Background 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.
Objectives 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.
Methods 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 .
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  (“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.
Results 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.
Conclusions 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%; p<0.0001) and massive AL-λ deposition in the skin (1.45 versus 0.0; p<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].
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Disclosure of Interest None declared