Complement split product C4d deposition in placenta in systemic lupus erythematosus and pregnancy-induced hypertension

Pregnancy as a susceptible state for thrombotic microangiopathies

Pregnancy and the postpartum period represent phases of heightened vulnerability to thrombotic microangiopathies (TMAs), as evidenced by distinct patterns of pregnancy-specific TMAs (e.g., preeclampsia, HELLP syndrome), as well as a higher incidence of nonspecific TMAs, such as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, during pregnancy. Significant strides have been taken in understanding the underlying mechanisms of these disorders in the past 40 years. This progress has involved the identification of pivotal factors contributing to TMAs, such as the complement system, ADAMTS13, and the soluble VEGF receptor Flt1. Regardless of the specific causal factor (which is not generally unique in relation to the usual multifactorial origin of TMAs), the endothelial cell stands as a central player in the pathophysiology of TMAs. Pregnancy has a major impact on the physiology of the endothelium. Besides to the development of placenta and its vascular consequences, pregnancy modifies the characteristics of the women's microvascular endothelium and tends to render it more prone to thrombosis. This review aims to delineate the distinct features of pregnancy-related TMAs and explore the contributing mechanisms that lead to this increased susceptibility, particularly influenced by the "gravid endothelium." Furthermore, we will discuss the potential contribution of histopathological studies in facilitating the etiological diagnosis of pregnancy-related TMAs.

Placental damage in pregnancies with systemic lupus erythematosus: A narrative review

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease of unknown cause, which mainly affects women of childbearing age, especially between 15 and 55 years of age. During pregnancy, SLE is associated with a high risk of perinatal morbidity and mortality. Among the most frequent complications are spontaneous abortion, fetal death, prematurity, intrauterine Fetal growth restriction (FGR), and preeclampsia (PE). The pathophysiology underlying obstetric mortality and morbidity in SLE is still under investigation, but several studies in recent years have suggested that placental dysfunction may play a crucial role. Understanding this association will contribute to developing therapeutic options and improving patient management thus reducing the occurrence of adverse pregnancy outcomes in this group of women. In this review, we will focus on the relationship between SLE and placental insufficiency leading to adverse pregnancy outcomes.

Characteristics of childhood-onset systemic lupus erythematosus in pregnancy and its association with pregnancy outcomes: a retrospective comparative cohort study

BACKGROUND

Disease situations are more aggressive in patients with childhood-onset systemic lupus erythematosus (cSLE) than in those with adult-onset SLE (aSLE). However, information on pregnant women with cSLE and its association with pregnancy outcomes is limited. This study aimed to compare pregnancies in patients with cSLE vs. aSLE, and further analyse the characteristics of cSLE in pregnant women and explore its association with adverse pregnancy outcomes.

METHODS

Altogether, data of 167 pregnancies from 150 women, including 22 pregnancies with cSLE and 145 pregnancies with aSLE, were retrospectively analysed. Characteristics and disease activity were compared between the cSLE and aSLE groups during pregnancy. Associations between cSLE and the risk of active SLE (SLEPDAI > 4), active lupus nephritis (LN), and adverse pregnancy outcomes were analysed using logistic regression.

RESULTS

The cSLE group had a higher incidence of active SLE (12/22 vs. 30/145, P = 0.001) and active LN (11/22 vs. 26/145, P = 0.001) than the aSLE group. In the multivariable analysis, cSLE was a risk factor for active SLE and active LN during pregnancy, with ORs of 4.742 (95%CI 1.678-13.405, P = 0.003) and 4.652 (95%CI 1.630-13.279, P = 0.004), respectively. No significant association between cSLE and the risk of composite adverse gestational outcomes was identified after sequentially adjusting pre-pregnancy characteristics and pregnancy factors (P > 0.05).

CONCLUSION

Disease activity of women with cSLE in pregnancy was more aggressive than that of women with aSLE, which was similar to the characteristics of non-pregnant women with SLE. cSLE might have indirect effects on the risk of adverse pregnancy outcomes through LN and active disease. Therefore, closely monitoring patients with cSLE during pregnancy is crucial.

An Overview of Neonatal Lupus with Anti-Ro Characteristics

Neonatal lupus erythematosus (NLE) is a syndrome of clinical symptoms observed in neonates born to mothers with antibodies to soluble antigens of the cell nucleus. The main factors contributing to the pathogenesis of this disease are anti-Sjögren Syndrome A (anti-SS-A) antibodies, known as anti-Ro, and anti-Sjögren Syndrome B (anti-SS-B) antibodies, known as anti-La. Recent publications have also shown the significant role of anti-ribonucleoprotein antibodies (anti-RNP). Seropositive mothers may have a diagnosed rheumatic disease or they can be asymptomatic without diagnosis at the time of childbirth. These antibodies, after crossing the placenta, may trigger a cascade of inflammatory reactions. The symptoms of NLE can be divided into reversible symptoms, which concern skin, hematological, and hepatological changes, but 2% of children develop irreversible symptoms, which include disturbances of the cardiac stimulatory and conduction system. Preconceptive care and pharmacological prophylaxis of NLE in the case of mothers from the risk group are important, as well as the monitoring of the clinical condition of the mother and fetus throughout pregnancy and the neonatal period. The aim of this manuscript is to summarize the previous literature and current state of knowledge about neonatal lupus and to discuss the role of anti-Ro in the inflammatory process.

The Complement System in the Pathophysiology of Pregnancy and in Systemic Autoimmune Rheumatic Diseases During Pregnancy

The complement system plays a double role in pregnancy exerting both protective and damaging effects at placental level. Complement activation at fetal-maternal interface participates in protection against infectious agents and helps remove apoptotic and necrotic cells. Locally synthesized C1q contributes to the physiologic vascular remodeling of spiral arteries characterized by loss of smooth muscle cells and transformation into large dilated vessels. Complement activation triggered by the inflammatory process induced by embryo implantation can damage trophoblast and other decidual cells that may lead to pregnancy complications if the cells are not protected by the complement regulators CD55, CD46, and CD59 expressed on cell surface. However, uncontrolled complement activation induces placental alterations resulting in adverse pregnancy outcomes. This may occur in pathological conditions characterized by placental localization of complement fixing antibodies directed against beta2-glycoprotein 1, as in patients with anti-phospholipid syndrome, or circulating immune complexes deposited in placenta, as in patients with systemic lupus erythematosus. In other diseases, such as preeclampsia, the mechanism of complement activation responsible for complement deposits in placenta is unclear. Conflicting results have been reported on the relevance of complement assays as diagnostic and prognostic tools to assess complement involvement in pregnant patients with these disorders.

Elevated C-reactive protein and complement C3 levels are associated with preterm birth: a nested case-control study in Chinese women

BACKGROUND

Currently, there are many studies researched the associations between maternal serum inflammatory indicators (i.e. ferritin, C-reactive protein [CRP], C3 and C4) and preterm birth (PTB). The results, however, are inconsistent. Therefore, the aim of this study was to estimate the relationship between maternal serum inflammatory indicators and PTB in a nested case-control (NCC)study.

METHODS

A NCC study was conducted by Guangxi Birth Cohort Study which enrolled a total of 6203 pregnant women between 5^0/7 and 34^6/7 weeks of gestational age (wGA) from six cities in China between 2015 and 2016. There were 206women who delivered preterm (< 37^0/7 wGA), and 412 women who delivered term birth, those women were matched by maternal age, birth place, gender of infants, and wGA at blood collection. The inflammatory indicators were quantified by immunoturbidimetric methods.

RESULTS

Highest quartile concentrations of all inflammatory indicators were determined versus median. After adjusting for maternal age, high levels of CRP (CRP > 16.60 mg/L) are related to the risk of PTB (OR = 2.16, 95% CI: 1.02-4.56, p = 0.044) in the first trimester. The association of C3 was extremely related to those who delivered PTB (OR = 2.53, 95% CI: 1.14-5.64, p = 0.023) in the first trimester. Moreover, no significant associations were found in C4 (p = 0.079) and ferritin (p = 0.067) between PTB.

CONCLUSIONS

Elevated concentrations of CRP and C3 in the first trimester were associated with increased risk of PTB. Inflammatory indicators may act a pivotal part in early diagnosis and prognosis of PTB.

Effect of hypocomplementemia on perinatal outcomes of pregnancies with autoimmune disorders

OBJECTIVE

To demonstrate the effect of preconceptional complement levels on perinatal outcomes of pregnancies with autoimmune disorders.

METHODS

Pregnant women with autoimmune disorders (autoimmune disease and/or autoimmune antibody positivity) who were screened for complement levels (C3 and C4) prior to their pregnancies were enrolled in a special antenatal care program. These patients were administered low-dose low-molecular-weight heparin (enoxaparine, 1 × 2000 Anti-XA IU/0.2 mL/day), low-dose salysilic acid (100 mg/day) and low-dose corticosteroid (methylprednisolone, 1 × 4 mg/day orally) as soon as their pregnancies were confirmed according to the institutional protocol. We have compared hypo- and normocomplement pregnancies with autoimmune disorders in terms of their obstetric and perinatal outcomes. We have also used Beksac Obstetric Index (BOI) which is "[living child + (π/10)]/gravidity" for the comparison of their previous obstetric histories.

RESULTS

Obstetric and neonatal outcomes showed no significant difference between hypocomplement patients (n= 38) and control group (n= 157) (p> 0.05). "Composite obstetric and perinatal adverse outcome" rates were 26.2% and 27.3% in study and control groups, respectively (p> 0.05). BOI was significantly lower in hypocomplement patients (p: 0.002). Then, we have classified hypocomplement patients into 3 subgroups according to the type of complement (C3, C4 or both). Comparison inbetween these groups revealed no statistical significance in any of the analyzed parameters (p> 0.05).

CONCLUSION

Low complement levels in pregnant women with autoimmune disorders may be associated with gestational problems and poor obstetric history. Immunomodulatory treatment modalities such as ours may be beneficial for improving the obstetric and neonatal outcomes.

Absence of Distinct Immunohistochemical Distribution of Annexin A5, C3b, C4d, and C5b-9 in Placentas From Patients With Antiphospholipid Antibodies, Preeclampsia, and Systemic Lupus Erythematosus

INTRODUCTION

In pregnancy, the presence of preeclampsia (PEC), systemic lupus erythematosus (SLE), and/or antiphospholipid antibody syndrome (APLS) is characterized by poor obstetric outcomes, with potential adverse effects for both mother and fetus. Although the histopathologic changes observed in these entities have been well established, the pathogenic mediators associated with tissue injury are poorly understood.

METHODS

Forty placentas were evaluated, including 10 patients with preeclampsia, 9 with SLE, 11 with APLS, and 10 disease-free controls. Each case was subjected to a panel of immunohistochemical markers including C3b, C4d, Annexin A5, and C5b-9. Staining was graded on intensity and distribution.

RESULTS

C4d staining was distinctly different among disease groups and controls. Moreover, 6/10 PEC cases, 3/9 SLE cases, and 4/11 APLS cases showed at least focal staining for C4d. All controls were negative. Annexin A5 (AnxA5) staining showed intrinsic variability in all disease groups, while 10/10 controls showed diffuse, strong staining (2+ or 3+). C3b staining was heterogeneous among groups.

DISCUSSION

Previously, antiphospholipid antibody (aPLA)-associated pregnancy complications have been thought to be a consequence of a unique aPLA-mediated pathogenic mechanism. However, the immunohistochemical similarity (increased complement and decreased AnxA5 staining) observed in placentas from patients with APLS, PEC, and SLE suggests that aPLA-associated pregnancy complications may reflect a more general autoimmune mechanism.

C4d Deposition in Fetal Vessels of the Placenta in Neonatal Lupus Syndrome

Neonatal lupus syndrome (NLS) is a rare, passively acquired autoimmune syndrome caused by maternal autoantibodies. We describe a case of a newborn with NLS and the accompanying placental findings. A female neonate was born by emergency cesarean delivery due to non-reassuring fetal status at 35 weeks and 3 days. This neonate had congenital erythematous and scar lesions on the face, back, and upper and lower extremities. Maternal and fetal anti-SSA and SSB antibodies were elevated and this baby was diagnosed as NLS. Histologically, the chorionic villi demonstrated capillary shrinkage. An immunohistochemical study revealed complement deposition (C4d) in the capillaries of the villi and umbilical vessels. Our findings suggest that maternal autoantibodies affect the inflammatory response of the fetus through the placenta and that C4d deposition may be useful for diagnosing NLS.

Increased risk of systemic lupus erythematosus in pregnancy-induced hypertension: A nationwide population-based retrospective cohort study

Dysregulation of the immune system plays a role in the pathogenesis of both, pregnancy-induced hypertension (PIH) and systemic lupus erythematosus (SLE). It is well known that SLE predisposes to be complicated with PIH. However, few studies have attempted to investigate whether PIH increased subsequent SLE risk.The objectives of this study were to assess the association between PIH and subsequent SLE risk and identify predictive risk factors.Patients with newly diagnosed PIH were selected from the Taiwan National Health Insurance Research Database (NHIRD) and compared with a matched cohort without PIH based on age and the year of delivery. The incidence of new-onset SLE was evaluated in both cohorts. The overall observational period was from January 1, 2000 to December 31, 2013.Among the 23.3 million individuals registered in the NHIRD, 29,091 patients with PIH and 116,364 matched controls were identified. The incidence of SLE was higher among patients with PIH than in the matched controls (incidence rate ratio [IRR] = 4.02, 95% confidence interval [CI] 3.98-4.05, P < 0.0001). The IRR for subsequent SLE development remained significantly higher in all stratifications during the follow-up years. The multivariate Cox regression model was performed and the results showed that PIH may be an independent risk factors for the development of subsequent SLE (hazard ratio [HR] = 2.87, 95% CI 2.07-3.98, P < 0.0001). Moreover, multivariate Cox regression model was used again among the PIH cohort only in order to identify the possible risk factors for subsequent SLE in the population with PIH.Patients with PIH may have higher risk of developing newly diagnosed SLE than those without PIH. In addition, among individuals who have experienced PIH, those younger than 30 years, having experienced preeclampsia/eclampsia, single parity, preterm birth, or chronic kidney disease, may display an increased subsequent risk of 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.

Understanding and Managing Pregnancy in Patients with Lupus

Systemic lupus erythematosus (SLE) is a chronic, multisystemic autoimmune disease that occurs predominantly in women of fertile age. The association of SLE and pregnancy, mainly with active disease and especially with nephritis, has poorer pregnancy outcomes, with increased frequency of preeclampsia, fetal loss, prematurity, growth restriction, and newborns small for gestational age. Therefore, SLE pregnancies are considered high risk condition, should be monitored frequently during pregnancy and delivery should occur in a controlled setting. Pregnancy induces dramatic immune and neuroendocrine changes in the maternal body in order to protect the fetus from immunologic attack and these modifications can be affected by SLE. The risk of flares depends on the level of maternal disease activity in the 6–12 months before conception and is higher in women with repeated flares before conception, in those who discontinue useful medications and in women with active glomerulonephritis at conception. It is a challenge to differentiate lupus nephritis from preeclampsia and, in this context, the angiogenic and antiangiogenic cytokines are promising. Prenatal care of pregnant patients with SLE requires close collaboration between rheumatologist and obstetrician. Planning pregnancy is essential to increase the probability of successful pregnancies.

Placental C4d deposition is a feature of defective placentation: observations in cases of preeclampsia and miscarriage

Placental C4d deposition is frequent in preeclampsia, and shallow placentation is a characteristic of both preeclampsia and miscarriage. This study was conducted to determine the relationship among placental C4d, maternal human leukocyte antigen (HLA) antibodies, and placental pathology in preeclampsia and miscarriage cases. The patient population (N = 104) included those with (1) preterm preeclampsia with fetal growth restriction (PE-FGR; n = 21), (2) preterm preeclampsia (PE; n = 20), (3) spontaneous preterm delivery (sPTD; n = 39), and (4) miscarriage (n = 24). C4d immunohistochemistry was performed, and the presence of maternal plasma HLA antibodies was examined. C4d staining of the syncytiotrophoblast was more frequent in PE-FGR patients (76.2 %) than in PE (10.0 %; p < 0.001) and sPTD (2.6 %; p < 0.001) patients. Maternal HLA antibody-positive rate was not different among the study groups. There was a significant correlation between C4d immunoreactivity and placental pathology consistent with maternal vascular underperfusion (p < 0.001) but not with maternal HLA antibody status. In miscarriages, the positive rates of C4d, HLA class I, and HLA class II antibodies were 58.3, 25.0, and 12.5 %, respectively. There was no correlation between the presence of maternal HLA class I or II antibodies and placental C4d immunoreactivity. This study confirms frequent placental C4d deposition in preeclampsia with fetal growth restriction and miscarriage. The association between placental C4d deposition and pathological findings of maternal vascular underperfusion suggests that C4d staining of the syncytiotrophoblast is a consequence of defective placentation rather than of a specific maternal immune response against fetal HLA. The study also demonstrates the usefulness of C4d as a biomarker of placentas at risk.

Placental infarction probably associated with late term premature delivery

Here the histopathology findings of placental infarction associated with late preterm birth are reported. The subject was a male neonate delivered at 34 weeks and 5 days of gestation with a birth weight of ∼2500 g. His mother had been diagnosed with a threatened premature birth at 27 weeks of pregnancy. The size and weight of the placenta was considered appropriate for gestational age. On the cut surface of the placenta, a white-colored focal infarct was noted beneath the site of the umbilical cord insertion. There were small focal infarcts scattered within the marginal area. There were no particular vascular abnormalities or apparent thrombi. The placental villi were of appropriate maturity for the gestational age and the villous vessels showed no structural abnormalities. This case highlights the benefits of examining the histopathology of postpartum placentas for preterm children to explore their significance in premature birth.