The role of pregnancy in the course and aetiology of rheumatoid arthritis

Etiology and Risk Factors for Rheumatoid Arthritis: A State-of-the-Art Review

Rheumatoid arthritis (RA) is the most common systemic inflammatory rheumatic disease. It is associated with significant burden at the patient and societal level. Extensive efforts have been devoted to identifying a potential cause for the development of RA. Epidemiological studies have thoroughly investigated the association of several factors with the risk and course of RA. Although a precise etiology remains elusive, the current understanding is that RA is a multifactorial disease, wherein complex interactions between host and environmental factors determine the overall risk of disease susceptibility, persistence and severity. Risk factors related to the host that have been associated with RA development may be divided into genetic; epigenetic; hormonal, reproductive and neuroendocrine; and comorbid host factors. In turn, environmental risk factors include smoking and other airborne exposures; microbiota and infectious agents; diet; and socioeconomic factors. In the present narrative review, aimed at clinicians and researchers in the field of RA, we provide a state-of-the-art overview of the current knowledge on this topic, focusing on recent progresses that have improved our comprehension of disease risk and development.

Once-monthly hemin suppresses inflammatory and autoreactive CD4+ T cell responses to robustly ameliorate experimental rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that would permanently damage the affected joints. Unfortunately, a large proportion of RA patients fail to respond adequately to current treatments. Here, repurposing hemin and its ultra-long-acting formulation were explored for the effective treatment of RA in animal models. We provided evidence that hemin prevented the onset and ameliorated the clinical course of RA. Notably, hemin treatment rescued the dysregulated gene expression in animal models of RA, resulting in attenuation of Th1/Th17 cell-mediated responses and proinflammatory cytokines. Moreover, we further formulated hemin into the in-situ forming implant, and a single injection of the ultra-long-acting hemin exerted potent disease-modifying effects for at least six weeks with a remarkable dose reduction. Taken together, given the potent anti-inflammatory and immunosuppressive effects, the once-monthly hemin injection holds promise for rapid clinical translation, and represents a potential strategy to treat RA and possibly other autoimmune diseases.

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Repurposing hemin prevents the onset and ameliorates the clinical course of RA

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Once-monthly hemin achieve sustained remission of RA for at least six weeks

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Hemin rescue dysregulated gene expression and attenuate autoreactive immune responses

Does Altered Cellular Metabolism Underpin the Normal Changes to the Maternal Immune System during Pregnancy?

Pregnancy is characterised by metabolic changes that occur to support the growth and development of the fetus over the course of gestation. These metabolic changes can be classified into two distinct phases: an initial anabolic phase to prepare an adequate store of substrates and energy which are then broken down and used during a catabolic phase to meet the energetic demands of the mother, placenta and fetus. Dynamic readjustment of immune homeostasis is also a feature of pregnancy and is likely linked to the changes in energy substrate utilisation at this time. As cellular metabolism is increasingly recognised as a key determinant of immune cell phenotype and function, we consider how changes in maternal metabolism might contribute to T cell plasticity during pregnancy.

Means, Motive, and Opportunity: Do Non-Islet-Reactive Infiltrating T Cells Contribute to Autoimmunity in Type 1 Diabetes?

In human type 1 diabetes and animal models of the disease, a diverse assortment of immune cells infiltrates the pancreatic islets. CD8⁺ T cells are well represented within infiltrates and HLA multimer staining of pancreas sections provides clear evidence that islet epitope reactive T cells are present within autoimmune lesions. These bona fide effectors have been a key research focus because these cells represent an intellectually attractive culprit for β cell destruction. However, T cell receptors are highly diverse in human insulitis. This suggests correspondingly broad antigen specificity, which includes a majority of T cells for which there is no evidence of islet-specific reactivity. The presence of “non-cognate” T cells in insulitis raises suspicion that their role could be beyond that of an innocent bystander. In this perspective, we consider the potential pathogenic contribution of non-islet-reactive T cells. Our intellectual framework will be that of a criminal investigation. Having arraigned islet-specific CD8⁺ T cells for the murder of pancreatic β cells, we then turn our attention to the non-target immune cells present in human insulitis and consider the possible regulatory, benign, or effector roles that they may play in disease. Considering available evidence, we overview the case that can be made that non-islet-reactive infiltrating T cells should be suspected as co-conspirators or accessories to the crime and suggest some possible routes forward for reaching a better understanding of their role in disease.

Out of balance: the role of evolutionary mismatches in the sex disparity in autoimmune disease

Over the past century autoimmune disease incidence has increased rapidly in (post-) industrialised, affluent societies, suggesting that changes in ecology and lifestyle are driving this development. Epidemiological studies show that (i) 80% of autoimmune disease patients are female, (ii) autoimmune diseases co-occur more often in women, and (iii) the incidence of some autoimmune diseases is increasing faster in women than in men. The female preponderance in autoimmunity is most pronounced between puberty and menopause, suggesting that diverging sex hormone levels during the reproductive years are implicated in autoimmune disease development. Using an evolutionary perspective, we build on the hypotheses that female immunity is cyclical in menstruating species and that natural selection shaped the female immune system to optimise the implantation and gestation of a semi-allogeneic foetus. We propose that cyclical immunomodulation and female immune tolerance mechanisms are currently out of balance because of a mismatch between the conditions under which they evolved and (post-)industrialised, affluent lifestyles. We suggest that current changes in autoimmune disease prevalence may be caused by increases in lifetime exposure to cyclical immunomodulation and ovarian hormone exposure, reduced immune challenges, increased reproductive lifespan, changed reproductive patterns, and enhanced positive energy balance associated with (post-)industrialised, affluent lifestyles. We discuss proximate mechanisms by which oestrogen and progesterone influence tolerance induction and immunomodulation, and review the effect of the menstrual cycle, pregnancy, and contraceptive use on autoimmune disease incidence and symptoms.

Improvement of Remyelination in Demyelinated Corpus Callosum Using Human Adipose-Derived Stem Cells (hADSCs) and Pregnenolone in the Cuprizone Rat Model of Multiple Sclerosis

Adipose-derived stem cells (ASCs) have neuroprotective effects, and their repair ability has been approved in neurodegenerative studies. Pregnenolone as a neurosteroid plays significant roles in neurogenesis. We aimed to consider the effect of ADSCs and pregnenolone injection on the multiple sclerosis (MS) model created by cuprizone. Male Wistar rats (n = 36) were fed with an ordinary diet or a diet with cuprizone (0.6%) for 3 weeks. H-ADSCs were taken from patients with lipoaspirate surgery. The rats were divided into six groups (n = 6): healthy, MS, sham, pregnenolone injection, ADSCs injection, pregnenolone and ADSCs injection. Behavioral test, histological examination and TEM were conducted. The specific markers for myelin and cell differentiation were assessed using immunohistochemistry staining. Additionally, the measure of MBP and MOG gene expression and the amount of related proteins were determined using real-time RT-PCR and ELISA techniques, respectively. Histologic results showed that induced demyelination in corpus callosum fibers. TEM revealed an increased thickness of myelin in fibers in the treated groups (P < 0.05). Injection of hADSC and pregnenolone significantly increased the expression levels of MBP and MOG (P < 0.001). The mean percentage of MOG and MBP markers were significantly increased in the treated groups compared to MS and sham groups (P < 0.05). Moreover, the OD level of MBP and MOG proteins showed that their values in the ADSCs/pregnenolone group were close to those of the control group without a significant difference. Our data indicated the remyelination potency and cell differentiation can improve with ADSCs and pregnenolone treatments in the multiple sclerosis model which created by cuprizone in rats.

The association between gravidity, parity and the risk of developing rheumatoid arthritis: A systematic review and meta-analysis

OBJECTIVE

To establish if gravidity and parity associate with the development of rheumatoid arthritis (RA), and to establish if this effect is influenced by the time elapsed since pregnancy/childbirth, the number of pregnancies/childbirths, and serological status, through systematically reviewing the literature and undertaking a meta-analysis.

METHODS

We searched Medline/EMBASE (from 1946 to 2018) using the terms "rheumatoid arthritis.mp" or "arthritis, rheumatoid/" and "pregnancy.mp" or "pregnancy/" or "parity.mp" or "parity/" or "gravidity.mp" or "gravidity/" (observational study filter applied). Case-control/cohort studies that examined the relationship between parity/gravidity and the risk of RA in women were included. Studies reporting effect size data for RA in ever vs. never parous/gravid women as ORs/RRs with 95% confidence intervals were included in a meta-analysis. Other relationships (i.e. risk by pregnancy/childbirth numbers) were analysed descriptively.

RESULTS

Twenty studies (from 626 articles) met our inclusion criteria, comprising 14 case-control (4799 cases; 11,941 controls) and 6 cohort studies (8575 cases; 2,368,439 individuals). No significant association was observed in the meta-analysis of studies reporting the risk of RA in ever vs. never parous women (OR 0.91; 95% CI 0.80-1.04) and ever vs. never gravid women (OR 0.86; 95% CI 0.46-1.62). No consistent evidence of a relationship between the number of pregnancies/childbirths and RA risk was seen. No significant association was observed between being pregnant, or in the immediate post-partum period, and the risk of developing RA.

CONCLUSION

Our systematic review does not support the concept that gravidity and parity are associated with the risk of RA development.

Sex differences in neuroimmunity and pain

Differences in the prevalence of chronic pain in women vs. men are well known, and decades of laboratory experimentation have demonstrated that women are more sensitive to pain than are men. Attention has thus shifted to investigating mechanisms underlying such differences. Recent evidence suggests that neuroimmune modulation of pain may represent an important cause of sex differences. The current Review examines the evidence for gonadal hormone modulation of the immune system, immune system modulation of pain, and interactions that might help to explain sex differences in pain. © 2016 Wiley Periodicals, Inc.

Age, estrogen, and immune response in breast adenocarcinoma and adjacent normal tissue

Chronic inflammation promotes breast tumor growth and invasion by accelerating angiogenesis and tissue remodeling in the tumor microenvironment. There is a complex relationship between inflammation and estrogen, which drives the growth of 70 percent of breast tumors. While low levels of estrogen exposure stimulate macrophages and other inflammatory cell populations, very high levels are immune suppressive. Breast tumor incidence is increased by obesity and age, which interact to influence inflammatory cell populations in normal breast tissue. To characterize the impact of these factors on tumors and the tumor microenvironment, we measured gene expression in 195 breast adenocarcinomas and matched adjacent normal breast tissue samples collected at Akershus University Hospital (AHUS). Age and Body Mass Index (BMI) were independently associated with inflammation in adjacent normal tissue but not tumors. Estrogen Receptor (ER)-negative tumors had elevated macrophage expression compared with matched normal tissue, but ER-positive tumors showed an unexpected decrease in macrophage expression. We found an inverse relationship between the increase in tumor estrogen pathway expression compared with adjacent normal tissue and tumor macrophage score. We validated this finding in 126 breast tumor-normal pairs from the previously published METABRIC cohort. We developed a novel statistic, the Rewiring Coefficient, to quantify the rewiring of gene co-expression networks at the level of individual genes. Differential correlation analysis demonstrated distinct pathways were rewired during tumorigenesis. Our data support an immune suppressive effect of high doses of estrogen signaling in breast tumor microenvironment, suggesting that this effect contributes to the greater presence of prognostic and therapeutically relevant immune cells in ER-negative tumors.

Variations in chemokine receptor and cytokine expression during pregnancy in multiple sclerosis patients

Although several T cell-mediated autoimmune diseases have shown a reduction in their clinical disease activity during pregnancy, the underlying mechanisms by which pregnancy causes such a beneficial effect on the disease activity are not fully understood. We performed a longitudinal study of chemokine receptors (CCR3, CCR4, CCR5, CXCR3, CXCR4) by flow cytometry in different subsets of peripheral blood mononuclear cells (PBMC) during pregnancy in multiple sclerosis (MS) patients. The levels of cytokine mRNA expression (IL-10, IFN-g) were also investigated by real-time quantitative reverse transcription polymerase chain reaction. The expression of CXCR3 by CD4 and CD8 positive T cells was decreased to a statistically significant extent during the second trimester of pregnancy. CD4 and CD8 T cells showed a statistically significant increase in the expression of CXCR4 during the third trimester of pregnancy. At the mRNA expression level, an increase in the IL-10/IFN-g ratio was observed during pregnancy, especially during the third trimester. These findings indicate immunomodulatory effects of pregnancy on the expression of chemokine receptors and cytokines, which may be related to changes in the clinical disease activity of T cell-mediated autoimmune diseases, such as MS.

Nudging oligodendrocyte intrinsic signaling to remyelinate and repair: Estrogen receptor ligand effects

Demyelination in multiple sclerosis (MS) leads to significant, progressive axonal and neuronal degeneration. Currently existing immunosuppressive and immunomodulatory therapies alleviate MS symptoms and slow, but fail to prevent or reverse, disease progression. Restoration of damaged myelin sheath by replenishment of mature oligodendrocytes (OLs) should not only restore saltatory axon conduction, but also provide a major boost to axon survival. Our previous work has shown that therapeutic treatment with the modestly selective generic estrogen receptor (ER) β agonist diarylpropionitrile (DPN) confers functional neuroprotection in a chronic experimental autoimmune encephalomyelitis (EAE) mouse model of MS by stimulating endogenous remyelination. Recently, we found that the more potent, selective ERβ agonist indazole-chloride (Ind-Cl) improves clinical disease and motor performance. Importantly, electrophysiological measures revealed improved corpus callosal conduction and reduced axon refractoriness. This Ind-Cl treatment-induced functional remyelination was attributable to increased OL progenitor cell (OPC) and mature OL numbers. At the intracellular signaling level, transition of early to late OPCs requires ERK1/2 signaling, and transition of immature to mature OLs requires mTOR signaling; thus, the PI3K/Akt/mTOR pathway plays a major role in the late stages of OL differentiation and myelination. Indeed, therapeutic treatment of EAE mice with various ERβ agonists results in increased brain-derived neurotrophic factor (BDNF) and phosphorylated (p) Akt and p-mTOR levels. It is notable that while DPN's neuroprotective effects occur in the presence of peripheral and central inflammation, Ind-Cl is directly neuroprotective, as demonstrated by remyelination effects in the cuprizone-induced demyelination model, as well as immunomodulatory. Elucidating the mechanisms by which ER agonists and other directly remyelinating agents modulate endogenous OPC and OL regulatory signaling is critical to the development of effective remyelinating drugs. The discovery of signaling targets to induce functional remyelination will valuably contribute to the treatment of demyelinating neurological diseases, including MS, stroke, and traumatic brain and spinal cord injury.

Potential Therapy for Rheumatoid Arthritis and Sjögren Syndrome With Human Chorionic Gonadotropin

Autoimmune diseases such as rheumatoid arthritis (RA) and Sjögren syndrome (SS) ameliorate during pregnancy, through dampening (immunotolerance) of the maternal immune system which protects the fetus from rejection. A large number of studies have shown that human chorionic gonadotropin (hCG) contributes to this tolerance. Studies on animal models have reaffirmed that hCG treatment mimics the benefits of pregnancy. Based on the scientific evidence, randomized clinical trials comparing hCG with current therapies and/or placebo are recommended for RA, SS, and for other autoimmune diseases such as, type 1 diabetes and ankylosing spondylitis, which also get better during pregnancy and hCG treatment seems to help.

The immunologic effects of estrogen on psoriasis: A comprehensive review

BACKGROUND

Immunological changes in pregnancy are associated with improvements in some pre-existing immune-mediated skin diseases. Estrogen has been hypothesized to contribute to these changes by creating a shift from Th1 and Th17 to Th2 immunity. As this hypothesis would predict, psoriasis (a primarily Th17 mediated immune disease) tends to improve during pregnancy. However, the precise mechanism by which estrogen induces immunological change in psoriasis remains poorly understood.

OBJECTIVE

To summarize the immunologic effects of estrogen as they relate to psoriasis during pregnancy.

METHODS

We performed an English-language PubMed search of articles from September 2004 to September 2014 combining the key terms "psoriasis," "estrogen," "autoimmune disease," and "pregnancy."

RESULTS

Estrogen appears to up-regulate Th2 cytokines and down-regulate Th1 and Th17 cytokines. This shift was initially observed in murine systems, which showed decreased mixed lymphocyte reactions of splenocytes and increased antibody production during pregnancy. Antigen stimulated splenocytes produced fewer Th1 cytokines and more Th2 cytokines in pregnant mice. IL17 producing T cells were significantly decreased in healthy pregnancies compared to non-pregnant controls.

LIMITATIONS

This review is limited by the paucity of studies evaluating immunological changes of psoriasis in pregnancy among human subjects.

CONCLUSIONS

Increased estrogen production in pregnancy is associated with decreased Th1 and Th17 cytokine production. While estrogen may be responsible for some of these immune shifts resulting in disease improvement, there remains no definitive evidence to prove the hypothesis that estrogen is responsible for such improvement.

Arthritis and prolactin: a phylogenetic viewpoint

Arthritic disorders are family of diseases that have existed since vertebrate life began. Their etiology is multifactorial with genetic, environmental, and gender factors driving chronic joint inflammation. Prolactin is a sexually dimorphic hormone in mammals that can act to both promote and ameliorate rheumatic diseases. It is found in all vertebrate groups where it exerts a wide diversity of actions. This review briefly addresses the presence and features of arthritic diseases in vertebrates, the effects of PRL on joint tissues and immune cells, and whether PRL actions could have contributed to the ubiquity of arthritis in nature. This comparative approach highlights the value of PRL as a biologically conserved factor influencing the development and progression of arthritis.

The influence of early menopause on cardiovascular risk in women with rheumatoid arthritis

OBJECTIVE

Early menopause is associated with an increased risk for developing rheumatoid arthritis (RA). The risk for cardiovascular disease (CVD) in women increases following menopause. Because RA is associated with an increased risk of CVD, this study was undertaken to determine whether early menopause affects the risk of developing CVD in women with RA.

METHODS

A population-based inception cohort of 600 women with RA who fulfilled 1987 American College of Rheumatology criteria for RA between 1955 and 2007 and were age ≥ 45 years at diagnosis was assembled and followed. Age at menopause and duration of hormone replacement therapy, along with occurrence of CVD, was ascertained by review of medical records. Cox proportional hazard models compared women who underwent early menopause (natural or artificial menopause at age ≤ 45 yrs) to those within the cohort who did not undergo early menopause.

RESULTS

Of 600 women, 79 experienced early menopause. Women who underwent early menopause were at significantly higher risk for developing CVD when compared to women who did not (HR 1.56; 95% CI 1.08-2.26).

CONCLUSION

The risk of CVD in women with RA was higher in those who experienced early menopause, and like other known risk factors should increase clinician concern for development of CVD in these patients.

Enhanced and persistent levels of interleukin (IL)-17⁺ CD4⁺ T cells and serum IL-17 in patients with early inflammatory arthritis

Prognosis of patients with early inflammatory arthritis (EIA) is highly variable. The aim of this study was to compare, longitudinally and cross-sectionally, the levels of cytokine-expressing cells in peripheral blood (PB) from patients with EIA to those in established rheumatoid arthritis (RA) and healthy controls (HC). PB mononuclear cells from HC (n = 30), patients with EIA (n = 20) or RA (n = 38) were stimulated with phorbol myristate acetate (PMA)/ionomycin for 3 h, and stained for cell markers and cytokines. Serum cytokines and chemokines were measured by Luminex. Patients with EIA were reassessed at 6 and 12 months. The percentage of interleukin (IL)-17⁺ interferon (IFN)-γ⁻ CD4⁺ T cells [T helper type 17 (Th17)] was increased in RA and EIA versus HC. Serum IL-1β, IL-2, IL-4 IL-17 and macrophage inflammatory protein (MIP)-1α were increased in RA and EIA versus HC. IL-1Ra, IL-15 and IFN-α were increased in EIA versus HC. IL-6 and tumour necrosis factor (TNF)-α was increased in RA but not EIA versus HC. Disease activity scores in EIA patients improved over 12 months' treatment. Th17 percentage at baseline was correlated with both rheumatoid factor (RF) titre and functional deficit at 12 months. Baseline levels of serum granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-6 and IL-8 were correlated with Larsen score at 12 months. There were no significant changes in cytokine-expressing CD4⁺ T cells over time, although the percentage of IL-6⁺monocytes increased. IL-17⁺ CD4⁺ T cells and serum IL-17 levels are increased in EIA. IL-6-expressing monocytes increase during the first year of disease, irrespective of disease-modifying anti-rheumatic drug (DMARD) therapy. We observed incomplete clinical responses, suggesting EIA patients need more intensive early therapy.

Bi-directional relationship between pregnancy and periodontal disease

During pregnancy profound perturbations in innate and adaptive immunity impact the clinical course of a number of infectious diseases, including those affecting periodontal tissues. Conversely, it has been suggested that periodontal infections may increase the risk of adverse pregnancy outcomes. In this review, a summary of the literature associated with the bidirectional relationship between pregnancy and periodontal disease as well as the possible mechanisms behind this interaction were examined.

Regulatory T cells and the immune pathogenesis of prenatal infection

Pregnancy in placental mammals offers exceptional comprehensive benefits of in utero protection, nutrition, and metabolic waste elimination for the developing fetus. However, these benefits also require durable strategies to mitigate maternal rejection of fetal tissues expressing foreign paternal antigens. Since the initial postulate of expanded maternal immune tolerance by Sir Peter Medawar 60 years ago, an amazingly elaborate assortment of molecular and cellular modifications acting both locally at the maternal-placental interface and systemically have been shown to silence potentially detrimental maternal immune responses. In turn, simultaneously maintaining host defense against the infinite array of potential pathogens during pregnancy is equally important. Fortunately, resistance against most infections is preserved seamlessly throughout gestation. On the other hand, recent studies on pathogens with unique predisposition for prenatal infections have uncovered distinctive holes in host defense associated with the reproductive process. Using these infections to probe the response during pregnancy, the immune suppressive regulatory subset of maternal CD4 T cells has been increasingly shown to dictate the inter-workings between prenatal infection susceptibility and pathogenesis of ensuing pregnancy complications. Herein, the recent literature suggesting a necessity for maternal regulatory T cells (Tregs) in pregnancy-induced immunological shifts that sustain fetal tolerance is reviewed. Additional discussion is focused on how expansion of maternal Treg suppression may become exploited by pathogens that cause prenatal infections and the perilous potential of infection-induced immune activation that may mitigate fetal tolerance and inadvertently inject hostility into the protective in utero environment.

Spatial modelling of rheumatoid arthritis in Turkey by geographic information systems (GIS)

We described the recent spatial distribution of rheumatoid arthritis in Turkey and assessed the role of environmental variables in this distribution. We developed an observed rheumatoid arthritis (RA) incidence grid map by using georeferenced rheumatoid arthritis case data (2011) from the centres of 81 provinces and the kriging method with a spherical variogram model in geographic information systems (GIS). We also modelled rheumatoid arthritis incidence in GIS by using complementary spatial database including the grid map layers of 14 environmental variables of Turkey. We conducted principle component analysis and multiple regression to investigate the relationships among variables and develop a model, respectively. The produced model was run in GIS to obtain a predicted (model) RA map. We tested the reliability of the model map by residual statistics and found the model map dependable. Observed and model incidence maps revealed the geographic distribution of rheumatoid arthritis cases in Turkey. The mean temperature, minimum temperature, maximum temperature, water vapour pressure, elevation, potential evapotranspiration, latitude, distance to seas, sunshine fraction, precipitation, longitude and aspect variables were found to have significant impacts on rheumatoid arthritis. Consequently, the model incidence map established a good background to predict rheumatoid arthritis cases following environmental changes.

Navigating motherhood choices in the context of rheumatoid arthritis: women's stories

OBJECTIVE

Planning a family is a complex decision. For women with chronic conditions such as rheumatoid arthritis (RA), there are additional concerns about their own and their baby's health. This qualitative study examined women's experiences of negotiating their family decisions in the context of RA.

METHODS

A qualitative study was conducted in 14 women who provided a written account of their motherhood decisions and experiences. Those 'stories' were then thematically analysed.

RESULTS

RA was found to affect women's motherhood decisions and experiences. Three key themes were identified for both the process of decision making and the experience of that decision: capacity, uncertainty and acceptance. Only two of the women decided not to have children, while for others the decision centred on changing expectations from the number of children they planned to have, to parenting within the restrictions of their physical abilities.

CONCLUSION

While many women struggled through the negotiations of their motherhood choices, those who chose to have children reported great joy in that experience. The challenges faced by women with RA contemplating motherhood, however, highlight the need for understanding and support from health professionals and the provision of resources so that women can make informed choices.

Pathogenesis of hepatitis C during pregnancy and childhood

The worldwide prevalence of HCV infection is between 1% and 8% in pregnant women and between 0.05% and 5% in children. Yet the pathogenesis of hepatitis C during pregnancy and in the neonatal period remains poorly understood. Mother-to-child transmission (MTCT), a leading cause of pediatric HCV infection, takes place at a rate of <10%. Factors that increase the risk of MTCT include high maternal HCV viral load and coinfection with HIV-1 but, intriguingly, not breastfeeding and mode of delivery. Pharmacological prevention of MTCT is not possible at the present time because both pegylated interferon alfa and ribavirin are contraindicated for use in pregnancy and during the neonatal period. However, this may change with the recent introduction of direct acting antiviral agents. This review summarizes what is currently known about HCV infection during pregnancy and childhood. Particular emphasis is placed on how pregnancy-associated immune modulation may influence the progression of HCV disease and impact MTCT, and on the differential evolution of perinatally acquired HCV infection in children. Taken together, these developments provide insights into the pathogenesis of hepatitis C and may inform strategies to prevent the transmission of HCV from mother to child.

What Have We Learned about the Pathogenesis of Rheumatoid Arthritis from TNF-Targeted Therapy?

Studies of cytokine regulation in rheumatoid arthritis led to the development of TNFα inhibitors which are now used for a number of indications, including rheumatoid arthritis, inflammatory bowel disease, psoriasis, psoriatic arthritis, and ankylosing spondylitis. The widespread use of biologics in the clinic offers unique opportunities for probing disease pathogenesis and this paper provides an overview of rheumatoid arthritis, with a particular emphasis on the impact of anti-TNFα therapy on pathogenetic mechanisms. An overview is also provided on the most commonly used animal models that mimic RA, including adjuvant-induced arthritis, collagen-induced arthritis, TNFα-transgenic mice, and the K/BxN and SKG models. These models have led to significant discoveries relating to the importance of pro-inflammatory cytokines in the pathogenesis of rheumatoid arthritis, resulting from disregulation of the normally finely tuned balance of pro- and anti-inflammatory cytokine signalling. In addition, experimental evidence is discussed suggesting how genetic and environmental factors can contribute to disease susceptibility. The role of effector and regulatory T cells is discussed in the light of the relatively disappointing therapeutic effects of T cell modifying agents such as anti-CD4 antibody and cyclosporin. It is concluded that comprehensive analyses of mechanisms of action of biologics and other drugs entering the clinic will be essential to optimise therapy, with the ultimate aim of providing a cure.

Regulatory T cells protect from autoimmune arthritis during pregnancy

Pregnancy frequently has a beneficial effect on the autoimmune disease Rheumatoid Arthritis, ranging from improvement in clinical symptoms to complete remission. Despite decades of study, a mechanistic explanation remains elusive. Here, we demonstrate that an analogous pregnancy-induced remission can be observed in a mouse model of arthritis. We demonstrate that during pregnancy mice are protected from collagen-induced arthritis, but are still capable of launching normal immune responses to influenza infections. We examine the role of regulatory T (T_R) cells in this beneficial effect. T_R cells are essential for many aspects of immune tolerance, including the suppression of autoimmune responses. Remarkably, transfer of regulatory T cells from pregnant ‘protected’ mice was sufficient to confer protection to non-pregnant mice. These results suggest that regulatory T cells are responsible for the pregnancy-induced amelioration of arthritis.

Parity, time since last live birth and long-term functional outcome: a study of women participating in the Norfolk Arthritis Register

OBJECTIVE

To investigate the relationship between pre-symptom onset live births and functional outcome in women with inflammatory polyarthritis (IP).

METHODS

1872 women with no subsequent pregnancies were registered with the Norfolk Arthritis Register between 1990 and 2004 and followed-up for a median of 5 years. Functional disability over time was assessed by Health Assessment Questionnaire (HAQ). The number and calendar year of past live births were recorded. Differences in HAQ score over time by parity and time since last live birth (latency), adjusted for age and symptom duration, were examined using linear random effects models. The results were then adjusted for a number of potential confounders.

RESULTS

1553 women (83%) had ≥1 live births before symptom onset. The median latency was 26 years (IQR 16-35). Parous women had significantly lower HAQ scores over time than nulliparous women (-0.19, 95% CI -0.32 to -0.06). Increasing latency was associated with increasing HAQ score; the mean HAQ score of women with a latency of approximately 32 years was the same as for nulliparous women. This was independent of autoantibody status, socioeconomic status, smoking history and comorbidity.

CONCLUSION

Parous women who develop IP have better functional outcome over time than nulliparous women who develop IP. The beneficial effect of parity diminishes with time.

Effect of raloxifene on arthritis and bone mineral density in rats with collagen-induced arthritis

We studied the effect of raloxifene (RAL) on arthritis and bone mineral density (BMD) in rats with collagen-induced arthritis (CIA). Seven-month-old female Sprague-Dawley rats were divided into five groups: rats without CIA (CNT), CIA rats that underwent ovariectomy (OVX) and were treated with RAL (CIA + OVX + RAL), CIA rats that underwent OVX and were treated with vehicle (CIA + OVX + Veh), CIA rats that had sham surgery and were treated with RAL (CIA + sham + RAL), and CIA rats that had sham surgery and were treated with vehicle (CIA + sham + Veh). RAL was orally administered at 10 mg/kg every day for 3 weeks, beginning 1 week after initial sensitization until death at 4 weeks. Every week until death, we evaluated hind paw thickness and arthritis score. BMD was measured by peripheral quantitative computed tomography at the distal metaphysis and the diaphysis of the femur; we also performed histomorphometry of the proximal tibia and histological evaluation of arthritis. RAL administration suppressed hind paw thickness and arthritis score and prevented decreases in BMD and cortical thickness. In the histomorphometric analysis, bone-resorption parameters were significantly lower in the RAL groups than in the Veh groups. RAL significantly inhibited synovial proliferation in CIA rats. RAL effects on arthritis and bone were apparent regardless of whether an animal had undergone OVX. RAL could suppress arthritis and bone loss in estrogen-replete or -depleted rats. These findings, using an animal model, indicate the potential usefulness of RAL as an effective treatment for premenopausal RA patients as well as postmenopausal ones.

Sex differences in autoimmune diseases

Women are more susceptible to a variety of autoimmune diseases including systemic lupus erythematosus (SLE), multiple sclerosis (MS), primary biliary cirrhosis, rheumatoid arthritis and Hashimoto's thyroiditis. This increased susceptibility in females compared to males is also present in animal models of autoimmune diseases such as spontaneous SLE in (NZBxNZW)F1 and NZM.2328 mice, experimental autoimmune encephalomyelitis (EAE) in SJL mice, thyroiditis, Sjogren's syndrome in MRL/Mp-lpr/lpr mice and diabetes in non-obese diabetic mice. Indeed, being female confers a greater risk of developing these diseases than any single genetic or environmental risk factor discovered to date. Understanding how the state of being female so profoundly affects autoimmune disease susceptibility would accomplish two major goals. First, it would lead to an insight into the major pathways of disease pathogenesis and, secondly, it would likely lead to novel treatments which would disrupt such pathways.

Leukocyte pyruvate kinase expression is reduced in normal human pregnancy but not in pre-eclampsia

PROBLEM

Emerging evidence suggests that metabolism influences immune cell signaling and immunoregulation. To examine the immunoregulatory role of glycolysis in pregnancy, we evaluated the properties of pyruvate kinase in leukocytes from non-pregnant women and those with normal pregnancy and pre-eclampsia.

METHOD OF STUDY

We evaluated pyruvate kinase expression in lymphocytes and neutrophils from non-pregnant, pregnant, and pre-eclampsia patients using fluorescence microscopy and flow cytometry. Leukocyte pyruvate kinase activity and pyruvate concentrations were also evaluated. To study pyruvate's effect on signaling, we labeled Jurkat T cells with Ca(2+) dyes and measured cell responses in the presence of agents influencing intracellular pyruvate.

RESULTS

The expression of pyruvate kinase is reduced in lymphocytes and neutrophils from normal pregnant women in comparison with those of non-pregnant women and pre-eclampsia patients. Similarly, the activity of pyruvate kinase and the intracellular pyruvate concentration are reduced in leukocytes of normal pregnant women in comparison with non-pregnant women and women with pre-eclampsia. Using Jurkat cells as a model of leukocyte signaling, we have shown that perturbations of intracellular pyruvate influence Ca(2+) signals.

CONCLUSION

Normal pregnancy is characterized by reduced pyruvate kinase expression within lymphocytes and neutrophils. We speculate that reduced pyruvate kinase expression modifies immune cell responses due to reduced pyruvate concentrations.

Estrogen treatment decreases matrix metalloproteinase (MMP)-9 in autoimmune demyelinating disease through estrogen receptor alpha (ERalpha)

Matrix metalloproteinases (MMPs) have a crucial function in migration of inflammatory cells into the central nervous system (CNS). Levels of MMP-9 are elevated in multiple sclerosis (MS) and predict the occurrence of new active lesions on magnetic resonance imaging (MRI). This translational study aims to determine whether in vivo treatment with the pregnancy hormone estriol affects MMP-9 levels from immune cells in patients with MS and mice with experimental autoimmune encephalomyelitis (EAE). Peripheral blood mononuclear cells (PBMCs) collected from three female MS patients treated with estriol and splenocytes from EAE mice treated with estriol, estrogen receptor (ER) alpha ligand, ERbeta ligand or vehicle were stimulated ex vivo and analyzed for levels of MMP-9. Markers of CNS infiltration were assessed using MRI in patients and immunohistochemistry in mice. Supernatants from PBMCs obtained during estriol treatment in female MS patients showed significantly decreased MMP-9 compared with pretreatment. Decreases in MMP-9 coincided with a decrease in enhancing lesion volume on MRI. Estriol treatment of mice with EAE reduced MMP-9 in supernatants from autoantigen-stimulated splenocytes, coinciding with decreased CNS infiltration by T cells and monocytes. Experiments with selective ER ligands showed that this effect was mediated through ERalpha. In conclusion, estriol acting through ERalpha to reduce MMP-9 from immune cells is one mechanism potentially underlying the estriol-mediated reduction in enhancing lesions in MS and inflammatory lesions in EAE.

Effects of ovariectomy and aging on tooth attachment in female mice assessed by morphometric analysis

OBJECTIVE

Non-human primates, dogs, rats, hamsters and ferrets, have frequently been used as laboratory animals in periodontal biology and pathology. In the past, mice have been used less for this purpose, but nowadays attract a lot of interest because gene knockout and transgenic technologies utilize mice primarily. In this study, we investigate the effects of ovariectomy and aging on tooth attachment in female mice.

MATERIAL AND METHODS

Eight-week-old mice (n=15) were divided into three experimental groups (control, n=5; sham-operated, n=5; ovariectomy, n=5) and ovaries removed bilaterally. Attachment level, assessed by measuring alveolar bone height and apical termination of the junctional epithelium, was determined 6 weeks post-ovariectomy by digital morphometric analysis in sagittal sections of the mandible. The plasma level of the inflammation marker serum amyloid A (SAA) was determined by ELISA. In another series of experiments, tooth attachment was determined in female mice (n=7) at 8-26 weeks of age.

RESULTS

Withdrawal of female sex hormone production by ovariectomy had no effect on alveolar bone height and apical termination of the junctional epithelium. The SAA level in plasma was unaffected by removal of the ovaries, suggesting that systemic inflammation is not induced by ovariectomy. Bone height was similar in mice sacrificed at 8-26 weeks of age and apical termination of the junctional epithelium was at the cemento-enamel junction at all ages.

CONCLUSIONS

Removal of ovarian production of female sex hormones by ovariectomy has no influence on tooth attachment, and further tooth attachment is preserved with age in female mice.

Estrogen treatment in multiple sclerosis

Currently available treatments for multiple sclerosis (MS) reduce inflammatory lesions on MRI and decrease clinical relapses but have limited effects on disability. Novel treatment options that target both the inflammatory as well as the neurodegenerative component of the disease are therefore needed. A growing body of evidence from basic science and clinical studies supports the therapeutic potential of estrogens in MS. Mechanisms of action include both immunomodulatory and directly neuroprotective pathways. A first pilot trial of oral estriol treatment showed encouraging results. There are now several phase II trials underway to further determine the efficacy of estrogen treatment in MS.

CSF and plasma cytokines at delivery and postpartum mood disturbances

BACKGROUND

Immune activation has been shown to be involved in the pathophysiology of anxiety states and major depression and pregnancy is associated with a characteristic immune activation to sustain the fetus. Despite the possibility of a relation between immune parameters and postpartum mood disturbance, few studies have explored this association. Further, no study to-date has examined CSF.

METHODS

Fifty-six Greek parturients were recruited and a detailed medical and obstetric history was recorded. All of them completed the Postpartum Blues Questionnaire (on admission and on days 1-4 postpartum) and the Edinburgh Postnatal Depression Scale (at first and sixth week postpartum). At delivery, a blood sample and a CSF sample while puncturing for epidural analgesia were taken from 33 participants; blood samples only were obtained from the rest of the 23 parturients. TNF-a and IL-6 were quantified with an ELISA assay.

RESULTS

A multiple regression analysis of psychometric scores depending on cytokine levels revealed that cytokine levels were positively associated with depressive mood during the first four days postpartum (p=0.035 for CSF IL-6, p=0.025 for CSF TnF-a, p=0.023 for serum TnF-a) and also at sixth week postpartum (p=0.012 for CSF IL-6, p=0.072 for CSF TnF-a). Pregnancy duration had an adverse association to psychometric scores.

CONCLUSIONS

It is suggested that immune mechanisms may play a role in the etiopathology of postpartum depressive mood shifts. The role of a "rebound" reaction of the maternal immune system postnatal should be further investigated.

Immunomodulation of EAE by alpha-fetoprotein involves elevation of immune cell apoptosis markers and the transcription factor FoxP3

Alpha-fetoprotein (AFP) is an immunomodulatory glycoprotein associated with the normal growth of the mammalian fetus. Ws have shown that treatment with recombinant human AFP (rhAFP) reduced lymphocyte reactivity and the extent of neuroinflammation in mice with experimental autoimmune encephalomyelitis (EAE). In the present study we found involvement of AFP in immune cell apoptosis, attesting to its possible mechanism of action. AFP increased the expression of the Bax, Bid, Bad and ApaF genes in peripheral lymphocytes, together with an enhanced expression of Caspase-3, Fas, FasL and TRAIL among infiltrating immune cells. The induction of apoptosis markers was accompanied with an increased expression of Foxp3 in lymph node cells, as well as accumulation of CD4+Foxp3+ regulatory T cells in the CNS. Overall, these immunological alterations gave rise to a milder disease and accelerated remission rate. Our results suggest a new role for AFP in controlling the autoimmune inflammation associated with EAE.

Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases

BACKGROUND

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation.

REVIEW

We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here.

CONCLUSION

Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.

Estrogen and testosterone therapies in multiple sclerosis

It has been known for decades that females are more susceptible than men to inflammatory autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis, and psoriasis. In addition, female patients with these diseases experience clinical improvements during pregnancy with a temporary "rebound" exacerbation postpartum. These clinical observations indicate an effect of sex hormones on disease and suggest the potential use of the male hormone testosterone and the pregnancy hormone estriol, respectively, for the treatment of MS. A growing number of studies using the MS animal model experimental autoimmune encephalomyelitis (EAE) support a therapeutic effect of these hormones. Both testosterone and estriol have been found to induce anti-inflammatory as well as neuroprotective effects. Findings from two recent pilot studies of transdermal testosterone in male MS patients and oral estriol in female MS patients are encouraging. In this paper, we review the preclinical and clinical evidence for sex hormone treatments in MS and discuss potential mechanisms of action.

The clinical content of preconception care: women with chronic medical conditions

This article reviews the medical conditions that are associated with adverse pregnancy outcomes for women and their offspring. We also present the degree to which specific preconception interventions and treatments can impact the effects of the condition on birth outcomes. Because avoiding, delaying, or achieving optimal timing of a pregnancy is often an important component of the preconception care of women with medical conditions, contraceptive considerations particular to the medical conditions are also presented.

Expression of microRNA-146 in rheumatoid arthritis synovial tissue

OBJECTIVE

Several microRNA, which are approximately 22-nucleotide noncoding RNAs, exhibit tissue-specific or developmental stage-specific expression patterns and are associated with human diseases. The objective of this study was to identify the expression pattern of microRNA-146 (miR-146) in synovial tissue from patients with rheumatoid arthritis (RA).

METHODS

The expression of miR-146 in synovial tissue from 5 patients with RA, 5 patients with osteoarthritis (OA), and 1 normal subject was analyzed by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and by in situ hybridization and immunohistochemistry of tissue sections. Induction of miR-146 following stimulation with tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) of cultures of human rheumatoid arthritis synovial fibroblasts (RASFs) was examined by quantitative PCR and RT-PCR.

RESULTS

Mature miR-146a and primary miR-146a/b were highly expressed in RA synovial tissue, which also expressed TNFalpha, but the 2 microRNA were less highly expressed in OA and normal synovial tissue. In situ hybridization showed primary miR-146a expression in cells of the superficial and sublining layers in synovial tissue from RA patients. Cells positive for miR-146a were primarily CD68+ macrophages, but included several CD3+ T cell subsets and CD79a+ B cells. Expression of miR-146a/b was markedly up-regulated in RASFs after stimulation with TNFalpha and IL-1beta.

CONCLUSION

This study shows that miR-146 is expressed in RA synovial tissue and that its expression is induced by stimulation with TNFalpha and IL-1beta. Further studies are required to elucidate the function of miR-146 in these tissues.

Unique effect of the pregnancy hormone estriol on antigen-induced production of specific antibodies in female BALB/c mice

We investigated the modulatory effect of estriol (E(3)), an estrogen predominantly produced during human pregnancy, on the antigen-induced production of specific antibodies in female BALB/c mice, and its effect was compared with 17beta-estradiol (E(2)). Estriol (E(3)) had a very different effect than E(2) on the antigen-induced production of specific antibodies in animals immunized with two different antigens, i.e., the bovine serum albumin (BSA) and pneumococcal polysaccharide serotype-14 (PPS-14). While E(2) strongly stimulated the production of BSA-specific antibodies (mostly IgG1), E(3) had little or no effect on their production. In comparison, when the bacterial PPS-14 was the immunogen, E(3) and E(2) both strongly increased the production of PPS-14-specific antibodies (mostly IgM). E(3) and E(2) also had a similar effect on the thymus weight reduction and on the spontaneous antibody production in these animals. Our results provided an example demonstrating that the pregnancy hormone E(3) has a distinctly different profile of modulatory actions in the immune system compared to E(2), while the former strongly enhanced the body's ability to produce bacteria-specific IgM antibodies, it had no effect on the production of specific antibodies against a soluble protein. This differential effect of E(3) may be beneficial for reducing the risk of developing antibody-mediated immune attack against the maternal and fetal elements during pregnancy.

Effect of estrogen replacement therapy on arthritis and bone mineral density in estrogen-replete rats with collagen-induced arthritis

The influence of estrogen therapy on changes in arthritis and bone mineral density (BMD) was evaluated using an estrogen-replete collagen-induced arthritis (CIA) rat model. Seven-month-old female Sprague-Dawley rats (n = 30) were divided into the three groups; control (CONT), collagen sensitization (CIA), and CIA + 17beta-estradiol administration for 7 weeks (CIA + E). BMD was measured by peripheral quantitative computed tomography in the proximal tibia every 2 weeks. Eight weeks after the initial sensitization the rats were killed and histomorphometry of tibia was performed. The hind paw thickness increased with time in CIA rats and there was a significant difference between CONT and CIA at 8 weeks after the initial sensitization. Estrogen tended to make the development of arthritis milder. In CIA, BMD at metaphyseal cancellous bone began to decrease with the onset of arthritis and became significantly lower than in CONT after 8 weeks. Compared with the CIA, the deterioration in BMD was inhibited in CIA + E. Histomorphometrical parameters of bone resorption were increased in CIA compared with CONT, and those elevations were reduced by estrogen treatment, but estrogen had no effect on bone formation parameters. In conclusion, estrogen could partially suppress arthritis and bone loss in estrogen-replete rats as well as estrogen-deplete ones.

Human chorionic gonadotropin is an immune modulator and can prevent autoimmune diabetes in NOD mice

AIMS/HYPOTHESIS

Expression of T helper (Th)1 cytokine mRNA in pregnant women is known to be inversely correlated with serum human chorionic gonadotropin (hCG). Type 1 diabetes is a Th1-mediated autoimmune disease, in which intervention at an early stage of the autoimmune process can prevent disease progression. We hypothesised that immune modulation by treating young NOD mice with hCG may prevent diabetes.

METHODS

Female NOD mice were treated with hCG or recombinant hCG from 3 to 15 weeks of age and the incidence of diabetes and development of insulitis was determined. CD4(+) and CD8(+) T cell populations, T cell proliferation, cytokine production and CD4(+)CD25(+) regulatory T cells were examined and adoptive transfer experiments were performed.

RESULTS

Both purified and recombinant hCG prevented development of diabetes in NOD mice. hCG decreased the proportion and number of CD4(+) and CD8(+) T cells and inhibited T cell proliferative responses against beta cell antigens. hCG treatment suppressed IFN-gamma production, but increased IL-10 and TGF-beta production in splenocytes stimulated with anti-CD3 antibody. hCG treatment also suppressed TNF-alpha production in splenocytes stimulated with lipopolysaccharide. Furthermore, hCG treatment increased the CD4(+)CD25(+)/CD4(+) T cell ratio in spleen and pancreatic lymph nodes. Depletion of CD4(+)CD25(+) T cells from splenocytes of hCG-treated NOD mice abolished their preventive effect on diabetes transfer.

CONCLUSIONS/INTERPRETATION

We conclude that hCG has an immunomodulatory effect by downregulating effector cells, including Th1 cells, CD8(+) T cells and macrophages, and increasing the CD4(+)CD25(+)/CD4(+) T cell ratio, thus preventing autoimmune diabetes in NOD mice.