CD44 splice variants in draining lymph nodes precede allograft rejection of endocrine cells

Upon allogeneic transplantation (Tx) of pancreatic islets under the kidney capsule of diabetic rats, cells from draining lymph nodes and, to a minor d egree, bone marrow transiently upregulate CD44 splice variants as detected by RT-PCR using CD44 variant exon specific primers. Maximal expression was on day 5 post Tx in lymph nodes and thus precedes islet rejection sufficien tly (in this model by 5 days) to still permit establishing rescue by immuno suppressive therapy. CD44 variant exon sequence could therefore serve as ea rly markers of allograft rejection.