AA amyloidosis

Livneh A, Zemer D, Langevitz P, Laor A, Sohar E, Pras M (1994) Colchicine treatment of AA amyloidosis of familial Mediterranean fever an analysis of factors affecting outcome. Arthritis Rheum 37 1804-1811... 

Approximately 1 % of patients with chronic inflammatory conditions (connective tissue disease, malignancy, infection, cystic fibrosis, Castleman s disease) express AA amyloid (34). The incidence of AA amyloid increases 5- to 10-fold in Europe due to larger number of patients with chronic inflammatory disease. In the Western world, AA amyloidosis occurs in 0.5% to 0.86% of autopsies (7). In contrast to AL amyloidosis, we evaluated only 31 patients with AA amyloidosis at Boston University Medical Center between 1994 and 2002. 

Pathology series confirm the clinical scarcity of lung disease in AA amyloidosis. Celli et al. (13) reported autopsy findings in seven patients with AA amyloid, none of who had signs or symptoms of lung disease. Amyloid deposits were identified in only three out of seven cases, limited to either lung vessels or airway walls. No interstitial amyloid was detected. An 88-year autopsy experience at Johns Hopkins included 113 cases of A A amyloid, with interstitial disease in one case (14). 

Four cases of pleural effusion and biopsy-proven pleural amyloid infiltration in patients with AA amyloidosis have been reported in the past 30 years (17-19). Three cases occurred in patients with long-standing rheumatoid arthritis and the remaining patient had cystic fibrosis. No amyloid-related pleural effusions have been reported in FMF. The rarity of pleural effusions in AA amyloidosis is further evidenced by the absence of pleural disease at autopsy in 113 A A patients (14), a registry of 287 Turkish AA patients (36), or autopsies of 7 patients— despite bronchial waU or pulmonary vessel amyloid deposition in over 70% (13). 

Amyloid cardiomyopathy is extremely unusual in AA amyloidosis, emphasizing the importance of pleural disruption by amyloid deposition in the formation of pleural effusions. Given the paucity of reports documenting amyloid-related pleural disease in this population, pleural effusions in AA patients should generally be ascribed to other causes. 

Rolla D, Cannella G, Ravetti JL. Toxic rhabdomyolysis induced by terlipressin infusion in a uraemic patient suffering from AA-type amyloidosis. Nephron 1999 83(2) 167-8. 

ApoSAA, normally a trace component of plasma, is an acute-phase plasma protein, that is, one that is elevated in a variety of disease states (R18). Its identification is interesting. A small protein of 76 residues, now called protein AA, was identified during the study of the proteins present in extracellular amyloid deposits in the type of amyloidosis particularly associated with inflammation (B24, H36, Lll, S38), Antibodies to protein AA reacted with two AA-related proteins in plasma, one of approximate Mr 180,000 (SAA) and the other found in HDL of Mr 14,000-15,000 or 12,000 (apoSAA) (A19, B25, B26, L12, L15). The N-terminal 76-amino-acid portion of apoSAA is identical to that of amyloid protein AA (E8). Human apoSAA has now been sequenced and has been shown to consist of 104 amino acid residues (B27). Further studies in man have demonstrated microheterogeneity in apoSAA (B18, B19, M30) and Benditt et al. describe specific amino acid substitutions (B27, P6). Shore et al. have described a second similar threonine-poor apolipoprotein, apparently a dimer of Mr 40,000... 

Cystic fibrosis, AA (secondary) amyloidosis Amyloid A protein Systemic... 

AA amyloid appears in a generalized form and is mainly stored perireticularly in the kidney, spleen and liver. This kind of amyloidosis occurs as (1.) a congenital form in cases of familial Mediterranean fever, (2.) an idiopathic (= primary) form without any associated basic disease, and (i.) a reactive (= secondary) form in chronic inflammations or tumours (e.g. Hodgkin s disease) as well as in drug abuse and AIDS. 

Menchel S, Cohen D, Gross E, Franglone B, Gallo G.AA protein-related renal amyloidosis in drug addicts. Am J Pathol 1983 112 195-199. 

Amyloid was not found in fhe skin biopsies of several of our patients with heroin related secondary amyloidosis, although interestingly, multiple pulmonary nodules due to AA amyloid have been described in an HIV positive intravenous drug abuser [31a]. 

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