Investigating the Effect of TNF α (-863) and TNF α (-308) genes Polymorphism on the Progression of Disease in Patients with Cystic Fibrosis

Recent studies have shown that the course of cystic fibrosis in patients with this disease differs despite the same mutation in CFTR gene. We aimed to investigate the role of polymorphism in TNF α (-308) and TNF α (-863), and its effect on the phenotype of the patients with cystic fibrosis and progression of disease.

In this case-control study, 50 children with cystic fibrosis and 50 healthy children were examined for TNF-α-308 GA and TNF α - 863CA polymorphism.Four ml of citrated blood was taken from the patients in order to perform the DNA purifying and PCR-RFLP. With custom designed primers, PCR was done. Then with restriction enzymes PCR-RFLP was performed on the product of previous PCR. Changes were analyzed taking the following into consideration: diagnosis age, starting point of the pulmonary disease. Hb O2 saturation level, FEV1, and FVC. Also, for each of them, a Schwachman index basis score was calculated and results are mentioned.

Patient’s average age was 21±5.1 years old (ranged 5-26 years), and 48.9% (n=24) of patients were females. The average age at diagnosis was also 39.78 ±13.51 months. Patients with genotype TNF-α-308GA were older in diagnostic time compared to TNF-α-308GG genotype. However, for other variables, such as O2 sat, FEV1, FVC no difference was observed. Patients Heterozygote genotypes for “C” allele (CA) of TNF-863 have better Schwachman score than CC genotype.

The results of this research emphasize the importance of genetic factors affecting inflammatory processes. Identifying these variables is helpful in treating patients with cystic fibrosis disease.