Diagnosis of Vasculitis Clinical evaluation Basic laboratory tests to detect inflammation or organ dysfunction (eg, complete blood count [CBC], erythrocyte sedimentation rate [ESR] or C-reactive protein, serum albumin and total protein, aspartate aminotransferase [AST] and alanine aminotransferase [ALT], blood urea nitrogen [BUN] and creatinine, urinalysis) and to stage disease process Laboratory tests to help determine the type of vasculitis (eg, antineutrophil cytoplasmic antibodies [ANCA]) if suggested by clinical assessment Laboratory and imaging studies that may help determine the cause of vasculitis (eg, cryoglobulins, hepatitis B surface antigen test, hepatitis B core and hepatitis B surface antibody tests and hepatitis C virus antibody test, blood cultures) and extent of organ involvement Biopsy Systemic vasculitis is suspected in patients with the following: Symptoms or signs suggestive of vasculitis (eg, temporal headache and jaw claudication suggesting giant cell arteritis) Ischemic manifestations (eg, ischemic stroke, limb claudication, mesenteric ischemia) out of proportion to a patient's risk factors for atherosclerosis Unexplained combinations of symptoms in more than one organ system that are compatible with vasculitis (eg, hypertension, myalgias, hemoptysis), particularly when symptoms of a systemic illness are present Primary vasculitic disorders are diagnosed based on the presence of characteristic symptoms, physical findings, compatible laboratory test results, and exclusion of other causes (ie, secondary vasculitis).