CHP2 Modifies Chronic Pseudomonas aeruginosa Airway Infection Risk in Cystic Fibrosis

Area of Science:

• Genetics
• Pulmonology
• Microbiology

Background:

• Chronic Pseudomonas aeruginosa infection significantly impacts lung function and survival in people with cystic fibrosis (PwCF).
• Existing treatments often fail to eradicate Pseudomonas aeruginosa in adolescents and adults with cystic fibrosis.
• Identifying genetic factors influencing chronic infection is crucial for understanding disease progression.

Purpose of the Study:

• To discover novel genetic modifiers affecting the development of chronic Pseudomonas aeruginosa infection in PwCF.
• To investigate the genetic underpinnings of Pseudomonas aeruginosa infection timing in cystic fibrosis.

Main Methods:

• Genome-wide association study (GWAS) utilizing whole-genome sequencing data from 4,945 CF Genome Project participants.
• Analysis linked genetic data with longitudinal clinical information from the Cystic Fibrosis Foundation Patient Registry.
• Time-to-event analysis was performed using two distinct definitions for chronic Pseudomonas aeruginosa infection.

Main Results:

• A genome-wide significant association was found between a variant (rs194810) near the CHP2 gene and delayed onset of chronic Pseudomonas aeruginosa infection (P = 2.2 × 10⁻⁸).
• Individuals with the minor A allele of rs194810 experienced chronic infection approximately three years later than those with the G allele.
• The CHP2 gene encodes calcineurin B homolog protein 2, suggesting its role in host defense against Pseudomonas aeruginosa.

Conclusions:

• Genetic variants in the vicinity of the CHP2 gene are associated with a significant delay in the age of acquiring chronic Pseudomonas aeruginosa infection in PwCF.
• These findings highlight CHP2 as a potential modifier of Pseudomonas aeruginosa infection risk in cystic fibrosis.
• Further research into CHP2's function could reveal new strategies for managing chronic infections in PwCF.