Daisy Alapat

A role for semaphorin 3A signaling in the degeneration of hippocampal neurons during Alzheimer's disease.

Among the earliest invariant neuropathological changes in Alzheimers disease (AD) is the degeneration of vulnerable hippocampal CA1 and subicular pyramidal neurons. Semaphorin 3A (Sema3A) is a secreted protein that functions in signaling growth cone collapse, chemorepulsion and neuronal apoptosis during early development of the central nervous system. In this report we show that accumulation of an internalized form of Sema3A is associated with degeneration of neurons in vulnerable fields of the hippocampus during AD. Accumulation of Sema3A overlaps the appearance of phosphorylated MAP1B and tau in many neurons, suggesting that Sema3A signaling at some level may be coupled to these previously identified cytoskeletal markers of neurodegeneration. Consistent with this, we isolated and partially characterized a multiprotein complex from the hippocampus of patients with AD that contains phosphorylated MAP1B, collapsin‐response mediator protein 2 (CRMP‐2), Plexins A1 and A2, and a processed form of Sema3A. A model is presented in which aberrant release of Sema3A from expressing neurons in the subiculum during AD results in the internalization and transport of Sema3A from this field to CA1. Within the context of the myriad of potential insults that contribute to Alzheimers and other neurodegenerative diseases, the bioactivity of Sema3A may contribute either directly to neurodegeneration by inducing neuronal collapse, or indirectly by abrogating the recovery capabilities of adult neurons faced with these insults.

Diagnostic Usefulness and Prognostic Impact of CD200 Expression in Lymphoid Malignancies and Plasma Cell Myeloma

The membrane glycoprotein MRC OX-2 (CD200) is expressed in several lymphoid malignancies. However, the diagnostic usefulness and potential prognostic importance of CD200 expression have not been rigorously examined. We show that CD200 is uniformly expressed in chronic lymphocytic leukemia (CLL) and absent in mantle cell lymphoma (MCL). It is important to note that expression of CD200 is retained even in CLLs with immunophenotypic aberrancies, making CD200 a particularly useful marker for discrimination between these cases and MCL. CD200 is expressed in nearly all precursor B-lymphoblastic leukemias, with aberrant overexpression or underexpression compared with normal B-cell progenitors in 55% of cases. More than 70% of plasma cell myelomas (PCMs) expressed CD200, and loss of CD200 expression in PCM may be associated with more clinically aggressive disease. CD200 is expressed in several hematolymphoid neoplasms. Analysis of its expression has several diagnostic and potentially prognostic applications in the flow cytometric evaluation of lymphoid malignancies.

Disparity between tissue and serum calcitonin and carcinoembryonic antigen in a patient with medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor of parafollicular or C-cells of thyroid that comprises 5–10% of all thyroid cancers [1, 2]. The neoplastic cells secrete calcitonin, carcinoembryonic antigen (CEA), and chromogranin A. Typically, increased serum levels of these tumor markers permit them to be used for initial diagnosis and long-term disease status surveillance. This article reports a case of sporadic MTC (pT2N0M0) in a young patient with normal serum tumor markers. A 16-year-old woman presented with MTC without evidence for this to be a familial case due to the absence of germline mutations in the RET proto-oncogene and negative family history. Surprisingly, there were normal preoperative serum levels of calcitonin, CEA, and chromogranin A, despite the immunohistochemistry showing strong and diffuse positive staining for these markers. This disparity between serum levels and tumor expression of calcitonin and CEA in MTC is quite rare. The relevant features of this case are discussed in consideration of the published experiences. This case may represent an unique subgroup of MTC with abnormal secretory capacity that requires reliance upon radiological evaluation for evidence of recurrent or disseminated disease, without the diagnostic benefit of serum tumor markers.

Dose-dense and less dose-intense Total Therapy 5 for gene expression profiling-defined high-risk multiple myeloma

Multiple myeloma (MM) is a heterogeneous disease with high-risk patients progressing rapidly despite treatment. Various definitions of high-risk MM are used and we reported that gene expression profile (GEP)-defined high risk was a major predictor of relapse. In spite of our best efforts, the majority of GEP70 high-risk patients relapse and we have noted higher relapse rates during drug-free intervals. This prompted us to explore the concept of less intense drug dosing with shorter intervals between courses with the aim of preventing inter-course relapse. Here we report the outcome of the Total Therapy 5 trial, where this concept was tested. This regimen effectively reduced early mortality and relapse but failed to improve progression-free survival and overall survival due to relapse early during maintenance.

Fiber-types of sarcomeric proteins expressed in cultured myogenic cells are modulated by the dose of myogenin activity.

The myogenic basic helix-loop-helix regulatory factors (MRFs) maintain commitment of proliferating cells to the skeletal myogenic lineage, and contribute to activation of transcription of muscle-specific genes in myocytes and muscle fibers. A clear role for any or all of the MRFs in muscle fiber-type determination, however, has not emerged from expression or genetic studies. During fetal, neonatal and adult life, diversification of muscle fiber types, and the dynamics of slow or fast fiber type adaptation and growth, are controlled by exogenous factors, including innervation, work load, and hormonal signaling. In contrast, stereotypical development of muscle fibers preferentially expressing slow or fast isoforms of sarcomeric proteins in the embryo occurs in the absence of these factors, and appears to be mediated both by input from the surrounding interstitial milieu, as well by cell autonomous mechanisms. We report here that diversification of myogenic cells in culture towards the expression of fast or slow skeletal muscle fiber types can be determined by the activity and dose of at least one MRF, myogenin. The dose of myogenin is modulated by two parameters: the phosphorylation state of the transcriptional activation domains, and the level of expression. Low doses of myogenin promoted a fast phenotype, whereas higher doses promoted a slow phenotype, and further studies suggested that diversification is mediated by both transcriptional and post-transcriptional mechanisms. The potential for dose or numeration signaling by basic helix-loop-helix regulators has been revealed by studies in Drosophila melanogaster, while the present results support the notion that this mechanism may be more commonly employed to generate subdiversity among developing cell types.

The level of deletion 17p and bi-allelic inactivation of TP53 has a significant impact on clinical outcome in multiple myeloma

Multiple myeloma (MM) is a malignant disorder of plasma cells with a heterogeneous clinical outcome that is affected by both numerical and structural chromosomal abnormalities, baseline characteristics (age, lactate dehydrogenase concentration, International Staging System score) and treatment

Plasmablastic lymphoma of the retroperitoneum in an HIV- and HCV-positive patient: hard to diagnose and harder to treat

Plasmablastic lymphoma (PBL) is an aggressive diffuse large B-cell lymphoma (DLBCL) with plasmablastic features that was initially described in the oral cavity of HIV-infected individuals. PBL remains a diagnostic challenge given its close morphologic resemblance and overlapping immunophenotypic patterns to other B-cell lymphoid malignancies and plasmablastic plasma cell myeloma (PCM) with extramedullary involvement. The presence of serum monoclonal protein and radiographic evidence of lytic bone lesions favors the diagnosis of plasma cell myeloma over PBL. Distinguishing PBL from PCM is important as PBL is treated with a completely different chemotherapy regimen compared to PCM. PBL carries a guarded prognostic profile among DLBCLs with high relapse rate and poor median survival. We present a case of a 44-year-old HIV-positive man who presented with a large retroperitoneal mass associated with obstructive uropathy, sacral radiculopathy, and inferior vena caval compression. The mass was initially mistaken to be a PCM on histopathology; however, subsequent investigations revealed an extra-oral PBL with plasmacytic differentiation. To our knowledge, this will be the first case of PBL of the retroperitoneum in an HIV- and HCV-positive patient and the second one at this location in the English-language literature. In this report, key differentiating points between PBL versus PCM and newer therapeutic agents such as proteasome inhibitors have been discussed along with related review of literature.

Flow cytometry defined cytoplasmic immunoglobulin index is a major prognostic factor for progression of asymptomatic monoclonal gammopathies to multiple myeloma (subset analysis of SWOG S0120).

Multiple myeloma (MM) is a clonal plasma cell (PC) disorder characterized by end organ damage that is in turn characterized by CRAB criteria (calcium and creatinine elevation, anemia and bone lesions).1 It is commonly accepted that nearly all cases of MM are preceded by a clinically benign phase of monoclonal gammopathy of undetermined significance (MGUS) that evolves through a stage of smoldering multiple myeloma (SMM) without end organ damage,2 collectively referred to as asymptomatic monoclonal gammopathies (AMG).3 Although traditionally SMM is considered more prone to MM progression than MGUS, additional variables, such as involved-to-uninvolved free light-chain ratio4 and magnetic resonance imaging-defined focal lesion number and size,5 have been linked to progression to MM and form the basis for the newest International Myeloma Working Group criteria for MM.6 As the treatment of MM has been greatly advanced, emphasis has been placed on identifying patients with AMG at high risk of progression to MM so that, with earlier treatment, end organ damage can be minimized.7 Many new high-risk variables have indeed been identified such as level of circulating plasma cells8 and gene expression profiling (GEP).9, 10 We have previously reported that two-parameter flow cytometry of DNA and cytoplasmic light-chain immunoglobulin (DNA/CIG) is highly predictive of progression-free and overall survival in newly diagnosed MM treated with Total Therapy.11 In the current subset analysis of S0120, we have investigated whether the DNA/CIG assay can also identify patients with AMG at high risk for progression to MM requiring therapy (time to therapy, TTT).12 Of 254 patients enrolled at the University of Arkansas in the observational SWOG S0120 protocol with AMG, 110 had evaluable DNA/CIG information and retained AMG status according to the revised International Myeloma Working Group criteria for MM.6 All patients underwent detailed clinical staging as previously reported.9, 10 DNA/CIG assay was performed on whole bone marrow aspirates along with metaphase cytogenetics and GEP of CD138+ purified PC.13 Imaging studies involved metastatic bone surveys and, in the majority of the cases, magnetic resonance imaging examination of the axial and appendicular skeleton. Details of the DNA/CIG method have been published elsewhere.14, 15 A technical modification of the assay was applied uniformly since August 2006. The assay is based on the two-parameter flow cytometry of cytoplasmic immunoglobulin and DNA of whole bone marrow aspirates. Single-cell suspensions were exposed to anti-light-chain reagents (Dako Kappa and Lambda light chain F(AB)2/FITC conjugated) and then counterstained for DNA with propidium iodide with the addition of RNase. To quantitate the cellular DNA content, DNA index (DI)16 was determined and calculated as the ratio of the mean for each light-chain-positive G0/1 DNA peak divided by the mean of the light-chain-negative diploid G0/1 peak on the X axis. A DI between 0.99 and 1.01 was referred to as diploid, while hyperdiploid implied DI>1.01 and hypodiploid DI<0.99. The excess of kappa- or lambda-positive cells identified the involved or light-chain-restricted (LCR) cell population, the percentage of which was calculated in relation to the total number of gated events. Among the LCR cell population, discrete populations of cells with different DI were identified, which we refer to from here on as DNA stem lines. The involved DNA stem line with the highest percentage was considered dominant. To quantitate the cytoplasmic immunoglobulin content of a light-chain-positive population, the cytoplasmic immunoglobulin index (CIg) was used and calculated from the ratio of the geometric mean of the Y axis (cytoplasmic immunoglobulin fluorescence intensity) for the light-chain-positive G0/1 peak divided by the Y axis geometric mean of the light-chain-negative diploid G0/1 population. The CIg of each distinct DNA stem line was calculated as explained above. Kaplan–Meier methods were used to generate survival distribution graphs, and comparisons were made employing the log-rank test. For continuous variables, the running log-rank method was applied for the calculation of optimal cutoff points. The R2 statistic was used to evaluate the predictive power of different models. Wilcoxon tests were used to compare the medians of continuous measurements between groups. The characteristics of the 110 patients lacking the revised International Myeloma Working Group criteria for MM are portrayed in Supplementary Table 1. The median follow-up time for the 110 patients was 4.8 years. Aneuploidy by DNA/CIG was evident in 64%, all of whom had hyperdiploid stem lines, while additional hypodiploid abnormalities were present in two cases. Low hemoglobin (<10 g/dl) pertained to only 4% (non-plasma cell dyscrasia-related reasons) while creatinine ⩾2 mg/dl was evident in one case due to hypertension-related nephrosclerosis. Metaphase cytogenetic abnormalities (CA) were documented in 16%, a GEP70 score⩾−0.26(ref. 3) pertained to 33% and a recently defined novel GEP4 score⩾9.28(ref. 17) to 12% of patients. We examined the TTT probability of AMG (Table 1). Optimal cutoff points were obtained for all continuous numerical values. We confirm other studies linking older age ⩾65 years, albumin 8.4 The presence of CA, GEP70- and GEP4- high-risk designations was strongly linked to inferior TTT. Among DNA/CIG-derived parameters, CIg 17 were both strongly linked to progression to MM. Other DNA/CIG variables associated with TTT included the presence of aneuploidy and the presence of ⩾2 DNA stem lines (Figure 1). The 26 patients with CIg 17 present in 20 patients conferred a 2-year MM progression rate of 60% versus 9% among the 90 with lower (Figure 1b). Consideration of both DNA/CIG features identified 14 patients displaying two high-risk features with 2-year TTT of 71.4% as opposed to 5.1% in 78 patients with only favorable features, while the presence of one adverse variable present in 18 patients was associated with a 2-year TTT probability of approximately 34% (Figure 1c). Figure 1 Kaplan–Meier plots for the time to progression from AMG to MM requiring therapy according to: CIg, (a) total LCR%, (b) the combination of CIg and total LCR% (c) and the combination of CIg and total LCR% for the SMM population ... Table 1 Cox regression for time to progression to MM In the multivariate model, serum-M⩾3 g/dl, CIg 17% independently conferred adverse outcomes (Table 1). All three parameters combined provided for a high R2 value of 0.861, implying that TTT probability could be accounted for in 86% (Supplementary Table 2). In comparison, the classical criteria of bone marrow plasmacytosis ⩾10% and serum-M⩾3 g/dl had a lower cumulative R2 of 0.632. When only the sub-population of SMM (80 patients; Supplementary Table 3) was considered, DNA/CIG-derived variables retained their statistical significance (Supplementary Table 4). Both LCR>17% and CIg 17% and serum-M⩾3 g/dl; albumin<3.5 g/dl and B2M⩾3.5 mg/l also conferred higher TTT probability for a R2 of 0.862 (Supplementary Tables 4 and 5). The inclusion of GEP variables, available in a subset of 61 patients, identified GEP-4 as a significant variable, dispelling CIg and B2M from the model (R2=0.895; Supplementary Tables 4 and 6). CIg is a measure of plasma cell immunoglobulin production.15 We therefore examined CIg values in patients with MGUS and SMM (both from the S0120 trial), and in newly diagnosed MM patients accrued to Total Therapy 3b.18 Median CIg values declined progressively with the transition from MGUS to SMM and later to MM (10.5 versus 5.6 versus 3.3, P<0.001; Supplementary Figure 1a). To exclude the possibility that the difference in CIg reflects the decreasing percentage of highly secreting normal plasma cells with the evolution of plasma cell dyscrasias,19, 20 the analysis was repeated for strictly aneuploid cases. Again, the evolution from MGUS to SMM to MM was characterized by a progressively lower CIg (16.0 versus 9.1 versus 3.5, P<0.0001; Supplementary Figure 1b). In summary, DNA/CIG offers powerful prognostic information for AMG even in the era of genomic profiling. While LCR% reflects tumor burden, the finding of progressively decreasing CIg with the evolution of plasma cell dyscrasias in this single institution subset analysis of S0120 is novel. It provides evidence that the progression of plasma cell dyscrasias is accompanied by a progressive decline in immunoglobulin production capacity.

Prolonged prothrombin time correlates with serum monoclonal protein concentration in patients with plasma cell dyscrasia

Abnormal screening coagulation tests are frequently observed in asymptomatic patients with multiple myeloma and other plasma cell neoplasms.

The prognostic value of the depth of response in multiple myeloma depends on the time of assessment, risk status and molecular subtype

Complete remission (CR) rates for multiple myeloma (MM) have increased to 60% with current treatment approaches, including high dose melphalan-based autologous stem cell transplant (ASCT) and novel agents, and are associated with improved survival.[1][1]–[3][2] Despite this improvement, highly