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).


CONCLUSIONS
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.
Sinico
Renato A
RA
Dipartimento di Nefrologia e Immunologia, Azienda Ospedaliera Ospedale San Carlo Borromeo, Milan, Italy. renato.sinico@oscb.sined.net
Di Toma
Lucafrancesco
L
Maggiore
Umberto
U
Bottero
Paolo
P
Radice
Antonella
A
Tosoni
Cinzia
C
Grasselli
Chiara
C
Pavone
Laura
L
Gregorini
Gina
G
Monti
Stefano
S
Frassi
Micol
M
Vecchio
Filomena
F
Corace
Caterina
C
Venegoni
Emanuela
E
Buzio
Carlo
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis*; D000918:Antibody Specificity / Q000276:immunology*; D002467:Cell Nucleus / Q000276:immunology / Q000473:pathology; D015267:Churg-Strauss Syndrome / Q000150:complications / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D005938:Glucocorticoids / Q000627:therapeutic use; D006470:Hemorrhage / Q000209:etiology / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007674:Kidney Diseases / Q000209:etiology / Q000473:pathology; D008171:Lung Diseases / Q000209:etiology / Q000473:pathology; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology; D012189:Retrospective Studies
D019268:Antibodies, Antineutrophil Cytoplasmic; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D009195:Peroxidase