Background Different types of amyloid deposits may be present in systemic sclerosis (SSc), as consequences (complications) of basic or associated diseases.
Objectives The aim of this study was to determine the type, prevalence and extent of amyloid deposits on different tissue structures in various organs in SSc.
Methods We studied histopathologically 12 SSc patients (females 11, average age: 54.82 years, range 66–32, onset of SSc: 48.86, average disease duration: 6.43 years; one male, age 65.0 years at death, onset of SSc and average disease duration not known, who died at the National Institute of Rheumatology. SSc was diagnosed clinically according to the criteria of the ACR . In 1 (8.0% of 12) 67 year old female patient (onset of SSc: 66 years, disease duration: 1 year) SSc was accompanied by B-cell lymphoma and complicated by systemic AL-l light-chain amyloidosis. In 1 (8.0% of 12) 53 year old female patient (onset of SSc: 41 years, disease duration: 12 years) SSc was complicated by systemic amyloid A (aA) deposition.
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), and nerve] of 6 organs [heart, lungs, kidney, gastrointestinal tract, skin and brain] were determined histologically. The extent of amyloid deposition 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 .
The prevalence and extent of amyloid-l light-chain and amyloid A deposits on different tissue structures were compared by Student (Welch) t-probe.
Results The involvement of different tissue structures (prevalence in %) and the average extent of AL-l light-chain and amyloid A deposits (absolute value) are summarized in Table 1.
Conclusions In SSc patients the prevalence and extent of l light-chain and amyloid A deposits on different tissue structures changed parallel.
The higher prevalence and extent of l light-chain deposits in contrast to amyloid A may be explained with qualitative differences of l light-chain and amyloid A; l light-chain seems to have greater affinity for tissues than amyloid A protein.
Infiltration of the vessel walls – regarding the amount of l light-chain and amyloid A deposits in arterioles and arteries in contrast to the veins – showed a converse tendency in SSc patients with AL-l or AAa. This may be related to sluggish blood flow or stasis (backward congestion and accumulation of circulating precursors) in both diseases.
van den Hoogen F et al: Ann Rheum Dis 2013; 72:1747–1755 doi: 10.1136/annrheumdis-2013-204424.
Bély M, Apáthy Άgnes: Clinical pathology of rheumatoid arthritis. 1–440 pp. Akadémiai Kiadό, Budapest 2012 http://www.akkrt.hu.
Disclosure of Interest None declared