Neuroendocrine, immunologic, and microvascular systems interactions in rheumatoid arthritis: physiopathogenetic and therapeutic perspectives

Potential mechanisms and drug prediction of Rheumatoid Arthritis and primary Sjögren's Syndrome: A public databases-based study

Rheumatoid arthritis (RA) and primary Sjögren's syndrome (pSS) are the most common systemic autoimmune diseases, and they are increasingly being recognized as occurring in the same patient population. These two diseases share several clinical features and laboratory parameters, but the exact mechanism of their co-pathogenesis remains unclear. The intention of this study was to investigate the common molecular mechanisms involved in RA and pSS using integrated bioinformatic analysis. RNA-seq data for RA and pSS were picked up from the Gene Expression Omnibus (GEO) database. Co-expression genes linked with RA and pSS were recognized using weighted gene co-expression network analysis (WGCNA) and differentially expressed gene (DEG) analysis. Then, we screened two public disease-gene interaction databases (GeneCards and Comparative Toxicogenomics Database) for common targets associated with RA and pSS. The DGIdb database was used to predict therapeutic drugs for RA and pSS. The Human microRNA Disease Database (HMDD) was used to screen out the common microRNAs associated with RA and pSS. Finally, a common miRNA-gene network was created using Cytoscape. Four hub genes (CXCL10, GZMA, ITGA4, and PSMB9) were obtained from the intersection of common genes from WGCNA, differential gene analysis and public databases. Twenty-four drugs corresponding to hub gene targets were predicted in the DGIdb database. Among the 24 drugs, five drugs had already been reported for the treatment of RA and pSS. Other drugs, such as bortezomib, carfilzomib, oprozomib, cyclosporine and zidovudine, may be ideal drugs for the future treatment of RA patients with pSS. According to the miRNA-gene network, hsa-mir-21 may play a significant role in the mechanisms shared by RA and pSS. In conclusion, we identified commom targets as potential biomarkers in RA and pSS from publicly available databases and predicted potential drugs based on the targets. A new understanding of the molecular mechanisms associated with RA and pSS is provided according to the miRNA-gene network.

Vitamin D Oral Replacement in Children With Obesity Related Asthma: VDORA1 Randomized Clinical Trial

Children with asthma and obesity are more likely to have lower vitamin D levels, but the optimal replacement dose is unknown in this population. The objective of this study is identifying a vitamin D dose in children with obesity-related asthma that safely achieves serum vitamin D levels of ≥ 40 ng/mL. This prospective multisite randomized controlled trial recruited children/adolescents with asthma and body mass index ≥ 85% for age/sex. Part 1 (dose finding), evaluated 4 oral vitamin D regimens for 16 weeks to identify a replacement dose that achieved serum vitamin D levels ≥ 40 ng/mL. Part 2 compared the replacement dose calculated from part 1 (50,000 IU loading dose with 8,000 IU daily) to standard of care (SOC) for 16 weeks to identify the proportion of children achieving target serum 25(OH)D level. Part 1 included 48 randomized participants. Part 2 included 64 participants. In Part 1, no SOC participants achieved target serum level, but 50-72.7% of participants in cohorts A-C achieved the target serum level. In part 2, 78.6% of replacement dose participants achieved target serum level compared with none in the SOC arm. No related serious adverse events were reported. This trial confirmed a 50,000 IU loading dose plus 8,000 IU daily oral vitamin D as safe and effective in increasing serum 25(OH)D levels in children/adolescents with overweight/obesity to levels ≥ 40 ng/mL. Given the critical role of vitamin D in many conditions complicating childhood obesity, these data close a critical gap in our understanding of vitamin D dosing in children.

Interactions between microbiota, diet/nutrients and immune/inflammatory response in rheumatic diseases: focus on rheumatoid arthritis

Rheumatic and musculoskeletal diseases (RMDs) are chronic systemic immune/inflammatory conditions characterized by the interaction between gene predisposition, autoimmunity and environmental factors. A growing scientific interest has focused on the role of diet in RMDs, suggesting its significant contribution to the pathogenesis and prognosis of these diseases. It is now clear that diet can directly modulate the immune response by providing a wide range of nutrients, which interfere with multiple pathways at both the gastro-intestinal and systemic level. Moreover, diet critically shapes the human gut microbiota, which is recognized to have a central role in the modulation of the immune response and in RMD pathogenesis. We hereby provide an in-depth analysis on the role of the microbiota in RMDs and on nutritional intervention as an integral part of a multidisciplinary approach. Particular attention will be given to the Mediterranean diet, as the only diet proven to support substantial benefits in RMD management.

Vitamin D, Inflammation and Immunity: Review of Literature and Considerations on Recent Translational and Clinical Research Developments

The most relevant and recent literature findings linking exposure to sunlight, Vitamin D (VD), inflammation and immune system in health and disease, are reviewed.

Reduced sunlight exposure determined hypo-vitaminosis D to be common among patients or even healthy subjects, especially at higher latitudes. Numerous studies support the hypothesis that VD insufficiency could contribute to the higher autoimmune diseases incidence in the same geographic areas.

In the present review, the ways in which VD was reported to influence immune system, contributing to organism homeostasis or disease development are addressed. In fact, some of the hormone activities were recognised to determine stimulation or inhibition of immune system components.

Several diseases, where an association with VD deficiency was studied, are summarised. Finally, the rationale for optimization of substitutive/additive therapy with VD analogues and the last innovations regarding these drugs are mentioned.

Meibomian Gland Dysfunction in Primary and Secondary Sjögren Syndrome

PURPOSE

We hypothesized that women with primary (pSS) and secondary Sjögren syndrome (sSS; with systemic lupus erythematosus [SLE] or rheumatoid arthritis [RA]) have meibomian gland dysfunction (MGD). We sought to test our hypothesis.

METHODS

Subjects with pSS, sSS + SLE, sSS + RA, and non-SS-related MGD were recruited from the Sjögren's Syndrome Foundation or outpatient clinics at Tufts University School of Dental Medicine or Brigham and Women's Hospital. The control population was recruited from the Greater Boston area. After providing written informed consent, the subjects underwent an eye examination and/or completed two questionnaires that assess symptoms of dry eye disease (DED).

RESULTS

Our results demonstrate that pSS and sSS patients have MGD. These subjects had meibomian gland orifice metaplasia, an increased number of occluded meibomian gland orifices, and a reduced quality of meibomian gland secretions. Further, patients with pSS, sSS + SLE, sSS + RA, and MGD had significant alterations in their tear film, lid margin, cornea, and conjunctiva. Symptoms of DED were increased ∼10-fold in all pSS, sSS, and MGD groups relative to controls.

CONCLUSIONS

Our findings support our hypothesis and show that individuals with pSS, sSS + SLE, and sSS + RA have MGD. In addition, our study indicates that patients with pSS and sSS have both aqueous-deficient and evaporative DED.

Glucocorticoid management in rheumatoid arthritis: morning or night low dose?

Morning symptoms of rheumatoid arthritis (RA) are linked to circadian increase of night inflammation, supported by inadequate cortisol secretion in active disease. Therefore, exogenous glucocorticoid administration in RA is recommended by EULAR and ACR from the beginning of the diagnosis, since may partially act like a "replacement therapy". In addition, the prevention/treatment of the night up-regulation of the immune/inflammatory reaction has been shown more effective when exogenous glucocorticoid administration is managed with a night-time-release formulation. Despite a considerably higher cost than conventional prednisone (immediate release), chronotherapy with night-time-release prednisone has been recognized a cost-effective option for RA patients not on glucocorticoids who are eligible for therapy with biologic disease-modifying antirheumatic drugs (DMARDs). Interestingly, since different cell populations involved in the inflammatory process are particularly activated during the night (i.e. monocytes, macrophages), other therapeutical approaches used in RA, such as conventional DMARDs and non-steroidal anti-inflammatory drugs (NSAIDs) should follow the same concepts of glucocorticoid chronotherapy. Therefore, bedtime methotrexate chronotherapy was found to better manage RA symptoms, and several available NSAIDs (i.e. indomethacin, aceclofenac, ketoprofen, flurbiprofen, lornoxicam) have been recently modified in their formulation, in order to obtain more focused night action.

Administration of testosterone to elderly hypogonadal men with Crohn's disease improves their Crohn's Disease Activity Index: a pilot study

BACKGROUND

Both elevated and depressed testosterone (T) levels have been reported in Crohn's disease (CD). In this pilot study, effects of T administration on CD were assessed.

MATERIALS AND METHODS

A total of 13 men with CD, aged 45-67 years, had subnormal plasma T (mean±SD=9.0±1.4 nmol/L) (reference >12.0); they were compared to a group of 110 men of similar age with sexual and urological problems whose plasma T was also subnormal: 10.4±1.4 nmol/L (p=0.02). All received treatment with parenteral T undecanoate for 24 months. The Crohn's Disease Activity Index (CDAI) was assessed as an indicator of the severity of the disease every 3 months. Levels of T and C-reactive protein (CRP) were compared between the 13 men with CD and the other men in this study. Values of CDAI and CRP were followed-up.

RESULTS

CRP levels were 22.7 mg/dL (95% confidence interval of the mean: 14.9-34.3) in the 13 men with CD vs. 3.5 (2.9-4.1) in 107 control men (p=0.001). Upon normalization of serum T, there was a significant decline of CDAI (from 243±19 to 89±9), CRP levels from 22.7±8.1 to 6.9±2.9 mg/dL, and white blood cell count. Hemoglobin/hematocrit increased significantly.

CONCLUSIONS

Upon normalization of plasma T the CDAI and CRP levels decreased in hypogonadal patients with CD. The mechanism of this improvement could be through immunosuppressive effects of T, reducing chronic inflammation of the intestinal wall in CD.

CYB5A polymorphism increases androgens and reduces risk of rheumatoid arthritis in women

Introduction

Rheumatoid arthritis (RA) is characterized by decreased androgen levels, which was the first hormonal abnormality described. Several studies indicated that steroidogenesis is directed towards endogenous glucocorticoids at the expense of androgens. The decisive step governing androgen synthesis is the 17,20-lyase activity of the CYP17A1 gene-encoded enzyme cytochrome P450 17A1. Here, we focused on the role in RA of the critical cofactor for 17,20-lyase activity, cytochrome b5, encoded by the CYB5A gene.

Methods

Data sets of two genome wide RA association studies (GWAS) were screened for single nucleotide polymorphisms (SNP) in the CYB5A gene. Candidate SNPs in CYB5A were studied in a case–control study population of Slovakia. Expression analyses were done in synovial fibroblasts from RA patients by quantitative real-time polymerase chain reaction, and cytochrome b5–expression was detected by immunohistochemistry. Real-life androgen production after steroid conversion was measured using radiolabeled substrates.

Results

The study identified the RA-associated intronic SNP rs1790834 in the CYB5A gene in one GWAS and confirmed the same SNP in our study. The minor allele reduced RA risk selectively in women (P = 4.1*10⁻³; OR = 0.63, 95% CI [0.46-0.86]). The protective effect was confined to rheumatoid factor-positive (OR = 0.53, [0.37-0.75]) and anti-cyclic citrullinated peptide-positive (OR = 0.58, [0.41-0.83]) cases, respectively. The protective allele doubles CYB5A mRNA-expression resulting in 2-3fold activation of steroid 17,20-lyase activity, and protective allele was accompanied by a higher density of cytochrome b5-positive cells in synovial tissue.

Conclusions

CYB5A is the first RA susceptibility gene involved in androgen synthesis. Our functional analysis of SNP rs1790834 indicates that it contributes to the sex bias observed in RA.

Evaluation of the hypothalamic–pituitary–adrenal axis in untreated patients with polymyalgia rheumatica and healthy controls

OBJECTIVE

To explore the hypothalamic-pituitary-adrenal (HPA) axis in polymyalgia rheumatica (PMR).

SUBJECTS AND METHODS

This study was carried out on 13 female patients with PMR who were diagnosed according to the criteria of Chuang et al (Ann Intern Med 1982;97:672-80) and 10 healthy female subjects in the Department of Physical Medicine and Rehabilitation, Erciyes University Medical School. In the patient and control groups, basal cortisol, adrenocorticotrophic hormone (ACTH), 17alpha-hydroxyprogesterone (17-OHP), 11-deoxycortisol (11-S), dehydroepiandrosterone sulfate (DHEAS), androstenedione (A), prolactin (PRL), and thyroid stimulating hormone (TSH) levels were measured. Cortisol, 17-OHP, 11-S and A responses after the low-dose (1 microg) ACTH stimulation test and cortisol and DHEAS responses after the dexamethasone suppression test were detected. We also measured acute phase reactants including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

RESULTS

Age and sex characteristics were similar in both patient and control groups. The levels of basal hormones including cortisol, ACTH, 17-OHP, 11-S, DHEAS, A, prolactin and TSH and cortisol and DHEAS levels after the low-dose dexamethasone suppression test were not significantly different between the patient and control groups. However, cortisol/CRP and ACTH/CRP ratios were significantly lower in the patient group. Cortisol and DHEAS responses after the low-dose dexamethasone suppression test were not significantly different between the patient and control groups. Cortisol response after the 1 microg ACTH stimulation test was significantly lower in the patients than in the control group, but there were no significant differences in 17-OHP, 11-S and A responses between the patients and controls. Correlation analysis showed that there was a negative correlation between peak cortisol levels after the ACTH stimulation test and disease duration, and also a positive correlation between cortisol levels after the low-dose dexamethasone suppression test and acute phase reactants including CRP and ESR.

CONCLUSION

A significant low cortisol response to ACTH stimulation was detected in the patients with PMR. In addition, a negative correlation after the 1 microg ACTH stimulation test between peak cortisol levels and disease duration was detected. These findings may indicate hypoactivation in the HPA axis.

A prospective study of androgen levels, hormone-related genes and risk of rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is more common in females than males and sex steroid hormones may in part explain this difference. We conducted a case–control study nested within two prospective studies to determine the associations between plasma steroid hormones measured prior to RA onset and polymorphisms in the androgen receptor (AR), estrogen receptor 2 (ESR2), aromatase (CYP19) and progesterone receptor (PGR) genes and RA risk.

Methods

We genotyped AR, ESR2, CYP19, PGR SNPs and the AR CAG repeat in RA case–control studies nested within the Nurses' Health Study (NHS), NHS II (449 RA cases, 449 controls) and the Women's Health Study (72 cases, and 202 controls). All controls were matched on cohort, age, Caucasian race, menopausal status, and postmenopausal hormone use. We measured plasma dehydroepiandrosterone sulfate (DHEAS), testosterone, and sex hormone binding globulin in 132 pre-RA samples and 396 matched controls in the NHS cohorts. We used conditional logistic regression models adjusted for potential confounders to assess RA risk.

Results

Mean age of RA diagnosis was 55 years in both cohorts; 58% of cases were rheumatoid factor positive at diagnosis. There was no significant association between plasma DHEAS, total testosterone, or calculated free testosterone and risk of future RA. There was no association between individual variants or haplotypes in any of the genes and RA or seropositive RA, nor any association for the AR CAG repeat.

Conclusions

Steroid hormone levels measured at a single time point prior to RA onset were not associated with RA risk in this study. Our findings do not suggest that androgens or the AR, ESR2, PGR, and CYP19 genes are important to RA risk in women.

Gonadal hormones in men with rheumatoid arthritis--from onset through 2 years

OBJECTIVE

To evaluate changes over a 2-year course in the hypothalamic-pituitary-gonadal (HPG) axis in men with early rheumatoid arthritis (RA) from start of treatment with disease modifying antirheumatic drugs.

METHODS

Forty-one men with early RA and with joint symptoms less than 1 year were studied. Mean age at inclusion was 53 years and mean disease duration 6 months. They were followed prospectively for 2 years for disease activity [Disease Activity Score 28 (DAS28)], physical impairment (Health Assessment Questionnaire), total serum testosterone, non-sex hormone-binding globulin-bound testosterone, and luteinizing hormone (LH). A group of 131 healthy, medicine-free men served as controls for baseline hormone concentrations.

RESULTS

The men with RA already had mean testosterone levels lower than controls early in the disease course. Patients older than 50 years also had significantly lower LH levels compared with controls, consistent with mild hypogonadotropic hypogonadism. In patients who responded to treatment at the 2-year followup the testosterone levels increased significantly. A decrease in DAS28 during the 2 years correlated significantly with increased testosterone levels (r(s) = -0.46, p = 0.006). LH levels were low and stable and did not correlate with disease activity.

CONCLUSION

In early RA, current inflammation seemed to affect the HPG axis, mainly at the gonadal rather than the hypothalamic-pituitary level. Prospective studies are indicated to determine if low HPG activity may be a cause rather than a consequence of a chronic inflammatory state.

Use of the dexamethasone-corticotrophin releasing hormone test to assess hypothalamic-pituitary-adrenal axis function in rheumatoid arthritis

Objectives. Hypothalamic-Pituitary-Adrenal axis function may be abnormal in rheumatoid arthritis (RA). A pilot study in 7 patients suggested impaired glucocorticoid feedback in some patients after the dexamethasone-corticotrophin releasing hormone (CRH) test. This study aimed to investigate the dexamethasone-corticotrophin releasing factor test in a larger group of patients and relate the results to characteristics of the disease. Methods. Outpatients with active RA (>/=3 swollen and tender joints and C-reactive protein > 10 mg/L) took dexamethasone (1.5 mg) at 23:00 hour in the evening. Next day, baseline saliva and plasma samples were collected, CRH was infused at 11:00 hour, and 4 serial blood and saliva samples were collected. Plasma samples were stored at -80 degrees C and a radioimmunoassay performed for saliva and plasma cortisol. Results. All 20 participants showed normal dexamethasone suppression and mounted no response to the CRH challenge. In samples with measurable cortisol, there was a strong correlation between saliva and plasma values (r = 0.876, n = 26, P < .01). Conclusion. No abnormalities were found in the Dexamethasone-CRH test in RA patients in contrast to a previous pilot study. Salivary cortisol measurement may offer an alternative noninvasive technique to plasma cortisol in RA patients in future studies.

Association of interleukin-6 (IL-6)-174G/C gene polymorphism with cardiovascular disease in patients with rheumatoid arthritis: the role of obesity and smoking

BACKGROUND

Cardiovascular morbidity and mortality are increased in rheumatoid arthritis (RA). Interleukin-6 (IL-6) is high in RA and, together with smoking and obesity, an important contributor to the development of cardiovascular disease (CVD). The present study examined the potential association of IL-6-174 G/C polymorphism, together with obesity and smoking, with the presence of CVD in RA patients.

METHODS AND RESULTS

DNA samples were collected from 383 RA patients (who also had extensive clinical and laboratory evaluations). IL-6-174 G/C was identified using real time PCR and melting curve analysis. Serum IL-6 levels were measured in a subgroup of 135 RA patients to examine the functionality of the polymorphism. Carriers of the IL6-174C-allele demonstrated increased prevalence of CVD (26.2% vs. 17.0%, p=0.041). There was a significant association with CVD, even after adjustment for traditional CVD risk factors (OR=1.92, 95%CI: 1.03 to 3.58, p=0.041). IL-6 levels were significantly increased in C-allele carriers [14.02 (3.21-38.81) vs. 4.48 (2.25-16.5), p=0.028]. No significant interactions were observed between adiposity and IL6-174G/C genotypes. There was only a trend for an interaction between ever smoking and IL6 C-allele carriers on CVD.

CONCLUSION

The IL-6-174C-allele may associate with CVD in RA patients and possibly exerts its effect via increased inflammation. This finding, if confirmed in future studies, may be used as a part of a genetic screening tool for RA patients at high CVD risk.

Treatment with testosterone or estradiol in melatonin treated females and males MRL/MpJ-Faslpr mice induces negative effects in developing systemic lupus erythematosus

MRL/MpJ-Fas(lpr) mice is widely accepted as a valuable model of systemic lupus erythematosus. As described in a previous work, the incidence of lupus in this strain is determined by sex hormones, i.e., estrogens and androgens. Moreover, we reported that the immunomodulatory action of melatonin in these mice was gender-dependent probably through modulation and inhibition of sex hormones. Herein, we performed an experiment using hormone therapy, by treating female MRL-lpr mice with testosterone and males with estradiol and with melatonin. A decrease in total serum immunoglobulin (Ig)G and IgM immunoglobulin titers, anti-double-stranded DNA, and anti-CII autoantibodies in female mice treated with both melatonin and testosterone was revealed, along with an increase in pro-inflammatory cytokines [interleukin (IL)-2, IL-6, interferon-gamma, tumor necrosis factor-alpha, and IL-1beta), nitrite/nitrate and a decrease in anti-inflammatory cytokines (IL-10). Melatonin and estradiol treatment exhibited a similar effect in male mice. Autoantibody titer elevation and pro-inflammatory versus anti-inflammatory cytokine prevalence degraded all immunological parameters. Similar results were obtained when spleen and lymph node lymphocytes were cultured. Again, melatonin and testosterone treatment stimulated pro-inflammatory and reduced anti-inflammatory cytokines produced by lymphocytes in females. The effect was similar in males treated with melatonin and estradiol. In summary, we observed that although melatonin alone prevents lupus development in females, adding testosterone, increased pro-inflammatory cytokine pattern. In contrary, estradiol-treated males did not show any decrease in pro-inflammatory cytokines but showed an increase in regard to melatonin controls. These findings confirm that melatonin action in MRL/MpJ-Fas(lpr) mice could be gender-dependent through modulation of sex hormones.

Tearful relationships? Sex, hormones, the lacrimal gland, and aqueous-deficient dry eye

Sex and the endocrine system exert a significant influence on the physiology and pathophysiology of the lacrimal gland. The purpose of this article is to briefly review the nature and magnitude of these interactions between sex, hormones and lacrimal tissue, and to address how they may relate to the pathogenesis of aqueous-deficient dry eye. Towards this end, this article has a 3-fold approach: first, to summarize the influence of androgens, estrogens, glucocorticoids, mineralocorticoids, retinoic acid, prolactin, alpha-melanocyte stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, thyroid-stimulating hormone, arginine vasopressin, oxytocin, thyroxine, parathyroid hormone, insulin, glucagon, melatonin, human chorionic gonadotropin and cholecystokinin on the structure and function of the lacrimal gland; second, to discuss the mechanism of action of each hormone on lacrimal tissue; and third, to discuss the clinical relevance of the endocrine-lacrimal gland interrelationship, with a particular focus on each hormone's role (i.e. if relevant) in the development of aqueous-tear deficiency.

Endocrine and cytokine responses in humans with pulmonary tuberculosis

Endocrine responses during chronic infections such as lung tuberculosis are poorly characterized. Hormonal changes are likely to occur since some of the cytokines produced during this disease could affect endocrine mechanisms that, in turn, influence the course of infectious/inflammatory processes. A main purpose of this work was to study endocrine responses involving pituitary, adrenal, gonadal, and thyroid hormones in parallel to IFN-gamma, IL-10, and IL-6 levels in tuberculosis patients with different degree of pulmonary involvement. We have also studied whether products derived from peripheral immune cells obtained from the patients can affect the in vitro production of adrenal steroids. The population studied comprised HIV-negative newly diagnosed, untreated male patients with mild, moderate, and advanced lung tuberculosis, and matched, healthy controls. IFN-gamma, IL-10, and IL-6 levels were elevated in patients with tuberculosis. Dehydroepiandrosterone and testosterone levels were profoundly decreased and growth hormone levels were markedly elevated in patients, in parallel to modest increases in cortisol, estradiol, prolactin, and thyroid hormone concentrations. Supernatants of peripheral blood mononuclear cells obtained from the patients and stimulated in vitro with Mycobacterium tuberculosis antigens significantly inhibited dehydroepiandrosterone secretion by the human adrenal cell line NCI-H295-R. These results support the hypothesis that at least some of the endocrine changes observed in the patients may be mediated by endogenous cytokines. The endocrine profile of tuberculosis patients would favor a reduction of protective cell-mediated immunity and an exacerbation of inflammation leading to perpetuation of the lung injury and to the hypercatabolic condition that characterizes this disease.

Sex Hormones and Risks of Rheumatoid Arthritis and Developmental or Environmental Influences

Sex hormone relationships for onset risks of rheumatoid arthritis (RA) were analyzed in a nested case-control study, derived from a large community-based prospective cohort. A self-reported history of RA in a first-degree relative, heavy cigarette smoking, and positive rheumatoid factor (RF) were confirmed predictors of subsequent RA onset in this data set. In the 11 premenopausal onset cases, lower serum dehydroepiandrosterone sulfate levels were observed as was an imbalance in serum IL-1beta to IL-1ra levels; the latter was not observed in the 43 controls (CNs). In the 18 male cases, significantly higher serum cortisol was observed in the six cases with positive family history versus the 12 with a negative history. To the contrary, a small minority of the male cases had combined low serum cortisol and testosterone, which was not observed in the 72 CNs. Significant gender dimorphism was observed between the sex hormones and serum log RF titers as well as in the correlations of serum log testosterone and estradiol. Principal component analysis of multiply-imputed data sets extracted four uncorrelated components, which provided concordant neuroendocrine immune relationships to the previously investigated univariate and multivariate analyses. The literature on developmental and environmental influences on sex hormones and risks of RA was reviewed.

Inflammation and Sex Hormone Metabolism

The incidence of autoimmune diseases is higher in females than in males. In both sexes, adrenal hormones, that is, glucocorticoids, dehydroepiandrosterone (DHEA), and androgens, are inadequately low in patients when compared to healthy controls. Hormonally active androgens are anti-inflammatory, whereas estrogens are pro-inflammatory. Therefore, the mechanisms responsible for the alterations of steroid profiles in inflammation are of major interest. The local metabolism of androgens and estrogens may determine whether a given steroid profile found in a subject's blood results in suppression or promotion of inflammation. The steroid metabolism in mixed synovial cells, fibroblasts, macrophages, and monocytes was assessed. Major focus was on cells from patients with rheumatoid arthritis (RA), while cells from patients with osteoarthritis served as controls. Enzymes directly or indirectly involved in local sex steroid metabolism in RA are: DHEA-sulfatase, 3beta-hydroxysteroid dehydrogenase, 17beta-hydroxysteroid dehydrogenase, and aromatase (CYP19), which are required for the synthesis of sex steroids from precursors, 5alpha-reductase and 16alpha-hydroxylase, which can be involved either in the generation of more active steroids or in the pathways leading to depletion of active hormones, and 3alpha-reductase and 7alpha-hydroxylase (CYP7B), which unidirectionally are involved in the depletion of active hormones. Androgens inhibit aromatization in synovial cells when their concentration is sufficiently high. As large amounts of estrogens are formed in synovial tissue, there may be a relative lack of androgens. Production of 5alpha-reduced androgens should increase the local anti-inflammatory activity; however, it also opens a pathway for the inactivation of androgens. The data discussed here suggest that therapy of RA patients may benefit from the use of nonaromatizable androgens and/or the use of aromatase inhibitors.

Integrated neuroendocrine immune risk factors in relation to rheumatoid arthritis: should rheumatologists now adopt a model of a multiyear, presymptomatic phase?

An integrative perspective of neuroendocrine immune (NEI) and related risk factors for the onset of rheumatoid arthritis (RA) is presented, based upon studies of the long-term presymptomatic phase. Besides the recognized genetic markers and familial predisposition, multiple immunological precursors of RA have been identified many years before the clinical onset of inflammatory manifestations. Rheumatoid factors and related antibodies occur in approximately one-half of presymptomatic susceptibles. Cigarette smoking in sufficient amount and duration is a major risk factor for RA, particularly for postmenopausal-onset women and for men. In premenopausal-onset RA, subtle insufficiency of adrenal cortical function is less well recognized. In such women, cytokine imbalance may also precede inflammatory onset of RA. In males alone, multiple hormonal and cytokine correlations were found many years before the onset of RA, implying long-term activation or perturbation of this NEI system. The proposed physiopathogenetic model of RA requires further controlled, prospective studies for validation of the multiyear presymptomatic phase of RA. Such studies promise to clarify the currently unknown causal and sequential chains in this enigmatic disease.

Dipeptidyl peptidase IV activity and/or structure homologs: contributing factors in the pathogenesis of rheumatoid arthritis?

Several of the proinflammatory peptides involved in rheumatoid arthritis pathogenesis, including peptides induced downstream of tumor necrosis factor-α as well as the monocyte/T cell-attracting chemokines RANTES and stromal cell-derived factor (SDF)-1α and the neuropeptides vasoactive intestinal peptide (VIP) and substance P, have their biological half-lives controlled by dipeptidyl peptidase IV (DPPIV). Proteolysis by DPPIV regulates not only the half-life but also receptor preference and downstream signaling. In this article, we examine the role of DPPIV homologs, including CD26, the canonical DPPIV, and their substrates in the pathogenesis of rheumatoid arthritis. The differing specific activities of the DPPIV family members and their differential inhibitor response provide new insights into therapeutic design.

Low levels of dehydroepiandrosterone sulphate in plasma, and reduced sympathoadrenal response to hypoglycaemia in premenopausal women with rheumatoid arthritis

OBJECTIVES

To evaluate the function of the hypothalamic-pituitary-adrenal axis and sympathoadrenal system in premenopausal women with rheumatoid arthritis (RA).

METHODS

Insulin-induced hypoglycaemia (0.1 IU/kg) was produced in 15 glucocorticoid-naive patients with long term RA with low disease activity and in 14 healthy women matched for age and body mass index. Concentrations of glucose, adrenocorticotropic hormone (ACTH), cortisol, Delta4-androstenedione (ASD), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), 17alpha-hydroxyprogesterone (17OHP), epinephrine (EPI), norepinephrine (NE), interleukin 6 (IL6), and tumour necrosis factor alpha (TNFalpha) were analysed in plasma.

RESULTS

Patients had comparable responses of glucose, cortisol, ACTH, ASD, and 17OHP to hypoglycaemia, without any signs of hypothalamic insufficiency. Patients had lower basal DHEAS than controls (3.03 (0.37) micromol/l v 5.1 (0.9) micromol/l, respectively; p<0.05); borderline lower basal DHEA levels (p = 0.067); while the response of DHEA to hypoglycaemia was comparable to that of controls. Patients with RA had lower EPI (p = 0.005) and NE (p<0.001) responses to hypoglycaemia. TNFalpha and IL6 were higher (p<0.05) in patients with RA (TNFalpha 8 (2.8) pg/ml in RA v 1.1 (0.5) pg/ml in controls and IL6 15.1 (6.7) pg/ml v 1.4 (0.7) pg/ml).

CONCLUSIONS

Lower basal DHEAS levels, without concomitant differences or changes in DHEA, ASD, 17OHP, and cortisol responses to hypoglycaemia in patients with RA, indicate an isolated decrease in adrenal androgen production. Significantly lower responses of EPI and NE to hypoglycaemia may suggest sympathoadrenal hyporeactivity in patients with RA.

Rheumatoid Arthritis: Neuroendocrine Immune Integrated Physiopathogenetic Perspectives and Therapy

Current concepts of neuroendocrine immune (NEI) aspects of rheumatoid arthritis (RA) are reviewed and recent clinical trials of glucocorticoids and sex steroids are summarized. A novel physiopathogenetic perspective is presented. Data are provided of amplified NEI interactions and dysregulation, many years before symptomatic onset of RA. Chronic imbalances between the NEI, vascular endothelial, neural, and other vital counterregulatory intertwined networks are proposed to cause RA and influence its disease activity. Future research may reveal means of diminishing the onset risk as well as disease activity of RA by controlling these imbalances of NEI and other vital networks.

Hypothalamic-pituitary-adrenal axis function in ankylosing spondylitis

OBJECTIVE

To assess basal function and responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in patients with ankylosing spondylitis during dynamic testing.

METHODS

Insulin induced hypoglycaemia (IIH) (Actrapid HM 0.1 IU/kg, as intravenous bolus) was induced in 17 patients and 11 healthy controls matched for age, sex, and body mass index. Concentrations of glucose, adrenocorticotrophic hormone (ACTH), cortisol, insulin, dehydroepiandrosterone sulphate (DHEAS), 17alpha-hydroxyprogesterone, interleukin 6 (IL-6), and tumour necrosis factor alpha (TNFalpha) were determined in plasma.

RESULTS

Comparable basal cortisol levels were found in the two groups, with a trend to be lower in ankylosing spondylitis. In the ankylosing spondylitis group, there were higher concentrations of IL-6 (mean (SEM): 16.6 (2.8) pg/ml v 1.41 (0.66) pg/ml in controls; p<0.001) and TNFalpha (8.5 (1.74) pg/ml v 4.08 (0.42) pg/ml in controls; p<0.01). Glucose, insulin, ACTH, DHEAS, and 17alpha-hydroxyprogesterone did not differ significantly from control. The IIH test was carried out successfully in 11 of the 17 patients with ankylosing spondylitis, and the ACTH and cortisol responses were comparable with control. General linear modelling showed a different course of glycaemia (p = 0.041) in the ankylosing spondylitis patients who met the criteria for a successful IIH test compared with the controls.

CONCLUSIONS

The results suggest there is no difference in basal HPA axis activity and completely preserved responsiveness of the HPA axis in patients with ankylosing spondylitis. The interpretation of the different course of glycaemia during IIH in ankylosing spondylitis requires further investigation.

A pattern of protein expression in peripheral blood mononuclear cells distinguishes rheumatoid arthritis patients from healthy individuals

We compared the expression levels of proteins in peripheral blood mononuclear cells (PBMCs) of healthy control individuals to those of patients diagnosed with rheumatoid arthritis (RA) using a proteomics approach. Using two-dimensional electrophoresis we identified 18 proteins that were 2-fold or more highly expressed in patients than in controls, and 11 proteins that were 2-fold or more highly expressed in controls than in patients. Some of these differentially expressed proteins, identified by MALDI-TOF spectrometry, have previously been shown to play a potential role in the pathogenesis of RA. Hierarchical cluster analyses of the data segregated the samples into two groups, one which contained only controls and the other which contained only patients, and was used to compare the expression pattern of these 29 proteins in individual samples with the median expression pattern determined in the healthy control and in the RA patient groups. This analyses was able to predict whether a sample was derived from a rheumatoid arthritis patient or from a healthy individual, suggesting that a comparison of such protein expression patterns may be of diagnostic value.

Nonpeptide corticotropin-releasing hormone receptor type 1 antagonists and their applications in psychosomatic disorders

Overproduction of corticotropin-releasing hormone (CRH) and stress system abnormalities are seen in psychiatric diseases such as depression, anxiety, eating disorders, and addiction. Investigations of CRH type 1 receptor (CRHR1) nonpeptide antagonists suggest therapeutic potential for treatment of these and other neuropsychiatric diseases. However, overproduction of CRH in the brain and on its periphery and disruption of the hypothalamic-pituitary-adrenal axis are also found in 'somatic' disorders. Some rare forms of Cushing's disease and related pituitary/adrenal disorders are obvious applications for CRHR1 antagonists. In addition, however, these antagonists may also be effective in treating more common somatic diseases. Patients with obesity and metabolic syndrome who often have subtle, but chronic hypothalamic-pituitary-adrenal hyperactivity, which may reflect central dysregulation of CRH and consequently glucocorticoid hypersecretion, could possibly be treated by administration of CRHR1 antagonists. Hormonal, autonomic, and immune aberrations are also present in chronic inflammatory, autoimmune, and allergic diseases, with considerable evidence linking CRH with the observed abnormalities. Furthermore, autonomic dysregulation is a prominent feature of common gastrointestinal disorders, such as irritable bowel syndrome and peptic ulcer disease. Patients with irritable bowel syndrome and other gastrointestinal disorders frequently develop altered pain perception and affective symptoms. CRH acts peripherally to modulate bowel activity both directly through the autonomic system and centrally by processing viscerosensory and visceromotor neural signals. This review presents clinical and preclinical evidence for the role of CRH in the pathophysiology of these disorders and for potential diagnostic and therapeutic applications of CRHR1 antagonists. Recognition of a dysfunctional stress system in these and other diseases will alter the understanding and treatment of 'psychosomatic' disorders.

Estrogen and other female reproductive risk factors are not strongly associated with the development of rheumatoid arthritis in elderly women

OBJECTIVE

Endogenous and exogenous reproductive hormones have been associated with rheumatoid arthritis (RA) in women, but data are inconsistent and no studies have assessed RA risk factors exclusively in elderly women.

METHODS

The authors examined the association between reproductive factors, exogenous hormone exposure, and RA in a prospective cohort study of 31,336 Iowa women who were aged 55 to 69 years at cohort baseline in 1986.

RESULTS

During 11 years of follow-up, 158 incident cases of RA were identified and validated. Age at last pregnancy (P trend =.01) and age at menopause (P trend =.03) were inversely associated with RA, whereas a history of polycystic ovary syndrome (relative risk [RR], 2.58; 95% confidence interval [CI], 1.06 to 6.30), endometriosis (RR, 1.72; 95% CI, 0.93 to 3.18), and former use of hormone replacement therapy (RR, 1.47; 95% CI, 1.04 to 2.06) were positively associated with RA. In multivariate analysis models, a history of polycystic ovary syndrome remained the most consistent predictor of RA, whereas the RRs for other factors attenuated.

CONCLUSION

Few reproductive factors showed a strong or statistically significant association with RA in elderly women. The association of polycystic ovary syndrome may be indicative of perturbations of endocrine-immune activity that may influence the development of RA. This prospective cohort study adds to the understanding of the potential contribution of hormonal factors to the cause of RA in older women.

Quantification of the influence of cigarette smoking on rheumatoid arthritis: results from a population based case-control study, using incident cases

OBJECTIVE

To quantify the influence of cigarette smoking on the risk of developing rheumatoid arthritis (RA).

METHODS

679 cases and 847 controls included during May 1996-June 2000 in a case-control study, using incident cases, comprising the population aged 18-70 years of a defined area of Sweden, were investigated. A case was defined as a person from the study base who received for the first time a diagnosis of RA using the 1987 American College of Rheumatology criteria, and controls were randomly selected from the study base. Self reported smoking habits among cases and controls, and rheumatoid factor status among cases were registered. The incidence of RA in current smokers, ex-smokers, and ever-smokers, respectively, was compared with that of never-smokers.

RESULTS

Current smokers, ex-smokers, and ever-smokers of both sexes had an increased risk for seropositive RA (for ever-smokers the odds ratio was 1.7 (95% confidence interval (95% CI) 1.2 to 2.3) for women, and 1.9 (95% CI 1.0 to 3.5) for men), but not for seronegative RA. The increased risk was only apparent among subjects who had smoked > or =20 years, was evident at an intensity of smoking of 6-9 cigarettes/day, and remained for up to 10-19 years after smoking cessation. The risk increased with increasing cumulative dose of smoking.

CONCLUSION

Smokers of both sexes have an increased risk of developing seropositive, but not seronegative, RA. The increased risk occurs after a long duration, but merely a moderate intensity, of smoking and may remain for several years after smoking cessation.

Advances in understanding the genetic basis of rheumatoid arthritis and osteoarthritis: implications for therapy

Rheumatoid arthritis (RA) and osteoarthritis (OA) are polygenic diseases. Polymorphisms in candidate genes have been studied for possible association with susceptibility to disease development. Aside from HLA polymorphisms, of particular interest are those in genes encoding cytokines, signaling molecules, and enzymes involved in the production and catabolism of oxygen and nitrogen radicals. Cytokines are involved in the modulation of the pathological process and have been the target for novel therapeutic interventions. Evidence for their involvement in RA and OA has been provided from genetic analyses in patient populations as well as from animal models of disease. Intracellular signaling cascades control cellular responses and thus regulate many aspects of the pathology manifested in rheumatic diseases. Deciphering the organization and activity of such signaling pathways in disease is underway. Polymorphisms have been identified in gene promoter regions regulating efficient binding of transcription factors, and in coding regions of genes whose products are involved in signal cascades relevant to RA. Among these are the NF-kappaB pathway, steroid receptors and the p53 tumor suppressor gene. Both reactive oxygen species (ROS) and reactive nitrogen species (RNS) have also been implicated in rheumatic diseases. It is thought that excess, damaging, ROS/RNS may arise from an imbalance between the production and removal of these chemical species. Polymorphisms in genes that encode enzymes involved in either generating or degrading ROS/RNS may contribute to such an imbalance. In the last few years, polymorphisms in such genes have indeed been identified as risk factors for rheumatic diseases.

Hypothalamic-pituitary-adrenocortical and gonadal functions in rheumatoid arthritis

Rheumatoid arthritis (RA) as well as most autoimmune disorders results from a combination of several predisposing factors including the relations between epitopes of the trigger agent (i.e., virus, self-antigens) and histocompatibility epitopes (i.e., HLA), the status of the stress response system including the hypothalamic-pituitary-adrenocortical axis (HPA) and the sympathetic nervous system (SNS), as well as the gonadal hormones (hypothalamic-pituitary-gonadal axis, HPG), with estrogens implicated as enhancers of the immune response and androgens and progesterone as natural suppressors. The regular observation of reduced cortisol and adrenal androgen secretion during testing in RA patients not treated with glucocorticoids should clearly be regarded as "relative adrenal insufficiency" in the setting of a sustained inflammatory process, as shown by high interleukin (IL)-6 levels. In polymyalgia rheumatica, several pathogenetic and clinical aspects of the disease might well overlap RA, at least with elderly onset RA (EORA). Therefore, reduced production of adrenal hormones (i.e., cortisol, DHEAS) at baseline in active and untreated patients with polymyalgia rheumatica was detected. The defect was mainly related to altered adrenal responsiveness to ACTH stimulation (i.e., increased 17-OHP), at least in untreated patients with polymyalgia rheumatica. Finally, normal serum estrogen and low androgen levels, but high synovial fluid estrogen and much lower androgen levels, have been found in RA patients, supporting the fundamental role of the peripheral sex hormone metabolism in the manifestations of the disease.

Inducible nitric oxide synthase is expressed in synovial fluid granulocytes

The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure l-arginine and l-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. l-arginine was elevated in SF compared to serum (257 +/- 78 versus 176 +/- 65 micro mol/l, P = 0.008), whereas a slight increase in l-citrulline (33 +/- 11 versus 26 +/- 9 micro mol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 +/- 20.7 versus 8.6 +/- 6.5 micro mol/l, P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.

Melatonin serum levels in rheumatoid arthritis

The pineal hormone melatonin (MLT) exerts a variety of effects on the immune system. MLT activates immune cells and enhances inflammatory cytokine and nitric oxide production. Cytokines are strongly involved in the synovial immune and inflammatory response in rheumatoid arthritis (RA) and reach the peak of concentration in the early morning, when MLT serum level is higher. Nocturnal MLT serum levels were evaluated in 10 RA patients and in 6 healthy controls. Blood samples were obtained at 8 and 12 p.m., as well as at 2, 4, 6, and 8 a.m. MLT serum levels at 8 p.m. and 8 a.m. were found to be higher in RA patients than in controls (p < 0.05). In both RA patients and healthy subjects, MLT progressively increased from 8 p.m. to the first hours of the morning, when the peak level was reached (p < 0.02). However, MLT serum level reached the peak at least two hours before in RA patients than in controls (p < 0.05). Subsequently, in RA patients, MLT concentration showed a plateau level lasting two to three hours, an effect not observed in healthy controls. After 2 a.m., MLT levels decreased similarly in both RA patients and healthy subjects. Several clinical symptoms of RA, such as morning gelling, stiffness, and swelling, which are more evident in the early morning, might be related to the neuroimmunomodulatory effects exerted by MLT on synovitis and might be explained by the imbalance between cortisol serum levels (lower in RA patients) and MLT serum levels (higher in RA patients).

Perspectives on the relationship of adrenal steroids to rheumatoid arthritis

An expanded model of RA is presented that incorporates cumulative multifactorial processes operating over a prolonged physiological phase prior to initial clinical manifestations. During this phase, progressive imbalances in the homeostasis of core neuroendocrine, immunological, and microvascular systems are believed to occur. Normal adrenal function plays an essential role in helping to maintain homeostasis of core systems in health. In RA, chronic adrenal hypocompetence is suspected to occur in a minority subset of females who have younger clinical onset and males who have associated low serum testosterone levels. Chronic, relative glucocorticoid insufficiency is believed to contribute to development of inflammatory manifestations in RA patients. Androgenic deficiencies, particularly of gonadal origin in males, may also contribute to RA, particularly its decreased anabolic features. Precise influences of hypocompetent adrenal steroid function on long-term modeling of the immunological compartment and control of microvascular activation processes are not well understood. These complex mechanisms need to be elucidated for better understanding of the physiopathogenesis of RA. Nevertheless, at a clinical level, sufficient data are currently available to endorse further controlled studies of early clinical onset patients and prospective investigations to determine more definitively the roles of adrenal (and gonadal) steroids in subsets of RA patients and unaffected susceptible persons in the population.

Influence of cytokines and growth factors on distinct steroidogenic enzymes in vitro: a short tabular data collection

Cytokines (IL-1, IL-6, IL-8, IL-11, TNF, IFN-gamma, and TGF-beta) and growth factors (EGF, bFGF, aFGF, and KGF) play an important role in modulation of hormone secretion by directly influencing specific enzyme steps of steroidogenesis in various endocrine cell types. For this tabular data collection, the following enzyme steps were considered: steroidogenic acute regulatory protein (StAR), side chain cleavage enzyme (P450scc), 3 beta-hydroxysteroid dehydrogenase, 17-alpha-hydroxylase/17,20-lyase (P450c17), 17-beta-hydroxysteroid-dehydrogenase, aromatase complex, 5-alpha-reductase, P450c21, DHEAS sulfatase, and DHEA sulfotransferase. This collection summarizes the current information on how the mentioned cytokines and growth factors influence particular enzyme steps.

Steroid hormones and disease activity during pregnancy in systemic lupus erythematosus

OBJECTIVES

To analyze the variation of steroid hormone levels during pregnancy in patients with systemic lupus erythematosus (SLE). Moreover, to investigate whether, during gestation, there is any relationship between steroid concentration and SLE activity.

METHODS

Seventeen consecutive pregnant SLE patients and 8 matched healthy pregnant controls were studied prospectively. Disease activity was evaluated by European Consensus Lupus Activity Measure (ECLAM) score modified for pregnancy. The following hormones were evaluated: testosterone, 17beta-estradiol (estradiol), cortisol, dehydroepiandrosterone sulfate (DHEAS), and progesterone.

RESULTS

Disease activity score significantly varied during pregnancy and postpartum (P< 0.05), being decreased in the third trimester and increased in the second trimester and postpartum. Serum levels of all steroids varied significantly during pregnancy and the postpartum period both in patients and in healthy subjects. In SLE patients, estradiol, progesterone, and DHEAS concentrations were found to be significantly reduced compared with controls. Serum level profiles of estradiol and progesterone were different from those observed in controls. No differences in the steroid levels were observed between patients taking prednisone <or=5 mg/day or >5 mg/day, apart from cortisol, which was, as expected, lower in the latter group.

CONCLUSIONS

The major hormonal alteration observed during pregnancy in SLE patients was an unexpected lack of estrogen serum level increase, and, to a lesser extent, progesterone serum level increase, during the second and-even more-the third trimester of gestation. This lack of increase probably was due to placental compromise. Therefore, these steroid hormone variations may result in a lower humoral immune response activation, probably related to a change in the estrogen/androgen balance, that in turn could account for the decrease in disease activity observed during the third trimester in pregnant SLE patients.

Hypothalamic-pituitary-adrenal axis regulation of inflammation in rheumatoid arthritis

The profound anti-inflammatory effects of glucocorticoids in drug therapy are reflected in the effects in vivo of endogenous glucocorticoids produced by the adrenals. The production of adrenal glucocorticoids is driven by the hypothalamus and pituitary, which in turn are responsive to circulating products of the inflammatory response, especially cytokines. That inflammation can drive the production of anti-inflammatory glucocorticoids denotes the hypothalamic-pituitary-adrenal (HPA)-immune axis as a classic negative feedback control loop. Defects in HPA axis function are implicated in susceptibility to, and severity of, animal models of rheumatoid arthritis (RA), and are hypothesized to contribute to the human disease. In this paper, data supporting the concept of the HPA axis as a regulator of the inflammatory response in animal models of arthritis are reviewed, along with data from studies in humans. Taken together, these data support the hypothesis that the HPA axis provides one of the key mechanisms for inhibitory regulation of the inflammatory response. Manipulation of HPA axis-driven endogenous anti-inflammatory responses may provide new methods for the therapeutic control of inflammatory diseases.

The hypothalamic-pituitary-adrenal and gonadal axes in rheumatoid arthritis

The hypothalamic-pituitary-adrenal (HPA) and the hypothalamic-pituitary-gonadal (HPG) axes involvement or response to immune activation seems crucial for the control of excessive inflammatory and immune conditions such as autoimmune rheumatic diseases, including rheumatoid arthritis (RA). However, female patients seem to depend more on the HPA axis, whereas male patients seem to depend more on the HPG axis. In particular, hypoandrogenism may play a pathogenetic role in male RA patients because adrenal and gonadal androgens, both products of the HPA and HPG axes, are considered natural immunosuppressors. A significantly altered steroidogenesis of adrenal androgens (i.e., dehydroepiandrosterone sulfate, DHEAS and DHEA) in nonglucocorticoid-treated premenopausal RA patients has been described. The menopausal peak of RA suggests that estrogens and/or progesterone deficiency also play a role in the disease, and many data indicate that estrogens suppress cellular immunity, but stimulate humoral immunity (i.e., deficiency promotes cellular Th1-type immunity). A range of physical and psychosocial stressors are also implicated in the activation of the HPA axis and related HPG changes. Chronic and acute stressors appear to have different actions on immune mechanisms with experimental and human studies indicating that acute severe stressors may be even immunosuppressive, while chronic stress may enhance immune responses. The interactions between the immunological and neuroendocrine circuits is the subject of active and extensive ongoing research and might in the near future offer highly promising strategies for hormone-replacement therapies in RA.

Involvement of the hypothalamic--pituitary--adrenal/gonadal axis and the peripheral nervous system in rheumatoid arthritis: viewpoint based on a systemic pathogenetic role

From the compendium presented above, the following statements become evident: 1) Inappropriately low secretion of cortisol in relation to inflammation is a typical feature of the inflammatory disease in patients with RA. 2) The secretion of adrenal androgens is significantly reduced, which is a problem in postmenopausal women and elderly men due to a lack of downstream sex hormones. 3) Serum levels of testosterone are markedly reduced in RA. 4) Sympathetic nerve fibers are markedly reduced in the synovial tissue of patients with RA, whereas proinflammatory sensory fibers (substance P) are present. 5) Substance P serves to continuously sense painful stimuli in the periphery, and the nociceptive input from the inflamed joint shows a large amplification in the spinal cord. This leads to continuous pain with stabilization of the afferent sensory input and continuous release of proinflammatory substance P into the lumen of the joint. From these facts it is obvious that alterations of the systemic antiinflammatory feedback systems contribute significantly to the pathogenesis of RA. Disease therapy directed at these alterations must provide a mechanism to replace the adrenal glands (glucocorticoids), the gonadal glands (androgens), and the sympathetic nervous system (adenosine increase by low-dose MTX, sulfasalazine, and salicylates) in order to integrate their immunosuppressive effects at the local site of synovial inflammation. Although local processes of the adaptive immune system are important in pathogenesis in the acute phase of RA, these mechanisms may be less important during the chronic phase of the disease in the absence of a specific trigger. We believe that a defect of systemic antiinflammatory feedback systems is an important factor in the perpetuation of RA. This review reinforces the belief that combined therapeutic approaches on a neuroendocrine immune basis are of crucial importance in a pathogenetically oriented therapy of RA.

Optimizing glucocorticoid therapy in rheumatoid arthritis

Glucocorticoids have a profound effect on the immune system and also on the HPA axis. Present insights into these mechanisms are discussed. Glucocorticoid resistance and clinical efficacy in the treatment of RA are reviewed. There is growing evidence for a positive effect of low-dose glucocorticoids on the retardation of erosive joint damage. Side effects of glucocorticoids on bone are now better controlled. Some guidelines to optimize glucocorticoid therapy in RA are given regarding dosage, timing, managing of side effects, and (new) types of glucocorticoids.

Neuroendocrine immune mechanisms in rheumatic diseases. An overview and future implications

A new physiopathogenetic paradigm may be proposed for RA and possibly its related systemic rheumatic diseases (i.e., mechanisms whereby multiple risk factors initially perturb the homeostasis of core physiologic components over an extended premorbid phase, which may progress to clinical disease in later decompensated stages). These complex interactive processes are likely to be individualized according to genetic, nongenomic somatic, developmental, behavioral, and environmental influences. Future research promises to further elucidate the roles of neuroendocrine mechanisms in the rheumatic diseases and offers promise for enhanced therapies and possible avenues for disease modification if not eventual prevention.

Hormonal preservation of bone in rheumatoid arthritis

Bone loss is a hallmark of RA. Factors influencing generalized bone loss include RA-specific factors such as the influence of disease activity and deficient sex hormone status and more general mechanisms (e.g., due to the use of glucocorticoids). Reducing disease activity has a positive effect on bone. Estrogens or androgens can restore deficiency of the sex hormones with a small positive effect on BMD. The more pronounced bone loss occurs when RA patients are being treated with glucocorticoids. This bone loss can be reduced by the concomitant use of calcium and vitamin D and, in most patients, by the use of bisphosphonates as well.

Sex hormone adjuvant therapy in rheumatoid arthritis

RA is an autoimmune rheumatic disorder resulting from the combination of several predisposing factors, including the relation between epitopes of possible triggering agents and histocompatibility epitopes, the status of the stress response system, and the sex hormone status. Estrogens are implicated as enhancers of humoral immunity, and androgens and progesterone are natural immune suppressors. Sex hormone concentrations have been evaluated in RA patients before glucocorticoid therapy and have frequently been found to be altered, especially in premenopausal women and male patients. In particular, low levels of gonadal and adrenal androgens (testosterone and DHT, DHEA and DHEAS) and a reduced androgen:estrogen ratio have been detected in body fluids (i.e., blood, synovial fluid, smears, saliva) of male and female RA patients. These observations support a possible pathogenic role for the decreased levels of the immune-suppressive androgens. Exposure to environmental estrogens (estrogenic xenobiotics), genetic polymorphisms of genes coding for hormone metabolic enzymes or receptors, and gonadal disturbances related to stress system activation (hypothalamic-pituitary-adrenocortical axis) and physiologic hormonal perturbations such as during aging, the menstrual cycle, pregnancy, the postpartum period, and menopause may interfere with the androgen:estrogen ratio. Sex hormones might exert their immune-modulating effects, at least in RA synovitis, because synovial macrophages, monocytes, and lymphocytes possess functional androgen and estrogen receptors and may metabolize gonadal hormones. The molecular basis for sex hormone adjuvant therapy in RA is thus experimentally substantiated. By considering the well-demonstrated immune-suppressive activities exerted by androgens, male hormones and their derivatives seem to be the most promising therapeutic approach. Recent studies have shown positive effects of androgen replacement therapy at least in male RA patients, particularly as adjuvant treatment. Interestingly, the increase in serum androgen metabolism induced by RA treatment with CSA should be regarded as a possible marker of androgen-mediated immune-suppressive activities exerted by CSA, at least in RA and at the level of sensitive target cells and tissues (i.e., synovial macrophages). The absence of altered serum levels of estrogens in RA patients and the reported immune-enhancing properties exerted by female hormones have represented a poor stimulus to test estrogen replacement therapy in RA. The different results obtained with OC use seem to depend on dose-related effects and the different type of response to estrogens in relation to the cytokine balance between Th1 cells (cellular immunity, i.e., RA) and Th2 cells (humoral immunity, i.e., SLE). The androgen replacement obtained directly (i.e., testosterone, DHT, DHEAS) or indirectly (i.e., antiestrogens) may represent a valuable concomitant or adjuvant treatment to be associated with other disease-modifying antirheumatic drugs (i.e., MTX, CSA) in the management of RA.

Interactions of autonomic nervous, neuroendocrine, and immune systems in rheumatoid arthritis

In general, it is assumed that the two pathways (i.e., HPA axis and sympathetic nervous system) probably act cooperatively to maintain homeostasis. The previously mentioned studies clearly point to a disturbance in the interaction between the ANS, the HPA axis, and the immune system in chronic rheumatic diseases (Fig. 2). Even early on in the course of RA, these changes can be observed. Along with the results obtained in animal models, an important role of neuroendocrine interactions in the pathogenesis of RA is proposed. Further studies are required to establish the exact contribution of the ANS in the initiation and perpetuation of RA. To date, it is quite obvious that neuropeptides play a part in the orchestration of the various molecules (e.g., cytokines) exerting modulatory effects on immune cells. One can speculate that therapeutic implications are likely to result from investigations on the ANS-immune interactions. Based on early observations that blocking catecholamine actions ameliorate symptoms of RA, it is quite promising to follow this avenue in investigating ANS-immune interactions of various time points of the disease. Conversely, further studies are required to determine the contribution of the HPA axis to the onset of RA. Results from ongoing studies are eagerly awaited so as to establish new therapeutic options. In the future,it may be possible to interfere with the inflammatory process in RA by an exactly timed neuroendocrine intervention right at or even before the onset of disease. Therapy with steroids in RA might be better planned based on the genetically determined reactivity of an individual's HPA axis. In this respect, a recent report by Masi et al is of special interest. Based on the current literature on the disturbances in the neuroendocrine, immune, and microvascular systems found in early RA, the authors hypothesize that an imbalance in the interactive homeostasis of these systems develops during a long preclinical phase and eventually leads to the outbreak of the disease in genetically predisposed individuals. This interesting hypothesis includes the perspective that individuals prone to develop RA may be identified in a preclinical phase and treated prophylactically. In any event, results from all these studies are promising in two ways: to gain more insight in the pathogenic process of RA and to establish novel therapies to help the patients bear their burden of a chronic rheumatic disease.