title: Regeneration of TdT+, pre-B, and B cells in bone marrow after allogeneic bone marrow transplantation.
abstract: In 15 children transplanted with allogeneic bone marrow for acute leukemia and in complete remission, regeneration of the early stages of the B cell system was studied. Bone marrow aspirates taken before and longitudinally after BMT were investigated for pre-B and B cells by immunofluorescence techniques; in some cases, TdT+ cells were also determined. Normal values were derived from bone marrow samples taken from 23 healthy individuals who served as bone marrow donors. In normal bone marrow, B cells outnumber pre-B cells and the latter are more numerous than TdT+ cells. Before BMT, the numbers of BM pre-B were outside the normal range in all cases; B cell numbers were abnormal in most of the 11 patients studied, probably due to the antileukemic remission induction/consolidation therapy. After BMT, two distinct patterns of regeneration of the B cell system were observed. In 9 patients, TdT+ cells were considerably increased early after BMT. This was followed by a rise in pre-B cells, with values well above the normal range, and resulting in ratios of TdT+:pre-B cells and of pre-B cells:B cells that were transiently greater than 1. In the other 6 patients, the regeneration of TdT+ cells varied and the reconstitution of the pre-B cells was more gradual than in the first group, with pre-B-to-B cell ratios less than 1 during the whole observation period. The only consistent difference between the patients of the two groups, possibly relevant to the regeneration of the B cell lineage, was the duration of corticosteroid therapy, which was much longer in the 6 patients with slow-pace reconstitution. The pace of regeneration of the B cell system in the bone marrow was correlated with the recovery of the humoral immunity, as indicated by a significant increase in specific antibody titers after the second vaccination with diphtheria-tetanus-poliomyelitis vaccine in 7 of 9 patients in the rapid-pace group, versus 2 of 6 patients in the slow-pace group.
authors.forename: G E
authors.initials: GE
authors.lastname: Asma
authors.forename: R L
authors.initials: RL
authors.lastname: van den Bergh
authors.forename: J M
authors.initials: JM
authors.lastname: Vossen
mesh_terms: D000293:Adolescent; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000166:cytology*; D001854:Bone Marrow Cells; D002648:Child; D002675:Child, Preschool; D004253:DNA Nucleotidylexotransferase / Q000097:blood*; D004254:DNA Nucleotidyltransferases / Q000097:blood*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007945:Leukemia, Lymphoid / Q000097:blood / Q000628:therapy; D008297:Male
chemical_list: D004254:DNA Nucleotidyltransferases; D004253:DNA Nucleotidylexotransferase