Background Systemic vasculitis of autoimmune origin (A-SV) may be regarded as a basic histological manifestation of rheumatoid arthritis (RA) [1,2].
Objectives The aim of this study was to characterize the severity of systemic autoimmune vasculitis at death in RA patients.
Methods A randomized autopsy population of 161 in-patients with RA was studied.
A-SV complicated RA in 32 (19.88%) patients .
RA was confirmed clinically according to the criteria of the ACR .
The severity of vasculitis was evaluated by semi-quantitative, visual estimation on a 0 to 3 plus scale in12 organs (heart, lung, liver, spleen, kidney, pancreas, gastrointestinal tract, adrenal gland, skeletal muscle, peripheral nerve, skin and brain) at death) . (“0”: no vasculitis, “1”: sporadically (scattered) located vasculitis, “2”: less than five, “3”: five or more involved blood vessels/microscopic field with a x20 objective)
The age at death, and the onset and duration of RA with mild (<0.2/patient), or severe (0.2A-SV, were compared by Student (Welch) t-probe.
Results 16 (50.0%) of 32 patients had a “mild” degree of A-SV (females 11, avg age of 70.91 years, range 80 – 63, onset of RA: 62.55, avg disease duration: 8.36 years at death; males 5, avg age of 71.6 years, range 83–58, onset of RA: 57.2, avg disease duration: 14.4 years).
16 (50.0%) of 32 patients had “severe A-SV” (females 8, age of 60.88 years, range 82–32,onset of RA: 52.67, avg disease duration: 13.5 years at death; males 8, avg age of 65.0 years, range 78–53, onset of RA: 53.25, avg disease duration: 11.75 years).
Four (12.5%) of 32 patients had “extremely severe A-SV” (with an average cumulative value of severity/RA patient with SV >0.630) (females 1, age of 82.0 years, onset of RA: 62.0, average disease duration: 20.0 years at death; males 3, average age of 69.7 years, range 78 – 59, onset of RA: 60.7, average disease duration: 9.0 years)
Severity of SV in 32 RA patients with A-SV – according to increasing average values of vasculitis/patient – is summarized in Figure.
Conclusions A-SV is caused by circulating immune complexes in RA. Immune complexes spread via the bloodstream and provoke vasculitis throughout the body.
We found no differences in the linear and basically parallel development of A-SV between patient groups with mild and severe vasculitis.
The progression of vasculits was the same in both patient groups suggesting differences in production of circulating immune complexes.
Quantitative differences in the production of circulating immune complexes may be related to a “benign” or “aggressive” clinical course of RA, which may be due to genetical and other factors.
In 4 of 32 RA patients the severity of vasculitis showed a “step-wise” growth curve with “extreme severe” A-SV (0.630 or <) according to increasing average values of vasculitis/patient (Figure 1). There was no gradual transition between the “extremely severe” and “severe” degrees A-SV. This profile of “step-wise” general severity in patients with vasculitis may represent a subgroup of patients with a different genetic-immunologic background.
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Disclosure of Interest None declared