BONE-MARROW PROGENITOR-CELL GROWTH AND KARYOTYPE CHANGES IN HEALTHY 88-YEAR-OLD SUBJECTS

Previous studies have indicated a decline in bone marrow progenitor ce ll function in subjects aged 75-82 years, possibly causing lower Hb co ncentrations. We studied the bone marrow with in vitro colony assays a nd cytogenetic analysis in 24 apparently healthy 88-year-olds with Hb concentrations ranging from moderate anaemia to normal levels. Twenty- two healthy younger subjects, aged 21-57 years, were used as a control group. The 88-year-olds showed significantly lower numbers of myeloid bone marrow progenitors than the controls, and the elderly men had lo wer numbers of both erythroid and myeloid progenitors than the elderly women. There were no in vitro growth differences between elderly subj ects with ''low'' or ''normal'' Hb concentrations. Ten out of 14 men h ad bone marrow cells with a missing Y-chromosome, which did not seem t o have any relationship to the erythroid function. No morphological or other cytogenetic indications of a clonal progenitor cell disorder we re found. A more rapid decline in Hb concentrations in healthy elderly men as compared to elderly women might be explained by differences in bone marrow progenitor cell function. However, progenitor cell abnorm alities do not seem to explain differences in Hb concentrations within groups of apparently healthy men and women of advanced age.