Simultaneous analysis of interleukin-10 gene microsatellites and single-nucleotide polymorphisms in parallel with tumour necrosis factor and interferon-gamma short tandem repeats by fluorescence-based polymerase chain reaction.

Different cytokine genotypes exist in the population, for example, as a result of selective pressure of infectious diseases. It may be that specific cytokine genotypes that are beneficial by creating a 'proinflammatory' phenotype predispose to severe inflammatory disease with worse clinical outcome. There is individual variation in the production of certain cytokines in relation to their genotypes. IL-10, IFN-gamma and TNF-alpha are key components in the regulation of immune responses and the balance of their expression levels is predictive in certain diseases. To describe cytokine genotypes, a one-tube PCR reaction was developed to analyse simultaneously DNA sequence variations of cytokine genes IL-10, IFN-gamma, and TNF. This multiplex PCR approach was used to provide genotypic data for two geographically independent donor groups from Germany and Gabon. Significant differences were obtained for the majority of sequence variations comparing both populations. However, the SNPs within the 5'-flanking region of the IL-10 gene at position -1087 and -6208 are comparable in their genic and genotypic behaviour. Comparing allelic and genotypic disequilibrium between pairs of loci revealed different association patterns for both populations according to the geographical polymorphism. This assay may improve immunogenetic studies in disease, characterized by disbalanced IL-10, IFN-gamma and TNF-alpha expression.