Identifying phenotypically aberrant T-cell population in peripheral blood as part of the diagnostic workup for Sezary syndrome
Roughly assessing the circulating tumor burden in mycosis fungoides, if the phenotype of the neoplastic cells is distinctive enough
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
FCIMS | Flow Cytometry Interp, 9-15 Markers | No | No |
FCINS | Flow Cytometry Interp,16 or greater | No | No |
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
FIRST | Flow Cytometry, Cell Surface, First | No | Yes |
ADD1 | Flow Cytometry, Cell Surface, Addl | No | Yes |
This Sezary panel is ordered for patients with a clinical suspicion of Sezary syndrome or cutaneous T-cell lymphoma (CTCL) with peripheral blood involvement. For patients without a previously confirmed diagnosis of Sezary syndrome, a triage panel will also be performed to exclude a B-cell lymphoproliferative disorder.
A triage panel is always performed. The panel is charged based on number of markers tested (FIRST for first marker, ADD1 for each additional marker). In addition, reflex testing may occur to fully characterize a disease state or clarify any abnormalities from the screening test. Reflex tests will be performed at an additional charge for each marker tested (ADD1 if applicable).
Immunophenotyping
Sezary
Leukemic CTCL
Mycosis fungoides
Circulating T-cell lymphoma
This Sezary panel is ordered for patients with a clinical suspicion of Sezary syndrome or cutaneous T-cell lymphoma (CTCL) with peripheral blood involvement. For patients without a previously confirmed diagnosis of Sezary syndrome, a triage panel will also be performed to exclude a B-cell lymphoproliferative disorder.
A triage panel is always performed. The panel is charged based on number of markers tested (FIRST for first marker, ADD1 for each additional marker). In addition, reflex testing may occur to fully characterize a disease state or clarify any abnormalities from the screening test. Reflex tests will be performed at an additional charge for each marker tested (ADD1 if applicable).
Whole blood
This test is not appropriate for monitoring patients with a diagnosis of Sezary syndrome. For monitoring purposes, order SZMON / Sezary Monitoring Flow Cytometry, Blood.
Container/Tube:
Preferred: Yellow top (ACD)
Acceptable: Lavender top (EDTA), green top (heparin)
Specimen Volume: 6 mL
Collection Instructions:
1. Send whole blood specimen in original tube. Do not aliquot.
2. Label specimen as blood.
If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
1 mL
Gross hemolysis | Reject |
Gross lipemia | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Ambient (preferred) | 72 hours | |
Refrigerated | 72 hours |
Identifying phenotypically aberrant T-cell population in peripheral blood as part of the diagnostic workup for Sezary syndrome
Roughly assessing the circulating tumor burden in mycosis fungoides, if the phenotype of the neoplastic cells is distinctive enough
This Sezary panel is ordered for patients with a clinical suspicion of Sezary syndrome or cutaneous T-cell lymphoma (CTCL) with peripheral blood involvement. For patients without a previously confirmed diagnosis of Sezary syndrome, a triage panel will also be performed to exclude a B-cell lymphoproliferative disorder.
A triage panel is always performed. The panel is charged based on number of markers tested (FIRST for first marker, ADD1 for each additional marker). In addition, reflex testing may occur to fully characterize a disease state or clarify any abnormalities from the screening test. Reflex tests will be performed at an additional charge for each marker tested (ADD1 if applicable).
Sezary syndrome is a leukemic form of cutaneous T-cell lymphoma (CTCL). It is associated with systemic skin involvement (erythroderma) and the presence of at least 1000/mcL of circulating cells with irregular nuclear features (Sezary cells). Morphologic assessment of the number of Sezary cells has been proven to have low reproducibility. Therefore, World Health Organization/European Organization for Research and Treatment of Cancer classification of skin tumors adopted alternative methods to assess circulating T cells in order to establish the diagnosis of Sezary syndrome. These include CD4:CD8 ratio of more than 10:1 and selective loss of CD7 and/or CD26 on 40% and 30% of the CD4-positive cell population, respectively. It is important to recognize that the later criteria (fulfilled by peripheral blood flow cytometry immunophenotyping) are relative and not in direct correlation with absolute counts of Sezary cells defined by morphology.
An interpretive report will be provided. This test will be processed as a laboratory consultation. An interpretation of the immunophenotypic findings and, if available, morphologic features will be provided by a board-certified hematopathologist for every case.
Sezary cells typically show loss of CD7 and/or CD26. As loss of these markers is not completely sensitive or specific for Sezary cells, and there are circulating normal CD4-positive T cells, which usually cannot be excluded from the analysis, the World Health Organization/European Organization for Research and Treatment of Cancer classification of skin tumors proposed cutoffs of 30% for CD26 loss and 40% for CD7 loss on CD4-positive T cells as diagnostic criteria for Sezary syndrome. In addition, a CD4:CD8 ratio of greater than or equal to 10:1 in a gated T-cell population is also considered abnormal and part of the diagnostic algorithm for Sezary syndrome.
In mycosis fungoides staging studies, the cutoffs are even less clearly defined. The clinical outcome was worse in patients with more than 5% of circulating lymphocytes showing Sezary-like morphology. However, flow cytometry immunophenotyping is deemed useful for relative quantification of these cells only if they can be separated by aberrant expression of other surface markers. In the majority of cases, this cannot be accomplished to the proposed cutoff point (5% of circulating lymphocytes).
The test will be resulted as "No phenotypically aberrant T-cell population detected" if there is no specific phenotype that allows separation of potentially abnormal CD4-positive T cells, loss of CD26 (and/or CD7) is present in less than 30% (40%), and CD4:CD8 ratio is less than 10:1. If any of the above aberrancies are present, the test will be resulted as "Phenotypically distinct T-cell population is detected" with a description of phenotype, percentage of total CD4-positive population, and percentage of total analyzed events. In addition, the phenotype will be compared to that of any distinct T-cell population previously seen in the same patient by our laboratory.
Correlation with clinical features is necessary for diagnosis of Sezary syndrome. This analysis can only describe a cell population with aberrant phenotype, but the significance of this finding in isolation is uncertain.
1. Horna P, Deaver DM, Qin D, et al: Quantitative flow cytometric identification of aberrant T cell clusters in erythrodermic cutaneous T cell lymphoma. Implications for staging and prognosis. J Clin Pathol. 2014;67:431-436
2. Berg H, Otteson GE, Corley H, et al: Flow cytometric evaluation of TRBC1 expression in tissue specimens and body fluids is a novel and specific method for assessment of T-cell clonality and diagnosis of T-cell neoplasms. Cytometry B Clin Cytom. 2021 May;100(3):361-369
3. Horna P, Shi M, Olteanu H, Johansson U: Emerging role of T-cell receptor constant beta chain-1 (TRBC1) expression in the flow cytometric diagnosis of T-cell malignancies. Int J Mol Sci. 2021 Feb 12;22(4):1817
4. Wilcox RA: Cutaneous T-cell lymphoma: 2016 update on diagnosis, risk-stratification, and management. Am J Hematol. 2016;91:152-165. doi: 10.1002/ajh.24233
5. Horna P, Olteanu H, Jevremovic D, et al: Single-antibody evaluation of T-cell receptor beta constant chain monotypia by flow cytometry facilitates the diagnosis of T-cell large granular lymphocytic leukemia. Am J Clin Pathol. 2021 Jun 17;156(1):139-148
6. Horna P, Shi M, Jevremovic D, Craig FE, Comfere NI, Olteanu H: Utility of TRBC1 expression in the diagnosis of peripheral blood involvement by cutaneous T-cell lymphoma. J Invest Dermatol. 2021 Apr;141(4):821-829
7. Scarisbrick JJ, Hodak E, Bagot M, et al: Blood classification and blood response criteria in mycosis fungoides and Sezary syndrome using flow cytometry: recommendations from the EORTC cutaneous lymphoma task force. Eur J Cancer. 2018 Apr;93:47-56
8. Illingworth A, Johansson U, Huang S, et al: International guidelines for the flow cytometric evaluation of peripheral blood for suspected Sézary syndrome or mycosis fungoides: Assay development/optimization, validation, and ongoing quality monitors. Cytometry B Clin Cytom. 2021 Mar;100(2):156-182
Flow cytometry immunophenotyping of peripheral blood is performed using the following antibodies:
-Triage Panel: CD3, CD10, CD16, CD19, CD34, CD45, and kappa and lambda light chains.
-Sezary Panel: CD2, CD3, CD4, CD5, CD7, CD8, CD26, CD45, and TRBC1.(Shi M, Jevremovic D, Otteson GE, Timm MM, Olteanu H, Horna P: Single antibody detection of T-cell receptor alpha-beta clonality by flow cytometry rapidly identifies mature T-cell neoplasms and monotypic small CD8-positive subsets of uncertain significance. Cytometry B Clin Cytom. 2020 Jan;98(1):99-107)
Monday through Saturday
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
88184-Flow cytometry; first cell surface, cytoplasmic or nuclear marker x 1
88185-Flow cytometry; additional cell surface, cytoplasmic or nuclear marker (each)
88188-Flow Cytometry Interpretation, 9 to15 markers (if appropriate)
88189-Flow Cytometry Interpretation, 16 or more markers (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
SZDIA | Sezary Diagnostic Flow Cytometry, B | 101118-8 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
CK126 | Sezary Diagnostic | No LOINC Needed |
CK127 | Final Diagnosis | 50398-7 |
CK128 | Special Studies | 30954-2 |
CK129 | Microscopic Description | 22635-7 |