Tuning phosphorene and MoS2 2D materials for detecting volatile organic compounds associated with respiratory diseases.

Efficient identification of volatile organic compounds (VOCs) is essential for the rapid diagnostication of respiratory diseases. By detecting specific biomarkers associated with different pathologies one may distinguish between tuberculosis, nosocomial pneumonia, Aspergillus fumigatus, influenza and SARS-CoV-2 virus infections. Phosphorene and MoS2 are potential candidates from the class of 2D graphene-like materials, which can be used as active layers for sensing elements. However, as the target molecules poorly adhere to the pristine layers, binding centers are created by introducing substitutional impurities. The adsorbed VOCs induce modifications in the electrical properties of the customized active layers. For each biomarker and a sequence of substitutional impurities, a pattern of conductivities is obtained, which enables the detection of an unknown test specimen. Exploring multiple biosensor configurations we find an optimal design yielding a considerable selectivity for the five biomarker compounds.

Electric-Field Control in Phosphorene-Based Heterostructures.

Phosphorene is a graphene-like material with an intermediate band gap, in contrast to zero-gap graphene and large-gap dichalcogenides or hexagonal boron nitride (hBN), which makes it more suitable for nanoelectronic devices. However, inducing band-gap modulation in freestanding phosphorene nanoribbons (PNRs) is problematic, as high in-plane electric fields are necessary to close the gap. We perform here a detailed investigation concerning the substrate influence on the electric-field control exerted by an external gate, using the density functional theory-non-equilibrium Green's functions (DFT-NEGF) framework. It is established that the interaction with a hexagonal boron nitride supporting layer significantly enhances the gap modulation. Furthermore, we address the issue of contacting the PNRs, by using conducting graphene nanoribbons embedded in the support hBN layer. Within this setup, a measurable spin polarization is achieved owing to the anti-ferromagnetic coupling between the edges of the graphene nanoribbons.

A historical perspective of the spondyloarthritis.

PURPOSE OF REVIEW: The history of ankylosing spondylitis, the main representative of the spondyloarthritides, is dating back to several thousand years BC and recently proven for medieval skeleton by HLA-B27 typing with modern molecular techniques. In modern time, the history of spondyloarthritis (SpA) is characterized by fluctuation between lumping and splitting. Actually, the recent advent of new classification criteria demands to discuss the consequences and clinical implications in the historical context of the development of the concept of SpA including the controversy of lumping and splitting. RECENT FINDINGS: The new Assessment of SpondyloArthritis International Society classification criteria for axial and peripheral SpA are primarily developed to provide support for clinical trials with biologicals and other treatment modalities, which intend to cover the whole spectrum, especially early clinical manifestations of spondyloarthritides. New insights into genetics and the evolving etiological role of Chlamydia in SpA including the most recent finding of the effective combination antibiotic therapy are major advances in the evolving history of SpA. SUMMARY: The concept of SpA is well accepted for the classification, diagnosis, and therapeutic management of a high proportion of individuals with inflammatory rheumatic conditions. For further advances research technologies are now available to enlarge the current body of clinical, immunologic, and genetic studies using pivotal microbiologic research and new antimicrobial therapeutic strategies.

Celecoxib and ankylosing spondylitis.

It is now over 100 years since the arrival of aspirin and, from the mid-20th Century onwards, we have seen numerous attempts at providing society with safer and more efficacious nonsteroidal drugs. Ironically, while aspirin went from strength to strength with an ever-increasing pharmaceutical profile, new nonsteroidal anti-inflammatory drugs arrived and disappeared with rapid succession. Finally, there appears to have been a breakthrough with the development of the coxibs but concern has recently developed because of potential toxic cardiovascular reactions. Although originally studied in rheumatoid arthritis and degenerative arthropathy, the coxibs have now been investigated in ankylosing spondylitis and efficacy appears to be favorable and, to date, there is little evidence of toxicity, although problems in the nonspondylarthropathic arena may spill over into the seronegative spondylarthritides.

Nonsteroidal antiinflammatory drugs reduce radiographic progression in patients with ankylosing spondylitis: a randomized clinical trial.

OBJECTIVE: A 2-year randomized controlled trial was performed to test the hypothesis that long-term, continuous treatment with nonsteroidal antiinflammatory drugs (NSAIDs), in comparison with NSAID treatment on demand only, influences radiographic progression in patients with ankylosing spondylitis (AS). METHODS: Patients with AS (n = 215), who had previously participated in a 6-week, randomized, double-blind clinical trial that compared celecoxib, ketoprofen, and placebo, were randomly allocated to receive either continuous treatment with NSAIDs or on-demand treatment with NSAIDs for a period of 2 years. All patients began treatment with celecoxib, at a starting dosage of 100 mg twice daily; patients could increase this dosage to 200 mg twice daily or could switch to another NSAID while maintaining the same treatment strategy. Structural changes were assessed by radiographs of the lumbar and cervical spine and scored according to the modified Stoke Ankylosing Spondylitis Spine Score by one observer who was blinded to the treatment strategy and temporal order of the radiographs. Statistical analyses included a between-group comparison of 1) radiographic progression scores (by Mann-Whitney U test), 2) time-averaged values of variables reflecting signs and symptoms of AS (by linear regression analysis), and 3) the frequency of reported site-specific adverse events (by chi-square test or Fisher's exact test, as appropriate). RESULTS: Complete sets of radiographs were available for 76 of the 111 patients in the continuous-treatment group and for 74 of the 104 patients in the on-demand group. The mean +/- SD scores for radiographic progression were 0.4 +/- 1.7 in the continuous-treatment group and 1.5 +/- 2.5 in the on-demand treatment group (P = 0.002). Parameters reflecting signs and symptoms were not statistically significantly different between groups. The between-group difference in radiographic progression did not disappear after adjusting for baseline values of radiographic damage or disease activity variables and for time-averaged values of disease activity variables, nor after input of missing data. Relevant adverse events tended to occur more frequently in the continuous-treatment group than in the on-demand group (for hypertension, 9% versus 3%; for abdominal pain, 11% versus 6%; for dyspepsia, 41% versus 38%), but the differences were not statistically significant. CONCLUSION: A strategy of continuous use of NSAIDs reduces radiographic progression in symptomatic patients with AS, without increasing toxicity substantially.

Evaluation of the efficacy of etoricoxib in ankylosing spondylitis: results of a fifty-two-week, randomized, controlled study.

OBJECTIVE: To assess the efficacy, safety, and tolerability of etoricoxib, a cyclooxygenase 2 (COX-2) selective inhibitor, administered continuously over 52 weeks for the treatment of ankylosing spondylitis (AS). METHODS: This 2-part, multicenter, double-blind, parallel-group, 52-week study evaluated 2 doses of etoricoxib (90 and 120 mg) compared with naproxen at 1,000 mg. A 6-week, active-comparator- and placebo-controlled period (part I) was followed by a 46-week active-comparator-controlled period (part II). The primary outcome measures (on 100-mm visual analog scales) were patient's assessment of spine pain, patient's global assessment of disease activity, and the Bath Ankylosing Spondylitis Functional Index. RESULTS: Of the 387 patients randomized to receive treatment, 301 (77.8%) completed part I and 284 (75.9%) completed part II. Compared with placebo over 6 weeks, those receiving 90 mg etoricoxib, 120 mg etoricoxib, and naproxen demonstrated significantly (P < 0.001) greater improvement in all primary end points; treatment effects (expressed as the difference in least squares mean change versus placebo) were 21-29 mm for spine pain, 18-25 mm for disease activity, and 11-15 mm for function. Compared with patients receiving naproxen, significantly greater improvement in all primary end points was demonstrated in the combined group receiving either 90 mg etoricoxib or 120 mg etoricoxib over 6 weeks, in each individual etoricoxib treatment group over 6 weeks, and in the combined etoricoxib group over 1 year (all P < 0.05); results for secondary and exploratory end points were generally consistent with those from the primary analysis. Among all groups, there were no significant differences in the incidence of overall clinical, drug-related, or serious adverse experiences (AEs) and discontinuations due to AEs. Safety observations during part II were generally consistent with those in part I. CONCLUSION: Etoricoxib at doses of 90 mg and 120 mg demonstrated superior efficacy compared with placebo over 6 weeks, and compared with naproxen over 1 year. These study results demonstrate that etoricoxib is generally safe, well-tolerated, and efficacious for the treatment of AS.

Establishment of the minimum clinically important difference for the bath ankylosing spondylitis indices: a prospective study.

OBJECTIVE: The minimum clinically important difference (MCID) is the minimum level of change of an outcome measure that is considered to be clinically relevant. This prospective study was conducted to establish the minimum level of change in the Bath Ankylosing Spondylitis (BAS) indices that is meaningful for both the patient and the clinician. METHODS: The BAS questionnaires [i.e., Bath Ankylosing Spondylitis Functional Index (BASFI); Bath Ankylosing Spondylitis Disease Activity Index (BASDAI); and Bath Ankylosing Spondylitis patient Global score (BAS-G)] were administered to 125 patients with ankylosing spondylitis (AS) at baseline and at the end of a 2-week intensive physiotherapy program. Together with the final assessment, a global validated rating scale was used to examine each domain. Receiver operating characteristic (ROC) curves were plotted to determine the BAS change score that most accurately classified patients with respect to a clinically meaningful change. This analysis was repeated to investigate whether the estimate of change was dependent upon the patients' baseline scores. RESULTS: According to analyses of ROC curves, the MCID are 7 mm or 17.5% for BASFI: sensitivity = 0.60/specificity = 0.85; 10 mm or 22.5% for BASDAI: sensitivity = 0.65/specificity = 0.82; and 15 mm or 27.5% for BAS-G: sensitivity = 0.61/specificity = 0.74. MCID values were independent of the patients' baseline scores (p = 0.09 to 0.72) by regression analysis. CONCLUSION: This prospective study gives MCID values for BASFI, BASDAI, and BAS-G that allow translation from the BAS indices to readily understood values for both patients and clinicians.

Concordance of disease severity among family members with ankylosing spondylitis?

OBJECTIVE: The heritability of disease activity and function in ankylosing spondylitis (AS) have been estimated at 0.51 and 0.63 (i.e., 51% and 63%), respectively. We examined the concordance of disease severity among family members in terms of disease activity, function, radiological change, prevalence of iritis, and juvenile onset. METHODS: Disease activity and functional impairment due to AS were studied using the Bath AS Disease Activity Index (BASDAI) and Functional Index (BASFI) self-administered questionnaires; radiographic involvement was measured using the Bath AS Radiology Index (BASRI) scale. Familial correlation of BASDAI and BASFI was assessed in 406 families with 2 or more cases, using the program PAP. Parent-child and sibling-sibling concordance for iritis and juvenile AS were also studied in these families. Heritability of radiological disease severity based on the BASRI was assessed in 29 families containing 60 affected individuals using the program SOLAR. RESULTS: Correlations between parent-child pairs for disease activity and function were 0.07 for both. Correlations between sibling pairs for disease activity and function were 0.27 and 0.36, respectively. The children of AS parents with iritis were more likely to develop iritis [27/71 (38%)] than children of non-iritis AS parents [13/70 (19%)] (p = 0.01). Parents with JAS were more likely to have children with JAS [17/30 (57%) compared to non-JAS parents 34/111 (30%)] (p = 0.002). The heritability of radiological disease severity based on the BASRI was 0.62. CONCLUSION: While correlation in severity between parent and child is poor, siblings do resemble each other in terms of severity, supporting the findings of segregation studies indicating significant genetic dominance in the heritable component of disease activity. Significant parent-child concordance for iritis and juvenile disease onset suggest that there are genetic risk factors for these traits independent of those determining the risk of AS itself. The finding of significant heritability of radiological change (BASRI) provides support using an objective measure for the observed heritability of the questionnaire-assessed disease severity scores, BASDAI and BASFI.

Assessment of disease severity (in terms of function) using the internet.

OBJECTIVE: To determine whether visual analog scales (VAS) can be used over the Internet to assess the patient with ankylosing spondylitis (AS) accurately or if the use of this different medium will affect the results. METHODS: Patients with AS (n = 50) attending a physiotherapy/educational course completed both an Internet based and a paper based version of the Bath Ankylosing Spondylitis Functional Index (BASFI) that uses VAS. The Internet version was completed twice to assess intrarespondent variation reliability and compared with the paper version to assess interrespondent variation reliability. Patients were also asked to assess ease of use and to suggest changes to the Internet version. RESULTS: The interclass coefficient of intra- and interrespondent reliability were 0.989 (p < 0.001) and 0.976 (p < 0.001), respectively. There was a 3% difference in assessments carried out over the Internet compared to those on paper and a 2% difference in repeatability of Internet assessed questionnaires. Bland and Altman plots showed a mean difference between paper compared to the Internet version was 0.0156 with 95% limits of agreement at -1.07 to 1.03. More than half the participants reported that the Internet version was easier to complete than the paper version (96% rated usability as 1 on a scale of 1-10, with 1 being extremely easy and 10 being impossible). CONCLUSION: Assessment of disease severity by VAS may be accurately carried out over the Internet. This means that the evaluation of disease status and the longterm followup of people in different countries and perhaps in different languages may now be possible, using the Internet.

The interleukin 1 gene cluster contains a major susceptibility locus for ankylosing spondylitis.

Ankylosing spondylitis (AS) is a common and highly heritable inflammatory arthropathy. Although the gene HLA-B27 is almost essential for the inheritance of the condition, it alone is not sufficient to explain the pattern of familial recurrence of the disease. We have previously demonstrated suggestive linkage of AS to chromosome 2q13, a region containing the interleukin 1 (IL-1) family gene cluster, which includes several strong candidates for involvement in the disease. In the current study, we describe strong association and transmission of IL-1 family gene cluster single-nucleotide polymorphisms and haplotypes with AS.

The interrelationship between sex, susceptibility factors, and outcome in ankylosing spondylitis and its associated disorders including inflammatory bowel disease, psoriasis, and iritis.

OBJECTIVE: To examine the evidence that families, where the mother has disease, carry more heritable factors and investigate the effect of maternal/paternal inheritance on phenotypic expression of disease in terms of (a) severity and outcome and (b) additional co-disorders. The children of women with ankylosing spondylitis (AS) develop the disease more often than the children of men. This suggests that either women with disease carry more susceptibility factors than men or that the uterine environment/breast feeding may play a role in AS. METHODS: The number of second degree relatives (i.e., grandparent, aunt/uncle) was calculated for those index patients with a mother with disease as opposed to a father. Outcome measures were compared and prevalence of secondary disorders (i.e., psoriasis, iritis, inflammatory bowel disease) was examined in patients with an AS mother as opposed to an AS father. RESULTS: The affected offspring of maternal cases had more second degree relatives with disease [20% vs 9%, respectively, p = 0.012, odds ratio (OR): 2.3, 95% confidence interval (CI): 1.2, 4.5] than did children of affected men. The affected children of a mother with AS were comparable in terms of disease activity, function, and radiology to children of a father with disease. Inflammatory bowel disease was more prevalent among children of AS mothers than AS fathers (15% vs 5%, respectively, p = 0.009, OR: 2.9, 95% CI: 1.3, 6.3). Psoriasis was less prevalent among sons of AS mothers than among sons of AS fathers (9% vs 22%, respectively, p = 0.03, OR: 0.4, 95% CI: 0.2, 0.9). CONCLUSION: The inherited susceptibility load is strongly linked to the sex of the parent with AS. Women with disease carry higher heritability (which is associated with inflammatory bowel disease) than do men. There is a male sex impact on susceptibility to psoriasis (when AS is present). However, there is no evidence that the susceptibility load has an effect on outcome or severity of disease (as measured by disease activity, function, and radiology), or that outcome is influenced by transmission of maternal as opposed to paternal factors.

Identification of major loci controlling clinical manifestations of ankylosing spondylitis.

OBJECTIVE: To identify genomic regions linked with determinants of age at symptom onset, disease activity, and functional impairment in ankylosing spondylitis (AS). METHODS: A whole genome linkage scan was performed in 188 affected sibling pair families with 454 affected individuals. Traits assessed were age at symptom onset, disease activity assessed by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and functional impairment assessed by the Bath Ankylosing Spondylitis Functional Index (BASFI). Parametric and nonparametric quantitative linkage analysis was performed using parameters defined in a previous segregation study. RESULTS: Heritabilities of the traits studied in this data set were as follows: BASDAI 0.49 (P = 0.0001, 95% confidence interval [95% CI] 0.23-0.75), BASFI 0.76 (P = 10(-7), 95% CI 0.49-1.0), and age at symptom onset 0.33 (P = 0.005, 95% CI 0.04-0.62). No linkage was observed between the major histocompatibility complex (MHC) and any of the traits studied (logarithm of odds [LOD] score <1.0). "Significant" linkage (LOD score 4.0) was observed between a region on chromosome 18p and the BASDAI. Age at symptom onset showed "suggestive" linkage to chromosome 11p (LOD score 3.3). Maximum linkage with the BASFI was seen at chromosome 2q (LOD score 2.9). CONCLUSION: In contrast to the genetic determinants of susceptibility to AS, clinical manifestations of the disease measured by the BASDAI, BASFI, and age at symptom onset are largely determined by a small number of genes not encoded within the MHC.

Predictors of longterm outcome in ankylosing spondylitis.

OBJECTIVE: To determine predictors of longterm outcome in ankylosing spondylitis (AS). METHODS: Data were collected retrospectively on constitutional and environmental factors that may predict outcome in AS in 311 patients (252 men, 81%). Univariate statistics and multivariable linear regression analyses were used to identify factors correlated with disease outcome, which was defined in terms of radiological (Bath AS Radiology Index, BASRI) and functional status (Bath AS Functional Index, BASFI). RESULTS: Disease duration, sex, and iritis are independently associated with BASRI and account for 23% (p < 0.001) of variation in radiological scores (BASRI-t), a measure that includes the hip joint in the score. Radiological hip involvement is significantly associated with higher scores of spinal radiological change (BASRI-s) (p < 0.001). Cigarette smoking, radiological status, and Bath AS Disease Activity Index score (BASDAI) are independently associated with and account for 50% of variability in functional status (p < 0.001). CONCLUSION: Much of the variability in disease severity in AS remains unexplained. All but one of the factors associated with outcome in this study are inherent. This suggests that genetic factors have a greater influence than environmental factors on radiological progression and disability in AS. It may, however, be possible to improve longterm functional outcome in AS by targeting high risk individuals early in the disease course with more aggressive management strategies and encouraging smoking cessation in all patients with AS.

Role of NOD2 variants in spondylarthritis.

OBJECTIVE: To investigate the role of the gene NOD2 in susceptibility to, and clinical manifestations of, ankylosing spondylitis (AS). METHODS: A case-control study of NOD2 polymorphisms known to be associated with Crohn's disease (CD) (Pro(268)Ser, Arg(702)Trp, Gly(908)Arg, and Leu(1007)fsinsC) was performed in 229 cases of primary AS with no diagnosed inflammatory bowel disease (IBD), 197 cases of AS associated with IBD (referred to as colitic spondylarthritis; comprising 78 with CD and 119 with ulcerative colitis [UC]), and 229 ethnically matched, healthy controls. Associations between NOD2 polymorphisms and several clinical features of AS, including disease severity assessed by questionnaire and age at spondylarthritis onset, were also investigated. Exclusion linkage mapping of chromosome 16 was performed in a separate group of 185 multicase families with AS. RESULTS: An association was identified between Gly(908)Arg and UC spondylarthritis (P = 0.016, odds ratio [OR] 4.6, 95% confidence interval [95% CI] 1.3-16), and a nonsignificant trend with a similar magnitude was observed in association with CD spondylarthritis (P = 0.08, OR 3.9, 95% CI 0.8-18). The Pro(268)Ser variant was inversely associated with UC spondylarthritis (P = 0.003, OR 0.55, 95% CI 0.37-0.82), but not with CD spondylarthritis. No association was demonstrated between NOD2 variants and primary AS, or between other variants of NOD2 and either UC or CD spondylarthritis. Carriage of the Pro(268)Ser polymorphism was associated with greater disease activity as measured by the Bath Ankylosing Spondylitis Disease Activity Index (P = 0.002). Although patients with CD had a younger age at spondylarthritis onset than did those with UC (22.4 years versus 26.4 years; P = 0.01), no association was noted between the NOD2 variants linked with CD and age at spondylarthritis onset. In primary AS, the presence of a gene with a magnitude of association >2.0 was excluded (exclusion logarithm of odds score less than -2.0), and no association was observed with the microsatellite D16S3136. CONCLUSION: NOD2 variants do not significantly affect the risk of developing primary AS, but may influence susceptibility to, and clinical manifestations of, colitic spondylarthritis.

The natural history of ankylosing spondylitis as defined by radiological progression.

OBJECTIVE: Radiological status is an important objective endpoint in the assessment of ankylosing spondylitis (AS). We investigated the disease development of AS using radiological change. METHODS: The existing radiographs (n = 2,284) of 571 AS patients attending the Royal National Hospital for Rheumatic Diseases were scored retrospectively using the Bath Ankylosing Spondylitis Radiology Index. (1) Progression of disease was initially examined cross sectionally. Univariate analysis was used to examine factors associated with joint involvement. (2) Progression of disease was then examined longitudinally for patients with films at time of symptom onset. (3) Rate of progression of radiological change was calculated using longitudinal data of 2 sets of radiographs taken 10 years apart (patient number = 54). The results from this were used to extrapolate backwards to age at first radiological change. RESULTS: (1) Progression to cervical spine disease was a function of: disease duration, severity of hip and lumbar involvement, and a history of iritis (p < 0.001). Lumbar involvement was associated with disease duration, age now, and severity of cervical and hip involvement (p < 0.001). Hip involvement was a marker for cervical disease and associated with disease duration (p < 0.001). (2) Longitudinal analysis revealed marked variation among patients with a slow general rate of progression. (3) The progression of AS over any 10 year period is linear [first 10 years = 30% (SD 0.3) of potential change, 10-20 yrs = 40% (SD 0.3) change, 20-30 yrs = 35% (SD 0.4) change (p = 0.5)]. Backward extrapolation suggests that the approximate time of first radiological change is at the age of 8 years. CONCLUSION. (1) AS is a linearly progressive disease with about 35% change every 10 years. Spinal involvement is largely an expression of disease duration while the hips become involved in about 25% of individuals and may predict a more severe outcome for the cervical spine. (2) Backward extrapolation shows that the disease process may start as young as 8 years of age. However, the time interval between the disease trigger and radiological change remains unknown.

Definition of disease flare in ankylosing spondylitis: the patients' perspective.

OBJECTIVE: Ankylosing spondylitis (AS) is a systemic disorder occurring in genetically predisposed individuals. The disease course appears to be characterized by bouts of partial remission and flares. However, we have little understanding of what is a flare, why they occur, and what lasting effects they have on the patient. We examine the patient's perception of the factors important in defining flare. METHODS: Twenty group meetings of 7-12 participants were held over a one year period. A summary statement was written at the end of each discussion and patients were asked to sign the statement if they considered it to be an accurate summary of their answers, or to amend the statement where they disagreed. RESULTS: There were 214 patients questioned (169 men, 45 women; average disease duration 25 years; age of disease onset 22 years). Data show that the main symptoms of flare are pain (100% of groups), immobility (90%), fatigue (80%), and emotional symptoms (depression, withdrawal, anger) (75%). There are 2 types of flare: (1) localized: during which the symptoms affect one area; and (2) generalized: this is a severe event including all the above symptoms and a flu-like illness (fever, sweating) with hot, burning joints, muscle spasm, and increased sensitivity. All patients experience between one and 5 localized flares per year. Fifty-five percent of groups contained patients (n = 85) who experienced a generalized flare. The main perceived triggers of flare were stress (80%) and "overdoing it" (50%). Patients reported that a flare may last anywhere from a few days to a few weeks and relief from flare can be gained by analgesic injections (including opiates) from a doctor, relaxation, sleep, and cannabis (3 individuals). Three-quarters of the groups agreed that there was no longterm effect on the AS following a flare. CONCLUSION: There are 2 forms of flare: (1) localized to one area or (2) throughout the entire body. Examining the differences between these types of flares may aid our understanding of the biological mechanism of the disease process of AS and allow us to help relieve the symptoms of flare, a highly painful and often depressing phenomenon.

The effect of a home based exercise intervention package on outcome in ankylosing spondylitis: a randomized controlled trial.

OBJECTIVE: Home based self-care is essential for successful management of ankylosing spondylitis (AS). We designed an intervention package aimed at promoting self-care and regular longterm exercise and evaluated its effect on outcome. METHOD: Members of our database (n = 4569) were randomly selected and randomized to an intervention group (IG) or a followup control group (CG). The intervention consisted of an exercise/information video, exercise progress chart, patient education booklet, and AS exercise reminder stickers. The outcome measures were function (BASFI), disease activity (BASDAI), global well being (BAS-G), exercise self-efficacy (ESE), arthritis self-efficacy (SES), and quantity of AS mobility/aerobic exercise assessed at baseline and 6 months. RESULTS: Of the 200 subjects, 155 completed the study (75 IG and 80 CG). Baseline analysis showed no differences between the CG and the IG. At 6 months, analysis revealed no statistically significant between-group differences for the BASFI, BASDAI, and BAS-G. although the p value of 0.08 for function approached significance. Self-efficacy for exercise showed a significant improvement in the IG (p = 0.045). There were no between-group differences for the SES pain and other symptoms subscales. Finally, there was a significant increase in self-reported AS mobility (p < 0.001) and aerobic exercise (p < 0.05) in the IG. CONCLUSION: An exercise intervention package designed to promote self-management in AS (1) significantly improves self-efficacy for exercise; (2) significantly improves self-reported levels of exercise; (3) reveals a trend for improvement in function (BASFI).

Birth order and ankylosing spondylitis: no increased risk of developing ankylosing spondylitis among first-born children.

OBJECTIVE: In the HLA-B27 transgenic mouse model the first litters have been shown to have a higher percentage of diseased offspring than later litters. First-born children (n = 162) have also been shown to have a higher risk of ankylosing spondylitis (AS) than later-born children. We examined this effect of birth order using similar methods but larger numbers. METHODS: Patients from the Bath AS database (n = 4517; M:F = 2.5:1) were examined according to position of birth within the family. Chi-squared analysis was used to examine if AS was more prevalent among first-born than later-born children. RESULTS: The first-born child was not significantly more likely to have AS than later-born children (p = 0.295). [Observed compared to expected: 1607 (36%) compared to 1641.13 (36%) for first-born children and 2910 (64%) compared to 2876.3 (64%) for later-born children, respectively.] There was no biological gradient (i.e., inverse correlation between birth order and disease risk). CONCLUSION: There was no statistically significant effect of birth order based on our data. Findings suggesting a birth order effect may be skewed, as it is possible that those parents who do have AS will be less likely to have a large family and yet it is their offspring who will be at greatest risk of developing disease. This will affect the data, as those children born into a large family (i.e., high birth order children) will be at a lower risk of AS than any child born into a small but family-history-positive unit.