Hepcidin is a critical inhibitor of iron export from macrophages, enterocytes, and hepatocytes. Given that it is filtered and degraded by the kidney, its elevated levels in renal failure have been suggested to play a role in the disordered iron metabolism of uremia, including erythropoietin resistance. Here, we used a novel radioimmunoassay for hepcidin-25, the active form of the hormone, to measure its levels in renal disease. There was a significant diurnal variation of hepcidin and a strong correlation to ferritin levels in normal volunteers. In 44 patients with mild to moderate kidney disease, hepcidin levels were significantly elevated, positively correlated with ferritin but inversely correlated with the estimated glomerular filtration rate. In 94 stable hemodialysis patients, hepcidin levels were also significantly elevated, but this did not correlate with interleukin-6 levels, suggesting that increased hepcidin was not due to a general inflammatory state. Elevated hepcidin was associated with anemia, but, intriguingly, the erythropoietin dose was negatively correlated with hepcidin, suggesting that erythropoietin suppresses hepcidin levels. This was confirmed in 7 patients when hepcidin levels significantly decreased after initiation of erythropoietin treatment. Our results show that hepcidin is elevated in renal disease and suggest that higher hepcidin levels do not predict increased erythropoietin requirements.

Observational studies of human conversations in relaxed social settings suggest that these consist predominantly of exchanges of social information (mostly concerning personal relationships and experiences). Most of these exchanges involve information about the speaker or third parties, and very few involve critical comments or the soliciting or giving of advice. Although a policing function may still be important (e.g., for controlling social cheats), it seems that this does not often involve overt criticism of other individuals' behavior. The few significant differences between the sexes in the proportion of conversation time devoted to particular topics are interpreted as reflecting females' concerns with networking and males' concerns with self-display in what amount to a conventional mating lek.

BackgroundDuring the coronavirus disease 2019 (COVID-19) epidemic, many countries have instituted population-wide measures for social distancing. The requirement of patients on dialysis for regular treatment in settings typically not conducive to social distancing may increase their vulnerability to COVID-19.MethodsOver a 6-week period, we recorded new COVID-19 infections and outcomes for all adult patients receiving dialysis in a large dialysis center. Rapidly introduced control measures included a two-stage routine screening process at dialysis entry (temperature and symptom check, with possible cases segregated within the unit and tested for SARS-CoV-2), isolated dialysis in a separate unit for patients with infection, and universal precautions that included masks for dialysis nursing staff.ResultsOf 1530 patients (median age 66 years; 58.2% men) receiving dialysis, 300 (19.6%) developed COVID-19 infection, creating a large demand for isolated outpatient dialysis and inpatient beds. An analysis that included 1219 patients attending satellite dialysis clinics found that older age was a risk factor for infection. COVID-19 infection was substantially more likely to occur among patients on in-center dialysis compared with those dialyzing at home. We observed clustering in specific units and on specific shifts, with possible implications for aspects of service design, and high rates of nursing staff illness. A predictive epidemic model estimated a reproduction number of 2.2; cumulative cases deviated favorably from the model from the fourth week, suggesting that the implemented measures controlled transmission.ConclusionsThe COVID-19 epidemic affected a large proportion of patients at this dialysis center, creating service pressures exacerbated by nursing staff illness. Details of the control strategy and characteristics of this epidemic may be useful for dialysis providers and other institutions providing patient care.