Blood-Cell Clonal Mutations Linked to Faster IPF Progression in Small Study

A study of patients with idiopathic pulmonary fibrosis (IPF) found that clonal hematopoiesis was associated with faster disease progression over 12 months. The findings suggest a relationship between age-related blood-cell mutations and an age-related lung disease whose causes remain poorly understood, but they do not establish that the mutations cause IPF or accelerate it.

The research included 123 people with IPF who provided informed consent and had blood samples analyzed. Researchers used a targeted sequencing panel to look for somatic mutations associated with clonal hematopoiesis, a condition in which genetically altered blood-cell clones expand despite the absence of other hematological abnormalities.

Mutations linked to clonal hematopoiesis were detected in 38% of the participants. The overall median variant allele frequency—the proportion of tested gene copies carrying a particular mutation—was 6.2%.

Clinical information collected at the time of blood sampling and during the following 12 months was used to classify disease progression. The study defined rapid progression using one of three criteria: at least a 10% absolute decline in forced vital capacity (FVC), a measure of lung function; at least a 5% FVC decline combined with radiologic progression; or radiologic progression alone. The progression analysis included 89 patients.

Among patients with clonal hematopoiesis mutations, 53% were classified as rapid progressors, compared with 25% of those without the mutations. The mutation-positive group also had a larger average loss in FVC over 12 months: 280 milliliters, compared with 90 milliliters among patients without detected clonal hematopoiesis.

The mutations were assessed in genes including DNMT3A, TET2, ASXL1, TP53 and several others. DNMT3A and TET2 were described as regulators of gene expression and disease-related immune responses. The source notes that clonal hematopoiesis has also been associated with other chronic diseases, including coronary heart disease and chronic obstructive pulmonary disease, when mutations reach a variant allele frequency of at least 2%.

The results come from a relatively small patient group and an analysis of associations between blood mutations and subsequent IPF progression. They do not show whether clonal hematopoiesis contributes directly to lung scarring, whether IPF promotes the expansion of these clones, or whether both reflect other shared risk factors. The biological relationship between disruptive blood-cell mutations, immune function and pulmonary fibrosis therefore remains unresolved.