James D. Hoyer

Translocations involving immunoglobulin (Ig) loci and chromosome 13 monosomy (Delta 13) are frequent cytogenetic findings in multiple myeloma (MM). Similar chromosomal aberrations have been identified in the monoclonal gammopathy of undetermined significance (MGUS), but their prevalence and significance remain uncertain. Bone marrow from 72 patients with MGUS (n = 62) and smoldering MM (n = 10) was evaluated for translocations between the Ig heavy chain (IgH) and chromosomes 4, 11, and 16, translocations involving Ig light chain-lambda (IgL-lambda, and Delta 13. Fluorescence in situ hybridization (FISH) analysis was done on clonal plasma cells (PCs) detected by immunofluorescence (cIg-FISH) of the cytoplasmic light chain. We also studied cells for cyclin D1 and FGFR3 up-regulation by immunohistochemistry and immunofluorescence, respectively. Twenty-seven (46%) of 59 patients had IgH translocations, and 4 (11%) of 37 had an IgL-lambda translocation. A t(11;14)(q13;q32) was found in 15 (25%) of 59 patients, a t(4;14)(p16.3;q32) in 9% of patients, and a t(14;16)(q32;q23) in 5% of patients. All patients with t(4;14)(p16.3;q32) tested (n = 3) had intense cytoplasmic fluorescence with an anti-FGFR3 antibody. PC nuclear staining of cyclin D1 was only observed in patients with t(11;14)(q13;q32); Delta 13 was detected in the clonal PCs in 50% of patients. The percentage of abnormal PCs varied with any given abnormality. No obvious clinical or biologic correlations were associated with these chromosome abnormalities. Similar translocations are found in both MGUS and MM, including t(4;14)(p16.3;q32) and t(14;16)(q32;q23). Moreover, Delta 13 is common in MGUS and unlikely to play a predominant role in the evolution of MGUS to MM.

The t(11;14)(q13;q32) results in up-regulation of cyclin D1 and is the most common translocation detected in multiple myeloma, where it is also associated with a lymphoplasmacytic morphology. We performed an interphase fluorescent in situ hybridization (FISH) study to determine the clinical and biologic significance of the abnormality when testing a large cohort of myeloma patients. Bone marrow slides from multiple myeloma patients entered into the Eastern Cooperative Oncology Group phase III clinical trial E9486 and associated laboratory correlative study E9487 were analyzed using interphase FISH combined with immune-fluorescent (cytoplasmic immunoglobulin-FISH) detection of clonal plasma cells. We used FISH probes that hybridize to the 14q32 and 11q13 chromosomal loci. The t(11;14)(q13;q32) was correlated with known biologic and prognostic factors. Of 336 evaluable patients, 53 (16%) had abnormal FISH patterns compatible with the t(11;14)(q13;q32). These patients appeared to be more likely to have a serum monoclonal protein of less than 10 g/L (1 g/dL) (28% vs 15%, P =.029) and a lower plasma cell labeling index (P =.09). More strikingly, patients were less likely to be hyperdiploid by DNA content analysis (n = 251, 14% vs 62%, P <.001). Patients with the t(11;14)(q13;q32) appeared to have better survival and response to treatment, although this did not reach statistical significance. Multiple myeloma with the t(11;14)(q13;q32) is a unique subset of patients, not only characterized by cyclin D1 up-regulation and a lymphoplasmacytic morphology, but is also more frequently associated with small serum monoclonal proteins and is much less likely to be hyperdiploid. These patients do not have a worsened prognosis as previously thought.

George Patrinos and colleagues report the first implementation of the microattribution approach to systematically document genetic variation associated with a disease, applied here to hemoglobinopathies and thalassemias. They developed a series of connected locus-specific databases that document genotype and phenotype information for genetic variation in 37 globin and erythroid protein genes in individuals with globin disorders, with reciprocal attribution to data contributors. We developed a series of interrelated locus-specific databases to store all published and unpublished genetic variation related to hemoglobinopathies and thalassemia and implemented microattribution to encourage submission of unpublished observations of genetic variation to these public repositories. A total of 1,941 unique genetic variants in 37 genes, encoding globins and other erythroid proteins, are currently documented in these databases, with reciprocal attribution of microcitations to data contributors. Our project provides the first example of implementing microattribution to incentivise submission of all known genetic variation in a defined system. It has demonstrably increased the reporting of human variants, leading to a comprehensive online resource for systematically describing human genetic variation in the globin genes and other genes contributing to hemoglobinopathies and thalassemias. The principles established here will serve as a model for other systems and for the analysis of other common and/or complex human genetic diseases.

We identified 24 cases of multiple myeloma with the t(11;14)(q13;q32). In 22 cases, the t(11;14)(q13;q32) was part of a complex karyotype, and in 2 cases it was an isolated abnormality. All patients had clinical and laboratory features consistent with multiple myeloma. The median degree of plasma cell involvement in the bone marrow was 60%, and in 10 cases, the plasma cells had a lymphoplasmacytoid appearance. Of the 24 cases, 21 had intermediate or high proliferative rates based on labeling index studies. Immunohistochemical studies performed on all bone marrow biopsy specimens showed strong cyclin D1 nuclear positivity in 19 cases. There also was strong cyclin D1 nuclear positivity found in 6 of 30 additional cases without the t(11;14)(q13;q32) demonstrated by routine cytogenetics. The t(11;14)(q13;q32) in multiple myeloma results in overexpression of the cyclin D1 protein, which can be demonstrated by immunohistochemical stain. The cyclin D1 stain results in the additional cases of multiple myeloma suggest that the t(11;14)(q13;q32) may be more common than previously thought and may be missed by routine cytogenetics, particularly if the proliferative rate is low.

POEMS is an uncommon syndromic disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. There are few descriptions of the bone marrow pathology of POEMS; therefore, peripheral blood smears and bone marrow aspirates and biopsies from 87 patients (143 total, 67 pretreatment, 76 posttreatment cases) with POEMS were studied. Plasma cell clonality was analyzed by flow cytometry, immunohistochemistry, and/or in situ hybridization. Monotypic plasma cells were detected in 44 pretreatment cases (66%); the majority of plasma cells expressed λ light chain (91%). The monotypic plasma cells typically were present in a background of increased polytypic plasma cells. Lymphoid aggregates were found in 33 (49%) pretreatment cases and in most cases were rimmed by plasma cells (97%). Megakaryocyte hyperplasia (36 cases) and clusters (62 cases) were frequent; however, none of the 43 cases tested had the JAK2(V617F) mutation. In summary, we have identified a novel constellation of features that should strongly suggest POEMS syndrome as part of the differential diagnosis. The constellation of λ-restricted monoclonal gammopathy, plasma cell rimming around lymphoid aggregates, and megakaryocytic hyperplasia in a bone marrow is highly suggestive of this diagnosis, especially in the context of a peripheral neuropathy.