Validity of the Ratio of Serum Concentration of Interleukin 6 to Transforming Growth Factor-Beta1 in a Sample of Patients With Rheumatoid Arthritis
Iraqi Postgraduate Medical Journal,
2016, Volume 15, Issue 2, Pages 296-301
Interleukin 6 (IL-6), a pro-inflammatory cytokine, plays a key role in the development of rheumatoid arthritis (RA). Transforming growth factor-beta1 (TGF-β1) is an anti-inflammatory cytokine which is considered to be an important (down) regulator of inflammation in RA.
To evaluate serum concentration of IL6 to TGF-β1 ratio in a sample of Iraqi patients with RA.
A case control single center study was conducted for 11 months. A total of 50 patients with RA diagnosed according to the 1987 American College of Rheumatology (ACR) and 30 individuals matched in age and sex as control group were included. Serum concentration of IL-6 to TGF-β1 ratio and serum IL-17 were determined in both RA groups using enzyme-linked immunosorbent assay (ELISA). The cut off value was assessed by receiver operating characteristics (ROC) test and correlation by spearman's Rholinear correlation coefficient.
Frequency of females was more than males in patients and controls (88% and 76.7% respectively). Ages of patients range between 20-70 years with a median 43.76 years while in controls, ages range between 20-60 years with a median 37.67 years. Serum concentration of IL-6 toTGF-β1 ratio was significantly more in patients than those in controls (p=0.018). Area under the curve (AUC) at value 0.686 was statistically significant (p=0.018) and had intermediate accuracy. Serum IL-6 to TGF- β1 ratio≥ 2.4pg/ml was the optimum cutoff value that can differentiate between RA and healthy controls with accuracy 71.9%. There was a significant positive linear correlation between IL-6 to TGF-β1 ratio and IL-17( r=0.56, p<0.001) and simple linear regression analysis showed that for each 1unit increase in IL6 to TGF-B1 ration there was a significant increase of 0.7 pcg/ml in IL-17(R2=0.467, P < 0.001)
Serum concentration of IL6 to TGF-β1 ratio was significantly higher in Iraqi sample of RA patients compared to controls. This may help in early diagnosis of RA and suggest potentially an early effective treatment.
KEY WORDS: Rheumatoid arthritis, IL6, TGF-β1, IL6 to TGF- β1 ratio, cytokines.
- Article View: 12
- PDF Download: 8