Systemic Vasculitis in Various Organs of 33 Rheumatoid Arthritis and 11 Progressive Systemic Sclerosis Patients – A Comparative Postmortem Study

Abstract

Objective: The aim of this study was (1) to compare the prevalence and severity of Systemic Vasculitis (SV) in various organs of Rheumatoid Arthritis (RA) and of progressive Systemic Sclerosis (SSc) patients, (2) To determine the complications and lethal outcome caused by vasculitis in RA and SSc. Patients and Methods: Twelve organs (heart, lung, liver, spleen, kidneys, pancreas, gastrointestinal tract, adrenal glands, skeletal muscle, peripheral nerve, skin and brain) of 33 RA and of 11 SSc with SV were studied microscopically. RA and SSc were confirmed clinically according to the criteria of the American College of Rheumatology. The basic disease, the complications, and the lethal outcome caused by vasculitis were determined and analyzed retrospectively, reviewing the clinical and pathological reports, tissue samples, and the histological slides. The existence (prevalence) of vasculitis in various organs was determined based on the presence of vasculitis in blood vessels of different calibers. The severity of vasculitis in various organs was evaluated by semi-quantitative, visual estimation on a 0 to 3 plus scale (based on the number of involved vessels/light microscopic field x40). Results and Conclusions: SV was observed in all of 33 RA and 11 SSc patients with variable prevalence and severity. The average value of prevalence and severity/organ in SSc was appreciably higher than that of RA. In RA patients, not all investigated organs were involved with SV and the existence of blood vessels with vasculitis in each organ was different. In SSc patients SV was present in each of the investigated organs, but with different severity. In RA the heart, skeletal muscle, pancreas, lung, kidneys and gastrointestinal tract were most markedly involved, while in SSc the kidneys, spleen, lung, pancreas, heart and gastrointestinal tract were. The high prevalence of SV and the consecutive fibrosis in these organs identify the main targets of autoimmune processes in RA and SSc prior to the more visible skin involvement. The most markedly involved organs denote a favorable site for histological diagnosis of SV, for example skeletal muscle with peripheral nerve (sural nerve) or gastrointestinal tract in RA and the gastrointestinal tract in SSc. The course of the disease, more precisely mortality due to SV,