Background: Clonal hematopoiesis of indeterminate potential (CHIP) is associated with increased risk of cancers and inflammation-related diseases. The phenomenon becomes very common in oldest-old individuals, in whom the implications of CHIP are not well defined. Here we investigate the relationships between CHIP and associated pathologies in people aged >80 years.
Methods: We performed a mutational screening in 1794 oldest-old individuals enrolled in two population-based studies (“Health_&_Anemia” and “Monzino_80+”).
Findings: Clonal mutations were observed in one third of oldest-old individuals and were associated with reduced survival and increased risk of cancers. Mutations in JAK2 and splicing genes (SF3B1, SRSF2, U2AF1, ZRSR2), multiple mutations (DNMT3A, TET2, ASXL1) combined with additional genetic lesions) and variant allele frequency ≥0.14 had positive predictive value for myeloid neoplasms. Combining mutation profiles with abnormalities in red blood cell indices improved the ability of myeloid neoplasm prediction. On this basis, we defined a predictive model that identifies 3 risk groups with different probabilities of developing myeloid neoplasms.
Mutations in DNMT3A, TET2, ASXL1 or JAK2 (most occurring as single lesion) were associated with coronary heart disease and rheumatoid arthritis. Cytopenia (most including anemia) was a common finding in oldest-old population (>20%), the underlying cause remaining unexplained in 30% of cases. Among individuals with unexplained cytopenia, the presence of highly-specific mutation patterns was associated with a myeloid neoplasms-like phenotype and a probability of survival comparable to that of myeloid neoplasms. Accordingly, 7.5% of oldest-old subjects with cytopenia had presumptive evidence of myeloid neoplasm.
Interpretation: Specific mutational patterns define different risk of developing cancers vs. inflammatory-associated diseases in oldest-old population. In individuals with unexplained cytopenia, mutational status may identify those subjects with presumptive evidence of myeloid neoplasms.
Trial Registration: (ClinicalTrials.gov number:NCT03907553)
Funding: Supported by European Union; Cariplo Foundation, Italy; Italian Association for Cancer Research; Italian Ministry of Health and Research.
Declaration of Interests: The Authors declare no competing interests.
Ethics Approval Statement: Study procedures were in accordance with the Declaration of Helsinki. Ethics Committees of Humanitas Research Hospital and Mario Negri Pharmacological Institute, Milan Italy approved the study. Written informed consent was obtained prior to blood sampling.