title: Expression of p53 and Ki-67 antigen in bone marrow giant proerythroblasts associated with human parvovirus B19 infection.
abstract: Giant proerythroblasts are hallmarks of human parvovirus B19 infection. We attempted to characterize these cells in 5 patients with parvovirus B19-induced pure red cell aplasia using immunostaining of paraffin-embedded bone marrow sections with antibodies against erythroid-lineage-specific proteins, viral capsid antigen VP-1, and apoptosis- and cell-cycle-related proteins. Giant proerythroblasts are immunohistochemically consistent with early erythroid precursors of cells in the differentiation stage of CD34-, cytoplasmic spectrin+, glycophorin A-, and band-3-. VP-1 was expressed in the nucleus and cytoplasm of small- to medium-sized spectrin+ erythroid cells but not in giant proerythroblasts. The giant proerythroblasts displayed nuclear staining for p53 (41%+/-16%) and Ki-67 antigen (100%+/-0%) and cytoplasmic staining for Bax (65%+/-11%) and procaspase-3 (78%+/-10%), whereas they were not stained for p21Wafl/Cip1, active form of caspase-3, or terminal deoxynucleotidyltransferase-mediated deoxyuridine nick-end labeling (TUNEL). Antiapoptotic proteins, Bcl-2 and Mcl-1, were not expressed in the giant cells, and Bcl-x was infrequently expressed in these cells (11%+/-4%). These immunohistochemical findings suggest that giant proerythroblasts are proliferating erythroid precursors with accumulation of nonfunctional p53.
authors.affiliation: Department of Pathology, Kawasaki Medical School, Kurashiki, Japan. sadapath@med.kawasaki-m.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Sadahira
authors.forename: T
authors.initials: T
authors.lastname: Sugihara
authors.forename: Y
authors.initials: Y
authors.lastname: Yawata
mesh_terms: D000293:Adolescent; D017209:Apoptosis; D001853:Bone Marrow / Q000737:chemistry / Q000473:pathology / Q000821:virology; D016022:Case-Control Studies; D016731:Erythema Infectiosum / Q000378:metabolism / Q000473:pathology*; D004900:Erythroblasts / Q000737:chemistry / Q000473:pathology* / Q000821:virology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D016732:Parvovirus B19, Human; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53