title: HSP70 is selectively over-expressed in the blast cells of the germinal centres and paracortex in reactive lymph nodes.
abstract: OBJECTIVE
  We evaluated by immunohistochemistry HSP70 expression in reactive lymph nodes since its morphological expression and location have not been previously described and correlated with lymphocyte kinetics.
  
  
  RESULTS
  Ninety-six cases of non-specific lymphadenitis were immunostained for HSP70, CD20, CD3, Ki67, Bcl-2, CD21. The type and the location of HSP70-positive cells were determined. Their number out of 2000 cells in each germinal centre and in each paracortical area was counted at 60x magnification with the help of a quantitative grid. Seventeen percent of germinal centre cells and 7.6% of the paracortex cells were positive. This difference was highly significant. The positively reacting cells were B-cells and had a blast (centroblast or immunoblast) morphology, with negative mantle and marginal lymphocytes and T-cells. Lymphoplasmacytoid cells and plasma cells reacted only weakly or were negative. Germinal centre antigen-presenting cells and interdigitating dendritic cells reacted from lightly to moderately.
  
  
  CONCLUSIONS
  HSP70 was selectively over-expressed by B-blasts mainly located within germinal centres with a lower number in the paracortex. The difference in the mean number between the two sites was statistically highly significant. No correlation was found with bcl-2 and Ki67 expression. Mantle, marginal and T-lymphocytes were always negative. The biological meaning and role of this over-expression in centroblasts and immunoblasts remain to be elucidated.
authors.affiliation: Department of Pathology, Ospedale Maggiore, Piazza Ospitale 10, 26900 Lodi, Italy.
authors.forename: O
authors.initials: O
authors.lastname: Leopardi
authors.forename: W
authors.initials: W
authors.lastname: Naughten
authors.forename: I
authors.initials: I
authors.lastname: Giannulis
authors.forename: M
authors.initials: M
authors.lastname: Mirra
authors.forename: B
authors.initials: B
authors.lastname: Frigo
mesh_terms: D018858:Germinal Center / Q000737:chemistry / Q000473:pathology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology*; D008199:Lymphadenitis / Q000378:metabolism / Q000473:pathology
chemical_list: D018840:HSP70 Heat-Shock Proteins