Physical measures and biomarker collection in health surveys: Propensity to participate

Population-based surveys have long been a key tool for health researchers, policy makers and program managers. The addition of bio-measures, including physical measures and specimen collection, to self-reported health and health behaviors can increase the value of the research for health sciences. At the same time, these bio-measures are likely to increase the perceived burden and intrusiveness to the respondent. Relatively little research has been reported on respondent willingness to participate in surveys that involve physical measures and specimen collection and whether there is any associated non-response bias.This paper explores the willingness of respondents to participate in surveys that involve physical measures and biomarkers. A Census-balanced sample of nearly 2000 adults from a national mobile panel of persons residing in the U.S. were interviewed. Willingness to participate in six specific bio-measures was assessed. The survey finds a high correlation in the willingness of respondents to participate among these specific bio-measures. This suggests there is a general propensity towards (and against) bio-measures among potential respondents, despite some differences in willingness to participate in the more sensitive, intrusive or burdensome biomarkers. This study finds the general propensity to participate in bio-measures is correlated with a number of key measures of health and illness. This suggests that the inclusion of biomarkers in health surveys may introduce some bias in key measures that need to be balanced against the value of the additional information.     

Therapeutic plasma exchange for thrombotic thrombocytopenic purpura with refractory thrombocytopenia

Thrombotic thrombocytopenic purpura (TTP) is an acute, life‐threatening illness with disseminated platelet‐rich thromboses of small vessels that variably presents with the classic clinical “pentad” of microangiopathic hemolytic anemia, thrombocytopenia, fever, altered mental status, and acute kidney injury. Most cases are caused by an acquired autoantibody to ADAMTS13, a metalloproteinase that cleaves large von Willebrand Factor (vWF) multimers. The mainstay of treatment is daily therapeutic plasma exchange (TPE), sometimes with adjunctive pharmacologic immunosuppression. TPE is generally continued until the platelet count is greater than 150 × 10³/µL and the lactate dehydrogenase is near normal for 2‐3 consecutive days. Unfortunately, there is no clear guidance for when thrombocytopenia is refractory for a prolonged period of time. The following case describes such a scenario in which consecutive ADAMTS13 activity and inhibitor levels were used to guide the decision to stop treatment with TPE in a patient who failed to recover their platelet count.     

Ziltivekimab for Treatment of Anemia of Inflammation in Patients on Hemodialysis: Results from a Phase 1/2 Multicenter,Randomized, Double-Blind,Placebo-Controlled Trial

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Coiled-coil irregularities of the M1 protein structure promote M1–fibrinogen interaction and influence group A Streptococcus host cell interactions and virulence

Group A Streptococcus (GAS) is a human pathogen causing a wide range of mild to severe and life-threatening diseases. The GAS M1 protein is a major virulence factor promoting GAS invasiveness and resistance to host innate immune clearance. M1 displays an irregular coiled-coil structure, including the B-repeats that bind fibrinogen. Previously, we found that B-repeat stabilisation generates an idealised version of M1 (M1*) characterised by decreased fibrinogen binding in vitro. To extend these findings based on a soluble truncated version of M1, we now studied the importance of the B-repeat coiled-coil irregularities in full length M1 and M1* expressed in live GAS and tested whether the modulation of M1–fibrinogen interactions would open up novel therapeutic approaches. We found that altering either the M1 structure on the GAS cell surface or removing its target host protein fibrinogen blunted GAS virulence. GAS expressing M1* showed an impaired ability to adhere to and to invade human endothelial cells, was more readily killed by whole blood or neutrophils and most importantly was less virulent in a murine necrotising fasciitis model. M1-mediated virulence of wild-type GAS was strictly dependent on the presence and concentration of fibrinogen complementing our finding that M1–fibrinogen interactions are crucial for GAS virulence. Consistently blocking M1–fibrinogen interactions by fragment D reduced GAS virulence in vitro and in vivo. This supports our conclusion that M1–fibrinogen interactions are crucial for GAS virulence and that interference may open up novel complementary treatment options for GAS infections caused by the leading invasive GAS strain M1.     

Avelumab: A Review in Metastatic Merkel Cell Carcinoma

Avelumab (Bavencio^®) is a fully human IgG1 monoclonal antibody that is directed against programmed cell death ligand 1 (PD-L1). Avelumab functions as an immune checkpoint inhibitor and has recently been approved in the USA, the EU and Japan for the treatment of metastatic Merkel cell carcinoma (MCC). It is thus the first therapeutic agent specifically approved for use in this indication, and is approved for use independent of line of treatment. Approval for avelumab in metastatic MCC was based on the two-part, single-arm, phase II trial, JAVELIN Merkel 200. In Part A of the study, confirmed objective responses were observed in approximately one-third of patients with chemotherapy-refractory metastatic MCC treated with avelumab. The responses were observed early and appeared to be durable, with an estimated 74% of responses having a duration ≥?12 months. Furthermore, interim results from a separate cohort of patients (Part B) indicate an objective response rate for avelumab of >?60% in patients who were chemotherapy-naïve in the metastatic disease setting. Avelumab is associated with a risk of immune-related adverse events but, overall, has an acceptable and manageable safety and tolerability profile. In conclusion, currently available data suggest that avelumab presents a clinically beneficial new treatment option for metastatic MCC, a rare but aggressive cancer associated with a poor prognosis.