Tumor necrosis factor alpha ( TNF-a)‎ genetic correlations with knee osteoarthritis

Abstract EN

Objective : To determine the incidence of TNF-α polymorphisms at G-238A and G-308A in primary knee OA.

Also, investigate the correlation between presence of TNF-α polymorphisms and severity of disease regards X-rays.

Methodology : Sixty knee primary OA patients 40-60 years old, diagnosed according to Altman's criteria were subjected to study.

A control group of 30 matching apparently healthy colleagues, employments and relatives of patients were included.

All were subjected to medical history, general examination, and clinical rheumatologic examination, functional assessment with visual analogue scale (VAS) and WOMAC OA index and radiological grading of OA knees.

DNA assessment was done with TNF-α polymorphism analysis and electrophoresis techniques.

Results : TNF-α -308 G /A was the most frequent genotype in OA patients (71.7%), whereas, G/G was so in healthy controls (76.7%).

The rare genotype A / A was detected only in three patients and was completely absent in controls.

In contrast, TNF-α-238 G / G was the most predominant genotype among patients and controls.

The A / A genotype were not detected in any subject.

The frequency of TNF-α -308 A allele was significantly higher among patients compared to controls (40.8% versus 11.7% ; p = 0.000).

There was no significant difference in frequency of TNF-α -238 A allele between patients and controls.

Moreover, the carriage rate of -308 A allele was significantly higher in patients compared to controls (76.7% versus 23.3% ; p = 0.000).

There was a significant difference in the distribution of homozygous A / A and heterozygous G / A forms of TNF-α -308 gene polymorphism in patients and controls with lower rate of occurrence of homozygote state in 5% of OA patients and its absence among controls.

In OA, there were highly significant correlations between TNFα-308 genotype and age, limitation of ROM, quadriceps muscle wasting, VAS pain score, WOMAC pain, WOMAC stiffness, WOMAC function, total WOMAC score, and radiological grading.

Conclusions : There is a significant difference in TNF-α polymorphisms between knee OA patients and healthy controls.

TNFα-308 genotype in OA patients significantly correlates with severity of the disease.