Evaluation of the T helper 17 cell specific genes and the innate lymphoid cells counts in the peripheral blood of patients with the common variable immunodeficiency

Background: common variable immunodeficiency (cvid) is characterized by a deficiency in the immune system with a heterogeneous collection of disorders resulting in antibody deficiency and recurrent infections. t helper 17 (th17) cells promote b-cell survival and synergize with the b-cell activating factor to induce their differentiation into the plasma cells. a sub-population of innate lymphoid cells (ilcs) also produces interleukin 17 (il-17). this study aimed to measure the th17 specific genes and ilcs counts in the cvid patients in comparison with control subjects. materials and methods: total messenger ribonucleic acid (mrna) was extracted from the whole blood samples of 10 cvid patients and 10 healthy individuals. il-17, retinoic acid receptor-related orphan receptor c2 (rorc2), il-23r, and il-9 gene expression were measured using the quantitative reverse transcriptase-polymerase chain reaction. count of lineage negative/cd127+/cd90+ ilcs in the blood samples was performed by the flow cytometry method. results: the transcript levels of il-17 and rorc2 in cvid patients was strongly lower than control subjects (p = 0.049 and p = 0.046, respectively), but slight reduction in the il-23r expression (p = 0.252) have seen in the cvid patients. accordingly, the number of ilcs decreased significantly (p = 0.04). interestingly, il-9 mrna level was more significantly in the cvid patients (p = 0.001). conclusion: the results presented in this study show that the th17 cell specific genes expression (as the determiner th17 cells) and ilcs (another lymphoid source of il-17) are decreased in patients with cvid and this could be an explanation for the defect of their humoral immune response. in addition, elevation of the il-9 gene expression may shed a new light into the way toward the understanding of the mechanism of autoimmunity in the cvid patients.