Increased levels of CD34+ hemopoietic progenitor cells in atopic subjects

Am J Respir Cell Mol Biol. 1996 Nov;15(5):645-55. doi: 10.1165/ajrcmb.15.5.8918371.


We investigated the contribution of hemopoietic progenitors to the accumulation of inflammatory cells in allergic airways disease. Using a multiparameter flow-cytometric method, the detection of peripheral blood (PB) and bone marrow (BM) cells expressing CD34, a progenitor cell marker, was explored. True CD34+ blast cells were detected as a discrete cluster exhibiting low intensity CD45 expression, low granularity, and low to intermediate cell size. A significantly greater number of CD34+ cells was detected in the PB of atopic individuals (1,438 +/- 347/10(6) nonadherent mononuclear cells [NAMNC], n = 19) compared with nonatopics (236 +/- 77/10(6) NAMNC, n = 13; P = 0.006). Similarly, in BM samples, a significantly greater number of CD34+ cells was detected in atopic (17,537 +/- 4,986/10(6) NAMNC, n = 7) compared with nonatopic subjects (6,422 +/- 1,853/10(6) NAMNC, n = 13, P = 0.02). Greater numbers of total colony-forming units (CFU) (granulocyte/macrophage [GM] and Eo/Baso) were present in cultures of PB NAMNC from atopics (24 +/- 5 CFU/10(6) NAMNC) cultured with recombinant human interleukin 5 (rhIL-5) (1 ng/ml) compared with nonatopics (5 +/- 2 CFU/10(6) NAMNC; P = 0.003). Analyses of colony subtypes showed significantly greater numbers of IL-5-responsive Eo/Baso-CFU in cultures from atopics (15 +/- 2 CFU/10(6) NAMNC) compared with nonatopics (5 +/- 2 CFU/10(6) NAMNC; P = 0.011). In contrast, no significant differences in colony counts were found between the two subject groups in cultures with rhIL-3 (1 ng/ml) or rhGM-CSF (10 ng/ml). A positive correlation was observed between PB CD34+ cell numbers and total CFU in cultures with rhIL-5 (r = 0.43, n = 32, P = 0.01) and rhGM-CSF (r = 0.45, n = 32, P = 0.009). Purging BM NAMNC with an anti-CD34 monoclonal antibody completely abrogated in vitro colony growth, supporting the view that a subset of CD34+ cells represents the relevant population of progenitors growing in culture. These data indicate that flow cytometric estimation of CD34+ cells is predictive of the colony-forming capacity of the sample and may be a useful alternative tool to clonogenic assays for enumerating progenitors. In addition, raised levels of CD34+ cells and IL-5-responsive Eo/Baso-CFU in atopics, including patients with atopic asthma, indicate a role for progenitors in allergic airways disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Antigens, CD34 / analysis
  • Antigens, CD34 / blood*
  • Bone Marrow Cells*
  • Cell Adhesion
  • Cell Differentiation
  • Cell Division
  • Cell Separation
  • Cells, Cultured
  • Colony-Forming Units Assay
  • Flow Cytometry / methods
  • Granulocyte-Macrophage Colony-Stimulating Factor / pharmacology
  • Hematopoietic Stem Cells* / chemistry
  • Humans
  • Hypersensitivity, Immediate / blood*
  • Hypersensitivity, Immediate / pathology
  • Immunomagnetic Separation
  • Interleukin-3 / pharmacology
  • Interleukin-5 / pharmacology
  • Leukocytes, Mononuclear / cytology
  • Recombinant Proteins
  • Rhinitis / blood
  • Rhinitis / pathology
  • Thoracotomy


  • Antibodies, Monoclonal
  • Antigens, CD34
  • Interleukin-3
  • Interleukin-5
  • Recombinant Proteins
  • Granulocyte-Macrophage Colony-Stimulating Factor