The decreased percentage of BAFF-R+ B cells after RTX treatment, which was also found in patients with rheumatoid arthritis may be due to a relative increase of memory-like B cells, which have lower or no BAFF-R expression. In addition, treatment with B-cell depleting agents has previously been shown to Trichostatin A HDAC inhibitor elevate BAFF levels, and increased BAFF levels in turn were inversely correlated with BAFF-R expression during B-cell repopulation. Another interesting observation was an increase in the percentage of transitional B cells at 12 months after treatment with RTX compared to triple immunosuppression therapy alone. Interestingly, BAFF-R deficiency in patients with common variable immunodeficiency was associated with B-cell lymphopenia and a relative increase in the number of transitional B cells. Taken together, an increase in BAFF level, reduced BAFF-R expression, and an increase in the proportion of transitional B cells appear to be interrelated phenomena which are associated with RTX treatment. Upon activation, B cells are able to proliferate, produce various cytokines and process antigen for presentation to T cells. Previously, we showed that in vitro RTX treatment can affect Bcell phenotype and function, resulting in an altered outcome of BT-cell interaction upon stimulation. However, in contrast, we did not observe any changes in the T-cell compartment in our patients treated with RTX. In another ex vivo study, we neither were able to show that RTX influenced the production of IL-17 and other monocyte- and T-cell-derived cytokines by PBMCs. It should be noted however that we only analyzed peripheral blood T cells. From a previous study in renal transplant patients, we know that a single dose of RTX leads a to nearly complete Bcell depletion in peripheral blood, but not in secondary lymphoid organs, and that these remaining B cells have different functional capacities. From our current data, it seems that this population of mostly memory type B cells residing in lymphoid organs does not noticeably affect the peripheral blood T-cell compartment as compared to transplant recipients on triple immunosuppression without RTX. Interestingly, several studies on patients with autoimmune disease revealed that the T-cell compartment was affected upon RTX treatment. However, in most of these patients the cumulative dose of RTX was higher than in our patients, who received only a single, relatively low dose. In summary, we have demonstrated that treatment of renal transplant recipients with tacrolimus, MMF and steroids leads to alterations in the T- and B-cell compartments. This detailed longitudinal analysis provides more insight into the immune status of renal transplant recipients with stable graft function and may be used as a reference in the monitoring of renal transplant patients. Although large-scale mortality of bats has never been documented in Europe, 90% mortality of bats occurs in North American hibernacula after Pd is introduced. Such high mortality rates have led to predictions of regional extinctions, although not all bat species appear equally affected by the disease. Despite the high mortality rates of little brown myotis inhabiting Pd-contaminated hibernacula.