Prognostic Implications of Blood B Ratings for Erythrodermic Cutaneous T cell Lymphoma

Abstract

Objective: The magnitude of blood involvement in cutaneous T cell lymphoma (CTCL) has prognostic significance. Several groups have proposed hematologic criteria for B ratings for use in clinical staging of CTCL, but in practice B ratings are only relevant for the staging of erythrodermic CTCL without lymph node or visceral involvement, i.e., T4N0-2M0B0 defines sub-stage IIIA, T4N0-2M0B1 defines sub-stage IIIB and T4N0-2M0B2 defines sub-stage IVA1. This retrospective study examines the effect of various B rating criteria on prognoses of patients with erythrodermic CTCL. Methods: At initial presentation, 152 patients diagnosed with E-CTCL had quantitative Sézary cell counts performed on blood smears and CD4/CD8 ratios determined in the blood by flow cytometry. In addition, 39 patients had percentages of CD4 + CD26and CD4 + CD7lymphocytes directly measured. The Kaplan-Meier method and Cox proportional hazards model were used to estimate mean overall and CTCL-specific survival and to compare survival curves of sub-stages of erythrodermic CTCL. Results: With B2 rating defined as absolute Sézary cell counts ≥ 1.0 K/µL or CD4/CD8 ratio ≥ 10, a better separation of survival curves between sub-stages IIIA and IIIB was observed if the threshold for B1 was defined as Sézary cells ≥ 20% and CD4/CD8 ratio defined as ≥ 4 plus confirmation of blood involvement. With either criterion, the survival of patients at sub-stages IVA1 and IVA2 were not statistically different. There was also a suggestion that percentage of CD4 + CD26or CD4 + CD7cells (which ever was higher) might be used to define B1 and B2 thresholds (≥ 30% and ≥ 60%, respectively) as an alternative to absolute counts. Maximum CD4 + CD26-/CD4 + CD7-≥ 30% plus confirmation also might provide a hematologic definition of leukemic CTCL. Conclusion: Additional studies on larger number of patients and evaluation with other measures of blood tumor burden are indicated.

A histo‐immunopathologic and prognostic study of erythrodermic cutaneous T‐cell lymphoma

“…Other criteria are based on flow cytometry and include an expanded population of clonal T‐cells resulting in a CD4/CD8 ratio ≥10 or an absolute count of CD4 + CD7− or CD4 + CD26− lymphocytes ≥1000/μL . In addition to molecular genetic evidence of a clone, blood involvement can be confirmed by the presence of very large Sézary cells (cell diameter >14 μm), cytogenetic abnormalities, and T‐cells with diminished expression levels of CD3 or restricted expression of T‐cell receptor Vβ …”

“…[3][4][5] In addition to molecular genetic evidence of a clone, blood involvement can be confirmed by the presence of very large Sézary cells (cell diameter >14 μm), cytogenetic abnormalities, and Tcells with diminished expression levels of CD3 or restricted expression of T-cell receptor Vβ. 6 The histopathologic features of E-CTCL have been extensively studied with comparison of SS to pre-SS,* 7 E-CTCL to typical MF, 8,9 and E-CTCL to EID. [10][11][12] Two studies have compared immunopathologic features of SS to EID.…”