Gonadal and adrenal sex steroids in ankylosing spondylitis

No increased risk of alopecia in ankylosing spondylitis patients: A population-based cohort study in Taiwan

AIM

To investigate the association between ankylosing spondylitis (AS) and alopecia.

METHODS

In this cohort study, data from over 1 000 000 patients in the Taiwan Longitudinal Health Insurance Database were extracted. We selected newly diagnosed (outpatient department visit three or more times or admission at least once) patients with AS (ICD-9-CM = 720.0) from 2000 to 2012. For the non-AS comparison group, patients never diagnosed with AS were chosen from 1999 to 2013. In all, 3640 AS patients and 14 560 non-AS controls were selected. Cox proportional hazard model and Kaplan-Meier analysis were used to present the results. The adjusted hazard ratio (HR) in the Cox proportional hazard model was adjusted for age, sex, hypertension, hyperlipidemia, diabetes, atopic dermatitis, and mental disorder.

RESULTS

No increased risk of alopecia in AS patients was shown in the Cox proportional hazard model (crude HR 1.16, P = 0.595; adjusted HR 1.16, P = 0.599). Negative results are found as well in subgroup analysis of different age, sex (age 20-40 y: HR 1.03, P = 0.925; Age ≥40 y: HR 1.49, P = 0.406; Female: HR 1.17, P = 0.759; Male: HR 1.15, P = 0.667), and phenotypes of alopecia (androgenetic alopecia: HR 1.19, 95% confidence interval [CI] 0.58-2.41; alopecia areata: HR 0.98, 95% CI 0.37-2.62). A significant positive correlation is found between atopic dermatitis and alopecia (adjusted HR 8.05, P = 0.039).

CONCLUSION

In this population-based cohort study, we found no association of risk of alopecia and AS.

Immunopathophysiology of Juvenile Spondyloarthritis (jSpA): The "Out of the Box" View on Epigenetics, Neuroendocrine Pathways and Role of the Macrophage Migration Inhibitory Factor (MIF)

Juvenile spondyloarthritis (jSpA) is a an umbrella term for heterogeneous group of related seronegative inflammatory disorders sharing common symptoms. Although it mainly affects children and adolescents, it often remains active during adulthood. Genetic and environmental factors are involved in its occurrence, although the exact underlying immunopathophysiology remains incompletely elucidated. Accumulated evidence suggests that, in affected patients, subclinical gut inflammation caused by intestinal dysbiosis, is pivotal to the future development of synovial-entheseal complex inflammation. While the predominant role of IL17/23 axis, TNF-α, and IL-7 in the pathophysiology of SpA, including jSpA, is firmly established, the role of the cytokine macrophage migration inhibitory factor (MIF) is generally overlooked. The purpose of this review is to discuss and emphasize the role of epigenetics, neuroendocrine pathways and the hypothalamic-pituitary (HPA) axis, and to propose a novel hypothesis of the role of decreased NLRP3 gene expression and possibly MIF in the early phases of jSpA development. The decreased NLRP3 gene expression in the latter, due to hypomethylation of promotor site, is (one of) the cause for inflammasome malfunction leading to gut dysbiosis observed in patients with early jSpA. In addition, we highlight the role of MIF in the complex innate, adaptive cellular and main effector cytokine network, Finally, since treatment of advanced bone pathology in SpA remains an unmet clinical need, I suggest possible new drug targets with the aim to ultimately improve treatment efficacy and long-term outcome of jSpA patients.

Erectile Dysfunction, Testosterone Levels and Disease Activity in Ankylosing Spondylitis Patients

OBJECTIVE

To study erectile function in male patients with Ankylosing Spondylitis (AS) trying to correlate it with sexual hormonal profile and disease activity.

METHODS

We included 35 AS patients and 104 controls. Patients and controls answered the IIEF (International Index of Erectile Dysfunction) and had dosing of total testosterone, free testosterone (FT), bioavailable testosterone (BT), SHBG (serum hormone binding globulin), albumin and LH (luteinizing hormone). AS patients had epidemiological, clinical and treatment data obtained from the charts. AS disease activity was measured simultaneously with blood collection through Bath AS Disease Activity Index, ASDAS (AS Disease Activity Score) -ESR (using erythrocyte sedimentation rate) and ASDAS-CRP (using C reactive protein).

RESULTS

The IIEF results were worse in AS patients than controls (P = .02). Total testosterone and SHBG were higher in AS (with P = .01 and P <.0001 respectively). Between the 2 groups, no differences in LH, FT, BT levels (all with P = ns) were found. In AS patients, the IIEF results did not correlate with total testosterone, SHBG, LH, FT, and BT but a negative association was found with Bath AS Disease Activity Index (P = .001) and ASDAS-CRP (P = .02).

CONCLUSION

AS patients had worst sexual performance than controls that was linked to disease activity but not to male sexual hormonal profile.

Surgical correction of rigid cervicothoracic deformity in a transgender patient: case report

A number of spinal pathologies result in fusion of the spine, including ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis (DISH), as well as severe degenerative arthropathies. This fusion of spinal elements may result in spinal deformity affecting any region of the spine. Cervicothoracic deformity resulting in chin on chest deformity is poorly tolerated due to inability to maintain a horizontal gaze. Surgical treatment options for this condition are complex and require extensive discussion between the patient and surgical team. Here we present a case report of a 26-year-old transgender female (male to female) patient with severe chin on chest deformity and a unique pattern of spinal fusion involving only the posterior elements. She underwent C2-T8 posterior spinal fusion with thoracic pedicle subtraction osteotomy and multiple cervical facet osteotomies with good functional result. She did have severe dysphagia and required feeding tube for several weeks but did very well by 1 year postoperatively. While posterior elements of the spine are normally affected first in spondyloarthropathies such as ankylosing spondylitis, the lack of anterior spinal involvement is unique and could be attributed to hormonal therapy in this patient. This case describes a unique pattern of spondyloarthropathy and highlights the importance of a having a multi-disciplinary team for the treatment of patients with complex spinal pathologies.

A Mechanism Underlying Sex-Associated Differences in Ankylosing Spondylitis: Troponin C2, Fast Skeletal Type (TNNC2) and Calcium Signaling Pathway

BACKGROUND Ankylosing spondylitis (AS) is a disease that causes pathological changes in the spine and sacroiliac joints. Numerous studies have shown that the characteristics of AS differ between males and females. The purpose of this study was to discover the key molecules that contribute to sex-associated differences in AS, which may provide a new molecular target for personalized treatment. MATERIAL AND METHODS The gene expression profile of GSE39340 was downloaded from the Gene Expression Comprehensive database, and 2 groups (AS vs. No-AS groups and male AS vs. female AS groups) of differentially expressed genes (EDGs) were obtained by GEO2R. The DAVID database was used for DEGs function and enrichment analysis. Based on data in the STRING online database, a protein-protein interaction (PPI) network was constructed in Cytoscape. Hub genes were selected from CytoHubba. With the intersection of the top 30 hub genes of 2 sets of EDGs, genes coexisting with the KEGG-related pathway were found. RESULTS We screened 560 genes between the AS and No-AS groups, and screened 710 genes that were differentially expressed between the male and female AS groups. GO analysis showed that DEGs were mainly co-enriched in molecular functions, including structural constituent of muscle. The KEGG pathway mainly included the structural constituent of muscle. Seven hub genes were obtained. Troponin C2 and fast skeletal type (TNNC2) were the key genes participating in the calcium signaling pathway. CONCLUSIONS This study contributes to understanding the molecular biological mechanism underlying sex-associated differences in AS. TNNC2 and calcium signaling pathway may be new targets for the individualized treatment of AS.

Ovarian reserve in patients with ankylosing spondylitis

PURPOSE

The aim of this study was to determine the autoimmune effects of ankylosing spondylitis (AS) on the fertility potential of women by evaluating ovarian reserves of AS patients.

METHODS

A total of 104 patients, 52 in the AS group (study group) and 52 in the control group were included in the study. Ovarian reserve was evaluated by serum anti-Müllerian hormone (AMH) levels, antral follicle count (AFC) and baseline serum follicle-stimulating hormone (FSH) levels.

RESULTS

The mean serum AMH levels were significantly lower in the study group when compared to the controls (2.203 ± 1.110 vs. 1.188 ± 0.891, p < 0.001). In addition, the mean AFC was also significantly lower in the study group. (10.67 ± 1.81 vs. 9.54 ± 2.50, p = 0.009). Mean FSH levels were calculated to be 6.72 ± 1.14 in the study group and 7.21 ± 1.22 in the control group. The difference was not statistically significant (p = 0.781).

CONCLUSION

This study shows that AS like several other autoimmune conditions has an adverse effect on the female fertility potential. Therefore, an early start and long-term management of AS patients who have fertility desire is recommended. Serum AMH levels can be used in monitoring ovarian reserve and in early detection of reproductive decline of AS patients.

CLINICALTRIAL NUMBER

NCT04209881.

Ankylosing spondylitis: etiology, pathogenesis, and treatments

Ankylosing spondylitis (AS), a common type of spondyloarthropathy, is a chronic inflammatory autoimmune disease that mainly affects spine joints, causing severe, chronic pain; additionally, in more advanced cases, it can cause spine fusion. Significant progress in its pathophysiology and treatment has been achieved in the last decade. Immune cells and innate cytokines have been suggested to be crucial in the pathogenesis of AS, especially human leukocyte antigen (HLA)‑B27 and the interleukin‑23/17 axis. However, the pathogenesis of AS remains unclear. The current study reviewed the etiology and pathogenesis of AS, including genome-wide association studies and cytokine pathways. This study also summarized the current pharmaceutical and surgical treatment with a discussion of future potential therapies.

Can the Second to Fourth Digit Ratio (2D : 4D) Be a Marker to Determine Ankylosing Spondylitis Disease Activity?

Objective

The length ratio of the index finger (2D) to the ring finger (4D) (2D : 4D ratio) is considered a biomarker of prenatal sex hormone exposure. The 2D : 4D ratio is influenced by prenatal androgen and estrogen levels. Because ankylosing spondylitis (AS) influences men more frequently and severely than women, androgens are proposed to be related to AS pathogenesis. Estrogens have immune-modulating effects and reduce AS disease activity. The aim of this study was to assess the relationship between 2D : 4D ratio and AS disease activity.

Material and Methods

In this study, 167 (43 female) patients diagnosed with AS were studied. The lengths of the second and fourth fingers were measured using a digital caliper. The 2D : 4D ratio was found by dividing the length of the second finger by the length of the fourth finger. AS disease activity was assessed with the Turkish version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). AS functional status was assessed with Bath Ankylosing Spondylitis Functional Index (BASFI). L-Schober, tragus to wall distance, finger to floor distance, and chest expansion were used to evaluate mobility.

Results

In female patients, the right hand 2D : 4D ratios were higher than those in male patients. Biologic drug use was more frequent in males. The BASDAI scores were higher in female patients than in male patients. There were significant negative correlations between right and left hand 2D : 4D ratio and BASFI and BASDAI in female patients. There was no significant correlation between the 2D : 4D ratio and BASFI or BASDAI in male patients. We found a positive correlation between L-Schober and right hand 2D : 4D and a negative correlation between the left hand 2D : 4D ratio and finger to floor distance in female patients with AS.

Conclusion

The 2D : 4D ratio of the right and left hand was low in female patients with high BASFI and BASDAI and low spinal mobility (L-Schober) was also linked to low female 2D : 4D. The lack of strong associations between 2D : 4D and AS in male patients may have resulted from their higher use of biologics.

Hidradenitis Suppurativa: A Systematic Review Integrating Inflammatory Pathways Into a Cohesive Pathogenic Model

Background: The pathogenesis of hidradenitis suppurativa (HS) is not fully understood. This systematic review examined the latest evidence for molecular inflammatory pathways involved in HS as a chronic inflammatory skin disease.

Methods: A systematic literature search was performed in PubMed/Medline and EMBASE from January 2013 through September 2017, according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Findings on HS pathogenesis were also compared with those of other immune-mediated inflammatory diseases (IMIDs) in a non-systematic review. In addition, current therapeutic options for HS are briefly discussed on the basis of the findings for the inflammatory pathways involved in HS.

Results: A total of 32 eligible publications were identified by the systematic search; these were supplemented with three additional publications. The extracted data indicated that four key themes underlie the pathogenesis of HS and related syndromic conditions. First, nicastrin (NCSTN) and PSTPIP1 mutations are directly associated with auto-inflammatory disease. Secondly, the up-regulation of several cytokines including tumor necrosis factor-α and T helper-17/interleukin-23 are connected to auto-inflammatory mechanisms in the pathogenesis of HS. Thirdly, the microbiome of lesional skin differs significantly vs. normal-appearing skin. Fourthly, HS risk is enhanced through physiological and environmental factors such as smoking, obesity, and mechanical friction. There is significant overlap between the pathogenesis of HS, its syndromic forms and other IMIDs, particularly with respect to aberrations in the innate immune response.

Conclusions: The evidence presented in this review supports HS as an auto-inflammatory skin disorder associated with alterations in the innate immune system. Based on these most recent data, an integrative viewpoint is presented on the pathogenesis of HS. Current management strategies on HS consist of anti-inflammatory therapies, surgical removal of chronic lesions, and lifestyle changes such as smoking cessation and weight loss. As large gaps remain in the understanding of the pathogenesis of HS, further research is warranted to ultimately improve the management and treatment of patients with HS and related syndromic conditions.

Analysis of the effect of the oral contraceptive pill on clinical outcomes in women with ankylosing spondylitis

OBJECTIVE

There are unexplained sex-specific changes in the clinical expression of ankylosing spondylitis (AS). We sought to examine the potential effect of exogenous estrogen in the form of oral contraceptive pills (OCP) on AS initiation and severity.

METHODS

This cross-sectional study consisted of women with AS from the membership of the Spondylitis Association of America. Measures of disease severity included use of biological agents and hip replacement surgery, while Bath AS Functional Index (BASFI) scores served as a surrogate marker of disability. Information was obtained using a patient questionnaire on patient demographics, OCP use, pregnancy history, AS duration, medication use, and hip replacement.

RESULTS

There were 571 women with AS who participated in our study, consisting of 448 OCP ever-users and 123 non-OCP users. The mean age of OCP users was 42.7 yrs (± 11.5) and of non-OCP users, 48.4 yrs (± 12.1). No difference was noted in the age at initial onset of back pain. However, OCP users were significantly younger at the time of diagnosis of AS (36.5 yrs vs 39.1 yrs, p = 0.02). There were no significant differences between the 2 groups in tumor necrosis factor inhibitor or opioid use, BASFI scores, pregnancy complications, or hip surgery.

CONCLUSION

The use of exogenous estrogens in the form of OCP is not associated with a measurable effect on initiation or severity of AS. Biologic and social factors may contribute to earlier diagnosis of AS in OCP users. This is the largest study to date investigating the potential effect of exogenous estrogens in women with AS.

Genetics, environment, and gene-environment interactions in the development of systemic rheumatic diseases

Rheumatic diseases offer distinct challenges to researchers because of heterogeneity in disease phenotypes, low disease incidence, and geographic variation in genetic and environmental factors. Emerging research areas, including epigenetics, metabolomics, and the microbiome, may provide additional links between genetic and environmental risk factors in the pathogenesis of rheumatic disease. This article reviews the methods used to establish genetic and environmental risk factors and studies gene-environment interactions in rheumatic diseases, and provides specific examples of successes and challenges in identifying gene-environment interactions in rheumatoid arthritis, systemic lupus erythematosus, and ankylosing spondylitis. Emerging research strategies and future challenges are discussed.

Low bone mineral density is related to male gender and decreased functional capacity in early spondylarthropathies

The objective of this study was to determine the prevalence and risk factors of low bone mineral density (BMD) in patients with spondylarthropathies (SpA) at an early stage of disease. In this cross-sectional study, the BMD of lumbar spine and hips was measured in 130 consecutive early SpA patients. The outcome measure BMD was defined as (1) osteoporosis, (2) osteopenia, and (3) normal bone density. Logistic regression analyses were used to investigate relations between the following variables: age, gender, disease duration, diagnosis, HLA-B27, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), extra-spinal manifestations and medication, with outcome measure low BMD (osteopenia and/or osteoporosis). The SpA population had a median time since diagnosis of 6.6 months and a disease duration of 6.3 years. In total, 9% of the early SpA patients had osteoporosis, 38% osteopenia, and 53% normal BMD. On univariate analyses, male gender, diagnosis of ankylosing spondylitis, increased CRP, high BASFI, and high BASMI were significantly associated with low BMD. Factors showing a relation with low BMD in the multivariate model were male gender (OR 4.18, 95% confidence interval (CI) 1.73–10.09), high BASMI (OR 1.54, 95% CI 1.14–2.07), and high BASFI (OR 1.18, 95% CI 1.00–1.39). In early SpA patients, a high frequency (47%) of low BMD in femur as well as in lumbar spine was found. Low BMD was associated with male gender and decreased functional capacity. These findings emphasize the need for more alertness for osteoporosis and osteopenia in spondylarthropathy patients at an early stage of the disease.

Impaired hypothalamo-pituitary-adrenal axis in patients with ankylosing spondylitis

BACKGROUND

To investigate the hypothalamic-pituitary- adrenal (HPA) axis in patients with ankylosing spondylitis (AS) and healthy controls.

METHODS

Forty-nine AS patients and 20 healthy controls were included. Lowdose ACTH test (LDST) was used to assess the HPA axis. Basal cortisol, stimulated peak cortisol levels, and acutephase reactants [C-reactive protein (CRP), erythrocyte sedimentation rate, and fibrinogen] were studied. Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Metrology Index were also evaluated.

RESULTS

Patient and control groups were not different regarding age, sex, body mass index and waist circumference (WC). Basal cortisol levels did not show a significant difference between groups. However, cortisol increment after low-dose ACTH was significantly impaired in AS subjects with respect to controls (20.0+/-4.4 vs 24+/-2.2 microg/dl, p<0.001). Eleven AS patients had impaired cortisol peak after LDST when a cortisol cut-off is accepted as 500 nmol/l (18 microg/dl) and none of the controls exhibited a peak cortisol responses to LDST<500 nmol/l. Comparison of AS subjects who were receiving anti-tumor necrosis factor (TNF) (no.=23), and conventional therapy (no.=26) yielded similar basal and peak cortisol concentrations. Peak cortisol concentrations were associated with basal cortisol, impaired cortisol response, CRP, and fibrinogen. Impaired cortisol response (subjects with peak cortisol levels <18 microg/dl) was significantly correlated with basal and peak cortisol concentrations and BASDAI.

CONCLUSION

Our results indicate an increased prevalence of subclinical glucocorticoid deficiency in AS patients. Anti-TNF treatment seems not to have effect on HPA axis.

Sexual dimorphism, but not testosterone itself, is responsible for ankylosing enthesitis of the ankle in B10.BR (H-2k) male mice

BACKGROUND

Ankylosing enthesopathy (ANKENT) with progressive stiffening of ankle and tarsal joints of the hind limbs is a naturally occurring arthropathy in B10.BR mice. Some features are similar to those of the spondyloarthropathies in humans.

OBJECTIVE

To study the role of sexual dimorphism and testosterone in the development of ANKENT.

METHODS

The incidence of ANKENT was observed in non-castrated, castrated, and testosterone substituted castrated male mice, and in control and testosterone treated female mice.

RESULTS

ANKENT occurred only in males; it did not develop in males castrated at age 2-3 months but occurred in castrated males injected with testosterone. Females injected with testosterone did not develop ANKENT.

CONCLUSION

Testosterone can replace what castration eliminates, at least in the postpubertally castrated males, but is itself not sufficient to induce joint disease.

Bone loss in males with ankylosing spondylitis: its relation to sex hormone levels

OBJECTIVE

Osteoporosis is a common complication of ankylosing spondylitis (AS). The aim of the present study was to assess the association of sex hormone levels with bone loss in males with AS.

DESIGN

A cross-sectional study. Patients The study group consisted of 58 male patients with primary AS. The mean age was 38.2 years (range 18-59 years).

MEASUREMENTS

Bone mineral density (BMD) was measured in the left proximal femur. Serum FSH, LH, total testosterone (T), dehydroepiandrosterone sulfate (DHEAS), oestradiol (E2) and progesterone levels were measured.

RESULTS

Bone loss was observed in 54.5% of cases at the femoral neck and in 52.3% of cases at the trochanter and total hip. Bone loss was found in 40 (69%) cases in at least one of these three regions. Serum DHEAS was low in 12 (30.8%) of the cases with bone loss, and one (5.9%) of those without (P = 0.043). The ratio of serum T/DHEAS was higher in those with bone loss (5.24 +/- 3.70) than in those without (3.58 +/- 3.16) (P = 0.026).

CONCLUSIONS

The results showed that bone loss might be related to low serum DHEAS levels in males with AS.

Modulation of bone morphogenetic protein signaling inhibits the onset and progression of ankylosing enthesitis

Joint ankylosis is a major cause of disability in the human spondyloarthropathies. Here we report that this process partially recapitulates embryonic endochondral bone formation in a spontaneous model of arthritis in DBA/1 mice. Bone morphogenetic protein (BMP) signaling appears to be a key molecular pathway involved in this pathological cascade. Systemic gene transfer of noggin, a BMP antagonist, is effective both as a preventive and a therapeutic strategy in the mouse model, mechanistically interfering with enthesial progenitor cell proliferation in early stages of the disease process. Immunohistochemical staining for phosphorylated smad1/5 in enthesial biopsies of patients with spondyloarthropathy reveals active BMP signaling in similar target cells. Our data suggest that BMP signaling is an attractive therapeutic target for interfering with structural changes in spondyloarthropathy either as an alternative or complementary approach to current antiinflammatory treatments.

Bone turnover markers, anterior pituitary and gonadal hormones, and bone mass evaluation using quantitative computed tomography in ankylosing spondylitis

The objective of this study was to determine bone mineral density (BMD) distribution in ankylosing spondylitis (AS) using quantitative computed tomography (QCT), to study bone turnover and anterior pituitary and gonadal hormonal axis in AS, and to look for correlations between BMD, bone remodeling markers and gonadal and anterior pituitary hormones. Forty-three male consecutive patients with AS were enrolled prospectively [mean (SD) age of 36.4 (11.3) years (range: 17-67) and mean disease duration of 6.8 (5.2) years (range: 0.4-19)]. Spine BMD was measured in all patients by QCT, and the results were compared to 29 male patients undergoing lumbar CT scan for sciatica. Bone turnover and anterior pituitary and gonadal axis were assessed in 29 patients, and the results were compared to 30 male healthy blood donors. The mean (SD) BMD was 127.7 mg/cm(3) (48.9) (range: 8.8-265.7) and 152.1 (25.3) (range: 34.2-190.4) in patients and controls, respectively (p = 0.018). Patients had lower serum levels of osteocalcin and higher levels of serum testosterone, luteinizing hormone (LH), and prolactin than controls with a significant statistical difference. There was a positive significant statistical correlation between BMD and chest expansion, Schober's test, C7-wall distance, and negative significant statistical correlation with age, disease duration, Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Radiology Index (BASRI), and serum prolactin. No correlation was observed between bone turnover parameters and AS symptomatic and structural severity indexes. BMD is lower with increasing age and late and severe disease. Decreased bone formation with normal resorption and increased levels of serum prolactin may be involved in its pathophysiology.

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 and immunologic risk factors for the development of rheumatoid arthritis: an integrative physiopathogenetic perspective

Evidence indicates that women who are susceptible to premenopausal onset of RA and men each have identifiable risk factors or risk markers long before onset of the clinical disease. Accordingly, further definition of such predictive factors promises to identify persons who are susceptible to developing RA during preclinical phases. Like coronary artery disease, once risks for developing RA can be reliably quantitated, research in primary prevention should become a realistic objective. Disease prevention objectives are central to the public health strategy of the National Arthritis Action Plan and the US Public Health Service "Healthy People 2000" plan (2010 plan also proposed). The decade of arthritis and musculoskeletal diseases (2000-2010) offers an incentive to nurture a new paradigm of RA prevention. Further research in neuroendocrine, immunologic, and microvascular risk factors for the development of RA promises to unravel its complex physiopathogenetic mechanisms and permit identification of persons who are at high risk for developing this disease. Successful research in identifying reliable risk factors (or markers) can be expected to lead to prevention strategies. Effective programs in identifying persons susceptible to RA could lead to earlier control measures and significantly reduce the enormous burden of this common disease, which affects all segments of the population.