Cristina Aiko Kumeda

Karyotypic and fluorescent in situ hybridization study of the centromere of chromosome 7 in secondary myeloid neoplasms

Background Secondary myeloid neoplasms comprise a group of secondary diseases following exposure to myelotoxic agents or due to congenital diseases. The improvement of anticancer agents and immunosuppressive drugs seem to be associated with an increased incidence of secondary myeloid neoplasms. Karyotyping of bone marrow is essential for diagnosis and prognosis. Previous use of alkylating agents and radiation are associated with clonal abnormalities such as recurrent unbalanced -5/5q-, -7/7q- and complex karyotypes, whereas topoisomerase-II inhibitors lead to changes such as the balanced 11q23 rearrangement, t(8;21), t(15;17) and inv(16). Objective To study the clinical and cytogenetic data of patients with secondary myeloid neoplasms who took antineoplastic and/or immunosuppressive drugs or progressed from aplastic anemia. Methods The clinical and cytogenetic characteristics of 42 patients diagnosed with secondary myeloid neoplasms in one institution were retrospectively evaluated. Of these, 25, 11 and 6 patients had had oncological diseases, aplastic anemia and other diseases, respectively. Conventional cytogenetic and FISH analyses were performed for monosomy 7. Results The cytogenetic study was conclusive in 32 cases with 84.4% of clonal abnormalities. Monosomy 7 and complex karyotypes were present in 44.4% and 37%, respectively. A high prevalence of unbalanced abnormalities (96.3%) was observed. Monosomy 7 was more prevalent in patients with myelodysplastic syndromes/myeloid neoplasms after aplastic anemia (66.6%). The median survival after diagnosis of myeloid neoplasms was only 5.7 months. Normal cytogenetics was associated to better survival (p-value = 0.03). There was a slightly worse trend of survival for patients with complex karyotypes (p-value = 0.057). Abnormal karyotype was an independent risk factor for poor survival (p-value = 0.012). Conclusion This study enhances the importance of cytogenetic analysis of patients at the time of diagnosis of secondary myeloid neoplasms.

Evaluation of chromosomal abnormalities by cIg-FISH and association with proliferative and apoptotic indexes in multiple myeloma

Eighty-six newly diagnosed multiple myeloma (MM) patients from a public hospital of São Paulo (Brazil) were evaluated by cIg-FISH for the presence of del(13)(q14), t(4;14)(p16.3;q32) and del(17)(p13). These abnormalities were observed in 46.5, 9.3, and 7.0% of the patients, respectively. In order to identify the possible role of del(13)(q14) in the physiopathology of MM, we investigated the association between this abnormality and the proliferative and apoptotic indexes of plasma cells. When cases demonstrating t(4;14)(p16.3;q32) and del(17)(p13) were excluded from the analysis, we observed a trend towards a positive correlation between the proportion of cells carrying del(13)(q14) and plasma cell proliferation, determined by Ki-67 expression (r = 0.23, P = 0.06). On the other hand, no correlation between the proportion of cells carrying del(13)(q14) and apoptosis, determined by annexin-V staining, was detected (r = 0.05, P = 0.69). In general, patients carrying del(13)(q14) did not have lower survival than patients without del(13)(q14) (P = 0.15), but patients with more than 80% of cells carrying del(13)(q14) showed a lower overall survival (P = 0.033). These results suggest that, when del(13)(q14) is observed in a high proportion of malignant cells, it may have a role in determining MM prognosis. Another finding was a statistically significant lower overall survival of patients with t(4;14)(p16.3;q32) (P = 0.026). In the present study, almost half the patients with t(4;14)(p16.3;q32) died just after diagnosis, before starting treatment. This fact suggests that, in São Paulo, there may be even more patients with this chromosomal abnormality, but they probably die before being diagnosed due to unfavorable socioeconomic conditions. This could explain the low prevalence of this chromosomal abnormality observed in the present study.

Simultaneous Occurrence of Biphenotypic T Cell/Myeloid Lesions Involving t(12;13)(p13;q14) in a Pediatric Patient

This paper chronicles a 2-year-old girl who presented with acute leukemia/lymphoma syndrome of the T cell immunophenotype. At this time, the cytogenetic analysis of her bone marrow cells showed a reciprocal translocation between the short arm of chromosome 12 and the long arm of chromosome 13, t(12;13)(p13;q14). The immunophenotyping of bone marrow blast cells by flow cytometry revealed a population of cells positive for CD56, CD117, CD45, partial CD33, partial HLA-DR, CD13, CD7, CD2 and CD5. Therefore, a diagnosis of acute leukemia with a mixed T cell/myeloid phenotype was made. The patient had a poor response to classic T cell acute lymphocytic leukemia/lymphoma therapy; thus, her treatment was changed to a myeloid leukemia protocol, which produced a good response. She underwent a successful cord blood transplantation from an unrelated HLA partially matched donor. The coexistence of these two phenotypes prompts questions about the existence of clonal instability, which might influence the choice of therapy. The rarity of the t(12;13)(p13;q14) and the coexistence of T cell/myeloid markers suggest a nonrandom association. To the best of our knowledge, this is the first reported case in which a cell clone bearing a t(12;13)(p13;q14) translocation in a mixed T cell/myeloid lesion was detected.

Secondary myeloid neoplasms: bone marrow cytogenetic and histological features may be relevant to prognosis

Background Secondary myeloid neoplasms comprise a group of diseases arising after chemotherapy, radiation, immunosuppressive therapy or from aplastic anemia. Few studies have addressed prognostic factors in these neoplasms. Method Forty-two patients diagnosed from 1987 to 2008 with secondary myeloid neoplasms were retrospectively evaluated concerning clinical, biochemical, peripheral blood, bone marrow aspirate, biopsy, and immunohistochemistry and cytogenetic features at diagnosis as prognostic factors. The International Prognostic Scoring System was applied. Statistical analysis employed the Kaplan–Meier method, log-rank and Fishers exact test. Results Twenty-three patients (54.8%) were male and the median age was 53.5 years (range: 4–88 years) at diagnosis of secondary myeloid neoplasms. Previous diseases included hematologic malignancies, solid tumors, aplastic anemia, autoimmune diseases and conditions requiring solid organ transplantations. One third of patients (33%) were submitted to chemotherapy alone, 2% to radiotherapy, 26% to both modalities and 28% to immunosuppressive agents. Five patients (11.9%) had undergone autologous hematopoietic stem cell transplantation. The median latency between the primary disease and secondary myeloid neoplasms was 85 months (range: 23–221 months). Eight patients were submitted to allogeneic hematopoietic stem cell transplantation to treat secondary myeloid neoplasms. Important changes in bone marrow were detected mainly by biopsy, immunohistochemistry and cytogenetics. The presence of clusters of CD117+ cells and p53+ cells were associated with low survival. p53 was associated to a higher risk according to the International Prognostic Scoring System. High prevalence of clonal abnormalities (84.3%) and thrombocytopenia (78.6%) were independent factors for poor survival. Conclusion This study demonstrated that cytogenetics, bone marrow biopsy and immunohistochemistry are very important prognostic tools in secondary myeloid neoplasms.

Características genéticas da leucemia promielocítica aguda de novo

Geneticamente, a leucemia promielocitica aguda (LPA) caracteriza-se por alteracoes cromossomicas estruturais recorrentes, na grande maioria das vezes translocacoes, envolvendo sempre o locus genico para o receptor alfa do acido retinoico (RARα) localizado no braco longo do cromossomo 17 (17q21), levando a formacao de genes quimericos e oncoproteinas de fusao. Em aproximadamente 98% dos casos, o gene RARα se encontra fusionado com o gene PML resultante da translocacao cromossomica reciproca t(15;17)(q22;q21) e, em cerca de 2% dos casos, o gene RARα pode estar fusionado com outros genes que nao o PML, levando a formacao de proteinas de fusao conhecidas genericamente como X-RARα. A leucemia promielocitica aguda e um exemplo de malignidade hematologica onde se tem a combinacao de alteracoes geneticas e epigeneticas (acetilacao, desacetilacao e metilacao) no processo de leucemogenese, alteracoes cromossomicas estruturais influenciando no equilibrio dinâmico da cromatina na regiao promotora de alguns genes. A utilizacao de tecnicas moleculares que auxiliam no diagnostico genetico mais preciso e o desenvolvimento de uma terapia alvo molecular permitiram alcancar alta taxa de cura desta doenca.