Investigation of mutations in IRAK4 and MYD88 genes in children undergoing invasive bacterial infection with streptococcus pneumonia, staphylococcus aureus and pseudomonas aeruginosa

Invasive bacterial infections are bacterial infections of sterile body fluids. Invasive bacterial infections include meningitis, bacteremia, sepsis, septic arthritis, osteomyelitis, pleural empyema, deep tissue and organ abscesses. Patients with IRAK4 and MyD88 deficiency are selectively predisposed to invasive bacterial infections with Streptococcus pneumoniae and Staphylococcus aureus. This study aimed to investigate the presence of mutations in IRAK-4 and MyD88 genes in addition to primary immunodeficiency screening tests in patients with invasive bacterial infections with Streptococcus pneumonia, Staphylococcus aureus. Fifteen patients who had invasive bacterial infections with Streptococcus pneumoniae and Staphylococcus aureus in Karadeniz Technical University Faculty of Medicine, Department of Pediatric Infection Disease were included in the study. Seven of the patients (46.7%) were girls. The median age of the patients was 48 months (min-max: 2.5-130 months). Six (40%) of the patients were complicated parapneumonic effusion, four (26.7%) septic arthritis, one (6.7%) acute bacterial meningitis, four (26.7%) bloodstream infection. Of the isolated agents, 10 (66.7%) were S. pneumonia and five (33.3%) were S. aureus. Heterozygous variant in the IRAK-4 gene were detected in seven of the patients included in the study (c.1282 G>A heterozygous, rs4251545 exon 11 Ala428Thr; one c.1172 G>A heterozygous rs55944915 exon 10 Arg391His), no mutation was detected in the MyD 88 gene. Although IRAK-4 and MyD88 deficiencies are autosomal recessive; further functional and genetic studies are needed to reveal that heterozygous individuals may also present with disease findings. Children with invasive pneumococcal and staphylococcal disease should be evaluated for an underlying PID and IRAK-4 and MyD88 deficiencies should be considered in the differential diagnosis of these children.