B cell depletion with ublituximab reshapes the T cell profile in multiple sclerosis patients.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system, thought to be mediated by myelin-specific CD4+ T cells. However, B cell depletion has proven to be an effective therapy for MS, but the mechanism is not well understood. This study was designed to determine how B cell depletion changes lymphocyte profiles. During a phase IIa clinical trial with ublituximab, a novel CD20 antibody, blood was collected from 48 MS patients at 11 time points over 24 weeks and the lymphocyte profiles were analyzed by flow cytometry. The percentage of naïve CD4+ and CD8+ T cells increased, while the percentage of both effector and central memory T cells declined. CD4+ Th1 effector cells decreased, while there was a significant increase in CD4+ regulatory T cells. The depletion of B cells had a favorable shift in the lymphocyte landscape, reducing the number of naïve T cells becoming activated and transitioning to memory T cells. The ratio of Th1 cells to CD4+ regulatory T cells declined, suggesting that immune regulation was being restored. These data suggest that loss of B cells as antigen presenting cells is a major mechanism of action for the beneficial effects of CD20 antibody therapy in MS.

Effects of perceived risk and strength of affiliation on decisions to help others: toward a convergence of evolutionary and social psychology.

In this study, the influence of perceived affiliation with a target and perceived risk on decisions to act altruistically were investigated. These are variables which have been suggested by the social and evolutionary psychology literatures, respectively. 12 participants responded to automobile accident scenarios that combined risk and affiliation with a target in descriptions of opportunities to render aid. Participants reported a lower likelihood to help when perceived risk was high, but only if their perceived affiliation with the targets was low or moderate; tendency to help highly affiliated targets was uniformly high throughout all risk conditions. Participants' ratings of certainty in their decisions to render aid were directly related to both perceived risk and perceived affiliation with a target. Decisions were arrived at more slowly when perceived risk and perceived affiliation were both moderate. Therefore, both risk and affiliation were considered by participants when deciding whether to act altruistically. This illustrates a convergence of predictions from social and evolutionary psychology.