At present infertility is affecting about 15% of couples and male factor is responsible for almost 50% of infertility cases. Oxidative stress, due to enhanced Reactive Oxygen Species (ROS) production and/or decreased antioxidants, has been repeatedly suggested as a new emerging causative factor of this condition. However, the central roles exerted by ROS in sperm physiology cannot be neglected. On these bases, the present review is focused on illustrating both the role of ROS in male infertility and their main sources of production. Oxidative stress assessment, the clinical use of redox biomarkers and the treatment of oxidative stress-related male infertility are also discussed.

Behçet’s syndrome (BS) is a systemic vasculitis with several clinical manifestations. Neutrophil hyperactivation mediates vascular BS pathogenesis, via both a massive reactive oxygen species (ROS) production and neutrophil extracellular traps (NETs) release. Here, we investigated neutrophil‐mediated mechanisms of damage in non‐vascular BS manifestations and explored the in‐vitro effects of colchicine in counteracting these mechanisms. NETs and intracellular ROS production was assessed in blood samples from 80 BS patients (46 with active non‐vascular BS, 34 with inactive disease) and 80 healthy controls. Moreover, isolated neutrophils were incubated for 1 h with an oxidating agent [2,2′‐azobis (2‐amidinopropane) dihydrochloride; 250 nM] and the ability of pure colchicine pretreatment (100 ng/ml) to counteract oxidation‐induced damage was assessed. Patients with active non‐vascular BS showed remarkably increased NET levels [21.2, interquartile range (IQR) = 18.3–25.9 mU/ml] compared to patients with inactive disease (16.8, IQR = 13.3–20.2 mU/ml) and to controls (7.1, IQR = 5.1–8.7 mU/ml, p < 0.001]. Also, intracellular ROS tended to increase in active BS, although not significantly. In active non‐vascular BS, NETs correlated with neutrophil ROS production (p < 0.001) and were particularly increased in patients with active mucosal (p < 0.001), articular (p = 0.004) and gastrointestinal symptoms (p = 0.006). In isolated neutrophils, colchicine significantly reduced oxidation‐induced NET production and cell apoptosis, although not via an anti‐oxidant activity. Neutrophil‐mediated mechanisms might be directly involved in non‐vascular BS, and NETs, more than ROS, might drive the pathogenesis of mucosal, articular and intestinal manifestations. Colchicine might be effective in counteracting neutrophils‐mediated damage in BS, although further studies are needed.

Thrombosis is a common disorder with a relevant burden of morbidity and mortality worldwide, particularly among elderly patients. Growing evidence demonstrated a direct role of oxidative stress in thrombosis, with various cell types contributing to this process. Among them, erythrocytes produce high quantities of intracellular reactive oxygen species (ROS) by NADPH oxidase activation and haemoglobin autoxidation. Concomitantly, extracellular ROS released by other cells in the blood flow can be uptaken and accumulate within erythrocytes. This oxidative milieu can alter erythrocyte membrane structure, leading to an impaired erythrocyte function, and promoting erythrocytes lysis, binding to endothelial cells, activation of platelet and of coagulation factors, phosphatidylserine exposure and release of microvesicles. Moreover, these abnormal erythrocytes are able to adhere to the vessel wall, contributing to thrombin generation within the thrombus. This process results in accelerated haemolysis and in a hypercoagulable state, in which structurally impaired erythrocytes contribute to increase thrombus size, to reduce its permeability and susceptibility to lysis. However, the wide plethora of mechanisms by which oxidised erythrocytes contribute to thrombosis is not completely elucidated. This review discusses the main biochemical aspects linking erythrocytes, oxidative stress and thrombosis, addressing their potential implication for clinical and therapeutic management.

Giant cell arteritis (GCA), medium and large vessel granulomatous vasculitis affecting the elderly, is characterized by a multitude of vascular complications, including venous thrombosis, myocardial infraction and stroke. The formation of granulomatous infiltrates and the enhanced accumulation of proinflammatory cytokines are typical features of this condition. The GCA pathogenesis remains largely unknown, but recent studies have suggested the involvement of oxidative stress, mainly sustained by an enhanced reactive oxygen species (ROS) production by immature neutrophils. On this basis, in the present study, we intended to evaluate, in GCA patients, the presence of systemic oxidative stress and possible alterations in the expression level of nuclear sirtuins, enzymes involved in the inhibition of inflammation and oxidative stress. Thirty GCA patients were included in the study and compared to 30 healthy controls in terms of leukocyte ROS production, oxidative stress and SIRT1 expression. Our results clearly indicated a significant increase (p < 0.05) both in the ROS levels in the leukocyte fractions and plasma oxidative stress markers (lipid peroxidation and total antioxidant capacity) in the GCA patients compared to the healthy controls. In PBMCs from the GCA patients, a significant decrease in SIRT1 expression (p < 0.05) but not in SIRT6 and SIRT7 expression was found. Taken together, our preliminary findings indicate that, in GCA patients, plasma oxidative stress is paralleled by a reduced SIRT1 expression in PBMC. Further studies are needed to highlight if and how these alterations contribute to GCA pathogenesis.

A large proportion of infertile men do not receive a clear diagnosis, being considered as idiopathic or unexplained cases due to infertility diagnosis based on standard semen parameters. Particularly in unexplained cases, the search for new indicators seems mandatory to provide specific information. In the etiopathogenesis of male infertility oxidative stress displays important roles by negatively affecting sperm quality and function. In this study, performed in a population of 34 idiopathic infertile men and in 52 age-matched controls, redox parameters were assessed in blood, leukocytes, spermatozoa, and seminal fluid and related to semen parameters. The main findings indicate that blood oxidative stress markers reflect seminal oxidative stress. Interestingly, blood leukocyte ROS production was significantly correlated to sperm ROS production and to semen parameters. Overall, these results suggest the potential employ of blood redox markers as a relevant and adjunctive tool for sperm quality evaluation aimed to preconception care.