Increased oxidative stress response in circulating blood of systemic sclerosis patients - relation to disease characteristics and inflammatory blood biomarkers

Serum IL-17 and TNFα as prognostic biomarkers in systemic sclerosis patients: a prospective study

Recent reports have demonstrated that endothelial injury is critical in the pathogenesis of systemic sclerosis (SSc) and is associated with increased levels of circulating inflammatory biomarkers. This study aims to analyze the serum concentrations of selected cytokines and evaluate their relationship with SSc clinics and the long-term course of the disease. This study included 43 SSc patients and 24 matched healthy controls. In both groups, we measured serum levels of inflammatory cytokines related to the inflammatory response, such as tumor necrosis factor (TNF)α, interferon (IFN)γ, interleukin (IL)-4, IL-6, IL-10, and IL-17, and fibroblast activation protein (FAP). Additionally, in SSc patients, we evaluated the presence of four single nucleotide polymorphisms (SNPs) located in the promotor region of the TNFA gene, namely rs361525, rs1800629, rs1799964, and rs1799724, which might be related to increased TNFα concentrations. The main aim consisted of associating inflammatory cytokines with (1) clinical disease characteristics and (2) longitudinal observation of survival and cancer prevalence. SSc patients were characterized by a 17% increase in serum TNFα. There was no other difference in serum cytokines between the studied groups and diffuse vs. limited SSc patients. As expected, evaluated serum cytokines correlated with inflammatory biomarkers (e.g., IL-6 and C-reactive protein). Interestingly, patients with higher IL-17 had decreased left ventricle ejection fraction. During the median 5-year follow-up, we recorded four cases of neoplastic diseases (lung cancer in two cases, squamous cell carcinoma of unknown origin, and breast cancer with concomitant multiple myeloma) and nine deaths. The causes of death included lung cancer (n = 2), renal crisis (n = 1), multiple-organ failure (n = 1), and unknown reasons in five cases. Surprisingly, higher TNFα was associated with an increased cancer prevalence, while elevated IL-17 with death risk in the follow-up. Furthermore, the AG rs361525 genotype referred to higher TNFα levels than GG carriers. Both AG rs361525 and CT rs1799964 genotypes were associated with increased cancer risk. Higher serum concentrations of TNFα characterize the SSc patients, with the highest values associated with cancer. On the other hand, increased IL-17 in peripheral blood might predict poor SSc prognosis. Further research is needed to validate these findings.

Higher gamma-glutamyl transferase levels are associated with an increased risk of incident systemic sclerosis: a nationwide population-based study

Gamma-glutamyl transferase (GGT) is known to promote oxidative stress. As oxidative stress is a key component in the pathogenesis of systemic sclerosis (SSc), we investigated whether GGT levels are associated with the risk of incident SSc. A cohort of individuals without SSc who underwent national health examination in 2009 were extracted from the Korean National Health Insurance Service database. The incidence rate of SSc during the observation period, between 2009 and 2019, was estimated. GGT levels measured in 2009 were categorized into quartiles (Q1 [lowest], Q2, Q3, and Q4 [highest]). Multivariable Cox proportional hazard models were used to estimate the risk of incident SSc according to the quartiles of GGT, using Q1 as the reference. A total of 6,091,788 individuals were included. Incidence rate of SSc was 1.16 per 100,000 person-years over a mean observation period of 9.2 years. After adjusting for age, sex, body mass index, economic income, smoking status, alcohol consumption, physical activity, hypertension, type 2 diabetes, dyslipidemia, and chronic kidney disease, higher quartiles of GGT levels were significantly associated with a higher risk of incident SSc (Q4: adjusted hazard ratio [aHR] 1.807, 95% confidence interval CI 1.446-2.259; Q3: aHR 1.221, 95% CI 0.971-1.536; and Q2: aHR 1.034, 95% CI 0.807-1.324; p for trend < 0.001). Higher GGT levels were associated with a higher risk of incident SSc. These findings could lead to a closer monitoring for high risk individuals and an earlier diagnosis and treatment.

Endothelial dysfunction, thrombophilia, and nailfold capillaroscopic features in livedoid vasculopathy

BACKGROUND

Livedoid vasculopathy (LV) is a rare, disabling disease characterized by painful ulcers, livedo reticularis and atrophy blanche. Hypercoagulation, endothelial, and microcirculatory dysfunction are believed to be responsible for the pathogenesis of this difficult-to-treat disease.

OBJECTIVES

This study sought to investigate the frequency of endothelial dysfunction, hypercoagulability, and nailfold capillaroscopic features in LV patients to shed light on its etiology.

METHODS

This case-control study included 16 patients with LV, 24 with systemic sclerosis (SSc), and 23 control subjects. Serum markers of endothelial dysfunction soluble endoglin, endocan, endothelin-1, lipoprotein a, plasminogen activator inhibitor-1 (PAI-1), soluble thrombomodulin, and von Willebrand factor were measured using enzyme-linked immunosorbent assays. Flow-mediated dilation and carotid intima-media thickness were examined as markers of endothelial dysfunction, and microcirculation was assessed with nailfold capillaroscopy. Thrombophilia-related parameters, including gene polymorphisms of factor V Leiden, prothrombin, PAI-1 genes, methylenetetrahydrofolate reductase (MTHFR) and factor XIII mutation and serum levels of protein C, protein S, antithrombin, homocysteine, D-dimer and antiphospholipid antibodies were investigated in LV patients.

RESULTS

Plasminogen activator inhibitor-1 and soluble thrombomodulin levels were significantly higher in LV patients compared to control subjects (2.3 [2.05-2.79] ng/ml vs. 1.89 [1.43-2.33] ng/ml, p = 0.007; 1.15 [0.88-1.4] ng/ml vs. 0.76 [0.56-0.9] ng/ml, p = 0.004, respectively). Flow-mediated dilation was 25.4 % lower in the LV patients compared to the control group (14.77 % [11.26-18.26] vs. 19.80 % [16.47-24.88], p = 0.034). Capillaroscopic features, including ramifications (75 % vs. 8.7 %, p < 0.001), avascular areas (25 % vs. 0 %, p = 0.011) and dilatations (33.2 % vs. 0 %, p = 0.016), were significantly higher in LV patients than in controls. LV patients had multiple biochemical or genetic abnormalities related to thrombophilia, including heterozygous factor V Leiden mutations (6.3 %), MTHFR (C677T) mutations (heterozygous 43.8 %, homozygous 18.8 %), MTHFR (A1298C) mutations (heterozygous 37.5 %, homozygous 12.5 %), factor XIII heterozygous mutation (12.5 %), antithrombin deficiency (31.3 %), protein S deficiency (12.5 %), hyperhomocysteinemia (31.3 %), D-dimer elevation (25 %), anti-β2-glycoprotein I (12.5 %), lupus anticoagulant antibodies (6.3 %), and anticardiolipin antibodies (6.3 %).

CONCLUSIONS

In conclusion, LV patients were characterized by an increased presence of thrombophilia-related parameters, and also exhibited vascular endothelial and microcirculatory dysfunction, resembling SSc. These findings support the complex interaction of thrombophilia, endothelial dysfunction, and microcirculation dysregulation in the pathogenesis of LV. Thus, the treatment of LV patients should be individualized, based on the identification of the predominant pathological pathways.

Malondialdehyde Serum Levels in Patients with Systemic Sclerosis Relate to Dyslipidemia and Low Ventricular Ejection Fraction

Systemic sclerosis (SSc) is a chronic disease characterized by vasculopathy with the involvement of dysfunctional microcirculatory vessels. Features of the disease include progressive fibrosis of the skin and internal organs and systemic inflammation characterized by the presence of circulating autoantibodies and proinflammatory cytokines. Furthermore, macrovascular disease and atherosclerosis are more common in patients with SSc than in the general population. Oxidative stress plays a crucial role in the development of several processes, including endothelial dysfunction, cancer, inflammation, and atherogenesis. Malondialdehyde (MDA) is a well-established marker of oxidative stress. In this work, we have analyzed the relationship between serum MDA levels and clinical, laboratory, and vascular characteristics in a well-characterized cohort of 53 patients with SSc. A multivariable analysis was performed to study the relationship between circulating MDA and disease characteristics in patients with SSc. Cardiovascular assessment was also performed, including ultrasonography of the carotid and aorta, and echocardiography. MDA showed a significant and positive relationship with the serum levels of lipid profile molecules such as total cholesterol (β coefficient = 0.006 (95% CI: 0.0004 to 0.01), nmol/mL, p = 0.037) and LDL cholesterol (β coefficient = 0.008 (95% CI: 0.001 to 0.01) nmol/mL, p = 0.017). On the contrary, most manifestations of the disease, including skin, lung, and joint involvement, as well as the presence of digital ulcers, were not related to MDA. However, high MDA levels were significantly and independently associated with lower ventricular ejection fraction after adjustment for covariates (β coefficient = -0.04 (95% CI: -0.06 to -0.02), nmol/mL, p = 0.001). In conclusion, serum MDA levels were related to higher levels of total and LDL cholesterol and a lower left ventricular ejection fraction in patients with SSc. MDA could serve as a potential biomarker of dyslipidemia and heart failure in SSc.