Dendritic cells in renal biopsies of patients with ANCA-associated vasculitis.
BACKGROUND
Dendritic cells (DCs) maintain immune tolerance and are able to initiate immune responses. Their involvement in ANCA-associated vasculitis (AAV) is unknown. In this study, the participation of DC subsets is investigated in renal biopsies of AAV patients.


METHODS
A total of 25 patients with biopsy-proven AAV and five healthy controls (HC) with normal renal histology were included. Renal biopsies were stained for mature (CD208), immature (CD209), plasmacytoid (CD303) and Langerhans (CD1a) DC subsets. Furthermore, T-cells were stained using a T-cell marker (CD3). The interstitial cellular infiltrate was graded semi-quantitatively from 0+ (= absence of cells) to 3+ (= numerous cells). Within the glomeruli, an absolute count was performed for positive cells.


RESULTS
CD208+ and CD209+ cells were found within patients' glomeruli but not in HC (1 +/- 0.3 versus 0.08 +/- 0.1 cells/glom; 2 +/- 0.3 versus 0.1 +/- 0.07 cells/glom). An average of 0.3 +/- 0.1 cell/glom expressed CD3 in patients while few cells were found in HC (0.1 +/- 0.7 cell/glom). Focal interstitial cellular infiltrates were observed in patients' biopsies but not in HC. Interstitial infiltration with CD3+ and CD209+ cells was assessed at an average of 1+, but some glomeruli and tubuli were surrounded by CD3+ and CD209+ cells forming clusters. Serial sections revealed that CD209+ cells were present in CD3+ rich areas.


CONCLUSIONS
Both mature and immature glomerular DCs are found in renal biopsies of patients with AAV. Immature DCs cluster with T-cells in interstitial infiltrates in these biopsies. Since DCs form aggregates in T-cell areas, we hypothesize that these cells interact with each other and are involved in lymphoid neogenesis.
Wilde
Benjamin
B
Division of Clinical and Experimental Immunology, Department of Internal Medicine, University Hospital Maastricht, Maastricht, The Netherlands.
van Paassen
Pieter
P
Damoiseaux
Jan
J
Heerings-Rewinkel
Petra
P
van Rie
Henk
H
Witzke
Oliver
O
Tervaert
Jan Willem Cohen
JW
D000328:Adult; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic; D001706:Biopsy; D003713:Dendritic Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D014657:Vasculitis / Q000276:immunology* / Q000473:pathology*; D055815:Young Adult
D019268:Antibodies, Antineutrophil Cytoplasmic