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The translocation (8;21) is a chromosome abnormality associated with acute myeloid leukemia (AML). As a consequence of the translocation the AML1 (CBFA2) gene in the 21q22 region is fused to the ETO(CDR,MTG8) gene in the 8q22 region, resulting in one transcriptionally active gene on the 8q- derivative chromosome. In this report we demonstrate the use of a highly specific dual-colour FISH method for the detection of t(8;21) on interphase cells. Genomic probes able to detect the chimeric AML1/ETO gene on the 8q- derivative chromosome were assayed on both normal and leukemic bone marrow and peripheral blood samples. Cut-off values were established by independent analysis of 15 bone marrow specimens negative for the translocation. The cut-off value of positive nuclei was determined to be 2% and the cut-off value for both positive nuclei and nuclei of uncertain classification, 4%. Persistence of cells above these cut-off values was interpreted as persistence of the mutated clone. A total of 36 samples at different disease stages were tested. Interphase cytogenetics detected the translocation at the onset and relapse in the BM or the PB of 14 AML patients with t(8;21). The technique appears to be an alternative tool to both conventional cytogenetics and reverse transcription polymerase chain reaction (RT-PCR) for the monitoring of disease during patients' follow-up. By enabling the analysis of individual cells, interphase FISH is ideal for clonality studies both for clinical and experimental applications. [ABSTRACT FROM AUTHOR]

Bone marrow from six patients with acute myeloid leukemia (AML) and t(8;21) (q22;q22) or a variant t(8;13;21) was studied by simultaneous analysis of cell morphology and karyotype. Combination of May-Grünwald-Giemsa (MGG) and fluorescence in situ hybridization (FISH) using probes specific for the breakpoint regions of chromosome 8 and 21 allowed us to establish the extent of cell-lineage involvement of the translocation. The translocation was found in all myeloid blasts and in high percentages of the more mature neutrophilic cells. In one patient we could demonstrate the translocation in the eosinophils as well. Erythroblasts and lymphocytes did not show the t(8;21) abnormality. These results indicate that the t(8;21) in AML is restricted to the myeloid (granulocytic) lineage. [ABSTRACT FROM AUTHOR]

Pure red cell aplasia is a rare condition, that can be either idiopathic or associated with a lymphoproliferative disorder. The latter is considered to result from T cell-mediated suppression of haematopoiesis, and usually responds well to treatment with immunosuppressive medication. We describe a patient with B-CLL-associated pure red cell aplasia who did not respond to several courses of immunosuppressive treatment. Erythropoiesis was finally restored after allogeneic bone marrow transplantation. Bone Marrow Transplantation (2001) 27, 771–773. [ABSTRACT FROM AUTHOR]