Neutrophil degranulation in antineutrophil cytoplasmic antibody-negative pauci-immune crescentic glomerulonephritis.
BACKGROUND
Patients with pauci-immune crescentic glomerulonephritis (CrGN) are frequently found to have antineutrophil cytoplasmic antibodies (ANCAs). It has been demonstrated that ANCAs can induce neutrophil activation and degranulation, which plays an important role in the pathogenesis of ANCA-associated vasculitis. However, the pathogenesis of ANCA-negative pauci-immune CrGN is not clear. This study aims to investigate the evidence for neutrophil activation and degranulation at disease presentation in patients with renal biopsy-proven ANCA-negative pauci-immune CrGN.


METHODS
Sera from 20 patients with ANCA-negative pauci-immune CrGN and 22 patients with ANCA-positive pauci-immune CrGN were collected at presentation. Serum neutrophil gelatinase-associated lipocalin (NGAL) and lactoferrin (LF) were measured using commercial ELISA kits.


RESULTS
Serum levels of NGAL in ANCA-negative patients were significantly higher than those of ANCA-positive patients (940.8 +/- 676.5 ng/mL vs. 569.3 +/- 287.2 ng/mL, p<0.05). This was still the case after adjustment for renal function. Serum levels of LF in ANCA-negative patients were also significantly higher than those of ANCA-positive patients (24.92 +/- 6.13 U/mL vs. 18.48 +/- 6.89 U/mL, p<0.05).


CONCLUSIONS
Neutrophil activation and degranulation occurs in patients with ANCA-negative pauci-immune CrGN in the absence of ANCA, and might be even more prominent than in their ANCA-positive counterparts.
Wang
Fang
F
Renal Division, Department of Medicine, Peking University First Hospital, Institute of Nephrology, Peking University, Beijing, China.
Chen
Min
M
Zhao
Ming-Hui
MH
D000209:Acute-Phase Proteins; D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D015550:Cell Degranulation; D005260:Female; D005921:Glomerulonephritis / Q000276:immunology*; D006801:Humans; D007781:Lactoferrin / Q000097:blood; D016014:Linear Models; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood; D008297:Male; D008875:Middle Aged; D018375:Neutrophil Activation; D009504:Neutrophils / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000097:blood
D000209:Acute-Phase Proteins; D019268:Antibodies, Antineutrophil Cytoplasmic; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D007781:Lactoferrin