Non-Toxicological Role of Aryl Hydrocarbon Receptor in Obesity-Associated Multiple Myeloma Cell Growth and Survival

Obesity is not only a risk factor for multiple myeloma (MM) incidence, but it is also associated with an increased risk of progression from myeloma precursors-monoclonal gammopathy of undetermined significance-and smoldering myeloma. Adipocytes in the bone marrow (BMAs) microenvironment have been shown to facilitate MM cell growth via secreted factors, but the nature of these secreted factors and their mechanism of action have not been fully elucidated. The elevated expression of aryl hydrocarbon receptor (AhR) is associated with a variety of different cancers, including MM; however, the role of AhR activity in obesity-associated MM cell growth and survival has not been explored. Indeed, this is of particular interest as it has been recently shown that bone marrow adipocytes are a source of endogenous AhR ligands. Using multiple in vitro models of tumor-adipocyte crosstalk to mimic the bone microenvironment, we identified a novel, non-toxicological role of the adipocyte-secreted factors in the suppression of AhR activity in MM cells. A panel of six MM cell lines were cultured in the presence of bone marrow adipocytes in (1) a direct co-culture, (2) a transwell co-culture, or (3) an adipocyte-conditioned media to interrogate the effects of the secreted factors on MM cell AhR activity. Nuclear localization and the transcriptional activity of the AhR, as measured by CYP1A1 and CYP1B1 gene induction, were suppressed by exposure to BMA-derived factors. Additionally, decreased AhR target gene expression was associated with worse clinical outcomes. The knockdown of AhR resulted in reduced CYP1B1 expression and increased cellular growth. This tumor-suppressing role of CYP1A1 and CYP1B1 was supported by patient data which demonstrated an association between reduced target gene expression and worse overall survival. These data demonstrated a novel mechanism by which bone marrow adipocytes promote MM progression.

Dynamic frailty risk assessment among older adults with multiple myeloma: A population-based cohort study

Multiple myeloma (MM) is a cancer of older adults and those who are more frail are at high risk of poor outcomes. Current tools for identifying and categorizing frail patients are often static and measured only at the time of diagnosis. The concept of dynamic frailty (i.e. frailty changing over time) is largely unexplored in MM. In our study, adults with newly-diagnosed MM who received novel drugs between the years 2007-2014 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked databases. Using a previously published cumulative deficit approach, a frailty index score was calculated at diagnosis and each landmark interval (1-yr, 2-yr, 3-yr post diagnosis). The association of frailty with overall survival (OS) both at baseline and at each landmark interval as well as factors associated with worsening frailty status over time were evaluated. Overall, 4617 patients were included. At baseline, 39% of the patients were categorized as moderately frail or severely frail. Among those who had 3 years of follow-up, frailty categorization changed post diagnosis in 93% of the cohort (78% improved and 72% deteriorated at least at one time point during the follow up period). In a landmark analysis, the predictive ability of frailty at the time of diagnosis decreased over time for OS (Harrell's C Statistic 0.65 at diagnosis, 0.63 at 1-yr, 0.62 at 2-yr, and 0.60 at 3-yr) and was inferior compared to current frailty status at each landmark interval. Our study is one of the first to demonstrate the dynamic nature of frailty among older adults with MM. Frailty may improve or deteriorate over time. Current frailty status is a better predictor of outcomes than frailty status at time of diagnosis, indicating the need for re-measurement in this high-risk patient population.

Assessment of renal outcome following therapy in monoclonal immunoglobulin deposition disease: Emphasizing the need for a consensus approach

Monoclonal immunoglobulin deposition disease (MIDD), often associated with plasma cell dyscrasias, predominantly affects the kidneys. In this disease, hematologic response (HR) to treatment can be reliably assessed by International Myeloma Working Group (IMWG) consensus criteria, while uniform criteria for assessing renal response are lacking. We report a retrospective analysis of renal outcomes among 34 patients with MIDD. With most patients treated with bortezomib and autologous stem cell transplantation, 26 of 28 (94%) achieved very good partial HR or better. We demonstrate that both IMWG (based on estimated glomerular filtration rate, eGFR) and amyloid (based on proteinuria) criteria are needed to capture renal response: among 28 evaluable patients, 6 (21%) had isolated proteinuria, while 13 (46%) had isolated decreased eGFR. Using both criteria, which were concordant in patients with both decreased eGFR and proteinuria, 22 of 28 patients (79%) achieved a renal response, including 2 of 7 discontinuing dialyses. All 6 patients (100%) with isolated proteinuria and 7 of 13 (54%) with isolated decreased eGFR achieved renal response, suggesting that isolated proteinuria is an early manifestation of MIDD associated with reversible renal damage. Baseline eGFR predicted renal response (p = .02 by quartile) and survival (p = .02), while HR (CR vs. non-CR) did not, probably because of high HR rate. With a median follow-up of 110 months, the median overall survival was 136 months (95% CI: 79-NR) and median renal survival had not been reached. Prospective studies using uniform renal response criteria are needed to optimize the management of MIDD.

Incidence and risk factors for bacterial infection using bortezomib, lenalidomide, and dexamethasone (RVd) in newly diagnosed multiple myeloma

Infections are an important cause of morbidity and mortality in newly diagnosed multiple myeloma (NDMM), but the real-world risk using modern induction regimens such as bortezomib, lenalidomide, and dexamethasone (RVd) is not well described. We performed a retrospective single-center cohort study to identify infections and risk factors in patients treated with first-line RVd from January 2014 to January 2020 and collected demographic and clinical data. Of 144 patients treated with RVd for NDMM, 21 patients (14.5%) experienced a bacterial infection during induction, of which 8 (5.5%) were grade 3 infections despite a low rate of antibiotic prophylaxis use (12%). Grade 3 neutropenia occurred in 11% of patients, 2% had febrile neutropenia and there were no deaths from infection. On multivariable analysis, age, smoking history, diabetes, antibiotic use in the 60 days preceding the start of RVd, and high-risk cytogenetics were associated with higher risk of bacterial infection.

Sustained Minimal Residual Disease Negativity in Multiple Myeloma is Associated with Stool Butyrate and Healthier Plant-Based Diets

PURPOSE

Sustained minimal residual disease (MRD) negativity is associated with long-term survival in multiple myeloma. The gut microbiome is affected by diet, and in turn can modulate host immunity, for example through production of short-chain fatty acids including butyrate. We hypothesized that dietary factors affect the microbiome (abundance of butyrate-producing bacteria or stool butyrate concentration) and may be associated with multiple myeloma outcomes.

EXPERIMENTAL DESIGN

We examined the relationship of dietary factors (via a food frequency questionnaire), stool metabolites (via gas chromatography-mass spectrometry), and the stool microbiome (via 16S sequencing - α-diversity and relative abundance of butyrate-producing bacteria) with sustained MRD negativity (via flow cytometry at two timepoints 1 year apart) in myeloma patients on lenalidomide maintenance. The Healthy Eating Index 2015 score and flavonoid nutrient values were calculated from the food frequency questionnaire. The Wilcoxon rank sum test was used to evaluate associations with two-sided P < 0.05 considered significant.

RESULTS

At 3 months, higher stool butyrate concentration (P = 0.037), butyrate producers (P = 0.025), and α-diversity (P = 0.0035) were associated with sustained MRD negativity. Healthier dietary proteins, (from seafood and plants), correlated with butyrate at 3 months (P = 0.009) and sustained MRD negativity (P = 0.05). Consumption of dietary flavonoids, plant nutrients with antioxidant effects, correlated with stool butyrate concentration (anthocyanidins P = 0.01, flavones P = 0.01, and flavanols P = 0.02).

CONCLUSIONS

This is the first study to demonstrate an association between a plant-based dietary pattern, stool butyrate production, and sustained MRD negativity in multiple myeloma, providing rationale to evaluate a prospective dietary intervention.

Host-microbe interactions and outcomes in multiple myeloma and hematopoietic stem cell transplantation

Microbiota are essential to normal immune development and there is growing recognition of its importance to human health and disease and deepening understanding of the complexity of host-microbe interactions in the human gut and other tissues. Commensal microbes not only can influence host immunity locally through impacts of bioactive microbial metabolites and direct interactions with epithelial cells and innate immune receptors but also can exert systemic immunomodulatory effects via impacts on host immune cells capable of trafficking beyond the gut. Emerging data suggest microbiota influence the development of multiple myeloma (MM), a malignancy of the immune system derived from immunoglobulin-producing bone marrow plasma cells, through the promotion of inflammation. Superior treatment outcomes for MM correlate with a higher abundance of commensal microbiota capable of influencing inflammatory responses through the production of butyrate. In patients with hematologic malignancies, higher levels of diversity of the gut microbiota correlate with superior outcomes after hematopoietic stem cell transplantation. Correlative data support the impact of commensal microbiota on survival, risk of infection, disease relapse, and graft-versus-host disease (GVHD) after transplant. In this review, we will discuss the current understanding of the role of host-microbe interactions and the inflammatory tumor microenvironment of multiple myeloma, discuss data describing the key role of microbiota in hematopoietic stem cell transplantation for treatment of hematologic malignancies, and highlight several possible concepts for interventions directed at the gut microbiota to influence treatment outcomes.

Checkpoint Blockade in Melanoma Patients With Underlying Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL) is associated with immune dysfunction and an increased risk of melanoma. For patients with metastatic melanoma, immunotherapy with checkpoint blocking antibodies is a standard of care. In patients with concomitant CLL and metastatic melanoma, it is not known whether CLL might influence the antimelanoma efficacy or immune-related toxicities of immune checkpoint blockade. Fifteen patients with locally advanced or metastatic melanoma and a concomitant diagnosis of CLL who received pembrolizumab or ipilimumab with or without nivolumab for the treatment of their melanoma at Memorial Sloan Kettering Cancer Center between January 1, 2010, and January 1, 2017, were retrospectively identified. Clinical characteristics including absolute lymphocyte counts during therapy were recorded along with a response to treatment (objective radiographic response, progression-free survival, and adverse events) for each patient. Of 9 response-evaluable patients treated with ipilimumab, 3 (33%) had a partial response, 1 (11%) had stable disease, and 5 (56%) developed progressive disease. Objective tumor responses were also observed with single-agent therapy pembrolizumab and with combination therapy of nivolumab and ipilimumab. Grade 3 or 4 toxicity was observed in 6 of 15 patients (40%), including diarrhea, transaminitis, rash, and hemolytic anemia. Although our retrospective assessment was limited, there was no evidence that CLL responded to the checkpoint blockade. This case series demonstrates that ipilimumab, pembrolizumab, and combined ipilimumab and nivolumab therapies show clinical activity in patients with melanoma and concomitant CLL, at rates consistent with those previously reported. This population may warrant closer surveillance for hematologic immune-related toxicities such as autoimmune hemolytic anemia.

Distinguishing Drug from Disease by Use of the Hydrashift 2/4 Daratumumab Assay

BACKGROUND

Daratumumab, a monoclonal antibody used to treat relapsed or refractory multiple myeloma, can interfere with protein electrophoresis and immunofixation assays. False-positive immunofixation results due to daratumumab can cause uncertainty regarding the status of a patient's disease and lead to potential misclassification of their response to therapy. The Hydrashift 2/4 Daratumumab assay (Sebia) was recently cleared by the Food and Drug Administration for resolving daratumumab interference on immunofixation. Here, we evaluate the performance of the Hydrashift assay in multiple myeloma patients receiving treatment with daratumumab-based regimens.

METHODS

Waste serum samples from multiple myeloma patients (n = 40) receiving daratumumab were analyzed by standard immunofixation and the Hydrashift assay. Results from these tests were compared and were evaluated along with pretreatment serum protein electrophoresis and immunofixation results, if available.

RESULTS

The Hydrashift assay shifted the migration of daratumumab in patient samples. In 27 cases, the patient's M protein was distinguishable from daratumumab by standard immunofixation. In these cases, the Hydrashift assay confirmed that the IgGκ band was daratumumab and helped identify the presence of treatment-related oligoclonal bands. There were 11 instances in which the patient's IgGκ M protein comigrated with daratumumab. In all 11 cases, the Hydrashift assay confirmed the presence of residual M protein. Finally, in 2 patients whose pretreatment immunofixation results were not available, the Hydrashift assay confirmed that the IgGκ band visible on immunofixation was due to daratumumab alone.

CONCLUSIONS

The Hydrashift 2/4 Daratumumab assay is a useful tool to clarify the source of an IgGκ band on immunofixation and allow a patient's M protein to be viewed without interference.

Immunotherapy of Lymphoma and Myeloma: Facts and Hopes

Immune checkpoint blockade has driven a revolution in modern oncology, and robust drug development of immune checkpoint inhibitors is underway in both solid tumors and hematologic malignancies. High response rates to programmed cell death 1 (PD-1) blockade using nivolumab or pembrolizumab in classical Hodgkin lymphoma (cHL) and several variants of non-Hodgkin lymphoma (NHL) revealed an intrinsic biological sensitivity to this approach, and work is ongoing exploring combinations with immune checkpoint inhibitors in both cHL and NHL. There are also preliminary data suggesting antitumor efficacy of PD-1 inhibitors used in combination with immunomodulatory drugs in multiple myeloma, and effects of novel monoclonal antibody therapies on the tumor microenvironment may lead to synergy with checkpoint blockade. Although immune checkpoint inhibitors are generally well tolerated, clinicians must use caution and remain vigilant when treating patients with these agents in order to identify immune-related toxicities and prevent treatment-related morbidity and mortality. Autologous stem cell transplant is a useful tool for treatment of hematologic malignancies and has potential as a platform for use of immune checkpoint inhibitors. An important safety signal has emerged surrounding the risk of graft-versus-host disease associated with use of PD-1 inhibitors before and after allogeneic stem cell transplant. We aim to discuss the facts known to date in the use of immune checkpoint inhibitors for patients with lymphoid malignancies and our hopes for expanding the benefits of immunotherapy to patients in the future. Clin Cancer Res; 24(5); 1002-10. ©2017 AACR.

Immune checkpoint blockade for hematologic malignancies: a review

Immune checkpoint blockade has revolutionized the treatment of cancer, with impressive responses seen in a broad variety of tumor types. Blockade of immune checkpoints and immune signaling antibodies has shown promise in multiple types of hematologic malignancies (HMs), with dramatic single agent responses for pembrolizumab and nivolumab in Hodgkin lymphoma (HL). In this review, we outline the current state of immune checkpoint blockade drug development in HMs, and discuss mechanisms of activity and resistance, and highlight potential targets in the immune tumor microenvironment (TME). Blockade of T-cell checkpoint molecules PD-1/PD-L1 and CTLA-4 are the most clinically mature of the immune checkpoint strategies. Novel and upcoming strategies for immune checkpoint blockade drug development in HMs using innovative combinations to modulate immunologic targets shows significant promise as a way to expand the number of patients with blood cancers who could benefit from immunotherapy.

Characterization of antigenic variants of hepatitis C virus in immune evasion

BACKGROUND

Antigenic variation is an effective way by which viruses evade host immune defense leading to viral persistence. Little is known about the inhibitory mechanisms of viral variants on CD4 T cell functions.

RESULTS

Using sythetic peptides of a HLA-DRB1*15-restricted CD4 epitope derived from the non-structural (NS) 3 protein of hepatitis C virus (HCV) and its antigenic variants and the peripheral blood mononuclear cells (PBMC) from six HLA-DRB1*15-positive patients chronically infected with HCV and 3 healthy subjects, the in vitro immune responses and the phenotypes of CD4+CD25+ cells of chronic HCV infection were investigated. The variants resulting from single or double amino acid substitutions at the center of the core region of the Th1 peptide not only induce failed T cell activation but also simultaneously up-regulate inhibitory IL-10, CD25-TGF-β+ Th3 and CD4+IL-10+ Tr1 cells. In contrast, other variants promote differentiation of CD25+TGF-β+ Th3 suppressors that attenuate T cell proliferation.

CONCLUSIONS

Naturally occuring HCV antigenic mutants of a CD4 epitope can shift a protective peripheral Th1 immune response into an inhibitory Th3 and/or Tr1 response. The modulation of antigenic variants on CD4 response is efficient and extensive, and is likely critical in viral persistence in HCV infection.

Ability of antioxidant liposomes to prevent acute and progressive pulmonary injury

We recently showed that acute oxidant-related lung injury (ALI) in rats after application of 2-chloroethyl ethyl sulfide (CEES) is attenuated by the airway instillation of antioxidants. We investigated whether intratracheal administration of antioxidant-containing liposomes immediately after instillation of CEES would attenuate short-term as well as long-term (fibrotic) effects of CEES-induced lung injury. In the acute injury model (4 h after injury), N-acetylcysteine (NAC)-containing liposomes were protective and reduced to baseline levels both the lung permeability index and the appearance of proinflammatory mediators in bronchoalveolar lavage fluids from CEES-exposed lungs. Similar results were obtained when rat alveolar macrophages were incubated in vitro with either CEES or lipopolysaccharide in the presence of NAC-liposomes. When lung fibrosis 3 weeks after CEES was quantitated by using hydroxyproline content, liposomes containing NAC or NAC + glutathione had no effects, but liposomes containing alpha/gamma-tocopherol alone or with NAC significantly suppressed the increase in lung hydroxyproline. The data demonstrate that delivery of antioxidants via liposomes to CEES-injured lungs is, depending on liposomal content, protective against ALI, prevents the appearance of proinflammatory mediators in bronchoalveolar fluids, and suppresses progressive fibrosis. Accordingly, the liposomal strategy may be therapeutically useful in CEES-induced lung injury in humans.

C5a-blockade improves burn-induced cardiac dysfunction

We previously reported that generation of the anaphylatoxin C5a is linked to the development of cardiac dysfunction in sepsis due to C5a interaction with its receptor (C5aR) on cardiomyocytes. Burn injury involves inflammatory mechanisms that can lead to C5a generation as well. In this study, we investigated the effects of C5a blockade on burn-induced cardiac dysfunction. Using a standardized rat model of full thickness scald injury, left ventricular pressures were recorded in vivo followed by in vitro assessment of sarcomere contraction of single cardiomyocytes. Left ventricular pressures in vivo and cardiomyocyte sarcomere contractility in vitro were significantly reduced following burn injury. In the presence of anti-C5a Ab, these defects were greatly attenuated 1, 6, and 12 h after burn injury and completely abolished 24 h after burn. In vitro incubation of cardiomyocytes with bacterial LPS accentuated the impaired contractility, which was partially prevented in cardiomyocytes from burned rats that had received an anti-C5a Ab. Based on Western blot analyses, real-time PCR, and immunostaining of left ventricular heart tissue, there was a significant increase in cardiomyocyte expression of C5aR after burn injury. In conclusion, an in vivo blockade of C5a attenuates burn-induced cardiac dysfunction. Further deterioration of contractility due to the exposure of cardiomyocytes to LPS was partially prevented by C5a-blockade. These results suggest a linkage between C5a and burn-induced cardiac dysfunction and a possible contribution of LPS to these events.

Harmful and protective roles of neutrophils in sepsis

The current studies demonstrate protective and harmful effects of neutrophils (PMN) during experimental sepsis after cecal ligation and puncture (CLP). It is known that CLP induces signaling defects in blood PMN. When PMN were depleted 12 h after CLP, there were dramatic reductions in levels of bacteremia, evidence for reduced liver and renal dysfunction, sharp reductions in serum levels of cytokines (IL-1beta, IL-6, IL-10, TNF-alpha, and IL-2), and improved survival. In contrast, PMN depletion before CLP resulted in substantial increases in bacteremia and no evidence for attenuation of liver and renal failure dysfunction. These data suggest that at the onset of sepsis, PMN are important in regulating the levels of bacteremia, whereas after the onset of sepsis, as they lose innate immune functions, their presence is associated with higher levels of bacteremia and intensified organ dysfunction.