Determination of age-dependent bone marrow normocellularity

Area of Science:

• Hematology
• Gerontology
• Biostatistics

Background:

• Bone marrow cellularity assessment is crucial for evaluating hematopoietic status.
• Traditional semiquantitative estimation has limitations, particularly in older adults.
• Existing age-adjusted normocellularity ranges lack sufficient characterization, especially for individuals over 70.

Purpose of the Study:

• To establish a more accurate normal range for bone marrow cellularity in adults.
• To specifically characterize age-adjusted normocellularity in older adult populations.
• To refine understanding of bone marrow cellularity decline with aging.

Main Methods:

• Analysis of 570 bone marrow samples from healthy donors and staging patients aged 1 to 93.
• Utilized linear regression modeling to assess cellularity trends across age groups.
• Determined 90% reference intervals for normocellularity.

Main Results:

• Bone marrow cellularity in adults declines by approximately 3% per decade, continuing after age 70.
• The 90% reference interval for normocellularity in US adults (18-90 years) is 30% to 75%.
• A slower, more stable decline was observed compared to the traditional '100% minus age' model.

Conclusions:

• Age-specific modeling of normocellularity is more accurate than a single linear decline.
• Recommended ranges: <20 yrs (45-85%), 20-40 yrs (40-70%), 40-60 yrs (35-65%), >60 yrs (30-60%).
• Individuals over 70 show no significant cellularity decrease compared to those aged 60-69.