TNF-α, IL1-β, and immunoglobulin (GM and KM) gene polymorphisms in sarcoidosis

In order to determine whether TNF-alpha, ILI-beta, GM, and KM genes affect susceptibility to sarcoidosis, coded DNA samples from 278 Caucasian and 219 African-American patients and an equal number of matched controls were genotyped by polymerase chain reaction methods. All genotypes were in Hardy-Weinberg equilibrium. Genotype frequencies in sarcoidosis patients, as a whole, were not significantly different from that in controls. Additional analyses were performed to determine whether patients with and without erythema nodosum had different genetic components. In African-American patients without erythema nodosum, the distribution of KM genotypes was significantly different from that in controls: compared to controls, the frequency of KM1 homozygotes was increased in patients (6.5% versus 13.0%, P = 0.01; odds ratio = 2.56). As KM genes have been reported to be associated with immune responsiveness to several pathogens, these results may be relevant to the etiology of sarcoidosis.