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

Neutrophil CD64 in diagnosis of infection in systemic lupus erythematosus patients

Infection is one of the major complications as well as cause of death in systemic lupus erythematosus patients [SLE]. Differentiation between early infection and disease flare in these patients is often clinically difficult because both have similar signs and symptoms. To evaluate CD64 expression on neutrophils as an early marker that can discriminate between infection and disease flare in SLE patients. Also, its clinical utility in comparison with traditional laboratory tests used for detecting infection will be studied. The study included 38 subjects; 10 apparently healthy individuals as healthy controls and 28 SLE patients divided into three groups [10 SLE patients with infection, 10 SLE patients with flare and 8 SLE patients without infection or flare]. CD64 on neutrophils was measured using flow cytometry. Total leucocytic count, erythrocyte sedimentation rate and high-sensitive C-reactive protein were also measured. The median of the percentage of neutrophils expressing CD64 was higher in all SLE patients compared to normal control. It was significantly higher in SLE patients with infection than those with disease activity [P 0.001]. Using a cutoff value of >/= 17.6,% of neutrophils expressing CD64; it revealed 100% sensitivity and 100% specificity. The results of the present work showed that measurement of CD64 expression on neutrophils could be used as a sensitive and specific marker for detection of infection in SLE patients and differentiation between infection and disease activity