ABSTRACT
Neutrophil extracellular traps (NETs) are cell-extruded DNA strands coated with neutrophils' nuclear proteins and enzymes from cytotoxic granules, produced by NETosis, a cell death pathway. They perform an important defensive role in innate immunity, but their increased production and/or inefficient degradation expose new antigens, such as DNA or citrullinated histone peptides, triggering autoimmunity. This study aimed to access possible associations between serum NETs levels with epidemiological, clinical, and serological data from a well-characterized SLE Brazilian patients' cohort. NET levels were evaluated in one hundred seventy serum samples of patients with Systemic Lupus Erythematosus (SLE) using an Immunoassay. Univariate and multivariate binary logistic regression used clinical patients' data as independent variables. Parametric and non-parametric tests compared log10 base serum NET levels transformed between patients' groups. SLE patients were also dichotomized into "High serum NET levels" and "Low serum NET levels" groups. All analyses were performed in R language 4.1.2, and p < 0.05 were considered significant. Increased susceptibility for high serum NET levels was observed in SLE patients with Raynaud's phenomenon (OR = 2.30, 95 % CI = 1.06-5.21 and p = 0.039), independently of any other risk factor. Also, SLE patients with Raynaud's phenomenon presented higher mean NET serum levels (mean = -0.13 vs. -0.51, p = 0.01). In addition, higher mean NET serum levels were associated with glomerulonephritis (mean = -0.45 vs. -0.12, p = 0.03). Ultimately, the SLEDAI index scored higher in the high NETs serum levels group (median = 2.0 vs. 0.0, p = 6 × 10-3). The formation of NETs might be implicated in Raynaud's phenomenon, glomerulonephritis, and disease index score in SLE patients. Our results highlight the importance of serum NET levels as a possible therapeutical target to modulate the clinical course of SLE.
Subject(s)
Extracellular Traps , Lupus Erythematosus, Systemic , Raynaud Disease , Humans , Extracellular Traps/metabolism , Extracellular Traps/immunology , Female , Male , Brazil/epidemiology , Adult , Lupus Erythematosus, Systemic/blood , Lupus Erythematosus, Systemic/diagnosis , Lupus Erythematosus, Systemic/immunology , Raynaud Disease/etiology , Raynaud Disease/blood , Raynaud Disease/immunology , Middle Aged , Neutrophils/immunology , Severity of Illness Index , Glomerulonephritis/blood , Glomerulonephritis/immunology , Glomerulonephritis/diagnosis , Young Adult , Biomarkers/bloodABSTRACT
BACKGROUND AND AIMS: The inflammatory response in preterm parturition is regulated by the innate immune system. Toll-like receptors (TLR)-2 and TLR-4 are innate immune receptors that recognize the microorganisms most frequently involved in amniotic cavity infections, which are associated with activating the inflammatory response at the maternal-fetal interface during preterm labor. This study aimed to evaluate the expression of TLR-2 and TLR-4 in maternal neutrophils in preterm labor. METHODS: A cross-sectional study was conducted in the Obstetrics Care Unit of Botucatu Medical School, UNESP, Brazil. The preterm group was composed of 20 pregnant women who presented preterm labor and preterm delivery. The control group was composed of 20 nonlaboring pregnant women matched to the preterm group by gestational age. Neutrophils were isolated from peripheral blood and TLR expressions were performed by real-time polymerase chain reaction and flow cytometry. RESULTS: Gene expressions of TLR-2 and TLR-4 in neutrophils from the preterm group were statistically higher than expressions in neutrophils from the matched control group. The percentage of TLR-4+ neutrophils was higher in the preterm group than the matched control group, while the percentage of TLR-2+ neutrophils did not differ between groups. CONCLUSION: TLR-4 expression in maternal neutrophils is associated with spontaneous preterm labor.