[1191] The Utility of Flow Cytometry TCR-V
Chain Analysis in Combination with Immunophenotyping for Assessing Blood Involvement by Cutaneous T-cell Lymphoma (CTCL)
B Feng, JL Jorgensen, DM Jones, LJ Medeiros, SAA Wang. UT MD Anderson Cancer Center, Houston, TX
Background: Blood involvement by tumor cells has adverse prognostic significance in patients with CTCL. Since the tumor-cells frequently show nonspecific morphology, clonality testing is required for confirmation. Commonly used TCR gene PCR has long turn-around time and can detect non-neoplastic clonal rearrangement. We assess the clinical usefulness of TCR-V flow cytometry analysis as a replacement technique for CTCL-blood staging.
Design: We studied the blood samples of 88 CTCL patients and 18 controls using a panel of TCR-V antibodies covering 70% of the TCR-V segments. To improve sensitivity, TCR-V was analyzed on abnormal T-cells with aberrant CD3, CD4 or CD26 expression. TCR-
and TCR- chain PCR testing were conducted in 40 cases in parallel. Circulating CTCL was determined by morphology, immunophenotype and clonality.
Results: Of the 88 samples, Sezary cells identified by manual differential were of 0-5% in 54(61%); 5-19% in 17(19%) and >20% in 17(19%) patients. Immunophenotypic aberrancies were detected in 23/54, 14/17 and 14/17 of these patients. Abnormal TCR-V was detected in 32/54, 17/17 and 17/17 of the CTCL cases but not in the controls, demonstrating a 92% concordance with blood involvement, similar to TCR gene PCR but with superior specificity (100% vs 75%). 44 cases had detectable tumor-associated V expression permitting the use for follow-up studies.
| %Sezary cells by morphology | Control(n=18) | <5% (n=54) | 5-19% (n=17) | >20% (n=17) |
| SS by CD4 CD3dim CD7- CD26- | ||||
 POS | 0 | 23 | 14 | 14 |
| NEG | 13 | 13 | 0 | 0 |
| Intermediate | 5 | 6 | 3 | 3 |
| Tumor cells by V beta | ||||
| POS | 0 | 32 | 17 | 17 |
| NEG | 18 | 22 | 0 | 0 |
| TCR gene rearrangement | ||||
| POS | 2 | 14 | 3 | 7 |
| NEG | 9 | 10 | 1 | 3 |
| ND | 6 | 30 | 13 | 7 |
Conclusions: TCR-V
chain analysis in combination with immunophenotyping improves the detection sensitivity and allows a definite identification of tumor cell-defining blood involvement. The V flow cytometry analysis is rapid, quantitative and suitable for monitoring tumor load during therapy.Category: Hematopathology
Monday, March 9, 2009 11:15 AM
Platform Session: Section D, Monday Morning