Distinct patterns of clonal hematopoiesis exist in a longevity enriched cohort Free

Introduction The impact of age-associated clonal hematopoiesis (CH) on healthspan and lifespan remains unclear with some studies linking it to increased risk of cardiovascular diseases, hematological malignancies, and mortality while others demonstrating its association with protection against Alzheimer's disease. To better define its role in aging and age-associated diseases, we leveraged a well characterized longevity-enriched cohort with previously described protection from age-related diseases. We characterized the prevalence, clonal dynamics, and gene-specific burden of CH in this cohort compared to the general population with the goal to identify CH features that are associated with risk vs. protection.

Method The longevity-enriched cohort includes 2,535 individuals, ranging in age from 21-110 (23%, age ≥95 referred to as centenarians, 40%, offspring who have at least one parent living to age ≥95, 30%, control without parental longevity, age-matched to offspring, 6%, age 21-60 as younger participant, 60% female). High-confidence CH mutations were identified from targeted sequencing data using a previously published Mutect2 pipeline and variant allele frequencies (VAFs) were used as proxy for clonal expansion. Age distributions across cohorts and CH status were assessed using non-parametric tests (Kruskal–Wallis and Mann–Whitney U), while categorical variables, including sex and cohort, were compared using chi-square tests. Post hoc analyses included Dunn's test for multiple comparisons. Logistic regression (adjusted for age, sex, and cohort), co-mutation matrix construction, and gene-level stratification were used to explore clonal complexity and mutation trends.

Results CH prevalence increased markedly with age, with highest proportion (30.3%) noted in centenarians and lowest in youngest age-group (21-60 years), with statistically significant differences across all age groups (χ² = 160.38, p < 1.0×10⁻³⁴). CH prevalence was lower in offspring (9.4%) compared tocontrols (12.3%). CH prevalence was higher in males, though not statistically significant. We benchmarked CH prevalence by age against the AllofUs cohort and found that our dataset included approximately 6.7-fold more individuals (n = 573 vs. 85) above age 95, and a higher proportion of CH+ cases among centenarians (30.19% vs. 25.88%). Logistic regression confirmed age as a strong independent predictor of CH (p < 1 × 10⁻⁵), while sex was not significant after adjustment. DNMT3A and TET2 were the two most frequently mutated genes, accounting for over 75% of all CH events. Notably in the centenarians, the next most frequently mutated genes were SF3B1, TP53, and PPM1D; a finding not previously described in individuals with average lifespans. Most CH+ individuals had a single mutation (n=278), though 66 carried two and 13 had three or more; these multi-mutation cases were enriched in centenarians. Nonetheless, approximately 70% of CH+ centenarians carried a single mutation. Co-mutation analysis revealed frequent DNMT3A–TET2 overlap (n=25). Notably, 88% of ASXL1 mutations co-occurred with another CH mutation in a different gene. VAF distributions differed significantly across genes (p=0.0002), with higher VAFs observed in SF3B1, GNB1, and PPM1D. VAF also showed a modest positive correlation with age. These patterns highlight the heterogeneous nature of CH in aging and suggest that even among long-lived individuals, clonal architectures vary in complexity and potential impact.

Conclusion Our findings highlight strong age-related trends in CH prevalence and clonal expansion within a longevity-enriched cohort, with centenarians exhibiting the highest burden and complexity. The enriched sampling of centenarians in our dataset, compared to a general population cohort, provided a unique opportunity to uncover distinct patterns associated with CH in extreme old age. While multi-mutation and co-mutation cases were enriched in centenarians, most CH+ carried only a single mutation. The mutation spectrum also differed from prior reports in older individuals. Additionally, offspring had a slightly lower rate of CH compared to age adjusted controls. These findings raise the possibility that long-lived individuals may tolerate clonal hematopoiesis without clinical consequences in the context of extreme aging. Ongoing work will explore CH-associated resilience in aging using longitudinal and clinical outcomes.