Circulating cell free DNA as a predictor of systemic lupus erythematosus severity and monitoring of therapy

Background: Systemic lupus erythematosus [SLE] is the most heterogeneous chronic autoimmune disease; it is characterized by the presence of auto reactive B and T cells, responsible for the aberrant production of a broad and heterogeneous group of autoantibodies. Recent studies using various detection methods have demonstrated the elevations of circulating DNA in SLE patients

Aim of the study: The current study aimed to measure cell-free DNA [cf-DNA] in SLE patients as a potential tool to predict disease activity and treatment follow up

Subjects and methods: 52 of SLE patients with age ranging from 10 to 48 years were randomly selected and 25 healthy subjects with age and gender matched with the patients were included as a control group. Thorough clinical examination stressing on the central nervous system, vascular, renal, rash, musculoskeletal, mucocutaneous manifestations, and fever was done for patients. The following investigations were done: Complete blood count [CBC], kidney function tests, C-reactive protein [CRP], routine autoantibodies for autoimmune diseases, complements [C3 and C4], anti-nucleosome antibodies and cf-DNA by real time PCR [RT-PCR]

Results: The levels of anti-double stranded DNA [anti-dsDNA], anti-nucleosome Ab, and cf-DNA were significantly increased in SLE patients compared to controls. The cf-DNA level was correlated to markers of disease severity namely CRP and anti-nucleosome. A significant reduction in levels of cf-DNA, anti-nucleosome Ab and anti-dsDNA was noticed after therapy

Conclusion: Our findings support that the measurement of cf-DNA appears to be a useful marker in addition to laboratory tests used in SLE diagnosis. High correlation with markers of disease severity suggesting its role in disease pathogenesis and decreasing its level after therapy makes it to be a marker of treatment follow-up

values of serum and ascetic fluid tumor necrosis factor-Alpha [TNF-alpha], TNF-receptor 1 and C-reactive protein [CRP] in patients with cirrhotic ascites

Spontaneous bacterial peritonitis [SBP] is defined as an infection of initially sterile ascitic fluid [AF] without a detectable, surgically treatable source of infection. It is a frequent and severe complication of cirrhotic ascites. Because of the high morbidity and mortality of SBP, the rapid and accurate diagnosis is required. The present study aimed to measure the levels of tumor necrosis factor-alpha [TNF-alpha], tumor necrosis factor receptor [TNF-r p55] and C-reactive protein [CRP] in both ascetic fluid and serum of patients with sterile and infected cirrhotic ascites to show their diagnostic values as compared to ascitic fluid culture and polymorphnuclear leukocyte [PMN] count. TNF-alpha, TNF-r p55 and CRP were measured in both ascetic fluid and serum of 20 patients with spontaneous bacterial peritonitis [SBP], in addition to 22 patients with sterile cirrhotic ascites. The results of clinical examination showed a significant difference as regard abdominal pain, fever jaundice, upper GIT bleedings, encephalopathy and Sclerotherapy among both groups. The serum levels of CRP and TNF-alpha were significantly higher in patients with SBP as comparing to patients have sterile ascites, but TNF-r p55 serum level showed no significant difference. On evaluation of ascetic fluid parameters, total leucocytic count [TLC], plymorphnuclear [PMN] count, CRP, TNF-alpha, TNF-r p55 are significantly higher in SBP patient group than group of sterile ascites. Sensitivity and specificity of ascitic fluid PMN [cut-off value >250 cells/ mm[3]] in discriminating infected ascites from sterile ascites were 70% and 86.4%, respectively. Sensitivity and specificity of ascitic fluid CRP [cut-off value >1.0 mg/dL] in discriminating infected ascites from sterile ascites were 85% and 72.7%, respectively. Sensitivity and specificity of ascitic fluid TNF-alpha [cut off value >12 pg/ml] in discriminating infected ascites from sterile ascites were 80% and 63.6%, respectively. Sensitivity and specificity of TNF-r p55 [cut-off value >6.2 pg/ml] in discriminating infected ascites from sterile ascites were 75% and 68.2%, respectively. We concluded that, the elevated serum and ascetic fluid levels of CRP, TNF-alpha and TNF-r may suggest their role in the pathogenesis of ascetic fluid infection and their higher sensitivity and specificity make them to be good discriminators in ascetic fluid infection [especially a cheap and easy ascitic fluid CRP levels]. Thus may help in rapid diagnosis and early start empirical antibiotic therapy without waiting the culture results