High prevalence of T-cell receptor V delta 2-(D)-D delta 3 or D delta 1/2-D delta 3 rearrangements in B-precursor acute lymphoblastic leukemias.
Rearrangement of the immunoglobulin (Ig) and T-cell receptor (TcR) genes generally has been considered a useful marker of B- and T-cell lineage in lymphoproliferative disorders. However, concomitant rearrangements of Ig and TcR genes have been commonly reported in the most immature lymphoid malignancies, mainly in B-cell precursor acute lymphoblastic leukemia (ALL). To better characterize the nature of this lineage promiscuity, we have analyzed the configuration of the TcR delta locus in 75 B-precursor ALL. The large majority of cases (87%) displayed a rearrangement or deletion at the delta locus. Among the 57 nondeletional rearrangements, two patterns were predominant and both appeared to derive from partial joining: a V delta-(D)-D delta 3 (32/57) and a D delta 1/2-D delta 3 (11/57) type. A single V delta gene (V delta 2) appeared to be involved in the first type of rearrangement. These findings are at variance with T-ALL, where rearrangements 5' to V delta 2 are usually found. It remains to be elucidated whether this incomplete attempt of V delta 2 gene assembly is related to the neoplastic event or represents a physiologic predisposition occurring during early stages of the normal lymphocyte differentiation.
Biondi
A
A
Clinica Pediatrica Università di Milano, Monza, Italy.
Francia di Celle
P
P
Rossi
V
V
Casorati
G
G
Matullo
G
G
Giudici
G
G
Foa
R
R
Migone
N
N
D001402:B-Lymphocytes / Q000276:immunology*; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology; D002051:Burkitt Lymphoma / Q000235:genetics / Q000276:immunology*; D015342:DNA Probes; D004273:DNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D015329:Gene Rearrangement, T-Lymphocyte; D006801:Humans; D046911:Macromolecular Substances; D015183:Restriction Mapping; D013601:T-Lymphocytes / Q000276:immunology*
D015342:DNA Probes; D004273:DNA, Neoplasm; D046911:Macromolecular Substances