Our study refers only to the peripheral blood mononuclear cells. The effect of glutamine to other lymphoid organs and their effects on the immune system remain open at this point. Compared to other studies, our findings lead to similar results concerning the frequency distribution of allele frequencies at the TNF-α -308 SNP and the IL-2 -330 SNPs as shown in Table 6 [23, 35, 36]. In vitro studies have shown that the guanine allele is associated with an early and sustained IL-2 production. The genotype is designated as a so-called high producer genotype. In a clinical study from 2003, MacMillan et al. [25] found that the risk of GVHD after

bone marrow transplantation was increased twofold dependent on the guanine allele in the IL-2 -330 SNP. In contrast, in a study by Morgun INK 128 price et al., in patients after renal transplantation at least one acute rejection within the first three months

after transplantation was associated with the T/T genotype [26].Because of the divergent results, we also wanted to know if the SNP at PCI-32765 in vivo position -330 influences the level of IL-2 release and if glutamine as an immunonutrient can change the cytokine production after stimulation. In our study, we found no effect of the IL-2 -330 polymorphism on the reactivity with glutamine. Even discrete effects in all three tertiles cannot be observed. The guanine allele, could not be verified as a ‘high producer’, because of the small number

of cases with the G/G genotype (n = 6). The genotype in our subjects seems not DNA Damage inhibitor to be crucial for the better sensitivity of the IL-2 release under glutamine. Like in a study by Grimble et al. [36], we designed a similar approach to investigate the TNF-α -308 SNP. Instead of supplementation with the ω-3 fatty acids, we have compared the distribution of TNF-α-308 SNP on the level of TNF-α production with and without supplementation of glutamine. Paradoxically, we showed in our study in contrast to other studies, an increased TNF-α production in probands who are heterozygous or homozygous for the guanine allele regardless of the amount of the glutamine concentration [29, 37]. In the study by Grimble et al., ω-3 fatty acids showed an anti-inflammatory effect. Corresponding to this study one might have been expected that glutamine depending on the genetic polymorphism also has an anti-inflammatory effect on the TNF-α production. This hypothesis cannot be confirmed. The comparison of our study with the other discussed studies is complicated by the form of the chosen methodology. In contrast to other investigators, who worked with isolated cells, we decided to stimulate immune cells which remain in their physiological medium blood.