CD7-positive acute leukemia lacking T cell receptor gene rearrangements and terminal deoxynucleotidyl transferase expression suggesting pre-T cell origin
✍ Scribed by James C. Jacobs; Dr. Ann Rearden
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 515 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0361-8609
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✦ Synopsis
In this report, we describe a case of acute leukemia possessing a unique immunophenotype. Leukemic cells isolated from peripheral blood were analyzed by automated fluorescence-activated flow cytometry. They demonstrated the following antigen pattern: CD7 +, CD38 +, transferrin receptor + , HLA-DR + , common ALL antigen (CALLA)-, and terminal deoxynucleotidyl transferase (TdT)-. No expression of B cell or myeloid antigens was observed. The observed antigen pattern suggests a pre-T cell origin. In addition, the tumor cells contained germline T cell receptor beta (T, ) and gamma (T, ) chain genes, and a germline immunoglobulin heavy chain (JH) gene. These findings support the concept that pre-T cell leukemias may demonstrate germline T, and T, genes as well as lack TdT expression. In addition, our results suggest that CD7 expression may be one of the earliest events in T cell differentiation, occurring prior to both T, and T, gene rearrangements, and TdT expression.