Mechanisms behind flare of renal lupus during murine pregnancy

Effects of autoimmune abnormalities on fertility and placental morphology in mice

Autoimmune diseases (AIDs) alter the placental immune environment leading to fetal loss. This study investigated the effects of AIDs on pregnancy and the placenta in AID-prone MRL/MpJ-Faslpr/lpr mice and wild-type MRL/MpJ, which were mated with male MRL/MpJ and MRL/MpJ-Faslpr/lpr at five months and defined as moLpr and moMpJ, respectively. AID indices (spleen weight and serum autoantibody levels) and fertility status (number and size of fetuses, morphology, and comprehensive gene expression of placentas) were evaluated on gestational day 15.5. Both strains showed equivalent fertility, but moLpr showed lighter placentas and fetuses than moMpJ, and decreased fertility with AID severity. moLpr placentas had a higher number of T cells, higher expression of genes associated with T helper 2 and T follicular helper functions, and altered expression of genes (Krt15, Slc7a3, Sprr2a3) that significantly regulate pregnancy or immunity. The gene expression of T cell migration-associated chemokines (Ccl5, Cxcl9) was significantly increased in moLpr placentas, and CCL5 and CXCL9 were detected in moLpr placentas, particularly in T cells and placenta-component cells, respectively. Thus, AID altered placental morphofunction and fertility in mice; however, fertility was maintained at the examined time points. This study enhances our understanding of placental alterations and gestational risk due to AIDs.

Role of Sex Hormones in Prevalent Kidney Diseases

Chronic kidney disease (CKD) is a constantly growing global health burden, with more than 840 million people affected worldwide. CKD presents sex disparities in the pathophysiology of the disease, as well as in the epidemiology, clinical manifestations, and disease progression. Overall, while CKD is more frequent in females, males have a higher risk to progress to end-stage kidney disease. In recent years, numerous studies have highlighted the role of sex hormones in the health and diseases of several organs, including the kidney. In this review, we present a clinical overview of the sex-differences in CKD and a selection of prominent kidney diseases causing CKD: lupus nephritis, diabetic kidney disease, IgA nephropathy, and autosomal dominant polycystic kidney disease. We report clinical and experimental findings on the role of sex hormones in the development of the disease and its progression to end-stage kidney disease.

Urticaria in Pregnancy and Lactation

Chronic urticaria (CU) is a mast cell-driven chronic inflammatory disease with a female predominance. Since CU affects mostly females in reproductive age, pregnancy is an important aspect to consider in the context of this disease. Sex hormones affect mast cell (MC) biology, and the hormonal changes that come with pregnancy can modulate the course of chronic inflammatory conditions, and they often do. Also, pregnancy-associated changes in the immune system, including local adaptation of innate and adaptive immune responses and skewing of adaptive immunity toward a Th2/Treg profile have been linked to changes in the course of inflammatory diseases. As of now, little is known about the effects of pregnancy on CU and the outcomes of pregnancy in CU patients. Also, there are no real-life studies to show the safety of urticaria medications during pregnancy. The recent PREG-CU study provided the first insights on this and showed that CU improves during pregnancy in half of the patients, whereas it worsens in one-third; and two of five CU patients experience flare-ups of their CU during pregnancy. The international EAACI/GA2LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends adopting the same management strategy in pregnant and lactating CU patients; starting treatment with standard doses of second-generation (non-sedative) H1 antihistamines, to increase the dose up to 4-folds in case of no response, and to add omalizumab in antihistamine-refractory patients; but also emphasizes the lack of evidence-based information on the safety and efficacy of urticaria treatments during pregnancy. The PREG-CU study assessed treatments and their outcomes during pregnancy. Here, we review the reported effects of sex hormones and pregnancy-specific immunological changes on urticaria, we discuss the impact of pregnancy on urticaria, and we provide information and guidance on the management of urticaria during pregnancy and lactation.

T helper cell immunity in pregnancy and influence on autoimmune disease progression

Pregnancy presents the maternal immune system with a unique immunological challenge since it has to defend against pathogens while tolerating paternal allo-antigens expressed by fetal tissues. T helper (Th) cells play a central role in modulating immune responses and recent advances have defined distinct contributions of various Th cell subsets throughout each phase of human pregnancy, while dysregulation in Th responses show association with multiple obstetrical complications. In addition to localized decidual mechanisms, modulation of Th cell immunity during gestation is mediated largely by oscillations in sex hormone concentrations. Aberrant Th cell responses also underlie several autoimmune disorders while pregnancy-induced changes in the balance of Th cell immunity has been shown to exert favorable outcomes in the progression Th1 and Th17 driven autoimmune conditions only to be followed by post-partal exacerbations in disease.

Nicotinamide alleviates kidney injury and pregnancy outcomes in lupus-prone MRL/lpr mice treated with lipopolysaccharide

Systemic lupus erythematosus (SLE) increases the risk of preterm birth and preeclampsia (PE). The flares of SLE during pregnancy or after delivery are also problematic. We have previously demonstrated that nicotinamide (NAM), a non-teratogenic amide of vitamin B3, reduces inflammation and oxidative stress and improves PE-like phenotype and pregnancy outcomes in the mouse models of PE. The present study aimed to establish a model to investigate the pregnancy outcomes and flares of SLE in pregnant mice with SLE and to examine whether NAM is beneficial to pregnant mice with SLE. We used pregnant and non-pregnant lupus-prone MRL/lpr mice treated with or without a Toll-like receptor (TLR) ligand lipopolysaccharide (LPS) because TLR4 signaling reportedly exacerbates SLE and pregnancy; MRL/+ mice were used as controls. Blood pressure (BP) and urinary albumin excretion were increased only in the pregnant MRL/lpr-LPS mice. LPS together with pregnancy exacerbated glomerulonephritis, and the most severe inflammation was observed in the kidneys of the pregnant MRL/lpr-LPS mice. The shortening of pregnancy periods, increase in fetal demise percentage, and reduction in fetal weight were observed only in the pregnant MRL/lpr-LPS mice. NAM improved BP and kidney injury, prolonged pregnancy periods, and improved fetal growth in the pregnant MRL/lpr-LPS mice. The results suggest that SLE patients are prone to develop poor pregnancy outcome, and likely develop severe nephropathy and kidney inflammation. NAM may be a novel therapeutic option that improves kidney injury and pregnancy outcomes, thereby benefiting pregnant patients with SLE.

Risk factors of systemic lupus erythematosus flares during pregnancy

This review examines the risk factors for the development of systemic lupus erythematosus (SLE) flares during pregnancy. In preconception, anti-DNA, hypocomplementemia, previous thrombosis, triple antiphospholipid (aPL) antibody positivity, active lupus nephritis and discontinuation of medications such as hydroxychloroquine and azathioprine are factors associated with pregnancy failure. During pregnancy, SLE flares are associated with aPL antibodies, synergic changes of pregnancy on Th1 and TH2 cytokines, other cytokines and chemokines that interact with hormones such as estrogen and prolactin that amplify the inflammatory effect. From the clinical point of view, SLE activity at pregnancy onset, thrombocytopenia, lupus nephritis, arterial hypertension, aPL syndromes, preeclampsia is associated with lupus flares and fetal complications. In puerperium, the risk factors of flares are similar to pregnancy. Hyperactivity of immune system, autoantibodies, hyperprolactinemia, active lupus nephritis, decrease in TH2 cytokines with increase in TH1 cytokines probably participate in SLE flare. The SLE flares during pregnancy make the difference between an uncomplicated pregnancy and pregnancy with maternal and fetal complications. Therefore, the knowledge of risk factors leads the best treatment strategies to reduce flares and fetal complications in SLE patients.