IgH DJ rearrangements within T-ALL correlate with cCD79a expression, an immature/TCRgammadelta phenotype and absence of IL7Ralpha/CD127 expression.
cCD79a and IgH VDJ/DJ rearrangements are considered to be relatively specific for B lymphoid precursors. We looked for both in cCD3+, CD7+, CD19- T-ALLs classified by TCR status into alphabeta or gammadelta/immature (IM) lineages, with individualization of HOX11L2+ T-ALLs since they represent an intermediate alphabeta/gammadelta category. cCD79a was expressed at low levels in 47% of T-ALL and was most frequent in IMgamma T-ALLs. IgH rearrangements were common in gammadelta/IM (45%) and HOX11L2+ (35%) T-ALLs compared to HOX11L2-negative cases (3%; P<0.001). CD127 (IL7Ralpha) expression was also more common in the gammadelta/IM lineage but its expression was virtually mutually exclusive of IgH rearrangement. Low-level cCD79a expression alone should therefore not be interpreted as evidence of B lineage affiliation in immature leukemias. gammadelta/IM lineage T-ALLs potentially include two distinct categories: predominantly IgH+, cCD79a+, CD127- cases which retain gammadelta and B lymphoid potential and IgH-, cCD79a-, CD127+ cases with restricted T lineage potential.
Biological Hematology, Assistance Publique, Hopitaux de Paris, Necker-Enfants-Malades, France.
V
V
Asnafi
K
K
Beldjord
R
R
Garand
C
C
Millien
M
M
Bahloul
P
P
LeTutour
L
L
Douay
F
F
Valensi
E
E
Macintyre
D015703:Antigens, CD / Q000378:metabolism*; D051925:CD79 Antigens; D019070:Cell Lineage; D015322:Gene Rearrangement, B-Lymphocyte; D015329:Gene Rearrangement, T-Lymphocyte; D016694:Gene Rearrangement, delta-Chain T-Cell Antigen Receptor / Q000235:genetics*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007144:Immunoglobulin J-Chains / Q000235:genetics*; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D020395:Receptors, Interleukin-7 / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D015703:Antigens, CD; D051925:CD79 Antigens; C497881:CD79A protein, human; D007143:Immunoglobulin Heavy Chains; D007144:Immunoglobulin J-Chains; D011947:Receptors, Antigen, B-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; D020395:Receptors, Interleukin-7