Combined use of PCR-based TCRG and TCRB clonality tests on paraffin-embedded skin tissue in the differential diagnosis of mycosis fungoides and inflammatory dermatoses.
The distinction between mycosis fungoides (MF) and inflammatory dermatoses (ID) by clinicopathologic criteria can be challenging. There is limited information regarding the performance characteristics and utility of TCRG and TCRB clonality assays in diagnosis of MF and ID from paraffin-embedded tissue sections. In this study, PCR tests were performed with both TCRG and TCRB BIOMED-2 clonality methods followed by capillary electrophoresis and Genescan analysis using DNA samples from 35 MF and 96 ID patients with 69 and 133 paraffin-embedded specimens, respectively. Performance characteristics were determined for each test individually and in combination. TCRG and TCRB tests demonstrated identical sensitivity (64%) and specificity (84%) when analyzed as individual assays. The positive predictive value, negative predictive value, and change of posttest MF probability over a range of MF pretest probabilities were obtained. These data were used to construct an algorithm for sequential use of TCRG and TCRB. As single tests, commercially available BIOMED-2 PCR-based TCRG and TCRB clonality tests on paraffin-embedded tissue have no significant difference in terms of sensitivity and specificity. Combined use of the two tests in patients with intermediate pretest probabilities as proposed in the algorithm could improve test utility.
Zhang
Bing
B
Department of Pathology, L235, Stanford University Medical Center, Stanford, CA 94305, USA.
Beck
Andrew H
AH
Taube
Janis M
JM
Kohler
Sabine
S
Seo
Katie
K
Zwerner
Jeffrey
J
Viakhereva
Natalie
N
Sundram
Uma
U
Kim
Youn H
YH
Schrijver
Iris
I
Arber
Daniel A
DA
Zehnder
James L
JL
D019672:Genes, T-Cell Receptor / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D009182:Mycosis Fungoides / Q000175:diagnosis* / Q000235:genetics; D016612:Paraffin Embedding / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology*; D012871:Skin Diseases / Q000175:diagnosis* / Q000235:genetics