Human IgG lacking effector functions demonstrate lower FcRn-binding and reduced transplacental transport.

We have previously generated human IgG1 antibodies that were engineered for reduced binding to the classical Fcγ receptors (FcγRI-III) and C1q, thereby eliminating their destructive effector functions (constant region G1Δnab). In their potential use as blocking agents, favorable binding to the neonatal Fc receptor (FcRn) is important to preserve the long half-life typical of IgG. An ability to cross the placenta, which is also mediated, at least in part, by FcRn is desirable in some indications, such as feto-maternal alloimmune disorders. Here, we show that G1Δnab mutants retain pH-dependent binding to human FcRn but that the amino acid alterations reduce the affinity of the IgG1:FcRn interaction by 2.0-fold and 1.6-fold for the two antibodies investigated. The transport of the modified G1Δnab mutants across monolayers of human cell lines expressing FcRn was approximately 75% of the wild-type, except that no difference was observed with human umbilical vein endothelial cells. G1Δnab mutation also reduced transport in an ex vivo placenta model. In conclusion, we demonstrate that, although the G1Δnab mutations are away from the FcRn-binding site, they have long-distance effects, modulating FcRn binding and transcellular transport. Our findings have implications for the design of therapeutic human IgG with tailored effector functions.

Alcohol and disadvantaged men: A feasibility trial of an intervention delivered by mobile phone.

INTRODUCTION AND AIMS: Disadvantaged men suffer substantial harm from heavy drinking. This feasibility study developed and evaluated the methods for a trial of a brief intervention delivered by text messages to disadvantaged men. It aimed to test the methods for recruitment and retention, to monitor engagement with the intervention and assess the overall acceptability of study methods. DESIGN AND METHODS: Disadvantaged men aged 25-44 years who had ≥2 episodes of binge drinking (≥8 units in one session) in the preceding month were recruited. Two recruitment strategies were assessed: recruitment from general practice registers and by a community outreach strategy. Theoretically and empirically based text messages were tailored to the target group. RESULTS: The study recruited 67 disadvantaged men at high risk of alcohol-related harm, exceeding the target of 60. Evaluation showed that 95% of text messages were delivered, and the men engaged enthusiastically with the intervention. Retention at follow up was 96%. Outcomes were successfully measured on all men followed up. This provided data for the sample size calculation for the full trial. Post-study evaluation showed high levels of satisfaction with the study. DISCUSSION AND CONCLUSIONS: This study has shown that disadvantaged men can be recruited and follow-up data obtained in an alcohol intervention study. The study methods were acceptable to the participants. The men recruited were at high risk of alcohol-related harms. It also clarified ways in which the recruitment strategy, the baseline questionnaire and the intervention could be improved. The full trial is currently underway. [Crombie IK, Irvine L, Falconer DW, Williams B, Ricketts IW, Jones C, Humphris G, Norrie J, Slane P, Rice P. Alcohol and disadvantaged men: A feasibility trial of an intervention delivered by mobile phone. Drug Alcohol Rev 2017;36:468-476].

Risky single-occasion drinking and disadvantaged men: will recruitment through primary care miss hazardous drinkers?

BACKGROUND: Men who are socially disadvantaged are at a substantially higher risk of developing alcohol-related diseases. People from deprived areas are known to be more difficult to recruit to research studies. As part of a feasibility assessment for an intervention study, 2 recruitment strategies were investigated. This article compares the drinking patterns of the disadvantaged men identified by the 2 strategies. METHODS: A cross-sectional survey compared 2 strategies for recruiting disadvantaged men to a study on alcohol consumption: recruitment through general practice (GP) registers and through a community outreach strategy, respondent-driven sampling (RDS). Men aged 25 to 44 years were recruited from deprived areas in the community. The entry criterion was binge drinking (≥8 units in a single session) at least twice in the previous 4 weeks. Demographic characteristics, total consumption of alcohol, frequency of binge drinking (≥8 units in a session), and heavy binge drinking (≥16 units in a session) were measured. RESULTS: Men recruited by RDS drank more than twice as much as the men recruited through GP (137 units in the previous 30 days compared with 62 units; p = 0.003). They also had many more binge drinking days: more than half (57%) of men from RDS had 6 or more binge drinking days in the previous 30 days, whereas only 16% of the GP sample had 6 or more binge drinking days (p = 0.001). Many more men recruited by RDS (37% vs. 5%; p = 0.002) had more than 5 very heavy drinking sessions in the previous month (≥16 units in a session). The RDS group also had fewer alcohol-free days. CONCLUSIONS: The 2 sampling strategies recruited different types of drinkers. The men recruited through RDS were much more likely to engage in frequent harmful drinking. The results indicate that the 2 methods recruit different samples of disadvantaged men. Intervention studies that are only conducted through primary care may miss many harmful drinkers.

Can text messages reach the parts other process measures cannot reach: an evaluation of a behavior change intervention delivered by mobile phone?

BACKGROUND: Process evaluation is essential in developing, piloting and evaluating complex interventions. This often involves observation of intervention delivery and interviews with study participants. Mobile telephone interventions involve no face to face contact, making conventional process evaluation difficult. This study assesses the utility of novel techniques for process evaluation involving no face to face contact. METHODS: Text messages were delivered to 34 disadvantaged men as part of a feasibility study of a brief alcohol intervention. Process evaluation focused on delivery of the text messages and responses received from study participants. The computerized delivery system captured data on receipt of the messages. The text messages, delivered over 28 days, included nine which asked questions. Responses to these questions served as one technique for process evaluation by ascertaining the nature of engagement with the study and with steps on the causal chain to behavior change. RESULTS: A total of 646 SMS text messages were sent to participants. Of these, 613 messages (95%) were recorded as delivered to participants' telephones. 88% of participants responded to messages that asked questions. There was little attenuation in responses to the questions across the intervention period. Content analysis of the responses revealed that participants engaged with text messages, thought deeply about their content and provided carefully considered personal responses to the questions. CONCLUSIONS: Socially disadvantaged men, a hard to reach population, engaged in a meaningful way over a sustained period with an interactive intervention delivered by text message. The novel process measures used in the study are unobtrusive, low cost and collect real-time data on all participants. They assessed the fidelity of delivery of the intervention and monitored retention in the study. They measured levels of engagement and identified participants' reactions to components of the intervention. These methods provide a valuable addition to conventional process evaluation techniques.