigate patients with a positive ANCA test for autoimmune disorders and vasculitis. Materials and Methods: This 4-year retrospective cohort research analyzed 9.480 Turkish tertiary hospital serum samples. The baseline evaluation included 218 eligible ANCA-positive patients with vasculitis (AAV) and other autoimmune and non-autoimmune diseases. Results: The other two groups have less pulmonary, renal, ear nose and throat (ENT), ophthalmic, and neurologic involvement than AAV individuals. AAV and autoimmune disease patients have higher joint and skin involvement than non-autoimmune disease patients. Hypertension and chronic renal failure are more common in AAV and non-autoimmune individuals than autoimmune ones. Chronic obstructive pulmonary disease (COPD) and proteinuria are higher in AAV patients than autoimmune disease patients. AAV patients have more hematuria than the other two. For non-autoimmune disease, myeloperoxidase (MPO) titer and erythrocyte sedimentation rate (ESR) are higher than for autoimmune disease. High proteinase 3 (PR3) titers are associated with AAV and autoimmune disorders. AAV patients have higher CRP and complement 3(C3) than the other two groups. In AAV, C4 and rheumatoid factor (RF) are higher than in non-autoimmune disease. Patients with autoimmune disease had higher initial GFR than the other two groups. Conclusion: We concluded that ANCA may be positive in numerous AAV-like diseases. A tertiary hospital found a strong correlation between ANCA titers, particularly PR3, and AAV clinical diagnosis. ANCA titre and organ system extent may be clinical AAV diagnostic indicators.