Which autoantibodies are strongly associated with granulomatosis with polyangiitis (Wegener's granulomatosis)?

Which autoantibodies are strongly associated with granulomatosis with polyangiitis (Wegener's granulomatosis)?

• A. ANA
• B. ANCA
• C. AMA
• D. SMA

Answer: (B)

Anti-neutrophil cytoplasmic antibodies (ANCA) are strongly linked to granulomatosis with polyangiitis. In this disease, the immune system frequently makes antibodies targeting neutrophil cytoplasmic antigens, most often proteinase 3 (PR3-ANCA, historically the c-ANCA pattern). This association helps support the diagnosis in the right clinical context and guides testing, as ANCA positivity is a common finding in GPA and can correlate with disease activity. The other antibodies listed identify other autoimmune conditions (ANA with systemic lupus or related diseases, AMA with primary biliary cholangitis, SMA with autoimmune hepatitis) and are not specifically tied to GPA.

Anti-neutrophil cytoplasmic antibodies (ANCA) are strongly linked to granulomatosis with polyangiitis. In this disease, the immune system frequently makes antibodies targeting neutrophil cytoplasmic antigens, most often proteinase 3 (PR3-ANCA, historically the c-ANCA pattern). This association helps support the diagnosis in the right clinical context and guides testing, as ANCA positivity is a common finding in GPA and can correlate with disease activity. The other antibodies listed identify other autoimmune conditions (ANA with systemic lupus or related diseases, AMA with primary biliary cholangitis, SMA with autoimmune hepatitis) and are not specifically tied to GPA.