Research Spotlight

Posted March 15th 2016

Mannose receptor-mediated delivery of moss-made alpha-galactosidase A efficiently corrects enzyme deficiency in Fabry mice.

Raphael Schiffmann M.D.

Raphael Schiffmann, M.D.

Shen, J. S., A. Busch, T. S. Day, X. L. Meng, C. I. Yu, P. Dabrowska-Schlepp, B. Fode, H. Niederkruger, S. Forni, S. Chen, R. Schiffmann, T. Frischmuth and A. Schaaf (2016). “Mannose receptor-mediated delivery of moss-made alpha-galactosidase A efficiently corrects enzyme deficiency in Fabry mice.” J Inherit Metab Dis 39(2): 293-303.

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Enzyme replacement therapy (ERT) is an effective treatment for several lysosomal storage disorders (LSDs). Intravenously infused enzymes are taken up by tissues through either the mannose 6-phosphate receptor (M6PR) or the mannose receptor (MR). It is generally believed that M6PR-mediated endocytosis is a key mechanism for ERT in treating LSDs that affect the non-macrophage cells of visceral organs. However, the therapeutic efficacy of MR-mediated delivery of mannose-terminated enzymes in these diseases has not been fully evaluated. We tested the effectiveness of a non-phosphorylated alpha-galactosidase A produced from moss (referred to as moss-aGal) in vitro and in a mouse model of Fabry disease. Endocytosis of moss-aGal was MR-dependent. Compared to agalsidase alfa, a phosphorylated form of alpha-galactosidase A, moss-aGal was more preferentially targeted to the kidney. Cellular localization of moss-aGal and agalsidase alfa in the heart and kidney was essentially identical. A single injection of moss-aGal led to clearance of accumulated substrate in the heart and kidney to an extent comparable to that achieved by agalsidase alfa. This study suggested that mannose-terminated enzymes may be sufficiently effective for some LSDs in which non-macrophage cells are affected, and that M6P residues may not always be a prerequisite for ERT as previously considered.


Posted March 15th 2016

Standardizing Flow Cytometry Immunophenotyping Analysis from the Human ImmunoPhenotyping Consortium.

Gerlinde Obermoser M.D.

Gerlinde Obermoser, M.D.

Finak, G., M. Langweiler, M. Jaimes, M. Malek, J. Taghiyar, Y. Korin, K. Raddassi, L. Devine, G. Obermoser, M. L. Pekalski, N. Pontikos, A. Diaz, S. Heck, F. Villanova, N. Terrazzini, F. Kern, Y. Qian, R. Stanton, K. Wang, A. Brandes, J. Ramey, N. Aghaeepour, T. Mosmann, R. H. Scheuermann, E. Reed, K. Palucka, V. Pascual, B. B. Blomberg, F. Nestle, R. B. Nussenblatt, R. R. Brinkman, R. Gottardo, H. Maecker and J. P. McCoy (2016). “Standardizing Flow Cytometry Immunophenotyping Analysis from the Human ImmunoPhenotyping Consortium.” Sci Rep 6 (Feb 10): 20686.

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Standardization of immunophenotyping requires careful attention to reagents, sample handling, instrument setup, and data analysis, and is essential for successful cross-study and cross-center comparison of data. Experts developed five standardized, eight-color panels for identification of major immune cell subsets in peripheral blood. These were produced as pre-configured, lyophilized, reagents in 96-well plates. We present the results of a coordinated analysis of samples across nine laboratories using these panels with standardized operating procedures (SOPs). Manual gating was performed by each site and by a central site. Automated gating algorithms were developed and tested by the FlowCAP consortium. Centralized manual gating can reduce cross-center variability, and we sought to determine whether automated methods could streamline and standardize the analysis. Within-site variability was low in all experiments, but cross-site variability was lower when central analysis was performed in comparison with site-specific analysis. It was also lower for clearly defined cell subsets than those based on dim markers and for rare populations. Automated gating was able to match the performance of central manual analysis for all tested panels, exhibiting little to no bias and comparable variability. Standardized staining, data collection, and automated gating can increase power, reduce variability, and streamline analysis for immunophenotyping.


Posted March 15th 2016

T follicular helper (Tfh) cells in lupus: Activation and involvement in SLE pathogenesis.

Hideki Ueno M.D.

Hideki Ueno, M.D.

Blanco, P., H. Ueno and N. Schmitt (2016). “T follicular helper (Tfh) cells in lupus: Activation and involvement in SLE pathogenesis.” Eur J Immunol 46(2): 281-290.

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Systemic lupus erythematosus (SLE) is a chronic systemic inflammatory autoimmune disease characterized by a breakdown of tolerance to self. The autoantibodies generated in SLE are directed against nuclear components, with which they form immune complexes (ICs). ICs play key roles in organ and tissue damage, as well as in the activation of the innate and adaptive immune system during the disease course. Therefore, it is of prime importance to understand the mechanisms responsible for the development of B cells producing these pathogenic autoantibodies. There is compelling evidence that T follicular helper (Tfh) cells play a fundamental role in this process. In this review, we will summarize the current knowledge regarding the involvement of Tfh cells in SLE pathogenesis, and discuss potential strategies to target Tfh cells and/or molecules as a therapeutic modality of SLE.


Posted March 15th 2016

Influence of Ejection Fraction on Outcomes and Efficacy of Sacubitril/Valsartan (LCZ696) in Heart Failure with Reduced Ejection Fraction: The Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) Trial.

Milton Packer M.D.

Milton Packer, M.D.

Solomon, S. D., B. Claggett, A. S. Desai, M. Packer, M. Zile, K. Swedberg, J. L. Rouleau, V. C. Shi, R. C. Starling, O. Kozan, A. Dukat, M. P. Lefkowitz and J. J. McMurray (2016). “Influence of Ejection Fraction on Outcomes and Efficacy of Sacubitril/Valsartan (LCZ696) in Heart Failure with Reduced Ejection Fraction: The Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) Trial.” Circ Heart Fail 9(3): e002744.

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BACKGROUND: The angiotensin receptor neprilysin inhibitor sacubitril/valsartan (LCZ696) reduced cardiovascular morbidity and mortality compared with enalapril in patients with heart failure (HF) and reduced ejection fraction (EF) in the Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial. We evaluated the influence of EF on clinical outcomes and on the effectiveness of sacubitril/valsartan compared with enalapril. METHODS AND RESULTS: Eight thousand three hundred ninety-nine patients with New York Heart Association class II to IV HF with reduced EF [left ventricular EF (LVEF) less than of equal to 40%] were randomized to sacubitril/valsartan 97/103 mg twice daily versus enalapril 10 mg twice daily and followed for a median of 27 months. The primary study end point was cardiovascular death or HF hospitalization. LVEF was assessed at the sites and recorded on case report forms. We related LVEF to study outcomes and assessed the effectiveness of sacubitril/valsartan across the LVEF spectrum. The mean LVEF in PARADIGM-HF, reported by sites, was 29.5 (interquartile range, 25-34). The risk of all outcomes increased with decreasing LVEF. Each 5-point reduction in LVEF was associated with a 9% increased risk of cardiovascular death or HF hospitalization (hazard ratio, 1.09; 95% confidence interval, 1.05-1.13; P<0.001), a 9% increased risk for CV death (hazard ratio, 1.09; 95% confidence interval, 1.04-1.14), a 9% increased risk in HF hospitalization (hazard ratio, 1.09; 95% confidence interval, 1.04-1.14) and a 7% increased risk in all-cause mortality (hazard ratio, 1.07; 95% confidence interval, 1.03-1.12) in adjusted analyses. Sacubitril/valsartan was effective across the LVEF spectrum, with no evidence of heterogeneity, when modeled either in tertiles (P interaction=0.87) or continuously (P interaction=0.95). CONCLUSIONS: In patients with HF and reduced EF enrolled in PARADIGM-HF, LVEF was a significant and independent predictor of all outcomes. Sacubitril/valsartan was effective at reducing cardiovascular death and HF hospitalization throughout the LVEF spectrum. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255.


Posted March 15th 2016

Interactions with Industry under the Sunshine Act: An Example from Gynecologic Oncology.

Monique A. Spillman M.D.

Monique A. Spillman, M.D.

Shalowitz, D. I., M. A. Spillman and M. A. Morgan (2016). “Interactions with Industry under the Sunshine Act: An Example from Gynecologic Oncology.” Am J Obstet Gynecol. Feb 20. [Epub ahead of print]

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THE PROBLEM: Clinicians may be unaware that industry payments to physicians are now publicly searchable under the Physician Payments Sunshine Act. Furthermore, the extent of industry’s financial involvement in subspecialty practice has not been previously accessible. As an example, 6,948 direct, research-unrelated payments totaling $1,957,004 were made to 765 gynecologic oncologists in 2014, the first full year of data available. 153 companies reported at least one payment; however, the ten manufacturers reporting the highest total payment amount accounted for 82% of all payments to physicians. 48 gynecologic oncologists received more than $10,000 from manufacturers, accounting for $1,202,228, or 61% of total payments. A SOLUTION: Obstetrician-gynecologists, including gynecologic oncologists, should be aware of their publicly reported payments from industry and ensure reports’ accuracy. Professional organizations, including the Society for Gynecologic Oncology, should strongly consider proactively developing guidelines regarding interactions with industry for their general memberships.