Functional and phenotypical impairment of polymorphonuclear cells in atopic dermatitis: an additional cause for the known susceptibility to infections?.
BACKGROUND
Atopic dermatitis (AD) patients present an high susceptibility to infections. The phagocytic activity of polymorphonuclear granulocytes (PMNs) is mediated by the interactions between Toll-like receptors (TLRs) and pathogen-associated molecular patterns.


OBJECTIVE
To investigate functional activity and phenotype of PMNs in AD patients.


METHODS
In vitro PMN phagocytosis and intracellular killing towards Klebsiella pneumoniae were evaluated in 24 AD patients; flow cytometry was applied to analyze PMN phenotype.


RESULTS
PMNs from AD patients displayed both reduced phagocytic activity and intracellular killing against K. pneumoniae than healthy subjects (HS). CD11b, CD66b, TLR2, TLR4 and TLR5 median fluorescence intensity (MFI) on PMN membrane were significantly higher in AD patients than in HS.


CONCLUSIONS
PMN functional impairment in AD patients could represent an additional cause of skin infections, coupled with other known defects in the innate immune system. The increased MFI of adhesion molecules and TLRs is rather a consequence of the increased skin barrier permeability to bacterial molecules capable of stimulating immunological reactions.
Department of Biomedical Sciences and Human Oncology, Section of Dermatology, Dermatologic Clinic, University of Turin, via Cherasco 23, Turin, Italy. mariateresa.fierro@unito.it
Maria Teresa
MT
Fierro
Giuliana
G
Banche
Federica
F
Marenco
Mauro
M
Novelli
Valeria
V
Allizond
Narcisa
N
Mandras
Pierangela
P
Murabito
Chiara
C
Merlino
Pietro
P
Quaglino
Maria Grazia
MG
Bernengo
Anna Maria
AM
Cuffini
D000328:Adult; D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000382:microbiology; D004198:Disease Susceptibility; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007710:Klebsiella Infections / Q000276:immunology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000502:physiology*; D010586:Phagocytes / Q000276:immunology*; D010587:Phagocytosis / Q000502:physiology; D010641:Phenotype; D051193:Toll-Like Receptors / Q000378:metabolism; D055815:Young Adult
D051193:Toll-Like Receptors