Cytokine gene polymorphisms in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by hypogammaglobulinemia and an increased susceptibility to recurrent infections, autoimmunity and cancers. There are some conflicting results regarding the cytokine profile of CVID patients. While cytokine production could be associated with gene polymorphism, genetic profiles of a number of cytokines were analyzed in this study. The allele and genotype frequencies of the polymorphic genes coding for interleukin (IL)-2, IL-12, interferon-gamma and transforming growth factor (TGF)-beta were investigated in 30 patients with CVID in comparison with 140 controls. The genotype TGF-beta CG at position +915 was significantly overrepresented in the patient group, while the frequencies of the genotypes TGF-beta TT at +869 and GG at +915 were significantly decreased in the patient group in comparison with controls. TGF-beta TC and IL-2 GT were the most frequent haplotypes in the patients, whereas the TGF-beta TG haplotype was significantly decreased in the patient group. The allele and genotype frequencies of interferon-gamma at position UTR +5644 and also IL-12 at position -1188 were similar in patients and controls. Cytokine single nucleotide polymorphisms could play a role in the pathophysiology of CVID. Considering the significantly lower frequency of the high production haplotype (TG) and the higher frequency of the low production halplotype (TC) of TGF-beta, low production of this cytokine is expected in some CVID patients.