RESUMO
BACKGROUND: Mycosis fungoides (MF) skin lesions are characterized by low-grade inflammation, which may be sustained by proinflammatory cytokines as probably interleukin-33 (IL-33). We compared serum concentrations of IL-33 and its receptor ST2 and the frequency of selected IL-33 single nucleotide polymorphisms (SNPs) between patients with MF and healthy controls. METHODS: In 88 patients with MF and 66 healthy controls, we analyzed SNPs in the 9894 and 11877 loci of the IL-33 gene. Moreover, we measured serum concentrations of IL-33 and its receptor ST2. RESULTS: There were no statistically significant differences in the frequencies of both IL-33 SNPs between patients and controls. Compared with controls, patients with MF had similar IL-33 serum concentrations (P = 0.71) but significantly increased ST2 concentrations (P < 0.001). Patients in MF-IA stage had significantly lower ST2 serum concentrations than those with the remaining MF stages (P = 0.002). The studied variables were not related to pruritus severity. Patients with the C(+) IL-33 11877 SNP had lower ST2 serum concentrations than patients with the C(-) 11877 SNP (P = 0.043). CONCLUSIONS: It was published before that the knockout of the ST2 gene after injection of IL-33 is associated with a reduced inflammatory reaction in the skin, as well as that IL-33 plays a role in allergic and neoplastic disorders. Concerning the difference in ST2 concentration between control and MF group, and C IL-33 11877 SNP possibly influencing the ST2 concentration, the role of IL-33/ST2 signaling, needs further studies.
