Toward a B-cell signature of tolerance?

Operational tolerance is a rare and still unexplained phenomenon in organ transplantation. Pallier et al. analyzed the peripheral B-cell compartment of 12 renal transplant patients with drug-free long-term graft function and found a peculiar blood B-cell phenotype, with an expansion of memory activated B cells and increased expression of inhibitory molecules, suggesting a role of B cells in maintaining graft tolerance. Kidney International (2010) 78, 435-437. doi:10.1038/ki.2010.159