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Abstract Background: Multiple myeloma (MM) is a plasma cell proliferative disorder that is incurable with the currently available therapeutics. New therapies based on better understanding of the disease biology are urgently needed. MM is characterized by accumulation of malignant plasma cells predominantly in the bone marrow. These plasma cells exhibit a relatively low proliferative rate as well as a low rate of apoptosis. Elevated expression of the anti-apoptotic Bcl-2 family members has been reported in MM cell lines as well as in primary patient samples and may be correlated with disease stage as well as resistance to therapy. ABT-737 (Abbott Laboratories, Abbott Park, IL) is a small-molecule inhibitor designed to specifically inhibit anti-apoptotic proteins of the Bcl-2 family and binds with high affinity to Bcl-XL, Bcl-2, and Bcl-w. ABT-737 exhibits toxicity in human tumor cell lines, malignant primary cells, and mouse tumor models. We have examined the in vitro activity of this compound in the context of MM to develop a rationale for future clinical evaluation. Methods: MM cell lines were cultured in RPMI 1640 containing 10% fetal bovine serum supplemented with L-Glutamine, penicillin, and streptomycin. The KAS-6/1 cell line was also supplemented with 1 ng/ml IL-6. Cytotoxicity of ABT-737 was measured using the MTT viability assay. Apoptosis was measured using flow cytometry upon cell staining with Annexin V-FITC and propidium iodide (PI). Flow cytometry was also used to measure BAX: Bcl-2 ratios after ABT-737 treatment and cell permeabilization with FIX & PERM (Caltag Laboratories, Burlingame, CA) Results: ABT-737 exhibited cytotoxicity in several MM cell lines including RPMI 8226, KAS-6/1, OPM-1, OPM-2, and U266 with an LC50 of 5-10μM. The drug also had significant activity against MM cell lines resistant to conventional agents such as melphalan (LR5) and dexamethasone (MM1.R) with similar LC50 (5-10 μM), as well as against doxorubicin resistant cells (Dox40), albeit at higher doses. Furthermore, ABT-737 retained activity in culture conditions reflective of the permissive tumor microenvironment, namely in the presence of VEGF, IL-6, or in co-culture with marrow-derived stromal cells. ABT-737 was also cytotoxic to freshly isolated primary patient MM cells. Time and dose dependent induction of apoptosis was confirmed using Annexin V/PI staining of the MM cell line RPMI 8226. Flow cytometry analysis of cells treated with ABT-737 demonstrated a time and dose dependent increase in pro-apoptotic BAX protein expression without significant change in the Bcl-XL or Bcl-2 expression. Ongoing studies are examining the parameters and mechanisms of ABT-737 cytotoxicity to MM cells in more detail. Conclusion: ABT-737 has significant activity against MM cell lines and patient derived primary MM cells in vitro. It is able to overcome resistance to conventional anti-myeloma agents suggesting a different mechanism of toxicity that may replace or supplement these therapies. Additionally, it appears to be able to overcome resistance offered by elements of the tumor microenvironment. The results of these studies will form the framework for future clinical evaluation of this agent in the clinical setting.

Abstract Background: Multiple myeloma (MM) is a plasma cell proliferative disorder that results in considerable morbidity and mortality. As it is incurable with the current therapeutic approaches, more effective therapies based on better understanding of the pathobiology of the disease are needed. In MM, malignant plasma cells are characterized by low proliferative and apoptotic rates compared to other malignancies. Studies have shown elevated expression of anti-apoptotic proteins of the Bcl-2 family in MM cells, which appear to correlate with resistance to therapy with certain drugs. Hence, accelerating the apoptotic process by targeting the Bcl-2 family of proteins appears to be an attractive strategy for the treatment of MM. AT-101 is an orally bioavailable derivative of gossypol in cancer clinical trials, and is being developed by Ascenta Therapeutics. AT-101 behaves as a small molecule inhibitor of Bcl-2 and Bcl-XL, binding to the BH3-binding pocket of these proteins and inhibiting their ability to suppress the activity of pro-apoptotic proteins, resulting in apoptosis. Methods and Results: AT-101 was cytotoxic to several different myeloma cell lines with a median effect observed at around 5μM concentration using an MTT cell proliferation assay. Additionally, at similar doses AT-101 induced cytotoxicity in myeloma cell lines resistant to conventional agents such as Melphalan (LR50), Doxorubicin (Dox40) and Dexamethasone (MM1.R), indicating non-overlapping mechanisms. To evaluate the ability of the drug to induce cell death in the tumor microenvironment, MM cells were co-cultured with marrow stromal cells or in the presence of VEGF or IL-6, two cytokines known to be important for myeloma growth and survival. AT-101 was cytotoxic to myeloma cells under these conditions as well with a median effect at concentrations of 5–10μM. AT-101 was able to induce apoptosis in myeloma cells in a dose- and time dependent fashion, as demonstrated by flow cytometry using Annexin/PI staining as well as cell cycle studies. AT-101 also resulted in cytotoxicity of freshly isolated primary patient myeloma cells, inducing apoptosis in a dose dependent manner. We also studied the effect of AT-101 on levels of different pro- and anti-apoptotic proteins using flow cytometry on permeabilized cells. A time-dependent increase in the level of BAX was observed following treatment with AT-101 without any associated change in levels of Bcl-xL or Bcl-2. Further studies evaluating the combination of AT101 with other active myeloma agents as well as a detailed evaluation of its mechanisms in myeloma are ongoing. Conclusion: AT-101 has significant activity in vitro in the setting of myeloma as demonstrated by its effect on myeloma cell lines and primary patient cells. More importantly, it has activity against cell lines resistant to conventional anti-myeloma agents. In addition, Phase I studies with this agent are currently ongoing in patients with solid tumors. The results from these studies form the rationale for early phase clinical trials in MM, either alone or in combination with other active therapies.

Abstract Background: Abnormally increased tumor associated neovasculature plays an important role in tumor progression in solid tumors and hematological malignancies. In multiple myeloma (MM) bone marrow angiogenesis, measured in terms of microvessel density (MVD), has prognostic value, and appear to increase with disease progression from monoclonal gammopathy of undetermined significance to relapsed MM. We have shown that MVD has prognostic value in patients with newly diagnosed MM including patients undergoing upfront high dose therapy and stem cell transplantation, but comparison with other known prognostic factors has been limited by sample size. It is also not known whether the MVD adds prognostic value once the recently described International Staging System (ISS) is applied. The goal of this study was to determine the prognostic effect of bone marrow MVD in newly diagnosed MM relative to the ISS and other known prognostic factors. Methods: We studied 400 patients with newly diagnosed MM seen at the Mayo Clinic between March of 1988 and December 2001. Sections from bone marrow biopsy blocks from the time of initial diagnosis were studied by immunohistochemistry using antibodies against CD34 antigen to high light the endothelial cells. Under low power (100X); three areas with maximum number of microvessels (hotspots) were identified. Each of these areas was further studied at 400X magnification and the number of microvessels per high power field counted. The average of the three readings was taken as the MVD for the sample. In addition, the samples were graded as low, intermediate or high by using a visual estimate as previously described. Additional clinical data was extracted from medical records. Some of the patients have been included in previous studies related to angiogenesis. Results: A total of 400 patients in whom a bone marrow biopsy from within 30 days of diagnosis was available were studied. The pts were followed for a median of 37 months (Range: 1 month to 16.5 years) and 318 pts (80%) had died at the time of this analysis. The median MVD for the entire group was 14.7 (Range 0–168). The median overall survival for the three groups according to the MVD grade was lower for the high grade group (31.9 months) compared to the intermediate grade group (37.2 months) and the low grade group (not reached); P <0.029, log rank test. We examined this group of patients for other factors prognostic for overall survival. Factors significant on univariate analysis included ISS stage, platelet count (<150 vs. >= 150 X 106/L), and plasma cell labeling index (<1 vs >=1). In a multivariate analysis using these variables and MVD as a continuous variable, high MVD and the ISS staging system were significantly associated with poorer survival (Table). Conclusion: In this large group of pts with newly diagnosed MM, we confirm the prognostic value of increased bone marrow angiogenesis. We examined the MVD as a continuous variable in the multivariate analysis for a closer evaluation of this measure in this comparison. More importantly, the prognostic value appears to be independent of the ISS and other major prognostic factors. The resultsof this study reinforces the biological relevance of this finding in MM. HR 95% CI P value MVD 1.006 (1.001, 1.011) 0.0279 ISS Stage I 0.37 (0.25, 0.56) <0.001 ISS Stage II 0.58 (0.41, 0.83) 0.0025

Abstract We previously have reported that autograft absolute lymphocyte count (A-ALC) is a possible prognostic factor for survival after autologous peripheral blood stem cell transplant (ASCT) for myeloma (MM). Factors affecting A-ALC in MM are unknown. We hypothesize that method of stem cell mobilization, hematopoietic growth factor (HGF) vs. HGF+Cytoxan chemotherapy (C+HGF), directly affects A-ALC collection. 191 consecutive MM patients between 1994 and 2004 were analyzed retrospectively. Patients generally were mobilized with C+HGF prior to 2003. Thereafter, C+HGF was reserved largely for those with ≥4% circulating peripheral blood plasma cells (PC), a negative prognostic indicator. No patients were transplanted in disease relapse or refractory disease. Patients also were matched for age, sex, β2-microglobulin, conventional cytogenetics, LDH, c-reactive protein, number of prior therapies, plasma cell labeling index (PCLI), pre-mobilization ALC, and % bone marrow (BM) PC. The groups HGF (n=80) and C+HGF (n=111) differed with respect to the conditioning regimen (p < 0.0001), and presence of (≥4%) circulating peripheral blood PC (p<0.005). The primary end-point of the study was to assess the correlation between HGF vs C+HGF, and A-ALC. The secondary endpoint was to determine if HGF vs C+HGF affected survival post-ASCT. Patients mobilized with HGF had a higher A-ALC compared to those mobilized with C+HGF [0.764 x 109 lymphocytes/kg (range: 0.146–1.803) vs. 0.212 (range: 0.016–1.26), p<0.0001]. No association was identified between A-ALC and conditioning regimens (p = 0.19) and PC (p = 0.31). Median overall survival (OS) and progression-free survival (PFS) were longer in those mobilized with HGF vs. C+HGF (not reached vs. 48 months, p<0.0150; not reached vs. 21 months, p<0.007, respectively). Multivariate analysis demonstrated that age ≥50 vs age ≤50 (p<0.05) and A-ALC ≥0.5 vs <0.5x109 lymphocytes/kg (p<0.0397) were independent predictors of OS. Factors influencing PFS in the multivariate analysis included circulating PC ≥4% vs <4% (p<0.0157), PCLI ≥ 1% vs PCLI ≤ 1% (p<0.0107), and A-ALC ≥0.5 vs <0.5x109 lymphocytes/kg (p<0.0042). On multivariate analysis, the method of stem cell mobilization and the conditioning regimen did not have a statistically significant effect on either OS or PFS. We hypothesize that the differences in PFS and OS seen between the HGF vs C+HGF mobilization groups are mediated through the A-ALC. These data suggest that mobilization regimens should not only collect CD34+ stem cells, but also be optimized to collect an A-ALC target which may impact on PFS and OS post-ASCT.

Abstract Introduction: Increased bone marrow angiogenesis is a characteristic feature of multiple myeloma (MM) and correlates with disease progression. Increased bone marrow angiogenesis at the time of diagnosis, measured in terms of microvessel density (MVD), is a powerful adverse prognostic factor for patients with MM. To better understand the biological basis of this phenomenon and to understand the mechanisms responsible for increased MVD in MM we compared the gene expression profiles of plasma cells from newly diagnosed MM patients with low and high MVD. Methods: Bone marrow biopsy sections from pts with newly diagnosed MM were studied using CD34 immunostaining and graded as low, intermediate, or high by MVD as previously described. 19 pts each, with low or high MVD were included for this study. RNA was isolated from CD138+ plasma cells of MM patients and analyzed using Affymetrix HG-U133A arrays. To examine differential expression, GC-RMA normalized data was analyzed using GeneSpring 7.2 software and genes with ≥ 2-fold differential expression between high and low MVD samples were identified. The Welch T-test was used to determine the significance of differential expression. Results and Conclusion: Expression of 42 transcripts was increased ≥ 2-fold in samples with high MVD in comparison to samples with low MVD. Of these transcripts, 14 were found to be significantly increased (P<0.05) using the Welch T-test (see Table 1). Expression of 16 transcripts was decreased ≥ 2-fold in samples with high MVD in comparison to samples with low MVD. Of these transcripts, 6 were found to be significantly decreased (P<0.05) using the Welch T-test (see Table 1). Genes differentially expressed include those involved in inhibiting apoptosis, facilitating IL-6 signaling, ion transport, extracellular matrix interaction, and regulating gene expression. Classical angiogenesis genes including VEGF, FGF, and IGF were not found to be differentially expressed (> 2-fold). In conclusion, the list of differentially expressed genes reveals many functions relevant to MM disease pathology including proliferation, apoptosis, regulation of gene expression, cytokine signaling, and adhesion. Current studies evaluating the expression and function of these genes in relation to MM may identify factors critical for angiogenesis and MM progression and provide insight for therapeutic intervention. Gene Description Fold Change COL1A2 collagen, type I, alpha 2 3.008 MCL1 myeloid cell leukemia sequence 1 (BCL2-related) 2.793 209183_s_at chromosome 10 open reading frame 10 2.541 VIL2 villin 2 2.478 IL6ST interleukin 6 signal transducer (gp130) 2.404 CLIC2 chloride intracellular channel 2 2.364 DEPDC6 DEP domain containing 6 2.35 PBXIP1 pre-B-cell leukemia transcription factor interacting protein 1 2.337 CLIC4 chloride intracellular channel 4 2.334 CYP51A1 cytochrome P450, family 51, subfamily A, polypeptide 1 2.095 LIMS1 LIM and senescent cell antigen-like domains 1 2.091 YWHAE tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, epsilon polypeptide 2.042 OAS1 2′,5′-oligoadenylate synthetase 1, 40/46kDa 2.031 S100A11 S100 calcium binding protein A11 2.018 222378_at unknown transcribed sequences 0.496 SLC5A3 mitochondrial ribosomal protein S6 0.463 213089_at unknown transcribed sequences 0.406 PDE4B phosphodiesterase 4B, cAMP-specific 0.454 SVIL supervillin 0.386 RIPX rap2 interacting protein x 0.383

Abstract Background: Thalidomide and dexamethasone combination has been shown to be an effective therapy for multiple myeloma (MM). In newly diagnosed patients with MM, the combination results in overall response rates of over 70% of patients. However, a considerable number of patients do not respond and will need to proceed to other therapies. The ability to identify patients who are unlikely to respond to particular therapies will allow tailoring of therapeutic approaches and in turn will reduce unnecessary toxicity and morbidity from lack of rapid disease control. With the availability of new technology such as gene expression profiling (GEP), this has become a possibility. We employed this approach to identify genes that can reliably predict lack of response to the thalidomide dexamethasone combination. Methods: Patient samples from the Eastern Co-operative Oncology Group clinical trial (E1A00), that compared thalidomide-dexamethasone combination with dexamethasone, and patient samples from the phase II Mayo Clinic study of thalidomide and dexamethasone, both for newly diagnosed MM, were used for this study. Thirty newly diagnosed patients who were evaluable for response were included in the analysis. GEP was performed using the Affymetrix U133A microarray platform as per manufacturer’s recommendation. The Affymetrix output (CEL files) was imported into Genespring 7.2 (Agilent Technologies) microarray analysis software, normalized across chips using GCRMA followed by per gene normalization to median. For the purposes of this study, responses were defined as reduction in the serum paraprotein (or the urinary M protein in the absence of a serum M protein) of >=50% (PR), 25 to 49% (MR), increase of >=50% (PD) and stable disease for the remaining. Results: Five of the 30 patients had no response to the thalidomide Dexamethasone therapy. Using the class prediction tool available in Genespring (Support Vector Machines), we identified 25 genes that reliable predicted non responders (PD, NC) from the responders (MR, PR, and CR). See table for a list of predictive genes with identified genes. Conclusion: Using a combination of two datasets we have identified a set of genes that can be used to reliably predict lack of response to thalidomide and dexamethasone in patients with newly diagnosed MM. We think that this represents a step towards creation of custom microarrays spotted with genes that are capable of predicting lack of response (or response) for the purpose of tailoring therapy to the patient. Gene Predictive strength hypothetical protein FLJ20719 1.655 Tubulin alpha 6 1.653 SEC3-like 1 (S. cerevisiae) 1.649 Ribosomal protein L18 1.546 Ribosomal protein L4 1.432 Tubulin alpha 6 1.409 cleavage stimulation factor 1.393 Tubulin, alpha, ubiquitous 1.393 CD99 antigen 1.38 hmel2 1.346 Leptin receptor 1.291 Integrin-linked kinaseSMC4 structural maintenance of chromosomes 4-like 1 1.269 Cornichon homolog 1.255 Williams-Beuren syndrome chromosome region 5 1.217 Ubiquitin specific protease 1 1.2 Sarcoma antigen NY-SAR-91 1.2

Abstract Introduction: We previously reported that serum cardiac biomarkers are among the most powerful predictors of overall survival. This observation was based on outcomes of more than 300 patients with primary systemic amyloidosis (AL) receiving either low dose chemotherapy or high dose chemotherapy with peripheral blood stem cell transplant (PBSCT). Not all institutions use the N-terminal pro-brain natriuretic peptide (NTproBNP) assay, but rather the B-type natriuretic peptide (BNP) assay. We therefore determined the relative utility of BNP in patients with AL undergoing PBSCT and up-dated our results using our NTproBNP-troponin T staging system. Methods: Between 4/10/96 and 2/24/05, 164 patients with AL undergoing PBSCT had measurements of serum cardiac biomarkers. All BNP measurements were done on fresh serum (Biosite Inc., San Diego). The NTproBNP (Roche Diagnostics, Indianapolis, IN) and troponin T (TnT) (Roche Diagnostics, Indianapolis, IN) measurements were done on either stored serum or on fresh samples as previously reported. Follow-up for patients was through March 2005. Results: Between 5/1/03 and 2/15/05, 72 patients had BNP measurements pre-transplant. The median value was 167 pg/ml (range 5 to 7739). Forty-two of these patients also had an NTproBNP measured. There was good agreement between the two tests in the 42 patients that had both measurements (rho 0.823, p<0.0001). To further test the relationship between the two tests, we evaluated the correlation between BNP and NTproBNP using 204 simultaneous measurements from 106 patients (rho=0.89, p<0.0001). Next, we tested the prognostic utility of BNP. Using a cut-off point of 120 pg/L (the upper limit of normal for women over the age of 70 and the 50th percentile of all measurements in our data set), we found that BNP was prognostic for survival post-transplant. It was independent of TnT values, and patients could be divided into 3 risk categories using these two measurements (low risk if both values were low, high-risk if both were high, and intermediate if either was high). This system was highly predictive of overall survival (Figure A). We next compared the BNP-TnT staging system to our previously reported NTproBNP-TnT staging system in the 42 patients that had all 3 values pre-transplant. The correlation between the two staging systems was excellent (rho=0.91, p<0.0001). Follow-up for the 100 patients who had been reported previously is now 26.9 months. As shown in Figure B, the NTproBNP-TnT system predicts for overall survival post transplant. Conclusions: Serum levels of cardiac biomarkers are invaluable prognostic markers in patients with AL. Preliminary data would suggest that a BNP-TnT system is as useful as the NTproBNP-TnT system. Risk thresholds: BNP <120 pg/ml; TnT <0.035 ng/ml; NT-proBNP < 332 pg/ml BNP-TnT statisfaction: low risk, both low; high risk, both high; intermediate, either high. NT-proBNP-TnT satisfaction: low risk, both low; high risk, both high; intermediate, either high. Risk thresholds: BNP <120 pg/ml; TnT <0.035 ng/ml; NT-proBNP < 332 pg/ml BNP-TnT statisfaction: low risk, both low; high risk, both high; intermediate, either high. NT-proBNP-TnT satisfaction: low risk, both low; high risk, both high; intermediate, either high.

Abstract Background: The free light chain (FLC) assay allows a nephelometric measurement of this free kappa and lambda light chains that circulate as monomers or dimers, not bound to the immunoglobulin heavy chain. Estimation of the free light chain levels and their ratio has utility in screening, prognostication and treatment response assessment in multiple myeloma, and is particularly useful in light chain myeloma. Previous studies have suggested that absence of a functional rearrangement on at least one of the IgH allele is the basis of light chain myeloma. Translocations involving the immunoglobulin heavy chain (IgH) locus on chromosome 14 can be detected using FISH in over half of the patients with myeloma. We hypothesized that presence of an IgH translocation may be associated with compromised production of heavy chains and leads to unbalanced, excess production of clonal light chain. Methods: From February 1988 to May 1992, 653 patients with previously untreated multiple myeloma were enrolled on the phase III clinical trial E9486. Serum free light chains were run on stored sera obtained at baseline in 495 patients as part of a previous study. Among these patients, 314 patients were previously studied using FISH for presence or absence of IgH translocations, p53 abnormalities and deletion 13 and were included in the current analysis. Results: The median difference between the involved and uninvolved FLC (FLCdiff) was higher among the group of patients with any IgH translocation abnormality compared to those with none (Figure 1). This was particularly evident among the patients with a t(14;16) who had the highest FLCdiff. In a multivariate analysis, we examined if the prognostic value seen with FLCdiff was independent of the presence of IgH translocations t(4:14) and t(14;16), which are associated with a worse outcome. The presence of t(4;14) or t(14;16) was associated with FLCdiff groups using a cutoff point of 185, with 13% of those with FLCd ≤185 and 27% of those with FLCd > 185 having the translocations (P= 0.008). At the cutoff value of 185, the prognostic value of the FLC-diff on progression free and overall survival appears to be independent of these high risk IgH translocations (P-value=0.03 and 0.003, respectively for PFS and OS) We then examined the prognostic value of the FLC-diff in the group of patients without these two high risk abnormalities and were able to confirm that they remained prognostic for PFS (P=0.009) and OS (p=0.005). However, among the group of patients with either of the two high risk IgH abnormalities, FLCdiff estimate added little to assessment of their outcome (P=0.97 and 0.20, respectively for PFS and OS). Conclusion: Elevated free light chain levels are associated with presence of IgH translocations and these patients are more likely to harbor the high risk genetic abnormalities. Routine FISH testing for patients with newly diagnosed myeloma will allow us to confirm these and allow better risk stratification of the patients. Additional work needs to be done to help us better understand the molecular basis for unbalanced light chain excretion by myeloma cells and the current finding of the association with IgH translocation abnormalities should form the basis for this work. Figure 1. Distribution of FLC ratio (inv vs. uninv) and FLC difference (inv − uninv) among patients. Solid squares represent patients with t(4;14) or t(14;16) or t(11;14) or other 14q32 translocation; open circles represent patients without t(4;14), t(14;16), t(11;14) and any other 14q32 translocations. The horizontal dashed lines refer to FLC ratio original values of 100 and 1000, and vertical dashed lines refer to FLC difference original values of 10 and 100. Solid line indicates significant association (P<=0.05) between the dichotomized FLC groups and translocation status. Figure 1. Distribution of FLC ratio (inv vs. uninv) and FLC difference (inv − uninv) among patients. Solid squares represent patients with t(4;14) or t(14;16) or t(11;14) or other 14q32 translocation; open circles represent patients without t(4;14), t(14;16), t(11;14) and any other 14q32 translocations. The horizontal dashed lines refer to FLC ratio original values of 100 and 1000, and vertical dashed lines refer to FLC difference original values of 10 and 100. Solid line indicates significant association (P<=0.05) between the dichotomized FLC groups and translocation status.

Abstract Background: Monoclonal gammopathy of undetermined significance (MGUS) is a common pre-malignant plasma cell disorder associated with a 1% per year risk of progression to multiple myeloma or related malignancy. Since the risk factors for MGUS are poorly defined, the goal of the present study was to determine if the risk of MGUS is increased in first degree relatives of patients with known multiple myeloma (MM) or MGUS. Methods: MGUS probands (index cases) were recruited from a population-based prevalence study of MGUS in Olmsted County, MN while MM probands were recruited through the Mayo Clinic practice. Consenting probands were asked to provide contact information on all first-degree relatives ages 40 years and older. Serum samples were then collected from first-degree relatives with informed consent and subjected to agaraose-gel electrophoresis and immunofixation. The prevalence of MGUS in first-degree relatives of MM and MGUS probands was compared to population-based rates from Olmsted County using risk ratios (RR). For comparisons to the reference population, only cases detected by protein electrophoresis and confirmed by immunofixation were included so that the diagnostic strategy was identical in the two groups being compared. Results: Serum samples were obtained from 911 relatives of 329 unique families, including 493 siblings, 324 children and 94 parents of patients with MGUS or MM. Using protein electrophoresis, monoclonal protein was detected in the serum of 55 (6%) while immunofixation identified 28 additional relatives (3%), for an age- and sex-adjusted prevalence rate of 8.1% (95%CI: 6.3, 9.8). The age-specific prevalence of MGUS in first-degree relatives increased with age (1.9%, 6.9%, 11.6%, 14.6%, and 21.0% for ages 40–49, 50–59, 60–69, 70–79 and ≥80, respectively; P<0.001). Based on similar MGUS detection methodology as the reference population, there was a significantly higher risk of MGUS in first-degree relatives (age-adjusted RR, 2.6, 95%CI: 1.9, 3.4) compared to the reference population. The increased risk (P<0.001) was seen both in relatives of MM probands (RR, 2.0, 95%CI: 1.4, 2.8), as well as MGUS probands (RR, 3.3, 95%CI: 2.1, 4.8). This association was similar across age of proband, age and gender of relative, and relationship of the first-degree relative. When examining whether the increased risk of MGUS in relatives was specific to probands with a large monoclonal protein concentration or specific monoclonal immunoglobulin isotype (i.e. high-risk MGUS phenotype), there was suggestion of a greater risk for relatives of probands with a high (3 1.5 g/dL) M-protein (RR, 2.8, 95%CI: 2.0,3.8) compared to lower M-protein levels (RR, 1.8, 95%CI: 1.1,2.8) although the difference did not reach statistical significance (P=0.12). The risk of MGUS in relatives did not differ by proband’s isotype (IgG vs. other). Conclusions: First-degree relatives of patients with MM or MGUS have a greater than two-fold risk of MGUS compared to the general population, implying underlying genetic predisposition for these diseases and providing rationale for identifying genetic determinants of MGUS. This study also provides important baseline rates of MGUS in first-degree relatives that impact the clinical care of these patients.

Abstract Introduction: The kidney is affected by immunoglobulin light chain amyloidosis (AL) in more than 50% of patients who present with the disease, but long-term predictors for and outcomes after renal replacement therapy have not been well described in this patient group Patients: 145 patients with AL who participated in Mayo Clinic treatment trials and were monitored for at least 11 years. No patient was lost to follow-up Results: Among patients presenting with renal AL, 42% ultimately received renal replacement therapy compared with 5% of patients who did not have an initial presentation involving the kidney. Table 1. Monoclonal Protein Studies in 145 Patients With Immunoglobulin Light Chain Amyloidosisa Patients, No. (%) Monoclonal Protein Renal Amyloid at Presentation (n=84) Nonrenal Amyloid at Presentation (n=61) a P=.02 l more likely to cause renal presentation None 7 (8) 2 (3) k 6 (7) 12 (20) l 71 (85) 47 (77) Table 2. Characteristics of All 145 Patients With Immunoglobulin Light Chain Amyloidosis Amyloid Renal (n=84) Nonrenal (n=61) P Value Abbreviations: IQR, interquartile range; NA, not applicable. a included in the definition of renal amyloidosis Patients with l immunoglobulin light chain amyloid were significantly more likely to have renal involvement and had significantly greater urinary protein loss than patients with κ or no monoclonal light chain amyloid Age, median (IQR), y 61 (52–67) 62 (55–68) .47 Sex, male/female 52/32 40/21 .72 24-hr urine protein loss, median (IQR), g/d 7.0 (4.4–11.7) 0.3 (0.1–6.4) NAa Creatinine, median (IQR), mg/dL 1.1 (0.9–2.2) 1.1 (0.9–1.3) .22 Cardiac involvement (yes/no) 35/48 48/16 .0001 Table 3 Distribution of Urinary Protein and Creatinine Based on Monoclonal Protein Monoclonal Protein Test k (n=18) l (n=118) None (n=9) P Value Abbreviation: IQR, interquartile range. Patients with renal amyloid who ultimately received dialysis support had significantly higher serum creatinine and 24-hour urine protein levels at presentation. Absence of cardiac involvement at diagnosis predicted an increased likelihood of dialysis All patients (N=145) 24-hr urine protein loss, median (IQR), g/d 0.73 (0.16–2.37) 3.61 (0.35–7.8) 5.68 (0.3–12.2) .001 Creatinine, median (IQR), mg/dL 1.1 (0.9–1.3) 1.1 (0.9–1.3) 1.5 (1.2–1.6) NS Patients with renal amyloid at presentation (n=84) 24-hr urine protein loss, median (IQR), g/d 2.93 (1.1–5.0) 7.2 (4.8–11.8) 7.8 (3.8–12.6) .04 Creatinine, median (IQR), mg/dL 1.0 (0.8–2.6) 1.1 (0.9–2.2) 1.5 (1.1–1.6) NS Table 4 Characteristics of 84 Patients Presenting With Renal Amyloidosis Dialysis Subsequently Not Required Characteristic Required (n=35) (n=49) P Value Abbreviation: IQR, interquartile range. The median time from diagnosis to dialysis was 29.5 months for those that went into renal failure.). However, the actuarial risk reached 50% at 12 years Kaplan-Meier failure curve demonstrating the actuarial time from diagnosis to the start of dialysis therapy N=145 For 38 patients who received dialysis, median survival from day 1 of dialysis was 10.4 months Kaplan-Meier survival of 38 patients from the start of dialysis therapy Age, median (IQR), y 60 (52–67) 62 (52–67) .90 Sex, male/female 21/14 31/18 .76 24-hr urine protein loss, median (IQR), g/d 7.4 (5.0–14.8) 5.9 (3.7–9.1) .03 Creatinine, median (IQR), mg/dL 1.4 (0.9–2.8) 1.1 (0.9–1.5) .01 Cardiac involvement (yes/no) 9/26 26/23 .01 Conclusion: In our study, 26% of all patients with AL ultimately received renal replacement therapy compared with 42% of patients who presented with renal AL specifically. The presenting 24-hour urine protein loss and creatinine values predict which patients will require dialysis. Median survival for patients starting dialysis is less than 1 year. Presence of l light chain amyloid predicts an increased likelihood of renal involvement and, when the kidney is affected, increased proteinuria.