Arturo Gullón

Cytogenetic analysis of 280 patients with multiple myeloma and related disorders: Primary breakpoints and clinical correlations

Cytogenetic analysis of unstimulated short‐term bone marrow cell cultures was performed on 280 patients with multiple myeloma and related disorders. In 65% of the cases, an additional short term B‐cell stimulated culture was also examined. Chromosomally abnormal clones were found in 31% of the patients, 15% in Waldenström macroglobulinemia, 25% in monoclonal gammopathies, 33% in multiple myeloma, and 50% in plasma cell leukemia. Three primary chromosomal breakpoints were recurrently involved: 14q32, 16q22, and 22q11. Structural rearrangements of chromosome I were the most frequent (26% of the abnormal cases), but always as a secondary change. Rearrangements of band 14q32 were found in 22% of the abnormal cases. Among the multiple myeloma patients who showed an abnormal karyotype, 33 (46%) were hyperdiploid, most frequently with 52–56 chromosomes, 29 patients (40%) were pseudodiploid, and the remaining 12 cases (14%) were hypodiploid. A highly significant relation was observed between the presence of an abnormal karyotype and the following clinical parameters: stage III (P = 0.0001), bone marrow plasma cell infiltration greater than 30% (P = 0.0001), presence of bone lesions (P = 0.0009), and β2‐microglobulin levels greater than 4 mg/L (P = 0.0001). Genes Chromosom. Cancer 18:84–93, 1997.

Hypodiploidy and 22q11 rearrangements at diagnosis are associated with poor prognosis in patients with multiple myeloma

Our aim was to evaluate the clinical use of cytogenetic analysis as a prognostic factor in the outcome of newly diagnosed multiple myeloma (MM) patients. The present series includes 111 newly diagnosed MM patients treated with one of three standard‐dose regimens or autologous transplantation over an 8‐year time interval. As expected, the presence of an abnormal karyotype (39% of patients) correlated with poor prognosis (progression rate 63% v 47%, P = 0.042), shorter event‐free (EFS, P = 0.014) and overall (OS, P = 0.005) survival. Two distinct cytogenetic abnormalities were the most significant variables that influenced EFS and OS in the univariate analysis. The presence of hypodiploid karyotypes or rearrangements of band 22q11 were associated with higher progression rate (P = 0.001) and shorter EFS (P < 0.024) and OS (P < 0.004). The median EFS and OS for patients with hypodiploidy was 4 and 7 months respectively. Multivariate analysis showed that absence of hypodiploidy was the most favourable prognostic variable for OS (P = 0.022) followed by stage ≤IIA, serum calcium ≤2875 μmol/l, and absence of abnormalities 22q. The data suggest that the presence of hypodiploid karyotypes and rearrangements on 22q11 band show a higher progression rate and shorter survival in MM patients.

Cytogenetic data in 41 patients with multiple myeloma: Karyotype and other clinical parameters

Cytogenetic data of 41 patients diagnosed with multiple myeloma (MM) are reported. In all samples, cytogenetic studies were made of short-term and B-cell-stimulated culture: 20 cases (48.8%) showed chromosome abnormalities; 14 karyotypes were hypo- or pseudodiploid, and six were hyperdiploid. The most frequent numerical changes affected chromosomes 7, 11, 5 (gains), 14, 20, and Y (losses). Chromosome structural rearrangements of 22q were noted in six patients. Other and recurrent cytogenetic abnormalities were changes involving chromosomes 1, 14, and 17. A significant relation was observed between presence of chromosome abnormalities and the following hematologic parameters: clinical stage III (p = 0.0212), bone marrow (BM) plasma cell infiltration greater than 30% (p = 0.0379), presence of bone lesions (p = 0.0051), and beta 2-microglobulin levels greater than 4,000 md/dl (p = 0.0194).

Enhancement of peptide immunogenicity by insertion of a cathepsin B cleavage site between determinants recognized by B and T cells

The insertion of two lysine residues (cleavage sites of cathepsin B) at the boundary of a peptide recognized by B cells (BD) and a class-II- presentable sequence (TDh) enhanced the anti-BD antibody induction capacity of this type of peptide construct, as well as production of IL2. It is postulated that these lysines generate a neoprocessable site which helps in release of the TDh moiety from the construct, enabling its presentation to class II molecules, an essential step in clonal expansion of the antibody-producing B cell after internalization of the construct via the BD moiety.

A variant t(14;17) in acute promyelocytic leukemia Positive response to retinoic acid treatment

We present a case of acute promyelocytic leukemia (APL) carrying an atypical translocation involving chromosomes 14 and 17. This translocation could be considered a variant of the APL-specific t(15;17). Positive response to retinoic acid treatment suggests molecular rearrangement of retinoic acid receptor alpha.

Complex karyotype including 14q+ marker in a case of Waldenström's macroglobulinemia

We describe a case of Waldenströms macroglobulinemia with a complex karyotype including a 14q+ marker. Secondary changes affected chromosomes 2, 4, 6, 7, 8, and 17. The cytogenetic significance of the changes and their prognostic value, as compared with those described in previous reports, are discussed.

A recurrent translocation, t(3;11)(q21;q13), found in two distinct cases of acute myeloid leukemia

We report two cases of acute myeloid leukemia (M1 and M5B subtypes) with a similar translocation, t(3;11)(q21;q13). We discuss the involvement of these breakpoints in acute leukemia and their putative clinical implications.