Single allelic C mu gene rearrangements in patients with T cell and undifferentiated leukemia

Presence of more than two rearranged immunoglobulin heavy-chain genes in adult precursor B-cell acute lymphoblastic leukemia

We examined the configuration of the immunoglobulin genes in the leukemic blast cell DNA of 20 adults with precursor B-cell acute lymphoblastic leukemia (ALL), treated according to the BMFT protocol. Sixteen of 20 (80%) patients expressed HLA-DR antigens and lacked detectable T-cell antigens. Eleven of the 20 patients (55%) were positive for the CD10 antigen and therefore classified as common ALL. Six patients were classified by immunological phenotyping as null-ALL (30%). Three patients (15%) expressed both immature B-cell markers CD19, CD22, or CD24 and myelomonocytic markers CDw65 or CD15, suggesting precursor B-ALL with cross-lineage expression of myeloid markers. In 18 of the 20 patients (90%), rearrangements and/or deletions of the immunoglobulin heavy-chain (IgH) gene locus were found. In none of the patients was a light-chain gene rearrangement observed. Two patients (10%) had a rearrangement of one allele for the J beta 1 gene region of the TCR-beta gene. In four patients (20%) more than two hybridizing bands for the IgH genes were detected. Two of these four patients with multiple hybridizing bands for the IgH genes had a t (4;11) translocation. Two of five patients with the t (4;11) translocation co-expressed both B-cell antigens and the myeloid antigens CD15 or CDw65. No correlation was found between the immunophenotype of the ALL and the arrangement pattern of their IgH genes. Kaplan-Meier plot analysis revealed no significant difference between adult precursor B-ALL patients with monoclonal or oligoclonal IgH gene rearrangements and their disease-free survival rates.

Unexpected immunoglobulin light chain gene rearrangements in myeloid antigen positive acute lymphoid leukemia

Blast cells from 10 immunologically diagnosed adult acute lymphoid leukemias expressing myeloid antigens (M+ALL) were studied for immunoglobulin heavy (IgH) and light chain as well as T-cell receptor (TCR)-beta chain gene rearrangements. All but one leukemic isolate met the FAB-criteria for ALL. DNA from 2 patients with pre-pre-B-ALL (CD10-) and 1 patient with common ALL contained rearranged Ig light chain (kappa in two, lambda in one case) in addition to rearranged IgH genes. The TCR-beta chain gene was germline in all pre-pre-B leukemias and rearranged in common ALLs (bigenotypic features). One patient with mature B-ALL showed IgH and light chain gene rearrangements. DNA from 2 pre-T-ALLs contained rearranged TCR-beta chain genes plus rearranged IgH genes in one case. Ig light chain gene rearrangements in immature M+ALL were not associated with gross chromosomal abnormalities except for one Philadelphia chromosome positive case. The occurrence of Ig light chain gene rearrangements in M+ALL with immature lymphoid immunophenotype might represent an hitherto unrecognized aberrant differentiation potential of transformed multipotential stem cells with commitment towards the lymphoid lineage.

Demonstration of clonal selection in a child with non-Hodgkin's lymphoma

A 2-year-old boy with B-lineage non-Hodgkin's lymphoma is described. He presented with growing skin tumors on his head, and biopsy specimens showed a malignant lymphoma of diffuse lymphoblastic type. Sixty-four percent of bone marrow cells were replaced with lymphoblasts, and they expressed B-lineage markers (CD19 and HLA/DR). Southern blot analysis demonstrated immunoglobulin heavy chain gene rearrangements (two rearranged and one germline) with the germline configuration of the T-cell receptor beta chain gene. Ten months later he relapsed with blasts of M5 morphologic type and a myeloid phenotype with the germline configuration of the immunoglobulin genes. During the next 2 months, myeloid blasts with immunoglobulin gene rearrangement which was identically rearranged with one of the two rearranged bands detected at diagnosis appeared. The most likely explanation for these findings is that initially the patient seemed to have at least two different clones of blasts, and clonal selections occurred during the treatments.

Rearrangement of TCR gamma chain gene involving JP1 suggests early thymocyte origin of peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTL) are morphologically and immunophenotypically heterogeneous. We have examined a series of cases to determine whether this heterogeneity is reflected at the level of developmentally specific T-cell receptor (TCR) gene rearrangement. 4 of 5 cases had clonal rearrangements of TCR beta and gamma chain genes; one of these also had a probable DQ52-J immunoglobulin heavy chain gene rearrangement. 2 of the 4 TCR gamma gene rearrangements involved the most 5' J region, JP1, a characteristic of immature thymocytes. These 2 cases also had immunophenotypic features of immaturity. Taken together, our results suggest that TCR gene rearrangement is correlated with surface marker data and shows that in some cases PTL may arise from a very early stage of thymocyte maturation.

T cell receptor delta gene rearrangements in acute lymphoblastic leukemia

Using a newly isolated cDNA clone encoding the TCR-delta gene and genomic probes, we have analyzed T cell receptor (TCR) delta gene rearrangement in 19 patients with T cell acute lymphoblastic leukemia (T-ALL) and 29 patients with B-precursor ALL. Five out of seven CD3- T-ALL and 4 of 12 CD3+ T-ALL showed bi-allelic rearrangements of the TCR-delta gene. In three CD3+ patients, a single allelic TCR-delta gene rearrangement was observed with rearrangement of the TCR-alpha gene on the other allele. In five CD3+ patients with bi-allelic rearrangements of the TCR-alpha gene, the TCR-delta gene locus was deleted. Transcription of the TCR-delta gene was also analyzed in six T-ALL. Five patients expressed TCR-delta transcripts. Only one T-ALL, presumably derived from the most immature T lineage cells, did not have TCR-delta transcripts, but expressed TCR-gamma and 1.0-kb truncated TCR-beta transcripts. In B-precursor ALL, 20 patients (69%) showed rearrangements of the TCR-delta gene. The frequency of TCR-delta gene rearrangement was higher than TCR-alpha (59%), gamma (52%), or beta (31%) genes. These findings suggest that TCR-alpha gene rearrangements may take place after rearrangements of the TCR-delta gene with concomitant deletion of rearranged TCR-delta genes in T cell differentiation. Among leukemic cells of B lineage, the TCR-delta gene is the earliest rearranging TCR gene, followed by TCR-gamma and beta gene rearrangements.

T cell receptor alpha-chain gene rearrangements in B-precursor leukemia are in contrast to the findings in T cell acute lymphoblastic leukemia. Comparative study of T cell receptor gene rearrangement in childhood leukemia

We have analyzed T cell receptor alpha-chain gene configuration using three genomic joining (J) region probes in 64 children with acute lymphoblastic leukemia (ALL). 11 out of 18 T-ALLs were T3 positive; alpha-chain gene rearrangements were demonstrated in only two of 18, indicating that the majority of T-ALLs would have rearrangements involving J alpha segments located upstream of these probes. In contrast, 15 out of 46 B-precursor ALLs showed rearrangements of the alpha-chain gene and J alpha segments located approximately 20-30 kb upstream of the constant region were involved in 13 of these patients. Nine of 15 B-precursor ALLs with rearranged alpha-chain genes had rearrangements of both gamma- and beta-chain genes, whereas the remaining six had no rearrangements of gamma- and beta-chain genes. These findings indicated that alpha-chain gene rearrangement is not specific for T lineage cells and gamma- and/or beta-chain gene rearrangement does not appear essential for alpha-chain gene rearrangement, at least in B-precursor leukemic cells.

Concomitant rearrangements of T-cell beta- and gamma-chain genes in childhood T-lineage leukemia/lymphoma

Similar to the immunoglobulin (Ig) gene rearrangements in B-lineage cells, identification of T-cell receptor (TCR) gene rearrangements is a novel clonal marker and necessary to establish a T-cell lineage. The function of T-cell gamma-chain (T gamma) gene is still unknown, but because of its shared properties with T-cell alpha-chain (T alpha) and T beta genes, we analysed T gamma gene organization in 10 patients with T-lineage leukemia/lymphoma as well as in non-T lineage leukemias. All 10 cases of T-lineage leukemia/lymphoma, whose phenotypes were different, demonstrated T gamma gene rearrangements as well as T beta gene rearrangements. In contrast, among the non-T-lineage leukemias, the emergence of T beta and/or T gamma gene rearrangements was varied. Based on these findings, concomitant rearrangements of T beta and T gamma genes are characteristic in childhood T-lineage leukemia/lymphoma regardless of their phenotypic differences. Furthermore, no obvious developmental hierarchy was observed between T beta and T gamma gene arrangements in these leukemia/lymphoma cells.

Kappa-chain gene rearrangement in an apparent T-lineage lymphoma

We describe a 10-yr-old boy with T-lineage non-Hodgkin's lymphoma. He had a mediastinal mass, swollen supraclavicular lymph nodes, and pleural effusion. A supraclavicular lymph node biopsy under light microscopy showed a malignant lymphoma of diffuse lymphoblastic type. Most of the cells taken from the malignant pleural effusion expressed T cell-associated antigens such as Leu-1 and OKT 8. To confirm these antigens as T-lineage lymphoma, we examined genomic DNA from malignant cells obtained from the pleural effusion. As was expected, T cell receptor beta-chain gene rearrangements were demonstrated. However, when the immunoglobulin gene organization was analyzed, we detected rearrangements in both the heavy- and kappa-chain genes. To our knowledge, this is the first case in which kappa-chain gene rearrangement was detected in apparent T-lineage cells. These findings provide important information relating to determination of the cellular lineage of lymphoid malignancy.

Rearrangement of immunoglobulin heavy chain genes and T3 expression in the absence of rearrangement of T-cell receptor beta-chain gene in a patient with T-cell malignant lymphoma

We describe the rearrangement of immunoglobulin genes and T3 expression in the absence of rearrangement of T-cell receptor beta-chain genes in a patient with T-cell malignant lymphoma. He had a mediastinal mass and his lymphoma cells expressed T-cell antigens (OKT3+, OKT9+, and OKT10+). When we examined genomic DNA from the lymphoma cells, we detected the rearrangement of immunoglobulin heavy chain genes with a germ-line configuration of light chain genes and no rearrangement of T-cell receptor beta-chain gene. These results indicated that the rearrangement of immunoglobulin genes could occur in T-cell malignant lymphoma, and that T3 antigen could be expressed prior to the rearrangement of T-cell receptor beta-chain genes under certain circumstances.