The Journal of Clinical Investigation reports results of a study showing that increases in CD21lo B cells and plasmablasts following that combination checkpoint blockade preceded the onset of immune-related adverse events.
While some have postulated that IRAEs are thought to be T cell mediated, B cells have also been implicated. Investigators studied 39 melanoma patients undergoing treatment with either anti-CTLA4 or anti-PD1, or combination CCB therapy. They analyzed changes in circulating B cells before and after the first cycle of therapy of immune checkpoint blockade (23 received combination therapy, 8 received anti-CTLA4, and 8 received anti-PD1).