Bone marrow progenitor cell growth and karyotype changes in healthy 88-year-old subjects.

Previous studies have indicated a decline in bone marrow progenitor cell function in subjects aged 75-82 years, possibly causing lower Hb concentrations. We studied the bone marrow with in vitro colony assays and 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 lower numbers of both erythroid and myeloid progenitors than the elderly women. There were no in vitro growth differences between elderly subjects with "low" or "normal" Hb concentrations. Ten out of 14 men had bone marrow cells with a missing Y-chromosome, which did not seem to have any relationship to the erythroid function. No morphological or other cytogenetic indications of a clonal progenitor cell disorder were 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 abnormalities do not seem to explain differences in Hb concentrations within groups of apparently healthy men and women of advanced age.