DO SEX HORMONES PLAY A ROLE IN ANKYLOSING SPONDYLITIS?

Sex differences in musculoskeletal injury and disease risks across the lifespan: Are there unique subsets of females at higher risk than males for these conditions at distinct stages of the life cycle?

Sex differences have been reported for diseases of the musculoskeletal system (MSK) as well as the risk for injuries to tissues of the MSK system. For females, some of these occur prior to the onset of puberty, following the onset of puberty, and following the onset of menopause. Therefore, they can occur across the lifespan. While some conditions are related to immune dysfunction, others are associated with specific tissues of the MSK more directly. Based on this life spectrum of sex differences in both risk for injury and onset of diseases, a role for sex hormones in the initiation and progression of this risk is somewhat variable. Sex hormone receptor expression and functioning can also vary with life events such as the menstrual cycle in females, with different tissues being affected. Furthermore, some sex hormone receptors can affect gene expression independent of sex hormones and some transitional events such as puberty are accompanied by epigenetic alterations that can further lead to sex differences in MSK gene regulation. Some of the sex differences in injury risk and the post-menopausal disease risk may be "imprinted" in the genomes of females and males during development and sex hormones and their consequences only modulators of such risks later in life as the sex hormone milieu changes. The purpose of this review is to discuss some of the relevant conditions associated with sex differences in risks for loss of MSK tissue integrity across the lifespan, and further discuss several of the implications of their variable relationship with sex hormones, their receptors and life events.

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.

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.

The sacroiliac joint: an overview of its anatomy, function and potential clinical implications

This article focuses on the (functional) anatomy and biomechanics of the pelvic girdle and specifically the sacroiliac joints (SIJs). The SIJs are essential for effective load transfer between the spine and legs. The sacrum, pelvis and spine, and the connections to the arms, legs and head, are functionally interrelated through muscular, fascial and ligamentous interconnections. A historical overview is presented on pelvic and especially SIJ research, followed by a general functional anatomical overview of the pelvis. In specific sections, the development and maturation of the SIJ is discussed, and a description of the bony anatomy and sexual morphism of the pelvis and SIJ is debated. The literature on the SIJ ligaments and innervation is discussed, followed by a section on the pathology of the SIJ. Pelvic movement studies are investigated and biomechanical models for SIJ stability analyzed, including examples of insufficient versus excessive sacroiliac force closure.

Integrative structural biomechanical concepts of ankylosing spondylitis

Ankylosing spondylitis (AS) is not fully explained by inflammatory processes. Clinical, epidemiological, genetic, and course of disease features indicate additional host-related risk processes and predispositions. Collectively, the pattern of predisposition to onset in adolescent and young adult ages, male preponderance, and widely varied severity of AS is unique among rheumatic diseases. However, this pattern could reflect biomechanical and structural differences between the sexes, naturally occurring musculoskeletal changes over life cycles, and a population polymorphism. During juvenile development, the body is more flexible and weaker than during adolescent maturation and young adulthood, when strengthening and stiffening considerably increase. During middle and later ages, the musculoskeletal system again weakens. The novel concept of an innate axial myofascial hypertonicity reflects basic mechanobiological principles in human function, tissue reactivity, and pathology. However, these processes have been little studied and require critical testing. The proposed physical mechanisms likely interact with recognized immunobiological pathways. The structural biomechanical processes and tissue reactions might possibly precede initiation of other AS-related pathways. Research in the combined structural mechanobiology and immunobiology processes promises to improve understanding of the initiation and perpetuation of AS than prevailing concepts. The combined processes might better explain characteristic enthesopathic and inflammatory processes in AS.

High frequencies of HLA-B27 in Chinese patients with suspected of ankylosing spondylitis

This study was performed to investigate the frequency of human leukocyte antigen (HLA)-B27 in Chinese patients with suspected of ankylosing spondylitis (AS) and to assess the clinical significance of HLA-B27 typing. A total of 1,016 patients suspected of AS were classified into six groups based on one major AS-related clinical manifestation. HLA-B27 was determined by polymerase chain reaction using sequence-specific primers. The frequency of B27 ranged between 24.3 and 46.7% among the patient groups, significantly higher than in healthy controls (2.4%). In the same group, the frequency of B27 in young (< or = 40 years) and in male patients was significantly higher than in the old and in female (P < 0.01). During a 1-year follow-up, 102 subjects were definitely diagnosed as AS, but only one B27(-) patient. Of the 102 definite patients, 69 (67.6%) definite patients were distributed in group 1 (low back pain and stiffness) with the higher incidence (28.5%) of AS. The incidence of AS in the same group was found with a similar pattern to the frequency of B27, in male and young patients significantly greater, except groups 4 and 6 (peripheral arthritis and alteration of skin). These findings confirm that HLA-B27 is one of sensitive diagnostic tools for early AS and suggest that there was a remarkable clinical significance of HLA-B27 typing in Chinese patients suspected of AS, particularly a young man who presents with low back pain and stiffness for > 3 months.

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.

Gonadal and adrenal sex steroids in ankylosing spondylitis

A role for sex steroids in the pathogenesis of AS is suggested by the male predominance, the peak age of onset in young adults, the increased number of first manifestations and flares after pregnancy, and the fact that sex steroids may modulate immune functions. There is a theoretic possibility that (normal levels of) androgens are indeed relevant in the male sex skew of AS. It has been reported that men with AS have higher than normal androgen levels; however, the evidence that serum testosterone levels are elevated in patients with AS is not robust. Elevated DHEAS and 17 alpha-hydroxyprogesterone levels have been reported in male AS patients; these may be secondary to inflammation and stress but may theoretically also be causally related to AS. These elevations might result from a partial late onset 11 beta- or 21-hydroxylase deficiency. Current data on sex steroid hormones provide no straightforward explanation for the male predominance in AS. It is fair to say that present data in patients with long-standing AS are too limited to suggest a role for androgens in the perpetuation of the disease, but a role in the initiation and the early stages of AS cannot be excluded. Such information can only be obtained from prospective studies. Cross-sectional studies cannot clearly distinguish causal relation from secondary disease effects, because blood sampling to test these hypotheses only takes place many years after the onset of disease. The impact of sex steroids on these features of AS is still unresolved. There is as yet no rationale for the use of medication that modifies sex steroid hormones in the management of AS. Alternative explanations for the higher male prevalence of AS may be found in the different chromosomal configuration and body composition of men and women.

Androgens and ankylosing spondylitis: a role in the pathogenesis?

The frequency and severity of ankylosing spondylitis (AS) show a male preponderance, and androgenic steroids have been implicated in its etiology. Some reports have indicated that serum androgen levels are slightly elevated relative to estrogen levels in patients with AS as compared to controls. In more recent studies, however, serum testosterone, 17 beta-estradiol, and androstenedione levels did not significantly differ between AS patients and controls. Moreover, testosterone levels measured directly in serum can be spuriously elevated, especially in patients using phenylbutazone. Elevated serum levels of the adrenal steroids 17 alpha-hydroxyprogesterone and dehydroepiandrosterone (DHEA) sulfate have been found in patients with AS. These elevations might be explained by partial 11 beta- or 21-hydroxylase deficiencies, but may also be secondary to an enhanced stress response. In vitro studies as well as studies in animals and humans indicate that DHEA enhanced, and 17 beta-estradiol and progesterone inhibit, the cell-mediated immune response, which may play a role in the pathogenesis of AS. Oral estrogen therapy in female patients and human chorionic gonadotrophin injections in male patients with AS, increased the 17 beta-estradiol/testosterone ratio and resulted in a moderate clinical improvement. In conclusion, serum testosterone levels are not elevated in patients with AS. Therefore testosterone probably has no role in the perpetuation of long-standing AS and provides no basis for antiandrogenic treatment. Cross-sectional case-control studies, however, cannot clearly distinguish etiological factors from secondary disease effects, especially when blood sampling occurs many years after the onset of AS. Consequently, the role of sex steroids in the pathogenesis is still insufficiently elucidated.

Spondyloarthritides in females

Few studies have been performed regarding clinical, radiological and prognostic features of females with spondyloarthropathies other than ankylosing spondylitis (AS). In AS, clinical manifestations appear similar in men and women, whereas radiological features appear more frequent and severe in males. However, no consistent differences in outcome and mortality between men and women have been disclosed. Although fetal outcome is not compromised in women with spondyloarthropathy (SpA), the interaction of pregnancy and SpA has been studied in detail only in AS. Spinal disease is unchanged while peripheral arthritis and uveitis are suppressed during childbearing. Due to possible maternal and fetal side-effects, NSAIDs must be discontinued during the last 8 weeks of pregnancy, but during lactation several NSAIDs can be used. Treatment with sulphasalazine is compatible with pregnancy and lactation. Children of AS patients exhibit a slightly increased risk of developing SpA later in life.

Juvenile-onset spondyloarthropathies

This article discusses the clinical spectrum and characteristics of juvenile-onset spondyloarthropathies and includes a review of the demographic, clinical, radiographic (and other imaging techniques), and laboratory data of conditions, syndromes, and diseases making up this group. The pathogenic role of several factors in the context of adult-onset patients, but also in regards to studies already performed in juvenile-onset patients, is discussed.

Clinical features and associated systemic diseases of HLA-B27 uveitis

PURPOSE

To delineate the clinical features, course, complications, and associated systemic diseases in patients with HLA-B27-associated uveitis.

METHODS

We reviewed the records of 148 patients with HLA-B27-associated uveitis from two large uveitis practices.

RESULTS

There were 127 (86%) white and 21 (14%) nonwhite patients, and a male-to-female ratio of 1.5:1. The median age at onset of uveitis was 32 years; eight patients (5%) had their first attack after age 55 years. Acute anterior uveitis was noted in 129 patients (87%), and nonacute inflammation was noted in 19 (13%). Ocular involvement was categorized as unilateral or unilateral alternating in 138 patients (93%), but ten patients (7%) had bilateral, concurrent disease. The median duration of an attack was six weeks, and the median number of recurrences for patients with more than 12 months of follow-up was three. Cataracts were associated with posterior synechiae (P = .03), increased intraocular pressure (P = .003), and cystoid macular edema (P = .04). An HLA-B27-associated systemic disorder was present in 83 patients (58%), 30 of whom were women, and it was diagnosed in 43 of the 83 patients as a result of the ophthalmologic consultation. Thirty-four (30%) of 112 patients had a family history of a spondyloarthropathy.

CONCLUSIONS

Although HLA-B27-associated uveitis is usually described as a disease of young white men, women and nonwhites may also be affected. A subgroup of patients have severe disease and consequently more complications. Most patients have an associated systemic disease, including women, who appear to have more atypical spondyloarthropathies. The systemic diseases were frequently undiagnosed before the onset of the ocular disease and before the uveitis consultation.