Association of Interleukin-1 Receptor Antagonist ( ) Gene Polymorphism with Community-Acquired Pneumonia in North Indian Children: A Case-Control Study.

 Community-acquired pneumonia (CAP) is the leading cause of death in children < 5 years of age. The primary objective of the study was to assess the association of gene polymorphism in children aged 2 to 59 months with CAP and the secondary objective was to assess the association of gene polymorphism with mortality among hospitalized CAP cases.  This case-control study was conducted in a tertiary teaching institute in Northern India. Hospitalized children aged 2 to 59 months with World Health Organization-defined CAP were included as cases after parental consent. Age-matched healthy controls were recruited from the immunization clinic of the hospital. Genotyping was done using polymerase chain reaction to analyze the variable number of tandem repeats of gene polymorphism.  From October 2019 to October 2021, 330 cases (123, 37.27% female), and 330 controls (151, 45.75% female) were recruited. Genotype A2/A2 of the gene was found to be associated with the increased risk for CAP children with adjusted odds ratio (AOR) of 12.24 (95% confidence interval [CI] 5.21-28.7,  < 0.001). A2 and A4 alleles were also found to be at risk for CAP. A1/A2 genotype was found to be protective for CAP with an AOR of 0.29 (95% CI 0.19-19.0.45). The genotype A2/A2 and A2 allele of gene was associated with child mortality with CAP cases.  In gene, A2/A2 genotype and A2 allele were associated with increased risk of CAP and A1/A2 were found to be protective for CAP. The genotype A2/A2 and A2 was associated with CAP mortality.