Eosinophilic granulomatosis with polyangiitis (EGPA), also known as
Churg-Strauss syndrome, is an
antineutrophil cytoplasmic antibody (
ANCA)-associated vasculitis characterized by a history of
asthma,
hypereosinophilia. The prevalence of
ANCA in EGPA is less common than in other
ANCA-associated vasculitis. Increasing evidence of complement activation in the pathogenesis of
ANCA-associated vasculitis has been provided by studies in animal models. We examined EGPA patients with cutaneous manifestations as an initial sign and investigated the correlations among clinical, serological and histopathological findings. We focused on differences among
ANCA, blood
urea nitrogen and
complement levels such as
complement 3 (C3), C4 and total
complement hemolytic activity (CH50). We retrospectively investigated the records of 22 patients (11 male and 11 female) with EGPA admitted to our hospital from 1997-2012. Ten of the 22 patients (46%) were positive for serum
myeloperoxidase (MPO)-
ANCA. In contrast, all the patients were negative for serum
proteinase 3 ANCA. There was a significantly positive correlation between serum CH50 and C4 levels in patients with EGPA. Serum blood
urea nitrogen (BUN) levels differed significantly between MPO-
ANCA-positive and -negative patients. Serum CH50 levels were higher in MPO-
ANCA-positive patients compared to negative patients. Serum BUN levels were higher in elevated CH50 patients compared to normal and low CH50-negative patients. We propose that positive findings for MPO-
ANCA with CH50 high activity may be a risk factor for developing
renal insufficiency. Assuming there are correlations between the presence of
ANCA and complements, earlier diagnosis based on initial efficacious treatment for EGPA.