Oligoclonal B‐cell leukemia characterized by spontaneous cell division and telomere association

Abstract

Cytogenetic analysis of unstimulated cultures from a female patient with chronic B-cell leukemia (CLL) revealed three cytogenetically distinct clones, suggesting that the patient's leukemia was oligoclonal. Immunoglobulin heavy chain gene rearrangement studies revealed 1 germline and 4 rearranged bands, indicative of an oligoclonal leukemic population. Further evidence of oligoclonality was provided by X-linked RFLP studies. This is the first report of oligoclonality in CLL demonstrated by cytogenetic, immunoglobulin gene rearrangement, and X-chromosome inactivation studies. In addition to oligoclonality, the patient's leukemic cells exhibited telomere association, a Robertsonian translocation, and clonal evolution, suggesting an underlying genomic instability.

A Case of monoclonal gammopathy associated with acute myelomonocytic leukemia with eosinophilia suggested to be the result of lineage infidelity

“…4B-D), a major population of leukemic cells with rearranged Ig gene and minor population(s) of leukemic cells with rearranged c-myc and/or c-jun proto-oncogenes may have arisen in this patient before starting chemotherapy. These observations indicated the occurrence of genetic evolutionary changes in leukemic cells in this patient, as reported in many types of neoplasm [19][20][21][22][23][24][25], and aberrations of c-myc and c-jun proto-oncogenes may have contributed to the evolution of leukemic cells in this patient. On the basis of these findings, the structural abnormalities of c-myc and c-jun proto-oncogenes observed in our case might play a role in the evolution of leukemic cells by induction of maturation arrest of the common progenitor of the monocytic and B-cell lineage.…”

Fine mapping of an apparently targeted latent human herpesvirus type 6 integration site in chromosome band 17p13.3

“…In many of the leukaemia cases the telomeric associations were nonrandom. Leukaemic cells of one patient showed involvement of the telomeric region of chromosome 17p [Saltman et al, 1989], and it is noteworthy that clonal rearrangements involving breakage and rejoining of sites on 17p were present in three other patients [Fitzgerald and Morris, 1984;Crossen et al, 1993;Howell et al, 1993]. It would be of interest to determine if latent integration of HHV-6 featured in the leukaemic cells of any of the latter patients.…”

Heterogeneity of VH–JH gene rearrangement patterns: an insight into the biology of B cell precursor ALL

“…16,17 It occurs early in differentiation and it has only been reported in rare cases of B chronic lymphoid malignancies. [18][19][20][21][22] The identification of oligoclonality among ALL patients has become more relevant since Ig and TCR rearrangements have been used for monitoring minimal residual disease (MRD) in patients following chemotherapy or BMT. The incidence of false negative results due to oligoclonality has recently been reduced by accurate assessment of diagnostic samples 23 and by the use of multiple molecular targets.…”