Plasma Cell Proliferative Disorder Research Articles

Idiopathic Bence Jones Proteinuria (Smoldering Monoclonal Light-Chain Proteinuria): Clinical Course and Prognosis

AbstractAbstract 1861Idiopathic Bence Jones Proteinuria (Smoldering Monoclonal Light-Chain Proteinuria), first reported in 1982, is an asymptomatic plasma cell proliferative disorder associated with an elevated risk of progression to symptomatic MM or amyloidosis (AL). We defined it as the presence of a monoclonal light chain in the urine ≥200 mg/24h, absence of an intact immunoglobulin M protein (IGH expression) in the serum and no evidence of MM, AL or other related plasma cell proliferative disorders. Following approval by our Institutional Review Board, we searched a computerized database and reviewed the records of all patients seen at Mayo Clinic within 30 days of the recognition of a monoclonal light chain (Bence Jones protein) in the urine from January 1, 1960 through June 30, 2004. Patients with end-organ damage at diagnosis resulting from the plasma cell proliferative disorder (including MM or AL), or who had received chemotherapy or had a nephrotic syndrome were excluded. Follow-up included review of each patient’s medical record at Mayo Clinic, as well as review of death certificates for patients who died. Patients were sent letters of inquiry if they had not visited Mayo Clinic in the preceding year. The risks of progression to MM and AL were compared to those expected on the basis of Surveillance, Epidemiology and End Results (SEER) rates for MM in Iowa and the incidence of AL in Olmsted County, Minnesota. One-hundred and one patients fulfilled the criteria for diagnosis during the 44-year period (1960–2004). The median age at diagnosis was 67 years (range 18–90 years), and only 2% were < 40 years old. Seventy-three percent were male. The urine M protein ranged from 200 mg/24h to 4.7 g/24h (median value, 500 mg/24h); 29% had > 1 g/24h. Kappa light chain accounted for 50% while the remaining 50% were lambda. Fifty-seven (56%) had a monoclonal light chain in the serum on immunofixation. Concentrations of uninvolved (normal, polyclonal or background) immunoglobulins were reduced in 62%. Eighty-eight percent of patients died during follow-up. During 900 person years of follow-up, 29 patients developed symptomatic MM (relative risk, 140.3; 95% CI, 93.9–201.5) and an additional 9 patients developed AL (relative risk, 104.4; 95% CI, 47.8–198.4). Four patients had both multiple myeloma and AL amyloidosis. The cumulative probability of progression to active MM or AL was 19% at 5 years, 31% at 10 years and 42% at 15 years. The factors associated with progression to MM or AL included size of urine M protein, percentage of bone marrow plasma cells, serum free light chain ratio < 1/100 or > 100, serum creatinine and reduction of all 3 uninvolved immunoglobulins. We conclude that patients with Idiopathic Bence Jones Proteinuria (Smoldering Monoclonal Light-Chain Proteinuria) are at risk for the development of MM or AL and must be followed indefinitely. Disclosures:No relevant conflicts of interest to declare.

How I treat plasma cell leukemia

AbstractPrimary plasma cell leukemia (pPCL) is a rare and aggressive plasma cell proliferative disorder with a very poor prognosis and with distinct biologic, clinical, and laboratory features. Compared with multiple myeloma, pPCL presents more often with extramedullary involvement, anemia, thrombocytopenia, hypercalcemia, elevated serum β2-microglobulin and lactate dehydrogenase levels, as well as impaired renal function. Many of the genetic aberrations observed in newly diagnosed pPCL are typically found in advanced multiple myeloma. These cytogenetic abnormalities and mutations lead to increased proliferation, enhanced inhibition of apoptosis, escape from immune surveillance, and independence from the BM microenvironment, with changes in expression of adhesion molecules or chemokine receptors. The outcome of pPCL has improved with the introduction of autologous stem cell transplantation and combination approaches with novel agents, including bortezomib and immunomodulatory drugs, such as lenalidomide. In this review, we provide an overview of currently available therapeutic options with recommendations of how these treatment modalities can best be used to improve outcome for plasma cell leukemia patients.

Single-nucleotide polymorphism rs1052501 associated with monoclonal gammopathy of undetermined significance and multiple myeloma

Monoclonal gammopathy of undetermined significance (MGUS) is the most prevalent clonal plasma cell proliferative disorder, present in over 3% of the population aged 50 years and older, with a rate of progression to malignancy of 1% per year. (Kyle, et al 2006, Kyle, et al 2002) MGUS has been shown to precede MM in almost all cases. (Landgren, et al 2009b) We, and others, have shown evidence for a familial component to MGUS, with first-degree relatives of MM or MGUS probands having a 2.5 fold increased risk of MGUS, indicative of an underlying genetic predisposition. (Landgren, et al 2009a, Vachon, et al 2009) While several genetic variants have been identified for MM, none have been identified that are associated with MGUS. (Greenberg, et al 2012) Broderick et al. (Broderick, et al 2011) recently conducted the first genome-wide association study (GWAS) of MM using case-control studies from the United Kingdom and Germany and identified three novel loci at 3p22.1 (rs1052501 in ULK4), 7p15.3 (rs4487645) and 2p23.3 (rs6746082) associated with risk of MM, although the latter did not reach genome wide significance (p<5×10−8). Here, we investigate whether these three loci for MM risk are also associated with risk of MGUS in order to provide evidence that genetic variation influences MM through MGUS. We also attempt to replicate the association of these loci with MM within a case-control study of MM.

Evaluation of the N Latex FLC free light chain assay on the Siemens BN analyser: precision, agreement, linearity and variation between reagent lots

The clinical utility of serum κ and λ free light chains (FLC) for the diagnosis and prognosis of plasma cell proliferative disorders is well established. We assessed the analytical performance of the N Latex FLC assays and compared it with the Freelite™ assays. Analytical precision was assessed according to the CLSI EP5-A2 protocol. Method comparison was performed with 116 clinical samples and linearity was assessed on samples with monoclonal and polyclonal elevations of FLC. Analytical bias and variance was measured with two lots of N Latex FLC reagent. The N Latex FLC κ and λ assays had a total coefficient of variation of 5-7% across the analytical range. The slopes were 1.36 and 1.37 and the between-method variances were 40.0% and 45.4%, respectively, compared with the Freelite™. Good agreement in classification was observed for κ, λ and the κ/λ ratio (Cohen's κ 0.84, 0.76 and 0.89). Statistical non-linearity occurred commonly, but clinically significant non-linearity was observed in only one instance. Between-reagent lot variation was 7.3% and 10% for κ and λ, respectively. The N Latex FLC assay has good precision, did not exhibit gross antigen excess and can be used in clinical practice based on the analytical performance characteristics.

Treatment for POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome.

POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes) syndrome is a rare cause of demyelinating and axonal mixed neuropathy with monoclonal plasma cell proliferative disorder and multiorgan involvement. The pathogenesis of POEMS syndrome is not well understood, but overproduction of vascular endothelial growth factor (VEGF), probably secreted by plasmacytomas, is likely to be responsible for most of the characteristic symptoms. POEMS syndrome is a potentially fatal disease, and patients' quality of life deteriorates because of progressive neuropathy, massive pleural effusion or ascites, or thromboembolic events. There is a need for efficacious therapy to improve prognosis. This is the first update of a review first published in 2008. To assess the effects of treatment for POEMS syndrome. We searched the Cochrane Neuromuscular Disease Group Specialized Register (23 February 2012), CENTRAL (2012, Issue 2), MEDLINE (January 1966 to February 2012), EMBASE (January 1980 to February 2012) and CINAHL Plus (January 1937 to February 2012) for all papers on POEMS syndrome We sought all randomized and quasi-randomized controlled trials, and non-randomized controlled studies. Since we discovered no such clinical trials, we assessed and summarized all retrospective case series including five or more patients in the 'Discussion' section. Two review authors independently reviewed and extracted details of all potentially relevant trials with any treatment for POEMS syndrome. We then collated and summarized information on the outcome. We found no randomized or non-randomized prospective controlled trials of treatment for POEMS syndrome. We summarized the results of retrospective case series containing five or more patients in the 'Discussion' section. There are no randomized or quasi-randomized controlled clinical trials of treatment for POEMS syndrome on which to base practice.

Light chain deposition disease affecting the gastrointestinal tract in the setting of post-living donor kidney transplantation

Light chain deposition disease (LCDD) is an uncommon, clonal plasma cell proliferative disorder, in which monoclonal immunoglobulin light chains deposit in various tissues, resulting in organ dysfunction. Gastrointestinal (GI) involvement has been described in both primary and secondary amyloidosis, but has rarely been reported in LCDD, and only as an incidental finding. We report a case of LCDD in living related kidney transplant recipient presenting with severe GI dysmotility, weight loss and progressive allograft dysfunction. A diagnosis of LCDD was based on the kidney biopsy findings in the failing renal allograft, along with the presence of excess serum free kappa light chains and abnormal kappa:lambda ratio. Subsequent review of GI biopsies confirmed kappa light chain immunoglobulin deposition within the stomach. Further investigation suggested additional hepatic and cardiac involvement. The patient went on to receive bortezomib, achieving a biochemical response and stabilization of his advanced renal dysfunction; however, bortezomib was discontinued due to toxicity. The patient was subsequently treated with lenalidomide and dexamethasone, which were better tolerated. Further biochemical response and resolution of the GI symptoms was observed after 10months of treatment. In summary, we present the first case of LCDD with symptomatic GI involvement, in which the diagnosis was established by intestinal biopsies. Our report also highlights the feasibility and effectiveness of lenalidomide in the treatment of LCDD.

Targeted therapy of multiple myeloma

The diagnosis of multiple myeloma requires the presence of monoclonal bone marrow plasma cells, a monoclonal (M) protein in serum and/or urine and evidence of end-organ damage from the plasma cell proliferative disorder. Initial therapy for transplant-eligible patients includes thalidomide, bortezomib or lenalidomide, all with dexamethasone. Stem cells for a possible autologous stem cell transplant (ASCT) should be collected if the patient is considered eligible for an ASCT. Initial therapy for patients ineligible for an autologous stem cell transplant includes melphalan and prednisone as well as thalidomide, bortezomib or lenalidomide. More than 100 agents are in phase I, II or III clinical trials. The most promising are carfilzomib and pomalidomide.

Discrepancies in Serum Free Light Chain Assays and Immunofixation for Response Evaluation and Prognostication in Plasma Cell Proliferative Disorders

Abstract 5099Plasma cell proliferative disorders are monitored by a variety of methods. Serum protein electrophoresis (SPE), M-spike quantitation and Immunoelectrophoresis (IFE) are commonly assessed in patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM) to determine disease progression, response, or relapse. sFLC quantitation provides a rapid indicator of response, detects the rare occurrence of FLC escape, and also allows disease monitoring in the absence of a measurable serum or urine M-spike. To improve sensitivity of response assessment in MM, the International Myeloma Working Group (IMWG) has recently introduced the stringent CR category. However, no formal studies have validated this criterion. Indeed, the role of the sFLC assay has recently been questioned because of the presence of discordant abnormal sFLC ratios in a significant proportion of patients in CR. This could be at least partly explained by the presence of oligoclonal bands in response to therapy, potentially leading to false-positive results. Accordingly it has been recommended that the serum M-spike be used to monitor disease, and that FLC quantitation be used only if there is no measurable disease by electrophoresis and if the monoclonal sFLC concentration is greater than 10 mg/dL in the context of an abnormal FLC ratio. By analyzing serial samples in our patient population we aim to help usefully interpret the sFLC results and in the long run validate the prognostic impact of attaining CR versus CR plus normal sFLC ratio (stringent CR) after therapy in MM.From a total of 566 samples submitted for FLC analysis over 24-month period at our institution, 94 cases were monoclonal (abnormal FLC ratio) with kappa being the involved chain in 63 and lambda in 31 cases. Serial data from 35 multiple myeloma patients were identified by the availability of 3 serum test results (SPE/IFE/sFLC) in at least 3 serial samples that were obtained 3 months to 6 months apart along with treatment outcome details. Kappa and lambda FLC were quantitated using a Siemens BNII® nephelometer and Freelite® reagent sets from The Binding Site, Birmingham, UK; M-spikes were quantitated Capillarys® system and reagent sets (Sebia Electrophoresis, Norcross, GA). The FLC data was analyzed as the involved FLC concentration (iFLC), the difference between the involved and uninvolved FLC concentration (dFLC), and the FLC K/L ratio (rFLC). Treatment modalities included allogeneic, or autologous stem cell transplantation, conventional, bortezomib or lenalidomide containing chemotherapy.There were 16 (45%) cases in which discordance was observed between the three techniques (sFLC/SPE/IFE) during the follow-up. 11/16 (68%) patients were found to have abnormal sFLC with both abnormal FLC ratio and involved chain (FLCi), while no M-band was detected by SPE/IFE. In two cases (13%) the pattern of discrepancy was opposite with IFE found to be positive while rFLC results were within normal range of 0.26 – 1.65 mg/l. In three cases (19%) abnormal FLC ratio was detected with SPE/IFE being normal but the sFLC ratio did not match the myeloma isotype (sFLC ratio <0.26 for kappa and >1.65 for lambda isotype). In a subgroup of patients (n = 4) who relapsed during follow-up from complete remission sequential monitoring of immunofixation and free light chain assays revealed normalization of SPE/IFE with only faint/ doubtful band detected in one while FLC results were abnormal.The variability of the serum M-spike, IFE and FLC measurements confirm the IMWG recommendations for patient monitoring. The free light chain assay ratio is widely reported as a useful marker for a faster detection of remission or progression in myeloma patients. These techniques in reality complement each other and the FLC results need to be interpreted with caution in context of the electrophoresis results in order to determine the status of remission. More sensitive methods such as multiparametric imunophenotyping analysis for minimal residual disease by multiparametric flowcytometry or molecular primer assays may be useful to determine the depth of complete remission as choosing the type of screening test will likely have a relevant impact in clinical decision making in MM. Disclosures:No relevant conflicts of interest to declare.

Extensive Bone Marrow Infiltration and Abnormal Free Light Chain Ratio Identifies Patients with Smoldering Myeloma At High Risk for Progression to Symptomatic Disease,

Abstract 3926Asymptomatic/smoldering multiple myeloma (SMM) is a proliferative plasma cell disorder characterized by a substantial risk of progression to symptomatic myeloma. According to current recommendations, patients with SMM should be followed without treatment until they develop symptomatic disease. However, the risk of progression to symptomatic myeloma varies between different series and for individual patients; thus, significant effort is needed in order to identify factors that could discriminate those who are at high risk for progression. Such patients should be followed closer and should be considered candidates for clinical trials. In order to evaluate previously recognized risk factors and study patterns of progression we analyzed our series of patients with SMM, who have been diagnosed and followed in the Department of Clinical Therapeutics in Athens, Greece.SMM was defined as serum monoclonal (M) protein (IgG or IgA) level of ≥3 g/dL and/or bone marrow plasma cells ≥10%, absence of end-organ damage, such as lytic bone lesions, anemia, hypercalcemia, or renal failure, that can attributed to a plasma cell proliferative disorder (IMWG criteria, Br J Haematol 2003;121:749–57). Progression to symptomatic myeloma was defined as per the IMWG proposed criteria.We analyzed 95 patients with SMM, 53% of whom were females, 70% had IgG heavy chain, 22% had IgA, 5% had a biclonal SMM and 3% had light chain only SMM, while 65% had a kappa light chain and 35% a lambda light chain. Median infiltration by clonal plasma cells in BM trephine biopsy was 20% (range 10–90%), 10% of patients had ≥60% clonal plasma cells in BM biopsy. Fifty patients had MRI of the spine at the time of diagnosis of SMM and 19.5% had an abnormal pattern of BM infiltration (diffuse, focal or variegated pattern). In patients with available bone marrow immunohistochemistry data, 61% had clonal plasma positive for CD56, 17% for CD20 and 19% for cyclin D1.The median follow up of the cohort was 27 months (range 1–253 months) and 23 (24%) patients have progressed to symptomatic myeloma. The one-year, 2-year and 3-year cumulative probability of progression was 7%, 12% and 20% respectively. Nine patients (9.5%) progressed within the first two years from the diagnosis of SMM. All these patients had an M-protein of ≥1 g/dl (10 g/L), 67% had bone marrow plasma cells >60% and 80% had an abnormal MRI pattern of BM infiltration. The 3-year probability of progression to symptomatic myeloma was 4%, 18% and 87% for patients with <20%, 20–59% and ≥60% clonal plasma cells in bone marrow biopsy (P<0.001). The 2-year probability of progression to symptomatic myeloma was 0%, 13% and 60% for patients with <20%, 20–59% and ≥60% clonal plasma cells in BM biopsy (P<0.001). Patients with significantly abnormal free light chain ratio (either kappa/lambda ≥8 or kappa/lambda ≤0.125, according to Dispenzieri et al, Blood 2008;111:785–9) had a 3-year probability of progression to symptomatic MM of 41% vs. 15% (p=0.07). There was no significant difference in the risk of progression to symptomatic MM for patients with IgA vs. IgG myeloma. In multivariate analysis, abnormal FLC ratio less than 0.125 or more than 8 (HR: 6.4, 95% CI 1.3–34.5 p=0.032) and BM clonal plasma cells infiltration ≥60% (HR: 23, 95% CI 5–125, p<0.001) were independent risk factors for progression to symptomatic myeloma.Progression to symptomatic MM was manifested by the development of anemia in 52% of patients who progressed to symptomatic MM, development of lytic bone lesions or pathologic fracture in 48%, an increase of serum creatinine to ≥2 mg/dl in 13%, development of a soft tissue plasmacytoma in 4% and development of hypercalcemia in 4%.In conclusion, in our series of patients the 3-year probability of progression to symptomatic myeloma is about 20%, but there is a subgroup of patients with extensive bone marrow infiltration (≥60%) and highly abnormal FLC ratio, who have a substantial risk of progression to symptomatic disease within the first two years from the diagnosis of SMM. These high risk patients may also have other features such as abnormal MRI of the spine. Patients at high risk for progression should be considered for clinical trials evaluating the role of treatment before the development of symptomatic disease, which in most cases is manifested with anemia and/or lytic bone disease or pathologic fractures. Disclosures:No relevant conflicts of interest to declare.

Promoter methylation of the bone morphogenetic protein 6 gene in multiple myeloma

Bone morphogenetic proteins (BMPs), which belong to the transforming growth factor-β superfamily, are multifunctional signaling molecules that have become of increasing interest in cancer research. Recent observations suggest that alterations in BMPs and BMP signaling are associated with tumorigenesis and disease progression in various types of malignancies. This study investigated the methylation status of the BMP6 gene promoter in various types of plasma cell proliferative disorders by combined bisulfite restriction analysis. While BMP6 methylation was not detected in any samples from monoclonal gammopathies of undetermined significance, intramedullary multiple myeloma (MM), plasma cell leukemia or solitary plasmacytoma, both case studies and cell line studies showed that multiple extramedullary plasmacytoma (MEP) consistently carried a methylated BMP6 promoter. The BMP6 methylation-positive MEP was an aggressive form of MM with extremely high levels of serum lactate dehydrogenase (LDH). Bisulfite sequencing analysis confirmed intensive methylation at CpG sites of the BMP6 promoter region. The methylation of BMP6 was correlated with decreased levels of mRNA transcripts. Expression of BMP6 was restored by the demethylating agent 5-aza-2'-deoxycytidine, suggesting that the methylation is associated with transcriptional silencing. Our study implied that BMP6 promoter methylation is not a common event in MMs, but occurs in aggressive MEP. These findings warrant further investigation to clarify whether BMP6 methylation together with elevated LDH could be a marker of poor prognosis in MEP patients who should be considered for early intensive treatment.

Monoclonal Gammopathy of Undetermined Significance Does Not Affect Outcomes in Patients Undergoing Solid Organ Transplants

Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic plasma cell proliferative disorder with a lifelong risk of progression to multiple myeloma or another plasma cell dyscrasia. Despite a high incidence in the general population and an increased relative risk for later malignancy, there are few reports about the clinical course of MGUS or risk profile in long-term immunosuppressed patients. We reviewed 1593 solid organ transplant patients and reported the frequency and outcomes of patients with MGUS identified pretransplant. Polyclonal gammopathy pretransplant is common with 17% of all patients and as many as 75% of liver transplant candidates having increased globulins.However, a monoclonal immunoglobulin was identified in only 3% of all solid organ transplant patients pretransplant (n=34). Importantly, in these 34 patients, no cases of progression to multiple myeloma, amyloid, or lymphoma were observed during immune suppression, and there was no association between posttransplant lymphoproliferative disorders and pretransplant MGUS. Death in MGUS patients was not associated with progression of the monoclonal clone or development of posttransplant lymphoproliferative disorders or other malignancy. In conclusion, routine testing for MGUS before transplantation is not prognostic nor a contraindication to transplant, and therefore, it is not recommended.

Chromothripsis identifies a rare and aggressive entity among newly diagnosed multiple myeloma patients

AbstractMultiple myeloma (MM) develops from a premalignant plasma cell proliferative disorder, and with time can progress to a more aggressive disease in extramedullary locations. The gradually clinical evolution is supported by clonal expansion of cells that acquire genetic lesions over years. This model of cancer evolution based on ongoing genomic instability mechanism may apply to development of most MM cases. However, in a small fraction of newly diagnosed MM who relapse quickly and finally die within 2 years, the gradual model appears to be untenable. Analysis of high resolution copy number profiles obtained using single nucleotide polymorphism array data from 764 newly diagnosed MM identified large numbers of genomic rearrangements with the hallmarks of chromothripsis in 1.3% of samples. Moreover, this catastrophic event confers a poor outcome. Because chromothripsis appears to occur in a single crisis, our results suggest that high-risk MM patients use this novel way of cancer evolution.

A Retrospective Study to Evaluate the Work-up and Follow-up of Patients With Monoclonal Gammopathy of Undetermined Significance

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell proliferative disorder that transforms into multiple myeloma and other serious B-cell disorders at an approximate rate of 1% per year; these patients are also at increased risk for fractures. We conducted a retrospective, multicenter study of 100 patients from seven community health clinics to gain a better understanding of the work-up, follow-up, and treatment of these patients. MGUS patients appear to undergo inadequate work-up, follow-up, and treatment in the community setting. Physicians should adhere to recently established guidelines to ensure that MGUS patients receive optimal care for this condition.

Case report: A case of light chain deposition disease involving liver and stomach with chronic hepatitis C virus infection and hepatocellular carcinoma

Light chain deposition disease (LCDD) is a rare, plasma cell proliferative disorder characterized by mainly abnormal light chain deposition in various organs. Hepatitis C virus (HCV) is a hepatotrophic and lymphotrophic virus and significantly related to B-cell proliferation. This is a case report of systemic LCDD involving liver, stomach, bone marrow, and probably kidney, in a patient with HCV-related hepatocellular carcinoma (HCC). A 62-year-old man with chronic HCV infection who presented with a small HCC in segment 8 of the liver and nephrotic syndrome showed kappa typed immunoglobulin light chain depositions in biopsy specimens of bone marrow, stomach, and non-tumorous liver parenchyma. After treatment of the HCC with transarterial chemoembolization, antiviral therapy for chronic hepatitis C was started. The patient showed early virologic response at 12 weeks of treatment; however, antiviral therapy was discontinued due to adverse effects and he was lost to follow-up. This is the first case of LCDD involving the liver and stomach in a patient with chronic HCV infection and HCC, which may represent LCDD as a rare HCV-associated B cell proliferative disease.

Sjogren’s syndrome with pulmonary nodular light chain deposition disease; response to mycophenolate mofetile

Light chain deposition disease associated with primary Sjogren’s syndrome has been rarely reported in the medical literature. We report a 65-year old Caucasian woman with Sjogren’s syndrome (SS) for twenty eight years associated with nodular pulmonary light chain deposition disease. This case is unique in the improvement of clinical symptoms and pulmonary function tests following treatment with mycophenolate mofetil (MMF). Primary SS is an automimmune exocrinopathy which is characterized by keratoconjunctivitis sicca and xerostomia. SS is known to be associated with B cell hyperactivity, polyclonal gammopathy and low grade marginal zone B cell lymphoma. Light chain deposition disease is a non-amyloid monoclonal immunoglobulin disorder that is caused by a clonal plasma cell proliferative disorder. Tissue deposits in light chain deposition disease are granular not fibrillar, and do not stain with Congo Red. The coexistence of SS and light chain depositon disease is unusual.

Pulmonary involvement complicating plasma cell proliferative disorders: a case report and review of the literature

Pulmonary involvement complicating plasma cell proliferative disorders: a case report and review of the literature

Monoclonal Gammopathy of Undetermined Significance (MGUS) in a Man with Fragile X-associated Tremor/Ataxia Syndrome

We report the clinical presentation and laboratory findings of a 69-year-old man with fragile X-associated tremor ataxia syndrome (FXTAS), a progressive neurodegenerative disorder, who was noted to have monoclonal gammopathy of undetermined significance (MGUS), a plasma cell proliferative disorder and a precursor disease of multiple myeloma. Both MGUS and FXTAS are associated with microRNA (miRNA) dysregulation. We speculate that individuals with FXTAS may be predisposed to MGUS and further studies are warranted regarding this association.

Mucous Membrane Plasmacytosis of the Larynx: A Case Report and Review of the Literature

Conclusions: Mucous membrane plasmacytosis is a rare, benign, plasma cell proliferative disorder with an unknown etiology. It is a diagnosis of exclusion as there are similar conditions such as extramedullary plasmacytoma which can affect the upper aerodigestive tract. The condition is generally of long standing duration and management is typically targeted at symptomatic relief. Mucous membrane plasmacytosis is an idiopathic disorder that can mimic other similar conditions of the upper aerodigestive tract. Diagnosis is made on the basis of exclusion using histology, serology and cultures to narrow the differential diagnosis.3 Table 1 illustrates the many other conditions of the upper aerodigestive tract that may appear similar clinically or histologically.

Multi-Parameter Flow Cytometry(FC) Can Detect Proliferating Myeloma Cells After Treatment: Implications for Targeting the Myeloma Proliferative Component

AbstractAbstract 4995 Background:Multiple myeloma results from an accumulation of monoclonal nonproliferating plasma cells arising from a small subpopulation of proliferating myeloma cells. In an effort to optimize detection of the human myeloma cell growth fraction and obviate the need for slide review, a novel FC strategy was developed combining elements of light chain restriction, surface antigen expression, and ploidy analysis. Methods:Bone marrow cells from 41 patients with plasma cell proliferative disorders were lysed with ACK and resuspended in 3% BSA. Cells were stained using a 6-color assay with anti-CD45, anti-CD38, anti-CD138, and anti-CD19. Cells were washed and 100 ul Caltag solution A was added for 15 min. Cells were washed and 100 ul of Caltag solution B, anti-kappa and anti-lambda were added for 10 min. Cells were washed and 100 ul PBS and 3 ul RNAse are added for 15 min. Cells were washed and 400 ul of a 1:1000 solution of 3uM DAPI in Tris 0.1% NP-40 was added. Cells were incubated at 4°C for 45 minutes before running on a FACSCanto instrument for ploidy determination. All patients were analyzed both by flow cytometry and the slide based plasma cell labeling index. Results: Forty-one patients were studied; 34 demonstrated a proliferative fraction and 7 had too few plasma cells for analysis after therapy. Of the 34 patients, 6 had MGUS/SMM, 5 newly diagnosed MM, 7 amyloid, and 16 were treated MM. The mean percent proliferating cells were 1.1% (range 0 – 8.6%) with PCLI and 1.4% (range 0.1 – 12.7%) by flow. The correlation between PCLI and flow gave a RSquare value of 0.54. Twelve patients with a PCLI of 0% had a flow proliferation between 0.1 – 1.4% (mean 0.49%). Treated patients received lenalidomide, dexamethasone, bortezomib, and/or autologous transplantation. All 16 treated myeloma patients with adequate plasma cells had a flow proliferation between 0.2 – 12.7% (mean 2.2%). Conclusion: Flow cytometry offers a useful way to detect the proliferative myeloma component at diagnosis and after treatment. The continued presence of proliferating myeloma cells after treatment may explain why most patients relapse and offers another important marker to monitor and cell population to target in patients with active disease. Disclosures:Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding.

Proteomic Analysis of Immunoglobulin Light Chains (LC) In AL Amyloidosis Shows That the Sequence of Clonal LC Secreted by the Neoplastic Plasma Cells Is Identical to the LC Deposited In the Amyloid Plaques

AbstractAbstract 1909AL amyloidosis is the most common type of systemic amyloidosis. It is caused by extracellular deposition of circulating immunoglobulin light chains (LC) thought to be secreted by a primarily bone marrow based clonal plasma cell proliferative disorder. Although, invariably, the type of LC secreted by the plasma cell clone is identical to the LC deposited in the amyloid plaque, a comprehensive analysis of the re-arranged clonal LC gene coding secreted LC protein, the protein sequence of the serum and urine monoclonal band and the LC protein deposited in the amyloid plaques have not been previously performed. In this study, we compared the protein sequence predicted by the clonal LC gene sequence with the protein sequence identified in the serum and urine monoclonal bands and protein plaques by mass spectrometry (MS) based proteomics.10 cases with systemic AL amyloidosis were studied. Bone marrow samples containing the clonal plasma cells were obtained and clonal LC variable gene sequences were determined by PCR amplification, cloning and sequencing as described previously (Abraham et al, Blood 2003, 101: 3801). For protein analysis, monoclonal protein bands identified in serum and/or urine protein electrophoresis and immunofixation were isolated from archival gels. For amyloid plaque protein analysis, the plaques were microdissected from paraffin embedded tissue. To identify the protein amino acid sequence of serum and urine bands and amyloid plaques, the samples were digested into peptides by trypsin and analyzed by MS based proteomic analysis. (see Vrana et al. and Blood 2009; 114: 4957 for methods). The results for amino acid sequence predicted from the clonal LC gene sequence, determined directly by MS from the serum and/or urine monoclonal band and amyloid plaques were then aligned and compared.In all 10 cases, the LC amino acid sequences predicted by sequencing of the clonal LC gene from bone marrow plasma cells, the amino acid sequence obtained directly from the monoclonal serum and/or urine protein and the amino acid sequence obtained from the amyloid plaque were identical. In most cases, both the complete variable region and constant regions were deposited as amyloid plaques. Some amyloid plaques showed cleavage of first 16 amino acids of the variable region suggesting that this part was not required for amyloid deposition. All LC variable region gene sequences were affected by somatic hypermutation, and identical mutations were present in both the serum and urine bands and in the amyloid plaques.In conclusion, these results, for the first time, comprehensively show that the monoclonal protein secreted by the neoplastic plasma cells is the pathogenetic protein causing the amyloid deposits in AL amyloidosis. Amyloid deposits contain virtually all of the LC protein identified in the serum or urine including both variable and constant regions, suggesting that the presence of the constant region may also play a role in amyloidogenesis. The technological capability to determine the complete protein sequence of the amyloidogenic monoclonal serum and urine LC protein isolated from archived gels will create new opportunities to develop diagnostic, predictive and prognostic serum or urine based tests for amyloidosis. Disclosures:Theis:Mayo Clinic: Patents & Royalties. Vrana:Mayo Clinic: Patents & Royalties. Dogan:Mayo Clinic: Patents & Royalties.