title: Antineutrophilic cytoplasmic antibody-associated vasculitis with hypocomplementemia has a higher incidence of serious organ damage and a poor prognosis.
abstract: A relationship between antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and complement has been shown, and complement has an important role in the pathogenesis of AAV. The clinical characteristics of AAV with hypocomplementemia still remain unclear.We conducted an observational study of 81 patients with AAV (median onset age 71 years; 58% female). Using medical records, we analyzed the patients' baseline variables, laboratory data, clinical symptoms, and therapeutic outcomes after treatments including episodes of relapses, initiation of dialysis, and death. We defined hypocomplementemia as the state in which at least one of the following was lower than the lower limit of the normal range: complement 3 (C3), complement 4 (C4), and total complement activity (CH50).Sixteen patients (20%) had hypocomplementemia at their diagnosis of AAV. Compared to the AAV patients without hypocomplementemia (n = 65), those with hypocomplementemia had significantly higher rates of the occurrence of skin lesions (8 [50%] vs. 8 [12%], P = 0.002), diffuse alveolar hemorrhage (DAH) (6 [38%] vs. 5 [8%], P = 0.006), and thrombotic microangiopathy (TMA) (3 [19%] vs. 0 [0%], P = 0.007). The AAV patients with hypocomplementemia had significantly lower platelet levels (16.5 × 10 vs. 24.9 × 10 cells/μL, P = 0.023) compared to those without hypocomplementemia. More positive immune complex deposits in renal biopsy specimens were seen in the AAV patients with hypocomplementemia than in those without hypocomplementemia (4 [80%] vs. 2 [18%], P = 0.036). Assessed by a log-rank test, hypocomplementemia at disease onset was significantly associated with death (P = 0.033).Hypocomplementemia in AAV at the disease onset was a risk factor for the serious organ damage, and a life prognostic factor. It is thus very important to pay attention to the levels of complement at the diagnosis of AAV.
authors.affiliation: Department of Immunology and Rheumatology Department of Public Health Department of Rehabilitation Sciences, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences Nagasaki University Hospital Clinical Research Center, Nagasaki, Japan..
authors.forename: Shoichi
authors.initials: S
authors.lastname: Fukui
authors.forename: Naoki
authors.initials: N
authors.lastname: Iwamoto
authors.forename: Masataka
authors.initials: M
authors.lastname: Umeda
authors.forename: Ayako
authors.initials: A
authors.lastname: Nishino
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Koga
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Kawashiri
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Ichinose
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hirai
authors.forename: Mami
authors.initials: M
authors.lastname: Tamai
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Tomoki
authors.initials: T
authors.lastname: Origuchi
authors.forename: Shuntaro
authors.initials: S
authors.lastname: Sato
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
mesh_terms: D000368:Aged; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000097:blood / Q000150:complications* / Q000188:drug therapy / Q000401:mortality; D003165:Complement System Proteins / Q000172:deficiency*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011239:Prednisolone / Q000627:therapeutic use; D012189:Retrospective Studies
chemical_list: D000893:Anti-Inflammatory Agents; D003165:Complement System Proteins; D011239:Prednisolone