Autoantibodies
This antibody is highly specific for systemic lupus erythematosus and targets double-stranded DNA.
What is anti–dsDNA?
Needle-shaped, negatively birefringent crystals are seen in this condition.
What is gout?
This cytokine is central to the pathogenesis of giant cell arteritis and is the target of tocilizumab therapy.
What is IL-6?
This interferon subtype is elevated in SLE and drives many of its immunologic features.
What is interferon-alpha?
This genetic marker is strongly associated with ankylosing spondylitis.
What is HLA-B27?
This antibody is commonly associated with limited cutaneous systemic sclerosis (CREST syndrome).
What is anti-centromere antibody?
Rhomboid-shaped, positively birefringent crystals are characteristic of this disease.
What is pseudogout (CPPD)?
This vasculitis affects children and is associated with strawberry tongue and coronary aneurysms.
What is Kawasaki disease?
This lupus nephritis class is characterized by subepithelial immune complex deposition and “spike and dome” appearance.
What is Class V lupus nephritis (membranous)?
This cytokine is a major therapeutic target in spondyloarthropathies, treated with biologics like infliximab.
What is TNF-alpha?
This antibody is strongly associated with diffuse systemic sclerosis and worse prognosis.
What is anti–Scl-70 (anti–topoisomerase I)?
This complication of gout results from deposition of urate crystals in soft tissues forming nodules.
What are tophi?
This immune complex-mediated vasculitis presents with palpable purpura, arthralgia, abdominal pain, and IgA deposition.
What is IgA vasculitis (Henoch-Schönlein purpura)?
This drug-induced lupus culprit is notable for causing anti-histone antibodies and rarely involves renal or CNS disease.
What is hydralazine?
This inflammatory cytokine, along with IL-23, plays a central role in enthesitis and is targeted by secukinumab.
What is IL-17?
This antibody is associated with polymyositis/dermatomyositis and interstitial lung disease.
What is anti–Jo-1?
This metabolic disorder is associated with chondrocalcinosis due to calcium pyrophosphate deposition and involves iron overload.
What is hemochromatosis?
This ANCA pattern targets myeloperoxidase and is most commonly associated with microscopic polyangiitis.
What is p-ANCA (MPO-ANCA)?
This antibody is associated with lupus anticoagulant activity and prolongs PTT while increasing thrombosis risk.
What is anti–beta-2 glycoprotein I?
This extra-articular manifestation of ankylosing spondylitis presents as acute unilateral eye pain with photophobia.
What is anterior uveitis?
This antibody targets a component of the signal recognition particle and is associated with severe necrotizing autoimmune myopathy.
What is anti-SRP?
This urate-lowering drug is contraindicated in patients with HLA-B*58:01 due to risk of severe cutaneous adverse reactions.
What is allopurinol?
This vasculitis is strongly associated with hepatitis B infection and involves medium-sized arteries without glomerulonephritis.
What is polyarteritis nodosa?
This class of lupus nephritis is the most severe and involves diffuse proliferative changes.
What is Class IV lupus nephritis?
This MRI finding in early axial spondyloarthritis reflects active inflammation at vertebral corners.
What is bone marrow edema (osteitis)?