Analysis of Normal Plasma Cell Distribution Across Distinct Age Cohorts Reveals Age-Dependent Changes

Area of Science:

• Hematology
• Immunology
• Cell Biology

Background:

• Bone marrow (BM) contains hematopoietic and stromal cells crucial for plasma cell (PC) survival.
• Previous studies in mice showed dynamic formation and dispersion of PC clusters in BM.
• PC clustering in normal human BM has not been extensively studied.

Purpose of the Study:

• To investigate the presence of PC clusters in human BM.
• To determine if PC clustering patterns change with age.
• To explore the relationship between PC numbers, clustering, and age.

Main Methods:

• Quantification of PCs and PC clusters in human BM sections.
• Analysis across six distinct age groups.
• Assessment of immunoglobulin heavy- and light-chain expression in PC clusters.

Main Results:

• PC clusters were observed in human BM.
• PC numbers and cluster counts were lowest in the youngest and oldest age groups.
• PC clustering peaked in the sixth decade and subsequently decreased.
• A positive correlation existed between PC numbers and PC cluster counts across all ages.
• PC clusters exhibited heterogeneity in immunoglobulin expression.

Conclusions:

• PC clusters are a feature of normal human BM.
• PC clustering dynamics are age-dependent, increasing until middle age and then declining.
• Age-related alterations in the spatial distribution of BM stromal cells may influence PC clustering.