Biologic therapies have revolutionized the treatment of rheumatoid arthritis, a common chronic inflammatory disease, mainly characterized by the chronic inflammation of the joints. The activity and progression of the disease are highly variable, both between subjects and between the successive assessments for the same subject. Standardized assessments of clinical variables have been developed to reflect the disease activity and evaluate new therapies. Pharmacokinetics-pharmacodynamic (PKPD) models and methods for analyzing the generated time-course data are needed to improve the interpretation of the clinical trials’ outcomes, and to describe the variability between subjects, including patients characteristics, disease factors and the use of concomitant treatments that may affect the response to treatment. In addition, good simulation properties are also desirable for predicting clinical responses for various populations or for different dosing schedules. The aim of this thesis was to develop methods and models for analyzing pharmacokinetic and pharmacokinetic-pharmacodynamic (PKPD) data from rheumatoid arthritis patients, illustrated by treatment with a new anti-TNFα biologic drug under clinical development, certolizumab pegol. Two models were developed that characterized the relationship between the exposure to the drug and the efficacy ACR variables that represent improvement of the disease; a logistic-type Markov model for 20% improvement (ACR20) and a continuous-type Markov model for simultaneous analysis of 20% (ACR20), 50% (ACR50) and 70% (ACR70) improvement. Both models accounted for the within-subjects correlation in the successive clinical assessments and were able to capture the observed ACR responses over time. Simulations from these models of the ACR20 response rate supported dosing regimens of 400 mg at weeks 0, 2 and 4 to achieve a rapid onset of response to the treatment, followed by 200 mg every 2 weeks, or alternative maintenance regimen of 400 mg every 4 weeks. The immunogenicity induced by the biologic drug was characterized by a time to event model describing the time to appearance of antibodies directed against the drug. The immunogenicity was predicted to appear mainly during the first 3 months following the start of the treatment and to be reduced at higher trough concentrations of CZP, as well as with concomitant administration of MTX. The full time-course of sequential events, such as dose-exposure-efficacy relations, is most accurately described by a simultaneous analysis of all data. However, due to the complexity and runtime limitations of such an analysis, alternatives are often used. In this thesis, a method, IPPSE, was developed and compared to the reference simultaneous method and to existing alternative methods. The IPPSE method was shown to provide accuracy and precision of estimates similar to the simultaneous method, but with easier implementation and shorter run times. In conclusion, two PKPD models and one immunogenicity model were developed for evaluation of the response of a biologic drug against rheumatoid arthritis that allowed accurate analysis and simulation of clinical trial data, as well as serving as examples for how a model-informed basis for decisions about biological drugs can be created.

Rheumatoid arthritis (RA) is a chronic disease characterized by an overactive immune system and joint inflammation. Population-based administrative health data (AHD) are widely used for RA outcomes research and surveillance. However, AHD may not completely capture all cases of RA in the population. Capture-recapture (CR) methods have been proposed to describe the completeness of AHD for estimating disease population size, but AHD may not conform to the assumptions that underlie CR models. A Monte Carlo simulation study was used to investigate the effects of violations of the assumptions for two-source CR methods: dependence between data sources and heterogeneity of capture probabilities. We compared the Chapman estimator and an estimator based on the multinomial logistic regression model (MLRM) to study relative bias (RB), coverage probability (CP) of 95% confidence intervals, width of 95% confidence intervals (WCI), and root-mean-square-error (RMSE) in prevalence estimates. The effects of misspecification of the MLRM were also investigated. In addition, the Chapman and MLRM estimators were used to estimate RA prevalence using AHD data from Saskatchewan, Canada. Population sizes were consistently underestimated for CR methods when the assumptions were violated. The estimated population size for both of the estimators did not differ substantially except for the RMSE values. Parameter estimates became biased when the MLRM model was misspecified, but there was little impact on population size estimates. In conclusion, CR methods are recommended to reduce bias in prevalence estimates based on AHDS. Because these methods may be sensitive to assumption violations, researchers should consider potential dependence between data sources. As well, sufficient overlap in the cases captured by each data source (e.g., 50% of the cases are captured by both data sources) or balanced capture probability in each data source is needed to effectively implement these methods. Researchers who estimate population size using CR methods in AHDs should favour the MLRM estimator over the Chapman estimator.

Aim: Most of the patients with Psoriatic Arthritis (PsA) develop arthritis following the onset of psoriasis. The aim of the project is to identify genetic and environmental risk factors for PsA among psoriasis patients. Methods: PsA and psoriasis patients from two prospective cohorts were analyzed. The incidence of PsA among a prospective cohort of psoriasis patients was assessed. The distribution of Human Leukocyte Antigen (HLA) alleles and Killer Cell Immunoglobulin like Receptors (KIRs) and their combinations was compared between PsA, psoriasis and healthy controls. In addition, the association between a wide range of environmental exposures and PsA was evaluated by comparing the frequencies of exposed individuals among patients with recent onset PsA and psoriasis. The association between smoking and PsA was further investigated. The prevalence of smoking was in PsA, psoriasis and the general population. The interaction between HLA-C*06 and smoking was also tested. Results: The genetic analysis revealed several HLA-B alleles and HLA haplotypes that are associated with PsA compared to psoriasis and can potentially serve as independent markers for PsA. Furthermore, several combinations of KIR genes and their respective HLA ligands were also found to be associated with PsA compared to psoriasis. The incidence of PsA among psoriasis patients was found to be higher than previously reported and its rate was constant over time. HLA-C*06 was associated with increased interval between psoriasis onset and PsA. Several environmental factors including occupational exposures, infections, injuries and smoking were associated with development of PsA. The prevalence of smoking was decreased among PsA patients compared to psoriasis. The interaction between HLA-C*06 and smoking was found to be significant. Conclusions: Genetic and environmental factors are associated with the development of PsA in patients with psoriasis. These factors may serve as specific markers to identify psoriasis patients at increased risk for PsA.

Aim: Most of the patients with Psoriatic Arthritis (PsA) develop arthritis following the onset of psoriasis. The aim of the project is to identify genetic and environmental risk factors for PsA among psoriasis patients. Methods: PsA and psoriasis patients from two prospective cohorts were analyzed. The incidence of PsA among a prospective cohort of psoriasis patients was assessed. The distribution of Human Leukocyte Antigen (HLA) alleles and Killer Cell Immunoglobulin like Receptors (KIRs) and their combinations was compared between PsA, psoriasis and healthy controls. In addition, the association between a wide range of environmental exposures and PsA was evaluated by comparing the frequencies of exposed individuals among patients with recent onset PsA and psoriasis. The association between smoking and PsA was further investigated. The prevalence of smoking was in PsA, psoriasis and the general population. The interaction between HLA-C*06 and smoking was also tested. Results: The genetic analysis revealed several HLA-B alleles and HLA haplotypes that are associated with PsA compared to psoriasis and can potentially serve as independent markers for PsA. Furthermore, several combinations of KIR genes and their respective HLA ligands were also found to be associated with PsA compared to psoriasis. The incidence of PsA among psoriasis patients was found to be higher than previously reported and its rate was constant over time. HLA-C*06 was associated with increased interval between psoriasis onset and PsA. Several environmental factors including occupational exposures, infections, injuries and smoking were associated with development of PsA. The prevalence of smoking was decreased among PsA patients compared to psoriasis. The interaction between HLA-C*06 and smoking was found to be significant. Conclusions: Genetic and environmental factors are associated with the development of PsA in patients with psoriasis. These factors may serve as specific markers to identify psoriasis patients at increased risk for PsA.

BACKGROUND Chronic pain is a common condition in children with juvenile idiopathic arthritis (JIA), affecting their ability to participate in physical activity, a necessary and integral part of a child’s growth and maturation. Resistance training specifically displays a paucity of research in children with JIA, and could potentially be a beneficial form of exercise training for this population. The purpose of this study was to determine the safety, feasibility, and effects of a six week resistance training program on pain in children with JIA. METHODS Seven JIA patients (8-18 years) participated in a home-based, three days per week exercise training program. Pain was measured using an electronic pain diary (PinGo©) for Android tablets. Participants answered questions initially a week prior to training, once a day on non-exercise days and three times a day (before exercise, after exercise, and end of day) on exercise days for a total of seven weeks. Secondary outcome measures included muscle size, muscle strength, and functional ability, measured at baseline and following the 6 week exercise program. Statistical analyses included attaining the average number of exercise sessions completed, pain changes over the seven weeks (averaged over the initial week and then biweekly) via repeated measures ANOVA, dependent t tests between before and after exercise pain intensity and affect, and dependent t tests between secondary outcomes. RESULTS Seven participants completed an average of 13.0 ± 3.6 exercise sessions out of a possible 18. The repeated measures ANOVA revealed no significant differences between pain scores over the seven weeks within each individual (p>0.05). When all participants were pooled dependent t tests before and after exercise showed no differences in pain intensity or pain affect (p>0.05). Secondary measures revealed a significant difference between vastus lateralis thickness before compared to after training (p<0.05). CONCLUSIONS The results of this study suggest that a 6 week home-based resistance training program was tolerable in children with JIA and did not cause a clinically significant increase in pain or any other adverse events. The uniqueness of this exercise program was that it was home-based, allowing children to undertake this emerging form of healthcare within their home environment. As well, the training program was able to significantly improve aspects of fitness in this population. Further research of resistance training in children with JIA is necessary to attain definitive results of its effects and optimal levels of resistance exercise in this population.

Die rheumatoide Arthritis (RA) ist eine Autoimmunerkrankung mit bevorzugter Manifestation an den Gelenken. Die RA ist charakterisiert durch eine chronische, systemische Entzündung, eine abnormale zelluläre und humorale Immunantwort und eine synoviale Hyperplasie. Die Ursache der synovialen Hyperplasie ist noch nicht eindeutig geklärt, aber es wird eine veränderte oder unvollständig ablaufende Apoptose der synovialen Fibroblasten vermutet. Die vorliegende Arbeit untersucht die Rolle des Apoptosemodulators death associated protein (Daxx) in rheumatoiden synovialen Fibroblasten (RA-SF). Als erstes wurde die Expression von Daxx in RA-SF gegenüber Osteoarthrosefibroblasten (OA-SF) untersucht. Dabei konnte gezeigt werden, dass die OA-SF eine höhere Expression von Daxx auf mRNA und Proteinebene gegenüber RA-SF aufweisen. Im weiteren Verlauf erfolgte die Untersuchung der subzellulären Lokalisation von Daxx in RA-SF mittels konfokaler Laserscan-Mikroskopie (Immunfluoreszenz). Dabei zeigte sich, dass Daxx vorwiegend im Zellkern und nur zu einem geringen Anteil im Zytoplasma lokalisiert ist. Weiterhin zeigte Daxx eine Kolokalisation mit dem Promyeloischen Leukämie Protein (PML), welches ausschließlich im Zellkern lokalisiert ist. Nun erfolgten die Untersuchungen zur Rolle von Daxx in der Apoptose von RA-SF mittels RNA Interferenz (RNAi). Zu diesem Zweck wurden 3 verschiedene small interfering RNA (siRNA) synthetisiert, die unterschiedliche Abschnitte auf der mRNA von Daxx umfassen. Die Überprüfung der Effektivität der siRNA erfolgte auf mRNA Ebene mittels Quantitativer Real Time PCR(TaqMan®) und auf Proteinebene im Westernblot in HeLa-Zellen und RA-SF. Dabei zeigte die siRNA(454-472) die stärkste Hemmung. In den Untersuchungen zur Apoptose in HeLa-Zellen und RA-SF, nach der Hemmung von Daxx durch die siRNA, zeigte sich, dass eine stärkere Hemmung von Daxx zu einer verminderten Empfindlichkeit der HeLa-Zellen und RA-SF auf die FasL-induzierte Apoptose führt. Die RA-SF und Makrophagen der Deckzellschicht synthetisieren Zytokine wie den Tumor Nekrose Faktor a (TNFa). Diese Erkenntnis dient als Grundlage zur Untersuchung des Einflusses von TNFa auf die Expression von Daxx auf mRNA- und Proteinebene. Dabei zeigte sich eine konzentrationsabhängige Erhöhung der Expression von Daxx. Als letztes erfolgte die Untersuchung zur Apoptose nach der TNFa Stimulation. Hierbei zeigte sich eine Reduktion der Apoptose, die von der TNFa Konzentration abhängig war, wobei sich hohe Schwankungsbreiten bei der Konzentration von 10ng/ml TNFa zeigten. In dieser Arbeit wurde durch die Hemmung von Daxx mittels siRNA eine pro-apoptotische Funktion des Moleküls in RA-SF nachgewiesen. Diese Ergebnisse sollen der weiteren Identifizierung von Signalwegen in der Apoptose bei RA-SF dienen.

<p>This study explored women's perceptions of how their illness (Rheumatoid Arthritis- RA) affects their relationship with their intimate life partner. RA is a chronic, inflammatory, auto-immune illnes, which mainly affects the synovial membranes of multiple joints. This highly inflammatory poly-arthritis may lead to joint destruction, chronic pain, deformity and loss of functioning as unfortunate outcomes of the established illness. RA affects key life domains such as psychological well-being, social well-being, family and couple relationships, employment, loss of independence and restrictions in daily functioning.</p>

The inflammatory response caused by the deposition of crystals of monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD) in the synovial fluid of joints, results from the interaction of the crystals with neutrophils. Neutrophils (whose function in the body is to remove hazardous microorganisms and inflammatory debris) are activated by the binding of the crystals to the neutrophil cellular membrane, which leads to respiratory burst activity, engulfment of the crystals and release of proteolytic enzymes. Furthermore, we have found that crystals delay the normal “cell death program” or apoptosis, thus allowing for the accumulation of these cells, and extended inflammatory responses. Very little is known about the mechanisms of activation and delay of apoptosis, however, bcl-2 family proteins have been implicated in the control of neutrophil apoptosis. This study helps to define the role of several bcl-2 family proteins (both pro- and anti-apoptotic) by examining the differential expression of these proteins upon stimulation with crystals. Subsequent identification of signaling targets that function to regulate this process in response to crystals could lead to potential therapeutics for crystal-induced inflammatory diseases.

Abstract Osteoarthritis (OA) is the most common musculoskeletal disorder affecting Australians and is the leading cause of pain and disability in the country. There is no known cure for OA, but pharmacological and non-pharmacological treatments can relieve symptoms and improve quality of life for OA sufferers: two of these are glucosamine sulphate (GS) and physical activity. Little is known about physical activity behavior and the correlates of physical activity participation among Australians with OA, or about the benefits of combining physical activity and GS for the management of OA. More generally, there is little information on the treatments used by OA sufferers in Australia. The first main aim of this thesis was to describe OA symptoms in people with hip or knee OA; their use of treatments for these symptoms; their health status; their current, past and future participation in physical activities; and their perceptions that could influence physical activity participation (Study 1). The second main aim was to compare the effectiveness of different frequencies and durations of walking, combined with GS intake, for reducing symptoms of OA and improving well-being in people with hip or knee OA (Study 2). Descriptive study (Study 1) A questionnaire was mailed to 2200 members of the Arthritis Queensland Foundation who lived in the Brisbane environs. Of these, 588 participants with hip or knee OA completed the survey. The most common treatments being used to manage osteoarthritic symptoms were weight loss (57%), range of motion exercises (56%), and strengthening exercises (49%). The most popular pharmacological treatments were glucosamine and/or chondroitin (54%) and anti-inflammatory medications (40%). Paracetamol (73%), topical liniment rubs (45%) and anti-inflammatory gels (35%) were the most commonly used ‘as needed’ medications. Most participants had fair to good health (68%). Many reported moderate levels of anxiety and depression as well as other health problems. Hypertension was the most common health problem (43.3%). Twenty-five percent reported that health problems were preventing them from walking, and 33% reported that health problems were preventing them from doing other exercises. Fifty-nine percent were meeting Australian physical activity guidelines (30 minutes of moderate-intensity physical activity most days of the week). Participants reported taking part in a wide range of sports and exercises, walking being the most common. They had moderate levels of self-efficacy for, and perceived many health benefits from being physically active, but perceived a moderate number of barriers to being active. Significant associations between past participation in sports and current OA symptoms were only found for men (p < 0.05), with past participation in Australian Rules football, basketball, soccer, skiing or volleyball associated with more severe symptoms in men. Feasibility study (Study 2) Thirty-six participants were given GS for 18 weeks. Starting in Week 6, they also participated in the 12-week Stepping Out walking program (after being randomly assigned to walk 3 or 5 days each week). Assessments were conducted at baseline, at Weeks 6, 12, and 18 during the intervention, and at a final follow-up during Week 24 of the study. Primary outcome measures were WOMAC pain, stiffness, physical function, and total scores and time to complete a self-paced step test, an objective measure of physical function. Comparisons were made between groups and between assessment weeks. As the data were not normally distributed, non-parametric techniques were used. Given that the study was a feasibility study, data were analysed on a per protocol basis. No significant between-group differences were found at any assessment week for the primary outcome measures. Therefore, changes between assessments were examined for the two groups combined. After 6 weeks of GS intake, WOMAC stiffness (p = 0.01) and physical function scores (p = 0.05) improved, as did physical function, measured objectively (p < .001). Between Weeks 6 and 12, when participants were asked to increase their daily steps over their current steps to an extra 1500-3000 per day, physical activity minutes increased (p = 0.01), and improvements were found for WOMAC pain (p = 0.03), WOMAC physical function (p = 0.03), and objectively-measured physical function (p < .001). Between Weeks 12 and 18, when participants were instructed to increase their daily steps by 6000 from baseline, physical activity minutes increased (p < .001), and further improvements were found for objectively-measured physical function (p < .001). During the follow up between Week 18 and 24, physical activity minutes decreased (p = 0.01) while objectively-measured physical function improved (p < .001). Both studies add to the body of literature on the management of OA of the hip and knee. Study 1 provides information about OA sufferers’ use of over-the-counter medications and their adoption of self-management strategies, information not routinely available from other sources, while Study 2 provides preliminary evidence for the walking ‘dose’ appropriate to relieve OA symptoms and on the effects of difference ‘doses’ on OA symptoms.

The Leukocyte Immunoglobulin-like Receptors (LILRs) are a family of receptors that is broadly expressed on all leukocytes and have the ability to regulate their function. A substantial amount of evidence suggests that LILRs may be involved in immune homeostasis but also immune dysregulation. We therefore studied the role of LILRs in relation to the autoimmune disease, rheumatoid arthritis (RA). RA is a chronic and systemic inflammatory disease involving inflammation of the joints affecting the synovial membrane, cartilage and bone. Much of the tissue damage is a result of an inappropriate immune response within the joint space caused by the unwarranted activation of leukocytes. Here were report that LILRA2 (an activating receptor) that has been previously shown to be highly expressed in the rheumatoid synovium, induces the production of pro-inflammatory cytokines TNF-α, IL-1, IL-6, IFN-γ and IL-10 in primary monocytes. These cytokines are known to have an important role in the pathogenesis of RA indicating a pathway by which LILRA2 exacerbates RA. Co-ligation of LILRB4 (an inhibitory receptor) with LILRA2 abolishes cytokine production suggesting that LILRB4 is able to suppress the function of LILRA2. Expression of both LILRA2 and LILRB4 are regulated by inflammatory cytokines and LPS, indicative of a feedback mechanism. There is also cross-talk between LILRs and TLR4 as co-stimulation with LPS and either LILRA2 or LILRB4 inhibits cytokine production. A differential expression of LILRs has also been identified on lymphocytes of patients with RA whereby an increase of LILRA1 (activating) and LILRB1 (inhibitory) expressing circulating lymphocytes is present in RA patients when compared to healthy control subjects. From these studies, we propose that LILRs have a functional role in RA by regulating local and systemic inflammation. The presence of LILRA2 in the RA joint is detrimental since its potent ability to induce inflammatory cytokines, particularly TNF-α, can initiate leukocyte recruitment and activation of proteases. Along with TLR4, LILRA2 and LILRB4 have the potential to moderate the innate immune system via regulation of cytokine production. Furthermore, suppression of LILRA2 function may serve as a therapeutic tool in many inflammatory diseases.