Diagnostic significance of antineutrophil cytoplasmic antibody (ANCA) titres: a retrospective case-control study

Recommendations for the diagnosis and treatment of anti-neutrophil cytoplasmic autoantibody associated vasculitis

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is characterised by small vessel necrotising inflammatory vasculitis. Prior to immunosupressant therapy availability it usually led to a fatal outcome. Current treatment has changed ANCA-associated vasculitis into a condition with a significant response rate, although with a not negligible relapse occurrence and cumulative organ lesions, mostly due to drug-related toxicities. The use of glucocorticoids, cyclophosphamide and other immunosupressants (such as azathioprine, mychophenolate and methotrexate) was optimised in a series of clinical trials that established the treatment of reference. In recent years, a better knowledge of B lymphocyte function and the role of complement inhibition has transformed the course of this disease while minimising treatment-related adverse effects. This multidisciplinary document of recommendations is based on the consensus of three scientific societies (Internal Medicine, Nephrology and Rheumatology) and on the best available evidence on diagnosis, treatment and follow-up of patients with ANCA-associated vasculitis, including some special situations. The aim of this document is to provide updated information and well-grounded clinical recommendations to practising physicians as to how to improve the diagnosis and treatment outcome of our patients.

A Case of Adult-Onset Still's Disease With Positive Antinuclear Antibodies and Positive Antineutrophil Cytoplasmic Antibodies

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease characterized by nonspecific symptoms such as fever, maculopapular rash, and arthralgias. The exact etiology and pathogenesis remain unclear despite advancements in medical science. Diagnosis is typically established using the Yamaguchi criteria, which include a negative antinuclear antibody (ANA) test as one of the minor criteria. However, some patients with AOSD exhibit positive ANA and even positive antineutrophil cytoplasmic antibodies (ANCA), complicating the diagnostic process. We present the case of a 19-year-old Asian woman of Yakut ethnicity who initially presented with symptoms resembling an upper respiratory tract infection. Laboratory tests revealed the presence of both ANA and ANCA. The diagnosis of AOSD was confirmed based on clinical presentation and the Yamaguchi criteria. Subsequent pulse therapy with prednisolone resulted in significant clinical improvement and a one-year remission. A review of the literature revealed that simultaneous ANCA and ANA positivity in AOSD has not been previously reported. Follow-up over 12 months showed no evidence of other autoimmune or autoinflammatory diseases, suggesting that the positive ANA and ANCA results may be either false positives or atypical laboratory manifestations in AOSD, which should be considered in the diagnosis.