AB0164 Amyloidosis in progressive systemic sclerosis – a postmortem clinicopathologic study of 12 patients
Authors: Ά Apáthy, M Bély
Journal: Annals of the Rheumatic Diseases (2017)

<h3>Background</h3> Systemic sclerosis (SSc), like all chronic autoimmune disorders, may be complicated by AA amyloidosis (AAa). An associated B-cell lymphoma my cause amyloid λ or κ light-chain deposition and AL amyloidosis (ALa) in SSc as well. <h3>Objectives</h3> The aim of this study was to determine the prevalence and type of amyloidosis in SSc patients, appraise the extent of amyloid deposits in various organs. <h3>Methods</h3> 12 patients (females 11, age: 54.82 years, range 66–32, onset of SSc: 48.86, disease duration: 6.43 years; one male, age: 65.0 years at death, onset of SSc and disease duration not known) were studied. All patients were autopsied. SSc was diagnosed clinically according to the criteria of the ACR [1]. Amyloid deposits on different tissue structures [arteriole, small artery, medium size artery, venule, small vein, medium size vein, interstitial collagen fiber, reticulin fiber (collagen IV), basal lamina, nerve, renal glomerulus] of 6 organs [heart, lungs, kidney, gastrointestinal tract, skin and brain] were determined histologically. The extent of amyloid A deposits was evaluated by semi-quantitative, visual estimation on a 0 to 3 plus scale, based on the number of involved tissue structures per light microscopic field [2] ("0": no amyloid deposits, "1": Sporadic, minimal amyloid deposits on different tissue structures, "2": less than five, "3": five or more involved tissue structures per microscopic field at objective magnification of x20) The prevalence and extent of amyloid deposits in various organs were compared by Student (Welch) t-probe. <h3>Results</h3> Systemic AL-l light-chain amyloidosis was diagnosed in 1 (8.0%) 67 year old female patient (onset of SSc: 66 years, disease duration 1 year), and systemic AAa in 1 (8.0%) 53 year old female patient (onset of SSc: 41 years, disease duration 12 years). The prevalence (in %) and the average extent of AL-l light-chain and amyloid A deposits (absolute value) in various organs of SSc patients are summarized in Table 1. <h3>Conclusions</h3> AL-λ deposits were present earlier and were more prominent in the skin, heart and kidney, than in the, G-I tract and the lung. Amyloid A deposits were present earlier and were more prominent in the G-I tract, heart and kidney, than in the, lung and the skin. In the brain AL-λ and amyloid A deposits were absent in both diseases. Higher prevalence (80.0% versus 0.0%; <i>p</i>&lt;0.0001) and massive AL-λ deposition in the skin (1.45 versus 0.0; <i>p</i>&lt;0.0002) may be explained by qualitative differences of AL-λ and amyloid A and by a diverse affinity of circulating amyloid precursors to the qualitative changed interstitial collagen and reticulin fibers. In systemic sclerosis patients qualitative change of collagens has been demonstrated [3–5]. <h3>References</h3> van den Hoogen F et al: Ann Rheum Dis 2013; 72:1747–1755. Bély M, Apáthy Ά: Clinical Pathology of rheumatoid arthritis. Akadémiai Kiadό, Budapest 2012 http://www.akkrt.hu. Istok R, et al. Annals Rheum Dis 1999; 58(Suppl1): 192. Istok R, et al: Reumatologia 2000; 2: 91. Istok R, et al: Exp Dermatol 2001; 26:545–547. <h3>Disclosure of Interest</h3> None declared