P164. Free DNA level in patients with inflammatory bowel diseases
P. Miheller1, K. Lorinczy1, Á. Patai1, Á. Csontos1, O. Galamb1, B. Molnár1, Z. Tulassay1
1Semmelweis University, 2nd Department of internal Medicine, Budapest, Hungary
Background: Recent results show that plasma free DNA concentration (fDNA) is increased in autoimmune and malignant diseases. Anti-nuclear antibody related to circulating fDNA plays a role in the disease pathogenesis in systemic lupus erythematosus. There is no data in regarding fDNA concentrations in inflammatory bowel disease (IBD). Our aim was to determine plasma fDNA in patients with clinically active and inactive IBD.
Methods: We included 28 people into the study. 7 patients with active (aCD), 7 with inactive Crohn's disease (iCD) and 7 inactive or mild ulcerative colitis (UC) and results were compared with 7 healthy controls. The CD was defined to be inactive by the Crohn's disease activity index (CDAI <150), while it was considered to be active in case of the CDAI was more than 250 and CRP is more than 5 mg/l. UC was considered inactive if the partial Mayo score was less than 3. Samples collected from patients were cooled after centrifugation. The fDNA was isolated with Roche Magna Pure Compact and measured with Qubit fluorometer.
Results: The mean plasma fDNA concentration was 0.309±0.250 in the healthy control subjects. Concentrations of fDNA did not differed significantly in aCD, iCD and UC patients compared to healthy controls (0.331±0.318, p = 0.458; 0.158±0.061, p = 0.068; and 0.208±0176, p = 0.147; respectively). However, a strong correlation had been observed between plasma fDNA levels and C‑reactive protein (r = 0.95) concentrations, and partial Mayo score (r = 0.78) also.
Conclusions: Initial results indicate that the plasma concentration of fDNA does not help to diagnose inflammatory bowel disease. Further investigations are needed to determine the use of fDNA concentration as a surrogate marker of severity in UC patients.