These authors reported the fact that expression of C3aR was increased in peripheral blood mononuclear cells (PBMC) from patients with active Beh?et disease and, upon stimulation with serum samples from patients, the expression of C3aR was significantly induced in PBMC (Wang et al

These authors reported the fact that expression of C3aR was increased in peripheral blood mononuclear cells (PBMC) from patients with active Beh?et disease and, upon stimulation with serum samples from patients, the expression of C3aR was significantly induced in PBMC (Wang et al., 2017). C5a induces translocation of ANCA antigens, favouring the detrimental role of antibodies. Complement deposition in the kidneys identifies patients with more aggressive renal disease; patients with active disease display low serum levels of C3 and C4. Even though in dermatomyositis sC5b-9 deposits are invariably present in affected muscles, data on C3 and C4 fluctuation during disease course are scarce. C3 Sapacitabine (CYC682) and C1q serum levels have been explored as potential markers of disease activity in Takayasu arteritis, whereas data in Beh?et disease are limited to observations. Pregnancies in women with rheumatologic conditions are still burdened by a higher rate of pregnancy complications, thus the early identification of women at risk would be invaluable. A fine-tuning of complement activation is required from a physiological progression of pregnancy, from pre-implantation stages, through placentation to labour. Complement deregulation has been implicated Sapacitabine (CYC682) in several pregnancy complications, such as recurrent abortion, eclampsia and premature birth; low complement levels have been shown to reliably identify women at risk of complications. Given its physiologic role in orchestrating pregnancy progression and its involvement as pathogenic effector in several rheumatologic conditions, complement system is an attractive candidate biomarker to stratify the obstetric risk among women with rheumatologic conditions. data have clearly demonstrated that the activation of both the classical and the alternative pathways is required to mediate thrombotic events and pregnancy loss induced by stimulation with anti-phospholipid antibodies (aPL). As recently reviewed, the relevance of activated complement in relation to obstetric complications has been confirmed in SLE as well as APS women: Sapacitabine (CYC682) immunohistochemical analysis of placental samples from complicated pregnancies has shown deposition of complement fragments, in particular C4d which provides a fingerprint of complement tissue activation due to its high stability (Chighizola et al., 2020). Furthermore, pregnant women with SLE and APS display higher serum levels of complement Sapacitabine (CYC682) degradation products compared to healthy expectant mothers (Kim et al., 2018; Scambi et al., 2019). Despite the progressively raising bulk of evidence, available data on C3 and C4 as predictors of adverse obstetric outcome in lupus and APS are not consistent, not yet allowing to draw definite conclusions about the clinical relevance of complement monitoring throughout pregnancy progression Rabbit polyclonal to AMID in these settings (Chighizola et al., 2020; Nalli et al., 2021). Of note, in SLE even the association between complement levels during pregnancy and disease flare is questioned, due to the physiologic fluctuation of complement levels during gestation. Nevertheless, it is common practice to monitor complement levels to discriminate between nephritis and pre-eclampsia in SLE expecting mothers presenting new-onset proteinuria: the serum C3 and C4 levels rise in patients with pre-eclampsia, while disease flares are classically characterized by consumed C3 and C4 and raise of anti-dsDNA titres (Mok, 2001). Scarce evidence on the relevance of complement testing to monitor disease activity and to predict obstetric outcome is available for pregnant patients with rheumatologic conditions other than SLE and APS. However, more and more often these patients express their desire for motherhood to the attending rheumatologist: most commonly, women with inflammatory arthritides, including rheumatoid arthritis (RA) and psoriatic arthritis (PsA); less frequently, women with Sj?gren syndrome (SjS) and systemic sclerosis (SSc), which tend to manifest later in life; seldom patient with vasculitides and idiopathic inflammatory myopathies (IIM), which are uncommon conditions. After addressing the contribution of complement system Sapacitabine (CYC682) to the progression of healthy pregnancy and the detrimental role of complement deregulation in pregnancy complications, this review will focus on the relevance of complement in rheumatologic conditions other than SLE and APS, discussing available evidence about the involvement of complement in disease pathogenesis and about the clinical significance of complement serum levels. We will also recapitulate available data on the.