Natalia Neparidze

Clinical regressions and broad immune activation following combination therapy targeting human NKT cells in myeloma

Natural killer T (iNKT) cells can help mediate immune surveillance against tumors in mice. Prior studies targeting human iNKT cells were limited to therapy of advanced cancer and led to only modest activation of innate immunity. Clinical myeloma is preceded by an asymptomatic precursor phase. Lenalidomide was shown to mediate antigen-specific costimulation of human iNKT cells. We treated 6 patients with asymptomatic myeloma with 3 cycles of combination of α-galactosylceramide-loaded monocyte-derived dendritic cells and low-dose lenalidomide. Therapy was well tolerated and led to reduction in tumor-associated monoclonal immunoglobulin in 3 of 4 patients with measurable disease. Combination therapy led to activation-induced decline in measurable iNKT cells and activation of NK cells with an increase in NKG2D and CD56 expression. Treatment also led to activation of monocytes with an increase in CD16 expression. Each cycle of therapy was associated with induction of eosinophilia as well as an increase in serum soluble IL2 receptor. Clinical responses correlated with pre-existing or treatment-induced antitumor T-cell immunity. These data demonstrate synergistic activation of several innate immune cells by this combination and the capacity to mediate tumor regression. Combination therapies targeting iNKT cells may be of benefit toward prevention of cancer in humans.

Harnessing CD1d-Restricted T Cells toward Antitumor Immunity in Humans

Natural killer T (NKT) cells are a distinct subset of T cells that recognize lipid antigens in the context of CD1d molecules. There is a considerable body of evidence implicating a role for NKT cells in regulating antitumor immunity in mice. α‐Galactosylceramide (α‐GalCer) is a potent agonist ligand for type I NKT cells. We and others have shown that injection of α‐GalCer‐loaded dendritic cells leads to clear expansion of NKT cells in vivo in cancer patients. Preclinical studies suggest the capacity of thalidomide analogues to enhance ligand‐dependent NKT activation and provide the rationale for combination approaches that are now being designed. Recently, we demonstrated the presence of CD1d‐restricted T cells specific for an inflammation‐associated lipid, lysophosphatidylcholine, in patients with advanced myeloma. These studies suggest that type II NKT cells may play a role in sensing and regulating inflammation. Harnessing CD1d‐restricted T cells in cancer may depend on regulating the balance between type I and II NKT cells and holds promise as a broad strategy for immune therapy of several cancers.

Whole-exome sequencing in evaluation of patients with venous thromboembolism

Genetics play a significant role in venous thromboembolism (VTE), yet current clinical laboratory-based testing identifies a known heritable thrombophilia (factor V Leiden, prothrombin gene mutation G20210A, or a deficiency of protein C, protein S, or antithrombin) in only a minority of VTE patients. We hypothesized that a substantial number of VTE patients could have lesser-known thrombophilia mutations. To test this hypothesis, we performed whole-exome sequencing (WES) in 64 patients with VTE, focusing our analysis on a novel 55-gene extended thrombophilia panel that we compiled. Our extended thrombophilia panel identified a probable disease-causing genetic variant or variant of unknown significance in 39 of 64 study patients (60.9%), compared with 6 of 237 control patients without VTE (2.5%) (P < .0001). Clinical laboratory-based thrombophilia testing identified a heritable thrombophilia in only 14 of 54 study patients (25.9%). The majority of WES variants were either associated with thrombosis based on prior reports in the literature or predicted to affect protein structure based on protein modeling performed as part of this study. Variants were found in major thrombophilia genes, various SERPIN genes, and highly conserved areas of other genes with established or potential roles in coagulation or fibrinolysis. Ten patients (15.6%) had >1 variant. Sanger sequencing performed in family members of 4 study patients with and without VTE showed generally concordant results with thrombotic history. WES and extended thrombophilia testing are promising tools for improving our understanding of VTE pathogenesis and identifying inherited thrombophilias.

Changes in bone marrow innate lymphoid cell subsets in monoclonal gammopathy: target for IMiD therapy

Altered number, subset composition, and function of bone marrow innate lymphoid cells are early events in monoclonal gammopathies.Pomalidomide therapy leads to reduction in Ikzf1 and Ikzf3 and enhanced human innate lymphoid cell function in vivo.

Antigen-mediated regulation in monoclonal gammopathies and myeloma

A role for antigen-driven stimulation has been proposed in the pathogenesis of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) based largely on the binding properties of monoclonal Ig. However, insights into antigen binding to clonal B cell receptors and in vivo responsiveness of the malignant clone to antigen-mediated stimulation are needed to understand the role of antigenic stimulation in tumor growth. Lysolipid-reactive clonal Ig were detected in Gaucher disease (GD) and some sporadic gammopathies. Here, we show that recombinant Ig (rIg) cloned from sort-purified single tumor cells from lipid-reactive sporadic and GD-associated gammopathy specifically bound lysolipids. Liposome sedimentation and binding assays confirmed specific interaction of lipid-reactive monoclonal Ig with lysolipids. The clonal nature of lysolipid-binding Ig was validated by protein sequencing. Gene expression profiling and cytogenetic analyses from 2 patient cohorts showed enrichment of nonhyperdiploid tumors in lipid-reactive patients. In vivo antigen-mediated stimulation led to an increase in clonal Ig and plasma cells (PCs) in GD gammopathy and also reactivated previously suppressed antigenically related nonclonal PCs. These data support a model wherein antigenic stimulation mediates an initial polyclonal phase, followed by evolution of monoclonal tumors enriched in nonhyperdiploid genomes, responsive to underlying antigen. Targeting underlying antigens may therefore prevent clinical MM.

The implementation of electronic hematology consults at a VA Hospital

To the editor: The widespread implementation of electronic medical records (EMR) allow providers ready access to large amounts of patient information, and for some specialties much of the data needed to provide recommendations can be gathered electronically.[1][1] Electronic consultation (e-consult

Hyperbilirubinemia following lenalidomide administration

Asymptomatic hyperbilirubinemia in a patient with no underlying liver disease or renal impairment while on lenalidomide therapy may be attributable to the unmasking of previously undiagnosed Gilberts syndrome, as previously shown in the literature. The hyperbilirubinemia should resolve after discontinuation of the drug.

Asymmetric Deep Stromal Keratopathy in a Patient With Multiple Myeloma.

Purpose: To report a case of asymmetric deep stromal keratopathy in a patient with multiple myeloma. Methods: Case report and literature review. Results: An 85-year-old woman was found to have progressive visually significant left-sided deep stromal opacity in the setting of monoclonal gammopathy. Hematologic workup resulted in a diagnosis of IgG kappa multiple myeloma. Histopathology was significant for semicrystalline deposits in the posterior stroma. The patients visual acuity improved to 20/50 7 months after penetrating keratoplasty. A similar deep stromal lesion appeared in the right eye 2 years after initial presentation. Conclusions: We present an unusual case of paraproteinemic keratopathy with a uniquely asymmetric presentation that resulted in a diagnosis of multiple myeloma.

Understanding the Role of Natural Killer T Cells in Hematologic Malignancies: Progress and Challenges

Natural Killer T (NKT) cells have emerged as important effector cells in tumor immunity. Hematologic malignancies are particularly attractive targets of NKT mediated anti-tumor effects as most hematologic tumors express CD1d. Patients with several hematologic malignancies have been reported to carry quantitative or qualitative defects in NKT cells. Preliminary clinical studies suggest the capacity of alpha-galactosylceramide (α-GalCer) loaded dendritic cells to stimulate NKT cells in vivo. However harnessing the effects of NKT cells in the clinic will also require attention to reversing the defects in NKT function in vivo. Improved understanding of the cross-talk between type I and II NKT cells, as well as the nature of naturally occurring CD1d binding ligands in these patients is needed to optimally target NKT cells in patients with hematologic malignancies.

NKT cells in p53 deficiency

In this issue of Blood , Swann and colleagues show that type I NKT cells mediate protection against tumor development in p53-deficient mice.