Page 329 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

Rheumatoid Arthritis Vasculitis 303

Histopathology

RV primarily affects small- and medium-sized vessels [18, 36]. Small-vessel disease may
histologically resemble a hypersensitivity vasculitis, whereas medium-vessel disease typically
resembles PAN [37]. A given patient with RV may have demonstrable vasculitic involvement
of both small- and medium-vessels, and histopathologically, there may be vascular necrosis,
occlusion, and tissue ischemia. In the series of 50 patients by Scott and colleagues [19],
vasculitis was noted in 28 patients including leukocytoclastic vasculitis (LCV) of dermal and
sub-dermal capillaries, and in 16 of 19 skin biopsies performed for cutaneous rashes.
Necrotizing vasculitis involving small arteries was also noted from rectal biopsy tissue in 8
patients, in renal biopsy tissue in 2 patients, in ovarian and appendix specimens of one
patient, and in the coronary artery at postmortem examination of another patient. Among nine
patients who died with RV and underwent postmortem examination, five showed active
vasculitis, three of which showed systemic vasculitis, and one each with vasculitis limited to
the coronary arteries, peripheral nerves and muscle, or skin. Inactive vasculitis was noted in
one patient and another failed to show vasculitis. In the later series by Scott and Bacon [9],
the clinical diagnosis of RV was confirmed histologically in 57% of the patients treated with
cyclophosphamide and methylprednisolone compared to 46% of those treated with other
conventional therapies. Biopsy tissue specimens of 10 skin rashes showed LCV capillaritis
among four patient receiving cyclophosphamide and methylprednisolone as did six patients
receiving other treatments. Deep rectal biopsy showed necrotizing arteritis in nine of 18
(50%) patients who received cyclophosphamide and methylprednisolone compared to four of
17 (24%) patients in the group receiving other treatments.

In the series of 32 patients with RV and PNS vasculitis described by Puéchal [35],
vasculitis was found in nerve biopsy tissue with the same frequency among those with
sensory or predominantly sensory neuropathy or predominantly motor findings (67% versus
64%).

Vasculitic nerve lesions were not more frequent in the patients with MNM than those
with distal symmetrical sensory or sensorimotor neuropathy (59% versus 78%). Among 44
nerve fascicles from 28 nerve specimens, Wallerian degeneration affected more than three-
quarters of fibers compared to segmental demyelination found in only 1% of fascicles. There
was a close correlation between the severity of the clinical neuropathy and degree of axonal
loss or fiber degeneration.

Vollerstein and colleagues [1] summarized a series of 52 patients with RV defined by the
presence of classical ischemic skin lesions including ulceration, gangrene, purpura or
petechiae in the absence of significant atherosclerosis; MNM, or a positive biopsy tissue
specimen. Altogether, 26 patients underwent biopsies of skin, nerve or other tissues that
showed vascular necrosis and inflammation in more than 90% of specimens. Vasculitis was
noted in 17 of 25 (68%) skin biopsy tissues and in 5 of 25 (25%) nerve biopsy tissues. In
addition, one patient each had histologic evidence of vasculitis of the kidney, gastrointestinal
tract, and muscle; however rectal biopsy specimens were not taken.

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