Progression of AA Amyloidosis (Sequence of Amyloid A Deposition) in the Pancreas - A Postmortem Clinicopathologic Study of 161 Patients

Authors: Bely M* and Apathy A

DOI: 10.23880/ghij-16000143

Volume 3, Issue 2

Abstract

The aim of our study was to determine the prevalence and severity of systemic AA amyloidosis (sAAa) in rheumatoid arthritis (RA), to specify amyloid A deposits in different tissue structures of the pancreas, to outline the development of pancreatic AA amyloidosis (pAAa), and to estimate the role of sAAa and pAAa in mortality. Patients and Methods: At the National Institute of Rheumatology 9475 patients died between 1969 and 1992; among them 161 with RA and all of them were autopsied. RA was confirmed clinically according to the criteria of the American College of Rheumatology (ACR). sAAa was specified histologically, based on evaluation of 5 organs (heart, lung, liver, kidney and pancreas). Tissue samples of pancreas were available for histologic evaluation in 118 of 161 patients. Amyloid A deposition was diagnosed according to Romhányi. The correlations between different patient cohorts were determined by the Student (Welch) t-probe. Results: sAAa complicated RA in 29 (24.58 %) of 118 patients. sAAa was histologically excluded in 89 (75.42 %) of 118 RA patients. The pancreas was involved in 26 (89.66 %) of 29 patients. Amyloid A deposits were not present in the pancreas in 3 (10.34 %) of 29 RA patients with sAAa. sAAa or pAAa complicated RA in both sexes, and at any time in the course of the disease. Discussion and Conclusion: Systemic AAa is one of the main and most insidious complications of rheumatoid arthritis affecting the pancreas with high prevalence and severity. sAAa is related to the cardiovascular system, and pAAa is connected with it. In sAAa the amyloid A deposition in the pancreas starts after a latent stage. Systemic and pancreatic amyloid a deposition is a progressive and cumulative process, involving in its early stage only a few structures in the pancreas, and increasingly more in later stages of the disease. Amyloid a deposition starts in the most frequently involved structures of the pancreas with more massive deposits. The chronology of amyloid A deposition allows an indirect assessment of the stage of pancreatic amyloidosis, which may have a prognostic value in everyday surgical pathology as well.

Keywords: Rheumatoid Arthritis; Systemic and Pancreatic AA Amyloidosis; Development (chronology) of Pancreatic AA Amyloidosis

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