Detection of trisomy 12 and centromeric alterations in CLL by interphase- and metaphase-FISH

The critical role of histology in an era of genomics and proteomics: a commentary and reflection

The role of histologic examination in lymphoma diagnosis has been called into question by proponents of new technologies, such as genomics and proteomics. We review the history and salient features of morphologic evaluation in lymphoid diseases, and discuss the general and specific limitations of mature ancillary techniques, such as immunohistochemistry, flow cytometry, and molecular studies. We then speculate on the future relationship between morphology and the new genomic and proteomic technologies as they become integrated into clinical practice.

Multicolor FISH in chronic lymphocytic leukemia. An interphase study of patients with early-onset disease

Trisomy 12 and deletions of 13q14.2 and 14q32 are the most common chromosome abnormalities in patients with B-chronic lymphocytic leukemia (B-CLL), but whether specific chromosomal defects influence the course of B-CLL is still a matter of discussion. The aim of our study was to assess the possible correlation between cytogenetic findings and clinical characteristics. Thirty patients with previously untreated early-onset B-CLL were recruited. The incidence of trisomy 12, and observations of 13q14.2 and 14q32 was analyzed in unstimulated bone marrow cells by means of multicolor interphase FISH. No correlation was found between trisomy 12 and the patients' clinical characteristics. The analysis of the patients with trisomy 12 and observations of 13q14.2 and 14q32 revealed heterogeneity of the leukemic cell population, thus indicating that these chromosomal abnormalities are probably a secondary event in CLL leukemogenesis. The finding of RB1 gene nullisomy and 14q32 deletions in patients at an advanced clinical stage suggests a possible correlation between these rearrangements and disease progression. Multicolor FISH analysis in B-CLL provides important diagnostic, clinical, and prognostic information that may help in assessing prognosis and making treatment decisions.

Chronic lymphocytic leukemia

Significant strides have been made in our understanding of the biology and treatment of B cell chronic lymphocytic leukemia. Recent studies have defined cytogenetic and molecular lesions that may be responsible for leukemogenesis or disease progression. Molecular analyses of immunoglobulin genes have delineated two or more subgroups of chronic lymphocytic leukemia that may differ in their clinical behavior. Research in the biochemistry of chronic lymphocytic leukemia has provided insight into the noted resistance of leukemia cells to cytotoxic drugs. Investigations into the immunology has revealed mechanisms whereby chronic lymphocytic leukemia cells can contribute to the immune deficiency that commonly develops in patients with this disease. Clinical studies have delineated factors that are helpful in predicting prognosis and have provided data on promising new therapies for patients with this disease, including stem cell transplantation, monoclonal antibodies, and gene therapy.

A translocation breakpoint at chromosome band 12q13 associated with B-cell chronic lymphocytic leukemia

Low-grade B-cell lymphoproliferative disorders are frequently associated with an extra copy of chromosome 12. This well-documented acquired anomaly is one of the most specific numerical chromosome alterations to occur in human hematological malignancies. We have cytogenetically characterized bone marrow and peripheral blood cells from a patient with B-cell chronic lymphocytic leukemia (CLL) having a unique acquired translocation involving chromosomes 6 and 12, t(6;12) (p21.3;q13), which implicates band 12q13 as the site of the gene(s) important in this lymphoproliferative B-cell disorder. Aneuploidy, in the form of trisomy of chromosome 12, is not a requirement for neoplastic transformation in B-cell CLL, but gene rearrangement (present case) or nondisjunctional acquisition of additional copies of defective genes on chromosome 12 at band q13 may be involved in the genesis or progression of this disorder.