Renal involvement in Churg-Strauss syndrome.

BACKGROUND: Churg-Strauss syndrome (CSS) is a rare disorder characterized by asthma, eosinophilia, and systemic vasculitis. Renal involvement is not regarded as a prominent feature, and its prevalence and severity vary widely in published reports that usually refer to small series of selected patients. METHODS: We examined the prevalence, clinicopathologic features, and prognosis of renal disease in 116 patients with CSS. RESULTS: There were 48 men and 68 women with a mean age of 51.9 years (range, 18 to 86 years). Signs of renal abnormalities were present in 31 patients (26.7%). Rapidly progressive renal insufficiency was documented in 16 patients (13.8%); urinary abnormalities, 14 patients (12.1%); and chronic renal impairment, 1 patient. There were 3 additional cases of obstructive uropathy. Sixteen patients underwent renal biopsy, which showed necrotizing crescentic glomerulonephritis in 11 patients. Other diagnoses were eosinophilic interstitial nephritis, mesangial glomerulonephritis, and focal sclerosis. Antineutrophil cytoplasmic antibody (ANCA) was positive in 21 of 28 patients (75.0%) with nephropathy versus 19 of 74 patients without (25.7%; P < 0.001). In particular, all patients with necrotizing crescentic glomerulonephritis were ANCA positive. After a median follow-up of 4.5 years, 10 patients died (5 patients with nephropathy) and 7 patients developed mild chronic renal insufficiency. Five-year mortality rates were 11.7% (95% confidence interval, 3.9 to 33.3) in patients with nephropathy and 2.7% (95% confidence interval, 0.7 to 10.7) in those without (P = 0.10). CONCLUSION: Renal abnormalities are present in about one quarter of patients with CSS. The prevailing picture is ANCA-associated necrotizing crescentic glomerulonephritis; however, other forms of nephropathy also may occur. Outcome and long-term follow-up usually are good

Prevalence and clinical significance of antineutrophil cytoplasmic antibodies in Churg-Strauss syndrome

OBJECTIVE: Churg-Strauss syndrome (CSS) is classified among the so-called antineutrophil cytoplasmic antibody-associated systemic vasculitides (AASVs) because of its clinicopathologic features that overlap with the other AASVs. However, while antineutrophil cytoplasmic antibodies (ANCAs) are consistently found in 75-95% of patients with Wegener's granulomatosis or microscopic polyangiitis, their prevalence in CSS varies widely and their clinical significance remains uncertain. We undertook this study to examine the prevalence and antigen specificity of ANCAs in a large cohort of patients with CSS. Moreover, we evaluated the relationship between ANCA positivity and clinicopathologic features. METHODS: Immunofluorescence and enzyme-linked immunosorbent assay were used to determine the presence or absence of ANCAs in 93 consecutive patients at the time of diagnosis. The main clinical and pathologic data, obtained by retrospective analysis, were correlated with ANCA status. RESULTS: ANCAs were present by immunofluorescence in 35 of 93 patients (37.6%). A perinuclear ANCA (pANCA) pattern was found in 26 of 35 patients (74.3%), with specificity for myeloperoxidase (MPO) in 24 patients, while a cytoplasmic ANCA pattern, with specificity for proteinase 3, was found in 3 of 35 patients (8.6%). Atypical patterns were found in 6 of 30 patients with anti-MPO antibodies (20.0%). ANCA positivity was associated with higher prevalences of renal disease (51.4% versus 12.1%; P < 0.001) and pulmonary hemorrhage (20.0% versus 0.0%; P = 0.001) and, to a lesser extent, with other organ system manifestations (purpura and mononeuritis multiplex), but with lower frequencies of lung disease (34.3% versus 60.3%; P = 0.019) and heart disease (5.7% versus 22.4%; P = 0.042). CONCLUSION: ANCAs are present in approximately 40% of patients with CSS. A pANCA pattern with specificity for MPO is found in most ANCA-positive patients. ANCA positivity is mainly associated with glomerular and alveolar capillaritis

PTPN22 R620W polymorphism in the ANCA-associated vasculitides

OBJECTIVES: PTPN22 is involved in T-cell activation and its R620W single-nucleotide polymorphism (SNP) has been shown to predispose to different autoimmune diseases. The aims of this study were to investigate the role of the PTPN22 R620W SNP in conferring susceptibility to the ANCA-associated vasculitides (AAVs), and to explore potential associations between the PTPN22 genotype and the disease manifestations. METHODS: PTPN22 R620W SNP was genotyped in a cohort of 344 AAV patients [143 with granulomatosis with polyangiitis (Wegener's) (GPA), 102 with microscopic polyangiitis (MPA) and 99 with Churg-Strauss syndrome (CSS)] and in 945 healthy controls. RESULTS: The frequency of the minor allele (620W) was significantly higher in GPA patients than in controls [P\u2009=\u20090.005, \u3c7(2\u2009)=\u20097.858, odds ratio (OR)\u2009=\u20091.91], while no statistically significant association was found with MPA or CSS. Among GPA patients, the 620W allele was particularly enriched in ANCA-positive patients as compared with controls (P\u2009=\u20090.00012, \u3c7(2\u2009)=\u200914.73, OR\u2009=\u20092.31); a particularly marked association was also found with ENT involvement (P\u2009=\u20090.0071, \u3c7(2\u2009)=\u20097.258, OR\u2009=\u20091.98), lung involvement (P\u2009=\u20090.0060, \u3c7(2\u2009)=\u20097.541, OR\u2009=\u20092.07) and skin manifestations of all kinds (P\u2009=\u20090.000047, \u3c7(2\u2009)=\u200916.567, OR\u2009=\u20093.73). CONCLUSION: The PTPN22 620W allele confers susceptibility to the development of GPA (but not of MPA or CSS), and particularly of its ANCA-positive subset