Quantitative PCR on 5 genes reliably identifies CTCL patients with 5% to 99% circulating tumor cells with 90% accuracy.
We previously identified a small number of genes using cDNA arrays that accurately diagnosed patients with Sézary Syndrome (SS), the erythrodermic and leukemic form of cutaneous T-cell lymphoma (CTCL). We now report the development of a quantitative real-time polymerase chain reaction (qRT-PCR) assay that uses expression values for just 5 of those genes: STAT4, GATA-3, PLS3, CD1D, and TRAIL. qRT-PCR data from peripheral blood mononuclear cells (PBMCs) accurately classified 88% of 17 patients with high blood tumor burden and 100% of 12 healthy controls in the training set using Fisher linear discriminant analysis (FLDA). The same 5 genes were then assayed on 56 new samples from 49 SS patients with blood tumor burdens of 5% to 99% and 69 samples from 65 new healthy controls. The average accuracy over 1000 resamplings was 90% using FLDA and 88% using support vector machine (SVM). We also tested the classifier on 14 samples from patients with CTCL with no detectable peripheral involvement and 3 patients with atopic dermatitis with severe erythroderma. The accuracy was 100% in identifying these samples as non-SS patients. These results are the first to demonstrate that gene expression profiling by quantitative PCR on a selected number of critical genes can be employed to molecularly diagnosis SS.
Nebozhyn
Michael
M
The Wistar Institute, 3601 Spruce St, Philadelphia, PA 19104, USA.
Loboda
Andrey
A
Kari
Laszlo
L
Rook
Alain H
AH
Vonderheid
Eric C
EC
Lessin
Stuart
S
Berger
Carole
C
Edelson
Richard
R
Nichols
Calen
C
Yousef
Malik
M
Gudipati
Lalitha
L
Shang
Meiling
M
Showe
Michael K
MK
Showe
Louise C
LC
D003876:Dermatitis, Atopic / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D003873:Dermatitis, Exfoliative / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D011237:Predictive Value of Tests; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012751:Sezary Syndrome / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D047368:Tumor Burden / Q000235:genetics