High-density oligonucleotide array analysis of mRNA transcripts in peripheral blood cells of severe atopic dermatitis patients.
BACKGROUND
There are few laboratory tests for evaluating atopic dermatitis (AD) with the exception of IgE levels or the eosinophil count. We attempted to identify new diagnostic markers by screening the genome-wide expression of transcripts in peripheral blood mononuclear cells (PBMC).


METHODS
For this study, we enrolled 7 nonatopic healthy volunteers, 5 AD patients who responded well to treatment and 6 who responded poorly. We compared genome-wide transcript levels in PBMC derived from patients with severe AD and healthy volunteers using high-density oligonucleotide arrays (GeneChip, Affymetrix). After the first screening with GeneChip, we employed real-time quantitative PCR to confirm differential expression levels.


RESULTS
Screening with GeneChip showed that the levels of a total of 92 transcripts increased at least 3-fold in one population compared to another. After further evaluation of these genes with real-time quantitative PCR, the levels of 4 transcripts were confirmed to be significantly different in PBMC from AD patients compared to controls, namely IFN-gamma, TRAIL (TNF-related apoptosis-inducing ligand), ISGF-3 (STAT1) and defensin-1. With the exception of IFN-gamma, none of these genes has previously been implicated in AD pathology.


CONCLUSIONS
These 4 transcripts in PBMC are expected to be useful markers for evaluating AD.
Heishi
Masayuki
M
Genox Research, Inc., Kanagawa, Japan.
Kagaya
Shinji
S
Katsunuma
Toshio
T
Nakajima
Toshiharu
T
Yuki
Keisuke
K
Akasawa
Akira
A
Maeda
Miyako
M
Gunji
Shigemiti
S
Sugita
Yuji
Y
Tsujimoto
Gozoh
G
Saito
Hirohisa
H
D002478:Cells, Cultured; D023082:Defensins / Q000235:genetics; D003876:Dermatitis, Atopic / Q000097:blood*; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D023082:Defensins; D012333:RNA, Messenger; D007371:Interferon-gamma