AA Amyloidosis in a Cohort of 128 Patients with Takayasu's Arteritis

Abstract

Systemic AA amyloidosis is a relatively rare complication of chronic inflammatory disorders, e.g. rheumatoid arthritis, ankylosing spondylitis, familial Mediterranean fever and other autoinflammatory syndromes, Crohn's disease, malignancies and recurrent infections. Isolated case of AA amyloidosis have been reported in many other chronic diseases, including systemic vasculitides, diffuse connective tissue diseases, sarcoidosis, chronic hepatitis, etc. In the past ten years the incidence of AA amyloidosis decreased significantly due to earlier and more aggressive treatment of underlying conditions such as rheumatoid arthritis or infections. In the recent series of 474 patients with renal amyloidosis from Mayo clinic there were only 7% cases of AA amyloidosis while 86% patients presented with AL form of disease. Nevertheless, AA amyloidosis remains a life-threatening complication of immune-mediated and inflammatory conditions and deserves effective prevention and treatment. Takayasu's arteritis (TAK) is a rare largevessel vasculitis of unknown etiology that more frequently affects women of childbearing age and is defined as "granulomatous inflammation of the aorta and its major branches" by the revised Chapel Hill Consensus Conference. The search in Pubmed database revealed only a dozen reports of AA amyloidosis in patients with TAK. The objective of our study was to evaluate the incidence of AA amyloidosis in a cohort of consecutive TAK patients.Keywords: Amyloidosis; Arteries; Hematuria; Proteinuria ObjectiveTo evaluate the incidence of AA amyloidosis in a cohort of consecutive TAK patients. Patients and MethodsWe retrospectively studied medical records of 128 consecutive patients with TAK who met the American College of Rheumatology classification criteria. The diagnosis of amyloidosis that was suspected clinically (new proteinuria or nephrotic syndrome) was confirmed histologically by the presence of congophilic fibrillar inclusions. MethodsWe retrospectively studied medical records of 128 consecutive patients with TAK who were evaluated from 1979 through 2012 in our clinic that serves as a tertiary center for systemic vasculitides in Russia. All patients met the American College of Rheumatology classification criteria for TAK [1] and the definition of the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides [2]. Imaging studies were available in all patients and included ultrasonography (n=118), conventional angiography (n=31), computed tomographic angiography (n=7) and positron emission tomography (n=32).The diagnosis of amyloidosis that was suspected clinically (new proteinuria or nephrotic syndrome) was confirmed histologically by the presence of congophilic fibrillar inclusions. Amyloidosis type AA was established by immunohistochemistry and by exclusion of other types of amyloidosis, e.g. light chain amyloidosis. Patient 1:A 27-year old male presented with a 16-year history of recurrent fever, arthritis, anemia, persistent increase in ESR (up to 64 mm/h) and C-...