title: Secondary colony formation after long-term bone marrow culture using peripheral blood and bone marrow of HIV-infected patients.
abstract: OBJECTIVE
  To determine if defective bone marrow function in HIV infection is associated with decreased numbers of progenitor cells or defective stromal cell function.
  
  
  METHODS
  Defective bone marrow function may in part be responsible for the cytopenias so frequently seen in patients with AIDS. Although a number of investigators have reported impaired growth of committed hematopoietic progenitor cells in HIV-1-infected patients, few studies have examined the most primitive hematopoietic stem cells. Our study was designed to determine the function and quality of the most immature hematopoietic progenitor and stem cells in the peripheral blood and bone marrow of HIV-1-infected patients and to assess stromal cell function.
  
  
  METHODS
  For quantification of these cells we used a modified long-term culture-initiating cell (LTCIC) assay in which the number of secondary colony-forming cells after 5 weeks of stromal culture served as a measure of LTCIC. Stromal cells from normal controls and HIV-1-infected patients were used for cross-matching experiments. Normal CD34+ cells or those derived from HIV-infected patients were plated and colony growth assessed.
  
  
  RESULTS
  We found that HIV-1-infected patients had a mean of 0.8 secondary colony-forming cells/10(5) peripheral blood mononuclear cells (PBMC), whereas normal controls showed 1.2 secondary colony-forming cells/10(5) PBMC (P = not significant) after long-term culture. Asymptomatic patients showed well preserved numbers of secondary colony-forming cells after long-term culture of PBMC, but a significant reduction was seen in patients with a history of opportunistic infections (P < 0.01), low CD4+ cell count (< 200 x 10(6)/l; P < 0.05), or leukopenia (P < 0.05). Decreased numbers of secondary colony-forming cells have also been found in bone marrow of HIV-1-infected patients with advanced disease. When normal CD34+ cells were cultured on stromal layers from bone marrow of HIV-1-infected patients or normal controls, no differences in the numbers of surviving progenitor cells were found.
  
  
  CONCLUSIONS
  Our data indicate that the hematopoietic defect in HIV-1 infection involves the most immature hematopoietic cells and becomes evident in advanced disease. Stromal function of HIV-infected patients appears normal.
authors.affiliation: Hematology Branch, National Heart, Lung and Blood Institute, Bethesda, Maryland, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Sloand
authors.forename: N S
authors.initials: NS
authors.lastname: Young
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: P
authors.initials: P
authors.lastname: Kumar
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: F F
authors.initials: FF
authors.lastname: Weichold
authors.forename: J P
authors.initials: JP
authors.lastname: Maciejewski
mesh_terms: D001853:Bone Marrow / Q000503:physiopathology*; D001854:Bone Marrow Cells; D016022:Case-Control Studies; D002452:Cell Count; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000503:physiopathology*; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells; D006801:Humans; D007963:Leukocytes, Mononuclear; D008297:Male; D017154:Stromal Cells; D013997:Time Factors