The spectrum of renal disease associated with microscopic polyangiitis and classic polyarteritis nodosa in Kuwait.

in retrospective analysis of causes of ESRD in dierent populations. Background. This study was conducted to examine prospectively the epidemiological profile of renal disease associated with microscopic polyangiitis (MPA) Key words: arteriography; classic polyarteritis nodosa; and classic polyarteritis nodosa (classic PAN ) in kidney biopsy; Kuwait; microscopic polyangiitis; Kuwait and its clinicopathological correlation. vasculitis Methods. Between 1 January 1993 and 31 December 1996, all patients referred to Al-Amiri renal centre were subjected to renal biopsy and/or arteriography if they manifested systemic manifestations of vasculitis or had rapid or unexplained renal failure with or Introduction without proteinuria. Patients who fulfilled the criteria of MPA and classic PAN, according to the Chapel Hill Systemic vasculitides are a group of heterogeneous Consensus Conference (CHCC ), were included in the conditions characterized by inflammatory cell infiltrate study. and necrosis of blood vessels. Polyarteritis nodosa was Results. Over those 4 years, 47 patients were diagnosed the first type described in the literature, by Kussmaul as having such vasculitides, 22 of whom were Kuwaiti and Maier in 1866 [1]. The authors observed gross nationals. This gave an average annual incidence of 45 aneurysms in several organ systems. Relatively few cases/million adult Kuwaiti nationals (95% CI, 27‐64). cases of vasculitis with such profound vascular disease Histological examination revealed necrotizing glom- have subsequently been reported. In 1948 Davson et al. erulonephritis (GN ) in 11 patients and crescentic GN proposed that renal involvement in polyarteritis in 13, while isolated small- and/or medium-sized- nodosa was of two distinct types: polyarteritis with arteritis were evident in six more patients. In 10 of the predominantly extraglomerular vasculitis (classic remaining patients; bands of fibrosis alternating with PAN ), and that with glomerulonephritis (GN ), which healthy renal tissue were seen and on arteriography they described as microscopic polyarteritis [2 ]. In the non-atherosclerotic stenoses, infarctions, and/or mic- early 1950s, Zeek modified the name of the latter form roaneurysms were evident. The remaining seven of polyarteritis to microscopic polyangiitis (MPA) to patients were diagnosed by arteriography alone, five reflect better its wider range of vascular involvement of whom had bilateral small kidneys. Constitutional [3]. Moreover, many cases of what was traditionally manifestations of vasculitis were present in 32 patients called idiopathic necrotizing and crescentic GN are ( 68%) and multisystem involvement in 19 (40%). considered a form of MPA with limited extrarenal ANCA levels were high in 24 (55%) of the 44 patients disease since; (a) their glomerular lesions are indistintested and seropositivity, as an antimyeloperoxidase, guishable from those of MPA [4], (b) high levels of was a constant finding. Only six patients presented antineutrophil cytoplasmic antibodies (ANCA) were with rapidly progressive renal failure, while 31 pre- detected in many patients [5], and (c) some had the sented with chronic renal disease, 18 of whom had potential for full expression of systemic vasculitis after protein excretion in excess of 2 g/day. prolonged follow-up [6 ]. Conclusions. These findings emphasize the limited role In the present study we prospectively examined all of clinical assessment in establishing a definite dia- patients referred for renal disease for the existence of gnosis of renal vasculitis and put in question its value these forms of vasculitis, using renal biopsy and/or arteriography, in an attempt to reveal some aspects of