B cell and long term graft function

A lot of transplant patients do so well and require very minimal amounts of medications. What is the magic recipe for that? Perhaps it is T regs cells and amount of T regs vs T effector cells. Perhaps it is a subset of B cells.
A recent paper in Kidney International addresses this topic.
The investigators compared B cells of people with stable graft function and ones with chronic rejection and healthy volunteers.  They found that the ones who had stable graft function with minimal drugs had increased B cells of activated, memory and early memory type. They had a enriched transcriptional profiling.  The costimulatory molecules like CD40 and CD80 ligand were upregulated in these B cells.  These cells were also giving out an inhibitory signal for proliferation and a preventive signal for Hyperactive B cell response.  They expressed CD1D and CD5 ( another recent paper had suggested this as well).
This suggests that there a specific type of B cells out there that patients with good graft function and minimal drugs have that might be regulatory in nature and allow long term graft functioning.

More studies should be done to look out for these type of cells
http://www.ncbi.nlm.nih.gov/pubmed/20531452
Also, perhaps using anti co stiumatory blockades might not be all that ideal then? Perhaps. not much data to say yes or no!