The same marker chromosome, mar17p+, in four consecutive cases of multiple myeloma

Cytogenetic abnormalities in 13 patients with multiple myeloma

Cytogenetic analysis was successfully performed in 45 consecutive multiple myeloma (MM) patients. Cytogenetic abnormalities were observed in 13 of 45 patients (29%). Eleven patients showed numerical changes and 9 showed structural abnormalities in chromosomes 5, 9, 11, 14, 15, and 19 were most frequently gained. Structural abnormalities preferentially involved chromosomes 6, 13, and 14.

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).

Karyotype in multiple myeloma and plasma cell leukaemia

Between October 1988 and October 1991, 104 patients with multiple myeloma and 6 with plasma cell leukaemia were studied cytogenetically. Abnormal karyotypes were found in bone marrow cells of 33 patients (30%). Most pathological karyotypes were complex with numerous modal and structural anomalies. Numerical anomalies most frequently involved chromosome 11 and structural aberrations occurred most often in chromosomes 1, 11 and 14. The most consistent structural aberration was a 14q+ chromosome (10 patients) resulting from a t(11;14)(q13;q32) in 4 patients and a t(8;14)(q24;q32) in 1 patient. Sequential cytogenetic studies were performed in 15 patients. In 5 of 8 cases with a normal karyotype at diagnosis, chromosomal anomalies were detected when disease progressed. In concomitant cytogenetic/cytological studies it was found that in the majority of patients with normal karyotype the mitoses originated from contaminating normal bone marrow cells. Pathological karyotypes were detected more frequently in pretreated than in untreated patients, in patients with plasma cell leukaemia than in patients with multiple myeloma, in patients with stage III and dense bone marrow infiltration than in patients with stage I. Patients with abnormal karyotype, irrespective if pretreated or not, had a significantly shorter median survival than those with normal karyotype. These findings suggest that karyotype is an independent prognostic factor in multiple myeloma.

Ring chromosomes in hypodiploid and hypotetraploid clones from an elderly patient with plasma cell leukemia

We describe a 77-year-old woman who had with what appears to be the first case of plasma cell leukemia (PCL) with a ring chromosome of variable size. Of the three clones evident, two of them were abnormal: a 41,X,-X hypodiploid clone with rings of two different sizes, and a 81-82,XX hypotetraploid clone with a double-sized dicentric ring or variable double rings. Additional structural and numerical abnormalities included a 14q+ marker, deletions of two chromosomes 1 and monosomies 8 and 13, all previously reported in PCLs. Ring chromosomes have been associated with a poor prognosis, especially in elderly patients. The patient declined active treatment and died within 4 weeks of diagnosis.

A new human plasma cell line, Karpas 620, with translocations involving chromosomes 1, 11 and 14

We report here the establishment of a new cell line, Karpas 620 (K620), from the peripheral blood of an elderly woman with an IgG-kappa plasma cell leukaemia (PCL). The line has the same hypotetraploid karyotype as the fresh cells from the patient. The cultured cells have the ultrastructural appearance of plasma cells with abundant rough endoplasmic reticulum (RER) and secrete kappa light chain. They are positive for surface antigens HLA DR, and WR17 (CD 37) and negative for CD1, CD3, CD4 and CD8. Using high resolution (HR) cytogenetic analysis it has been possible to identify all the marker chromosomes including several rearrangements commonly seen in malignancies of B cell lineage. These are a 14q+ marker with a typical 'Burkitt' morphology der(14)(pter----q32.3::8q24.1----qter) but with no reciprocal 8q-, and three translocations involving chromosome 11 at q13 with partners other than chromosome 14, namely 1q32.1, 8q24.22 and 13q14.3. An earlier report of molecular studies on the DNA of K620 has shown a rearrangement near the region on 11q13 designated BCL-1 (Rabbitts et al. 1988). This is the first report of a rearrangement in the region of 11q13 in a cell line originating from a case of plasma cell leukaemia.

Occurrence and type of chromosomal abnormalities in consecutive malignant monoclonal gammopathies: correlation with survival

Chromosome studies were done on 73 patients with multiple myeloma and three patients with plasma cell leukemia. Eighteen of 76 patients (24%) had chromosomally abnormal clones, including all three patients with PCL. The most common anomalous chromosomes were #1, #14, and #12. In addition, i(17q) was found in two patients with plasma cell leukemia. Among newly diagnosed patients there was no difference in survival for those with abnormal karyotypes and those with normal karyotypes. Among previously diagnosed patients receiving treatment, however, individuals with an abnormal clone had a significantly higher mortality during the first 2 years compared to those with a normal clone. Patients with no growth of metaphases in their bone marrow aspirate had a significantly lower mortality than other patients (p less than 0.05).

Chromosome findings in multiple myeloma

Cytogenetic studies were performed on six patients with multiple myeloma in which G-banding allowed the identification of clonal chromosome abnormalities. Normal cells and random chromosome gains and losses were seen in all cases. Numerical clonal aberrations were observed in two cases. Among the remaining cases, clonal chromosome rearrangements were seen in two cases, whereas, the other two patients revealed both numerical and structural clonal anomalies. The following marker chromosomes were identified: 1q-, 2p+, 2q+, 7q-, 17p-, and five unidentified abnormal chromosomes.

Non-random chromosomal aberrations associated with multiple myeloma

Myelomatous tissue from 30 patients was assessed for cytogenetic abnormalities and one-third showed chromosomal deletions, additions, and/or rearrangements. Evidence is presented that those cases with only normal cytogenetics represent metaphase cells of nonmyelomatous tissue. The findings of our abnormal cases when added to the 18 reported in two series by others show unique cytogenetic patterns are present in this disease. From analysis of these 27 banded cases of myeloma, we conclude: (1) cytogenetic abnormalities of myeloma are not random; (2) clonal evolution may be associated with disease progression, however the abnormalities identified late in the disease are similar to those found in early myeloma; (3) cytogenetic aberrations of multiple myeloma differ considerably from those of chronic lymphocytic leukemia, non-Hodgkin's lymphoma, and acute lymphocytic and nonlymphocytic leukemia; and (4) the myeloma karyotype often exhibits one or more of the following: rearrangements involving chromosome 1 and 14, trisomy 3, 5, 7, 9 and 11, and monosomy 8 and 13. These findings have great importance for molecular biologic studies of multiple myeloma.

High incidence of chromosome abnormalities in IgG3 myeloma

Chromosomes were studied in 33 untreated myeloma patients, and results were correlated with the class of Ig secreted by the myeloma cells. A high incidence of clonal karyotypic anomalies seemed to be present in IgG3 myeloma patients, in whom the disease was advanced at diagnosis and rapidly progressing. Among the chromosome anomalies, the t(11;14)(q14;q32) was particularly prominent, and this chromosome anomaly, in analogy with the Ph1 chromosome, may characterize a family of lymphoproliferative disorders.

2 translocations, t(11;14) and t(1;6), in a patient with plasma cell leukaemia and 2 populations of plasma cells

2 translocations, t(11;14) and t(1;6), were found in 24 out of 46 metaphases in bone marrow cells from an untreated patient with plasma cell leukaemia. The predominating cell population produced only kappa chains while a minute population produced IgG kappa. All serum Ig's were low and only minimal amounts of monoclonal IgG kappa were found in the serum and very small amounts of kappa light chains in the urine. Analyses of ours and 2 other reported patients indicated the possibility that the location of breakpoints on the chromosomes may be of etiologic importance for the type of light chain and perhaps for the class of heavy chain.