Distinctive distribution of lymphocytes in unruptured and previously untreated brain XXXX .

@entity469 @entity2225 @entity2758 @entity1284
AIM: To test the hypothesis that lymphocyte infiltration in brain @entity2758 (bAVM) is not associated with @entity1284 (indicator of microhemorrhage). METHODS: Sections of unruptured, previously untreated bAVM specimens (n=19) were stained immunohistochemically for T-lymphocytes (CD3(+)), B-lymphocytes ( @entity2225 (+)), plasma cells (CD138(+)) and macrophages ( @entity469 (+)). @entity1284 was assessed by hematoxylin and eosin and Prussian blue stains. Superficial temporal arteries (STA) were used as control. RESULTS: Both T lymphocytes and macrophages were present in unruptured, previously untreated bAVM specimens, whereas few B cells and plasma cells were detected. @entity1284 was detected in 8 specimens (42%; 95% confidence interval =20-67%). The samples with @entity1284 tended to have more macrophages than those without (666  313 vs 478  174 cells/mm(2); P=0.11). T-cells were clustered on the luminal side of the endothelial surface, on the vessel-wall, and in the perivascular regions. There was no correlation between T lymphocyte load and @entity1284 (P=0.88). No macrophages and lymphocytes were detected in STA controls. CONCLUSIONS: T-lymphocytes were present in bAVM specimens. Unlike macrophages, the load and location of T-lymphocytes were not associated with @entity1284 , suggesting the possibility of an independent cell-mediated immunological mechanism in bAVM pathogenesis.
