BACKGROUND

This study hypothesizes that predicted polymorphism of the interferon-gamma receptor 1 gene may play an important role in infection after trauma as supported by microsatellite analysis.

METHODS

DNA was extracted from the peripheral leukocytes of 38 trauma patients with Injury Severity Scores greater than 16. D6S471, a microsatellite marker on chromosome 6 near interferon-gamma receptor 1, was amplified with polymerase chain reaction, and genotypes were determined.

RESULTS

The mean Injury Severity Score was 32, and 63% of patients (24 of 38) developed major infection. Three alleles and 5 genotypes were identified for D6S471. Twenty-six percent of patients (10 of 38) had genotype AA, all of whom developed major infection (P =.004). Genotype BB accounted for 57% of the uninfected population (8 of 14) but only 21% of the infected group (P =.028). Allele A had a frequency of 33%, of which 22 alleles (88%) were found in infected patients (P =.001). In addition, allele B accounted for 61% of the uninfected group (17 of 28) but only 23% (11 of 48) of the infected group (P =.001). Allele C demonstrated no correlation.

CONCLUSIONS

Microsatellite polymorphism correlates strongly with infection. These findings portend polymorphism in the receptor itself and thereby represent a genetic basis for the development of infection. We suggest this identifies a high-risk group who could benefit from more specific therapy that may have the potential to overcome this receptor insufficiency.