Hintergrund: Die rheumatoide Arthritis ist eine chronisch inflammatorische Autoimmunerkrankung die 0,5-1% der Bevölkerung betrifft und zu Arthritis und Gelenksdestruktion führt. Eine wichtige Rolle bei dieser Autoimmunerkrankung nehmen die pro-inflammatorischen Zytokine wie IL-6, IFNγ, IL-1β und TNFα ein. Ihre Rolle in der Pathogenese der RA ist seit einigen Jahren das Hauptinteresse der Forschung in der Entwicklung neuer Behandlungsstrategien. Die dafür entwickelten Biologika, auch biologische disease-modifying-anti-rheumatic-drugs (bDMARDs) genannt, greifen als monoklonale Antikörper gezielt in diese Regelkreise ein und stellen eine neue Behandlungsoption bei Versagen der konventionellen DMARDs dar. Die Erforschung der Nebenwirkungen dieser neuen Therapieansätze ist aktuell immer noch Inhalt zahlreicher Studien. Rationale: Die Frage, inwieweit diese Biologika zu gehäuften Reaktivierungen von Varizella-Zoster-Virus (VZV) in Form von Herpes Zoster führen, ist bisher aus Surveillance-Daten gezeigt worden. Die zellulären Mechanismen sind diesbezüglich allerdings noch unverstanden. Aus diesem Grund wurde der Einfluss von verschiedenen Biologikatherapien bei RA Patienten auf die intrazelluläre Zytokinproduktion von VZV-stimulierten CD4+ und CD8+ T-Zellen untersucht und die Zytokin-Hemmung in vitro simuliert. Methoden: Die vorliegende Arbeit untersuchte die intrazelluläre Zytokinproduktion von CD4+ und CD8+ T-Zellen von 10 gesunden und 43 an RA erkrankten Probanden in verschiedenen Therapiegruppen (Adalimumab, Tocilizumab, Rituximab und Methotrexat Monotherapie) im Rahmen einer Querschnittstudie. Die mittels Durchflusszytometrie ausgewerteten Zytokinproduktionen der verschiedenen T-Zell-Subpopulationen wurden unter viralem Stimulus (VZV) und in Kombination der verschiedenen Zytokinblockaden durchgeführt. Resultate: Die Ergebnisse zur Korrelation bestätigten die Annahme, dass es keine Korrelation zwischen der anti-VZV-IgG Konzentration und der Avidität gibt. Dies konnte sowohl für die RA Patienten der verschiedenen Therapiegruppen, als auch die gesunden Kontrollen gezeigt werden. Es zeigten sich zahlreiche signifikante Einflüsse der Biologika auf die Zytokine, den größten Einfluss hatte Methotrexat auf die intrazelluläre Zytokinproduktion im Sinne einer Hemmung, insbesondere bei den aktivierten CD69+ T-Zellen und in den Memory, Effektor und TEMRA T-Zell-Subpopulationen. Bei den anderen Therapiegruppen fanden sich ebenfalls zahlreiche signifikant verminderte Zytokinproduktionen, jedoch meist eine zu den gesunden Kontrollpersonen vergleichbare intrazelluläre Zytokinproduktion, insbesondere von IFNγ, nach in vitro VZV Stimulation. Synergistische Effekte für die in vitro Blockade von einzelnen Zytokinen auf die intrazellulären Zytokin-Produktionen in CD4+ und CD8+ T-Zell-Subpopulationen konnten gezeigt werden. Diskussion: Zusammenfassend zeigt sich ein deutlicher Einfluss von Methotrexat und Biologika auf die intrazelluläre Zytokinproduktion in T-Zellen von RA Patienten, jedoch ein relativ gutes in vitro Ansprechen der intrazellulären Zytokinproduktion nach VZV Stimulation. Da in unserem Studiendesign jedoch intrazelluläre Zytokine gemessen wurden, kann derzeit keine definitive Aussage über ein möglich erhöhtes Risiko für VZV gemacht werden. Das virale Infektionsrisiko von Kombinationen von Zytokinblockaden ist Gegenstand weiterer Untersuchungen. / Background: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which affects 0,5-1% of the population and causes arthritis and joint damage. Pro-inflammatory cytokines including IL-6, IFNγ, IL-1β and TNFα play important roles. Their role in the pathogenesis of RA and the development of new therapeutic strategies targeting pro-inflammatory cytokines has been the main focus of research for several years. In comparison to conventional disease-modifying-anti-rheumatic drugs (DMARDs), biological drugs, so called bDMARDs, are antibodies that are directed at specific immunological targets and represent a new strategy in the case of failure of conventional DMARDs. The investigations of infectious risks by these new agents are still in the focus of many studies. Rationale: The increased risk of Herpes Zoster reactivation under therapy with biologicals has been shown in different studies including RA patients. The cellular mechanisms are still not understood. Therefore we explored the effects of various biological therapies and methotrexate in RA patients on the intracellular cytokine production in VZV-stimulated CD4+ and CD8+ T-cells and performed simulations of cytokine blocking strategies in vitro. Methods: This cross-sectional study investigated the intracellular cytokine production in CD4+ and CD8+ T-cells of 10 healthy donors and 43 RA patients treated with different drugs (Adalimumab, Tocilizumab, Rituximab and Methotrexat as mono-therapy). The intracellular cytokine productions of the T-cell subpopulations under VZV-stimulus and/or cytokine-blocking conditions were measured by flow cytometry. Results: No correlation between avidity and anti-VZV-IgG concentrations could be shown for RA patients and the healthy donors. A lot of significant effects of various treatment regimens were shown on the intracellular cytokine production of CD4+ and CD8+ T-cells, with methotrexate showing the greatest inhibitory effect on intracellular cytokine production particularly in CD69+, Effector and Memory T-cell subpopulations. Although other therapies reduced intracellular cytokine production, the cellular cytokine-producing reactivity to VZV-stimulus was almost similar to healthy controls. Discussion: In summary, we have found a significant association between methotrexate and other biologicals with reduced intracellular production of cytokines in T-cells of RA patients. However an almost normal response to in vitro stimulation with VZV was demonstrated in T-cells of RA patients. As the intracellular cytokine production was measured statements concerning the risk of VZV reactivation could not be derived from this study. The risk of viral infection under combined biological treatment is subject to further studies.

Osteoarthritis (OA) of the knee is a common condition. The condition causes pain and swelling in the knee joint and as a consequence knee range of motion, particularly knee extension, can be decreased. While a number of studies have indicated increases in knee extension range of motion (ROM) can be achieved following stretching interventions, these studies have been undertaken in young healthy populations mostly. To date, there have been no investigations of stretching as a single intervention in people with OA knee. Review of Literature: To gain an appreciation of the literature in this area, three structured literature reviews were undertaken. The first examined the efficacy of acute stretching interventions on lower limb joint ROM in young and elderly subjects, the second examined the efficacy of periodic muscle stretching interventions on lower limb joint ROM in elderly subjects and the third examined the efficacy of periodic muscle stretching interventions on ROM in subjects with OA of the knee joint. The results of the first review indicated that there is strong evidence for acute stretching interventions to increase joint ROM in the lower limb of young and elderly subjects. The results of the second review indicated that there is strong evidence for periodic stretching interventions to increase joint ROM in the lower limb of elderly subjects. The result of the third review indicated that there is limited evidence for stretching interventions alone to improve ROM in the lower limb in subjects with OA of the knee joint. As consequence of these findings two studies were designed to investigate the effects of acute and periodic stretching in people with OA of the knee joint. Study 1 Objective: The objective of this study was to investigate the effects of an acute hamstring-stretching programme on knee extension range of motion in individuals with osteoarthritis (OA) of the knee and compare them to individuals of a similar age without OA of the knee. Study Design: A cross sectional study design was used. Participants: Thirty one subjects (16 male and 15 female) with OA of the knee were recruited from the local population (mean age 67.8 yrs SD: 5.0, mass 81.4 kg, SD: 15.2, height 168.5 cm, SD 11.1). Thirty one subjects of a similar age (9 male and 23 female) were also recruited who were otherwise fit and healthy and did not have OA of the knee (mean age 68.8 yrs SD: 5.2, mass 71.4 kg, SD: 13.2, height 163.8 cm, SD 8.1). Method: Hamstring extensibility was assessed by a passive knee extension test using a Kincom® isokinetic dynamometer. Subjects undertook two trials of maximum knee extension. The Kincom® then stretched the hamstrings to a point determined as 80% of the initial maximum knee extension test. Three sets of 60 seconds stretching were undertaken with 60 seconds rest between sets. Two further maximal knee extension tests were performed after the stretching intervention. The variables of interests were maximal knee extension, peak passive torque and stiffness. Analysis: A 2-factor repeated measures ANOVA model was utilised. The alpha level was set at 0.05. Results: There was a significant main effect by time for knee extension ROM, peak passive torque and stiffness (p<0.05). There was no interaction effect between groups across time (p>0.05). Knee extension range of motion (ROM) in the OA group increased significantly from 75.6 (SD: 17.2) degrees to 80.5 (SD: 22.3) degrees after the intervention (p<0.05). Subjects in the non OA group increased significantly from 77.5 (SD: 15.5) degrees to 81.9 (SD: 18.2) degrees after the intervention (p<0.05). The knee extension ROM recorded at 50% of the peak torque level pre intervention for the OA group was 60.3 (SD: 18.7) degrees and this increased significantly to 67.2 (SD 16.7) degrees post intervention (p<0.05). For the non OA group, knee extension ROM at 50% of peak torque increased significantly from 60.1 (SD: 15.2) degrees to 65.8 (SD 16.0) degrees (p<0.05). Peak passive torque in the OA group increased significantly from 18.1 (SD: 9.6) Nm to 22.5 (SD: 12.9) Nm after the intervention (p<0.05). Subjects in the non OA group increased significantly from 21.05 (SD: 11.6) Nm to 22.05 (SD: 12.8) Nm after the intervention (p<0.05). For stiffness, there was a significant interaction effect (p <0.05) between groups across time. The OA group increased significantly from 0.70 (SD: 0.35) Nm/deg to 0.89 (SD: 0.5) Nm/deg after the intervention (p<0.05). Subjects in the non OA group increased significantly 0.78 (SD: 0.36) Nm/deg to 0.82 (SD: 0.42) Nm/deg after the intervention (p<0.05). Conclusions: The study demonstrated that knee extension ROM, passive resistive torque and stiffness increased with a single bout of stretching. These results indicate that both elderly subjects and those with degenerative joint disease are able to demonstrate immediate tissue adaptations with acute stretching interventions. This is important as clinicians often prescribe acute stretching exercises in the preparation for other activities such as strengthening and walking programmes. Improving joint range of motion prior to other subsequent activities may be beneficial to those people with OA in particular, as management guidelines for these populations recommend regular exercise to reduce the deterioration of the condition. Study 2 Objective: The purpose of this study was to investigate the effects of a six week stretching intervention to the key muscles of the lower limb, in people with osteoarthritis (OA) of the knee joint and compare them to individuals of a similar age without OA of the knee. A 12 week follow up was undertaken to see if these effects were maintained following the intervention. This study builds on the effects of an acute stretching intervention as demonstrated in Study 1. Study Design: A randomised control trial design was used. Participants: Forty three subjects (24 OA and 19 non OA) were recruited from the local population (mean age 68.8 yrs SD: 5.0, mass 79.5 kg, SD: 14.6, height 166 cm, SD 9.8). Subjects were randomly allocated by condition to either a stretch group or a control group. Methods: Hamstring extensibility was assessed by a passive knee extension test using a Kincom® isokinetic dynamometer at baseline, following the intervention and at a 12 week follow-up. Subjects in the intervention groups stretched the main lower limb muscles 3 x 60 seconds, 5 days a week for 6 weeks. The control groups did not stretch but received a placebo intervention of interferential current. The variables of interest were maximal knee extension, peak passive torque and stiffness. The following outcome measures were also used to assess activity levels: the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Lower Limb Task Questionnaire (LLTQ) and the Aggregated Locomotor Functional (ALF) score. Analysis: A 3-factor (group x condition x time) repeated measures ANOVA model was utilised. The alpha level was set at 0.05. Results: There was a significant main effect for time and a significant interaction effect for group (stretch and control) by time for knee extension ROM, peak passive torque and stiffness (p<0.05). There was no significant interaction for condition (OA vs non OA) (p>0.05). Subjects in the stretch group had 68.9 (SD: 15.5) degrees of knee extension before the intervention and this increased significantly to 76.8 (SD: 14.4) degrees after the intervention (p<0.05). At the 12 week follow up assessment, subjects had a mean of 72.5 (SD: 20.51) degrees. This difference was not significant when compared to the post intervention assessment (p>0.05). Subjects in the control group were not significantly different for knee extension ROM following the intervention or at the 12 week follow up (p>0.05). For the knee extension ROM at 50% of the maximum torque level, there was a significant main effect for time (p<0.05) but no significant interaction effect between groups across time (p >0.05). The mean knee extension ROM recorded at 50% of the peak torque level for the stretch group pre intervention was 55.9 (SD: 15.0) degrees and this decreased significantly to 50.8 (SD 12.3) degrees post intervention (p<0.05). The mean knee extension ROM recorded at 50% of the peak torque level pre intervention for the control group was 60.2 (SD: 11.4) degrees and this decreased significantly to 57.1 (SD 11.0) degrees post intervention (p<0.05). With respect to peak passive torque subjects in the stretch group were 13.2 (SD: 7.7) Nm before the intervention and increased significantly to 19.7 (SD: 9.5) Nm after the intervention (p<0.05). At the 12 week follow up assessment, the subjects in the stretch group generated a mean peak torque of 20.2 (SD: 11.5) Nm. This difference was not significant when compared to the post intervention assessment (p>0.05). With respect to stiffness, subjects in the stretch group were 0.62 (SD: 0.3) Nm/deg before the intervention and this increased significantly to 0.84 (SD: 0.3) Nm/deg after the intervention (p<0.05). At the 12 week follow up time point, the subjects in the stretch group had a mean stiffness of 0.88 (SD: 11.5) Nm/deg. This increase was not significant when compared to the post intervention assessment (p>0.05). Subjects in the control group were not significantly different for peak passive torque or stiffness following the intervention or at the 12 week follow up. There was no significant difference for time or condition for the WOMAC or LLTQ scores. There was a significant main effect for time for both groups for the ALF score (p<0.05), however there was no significant interaction for time by condition (p>0.05). Subjects in the stretch group had a mean ALF score of 23.1 (SD: 3.9) seconds pre intervention and this reduced significantly to 19.8 (SD: 5.4) seconds post intervention (p<0.05). Subjects in the control group had a mean AFL score of 24.8 (SD: 3.1) seconds pre intervention and this reduced significantly to 22.3 (SD: 3.0) seconds post intervention (p<0.05). Conclusions: The study demonstrated that knee extension range of motion, peak passive torque and stiffness increased in those subjects who undertook the six week stretching programme. Knee extension ROM was not maintained at the 12 week follow up assessment, however peak passive torque and stiffness were. These results indicate that both elderly subjects and those with degenerative joint disease are able to demonstrate long term adaptations with periodic stretching interventions. Functional improvements were also observed following the intervention in the stretch groups and the control groups. As previous studies investigating exercise interventions in subjects with OA of the knee joint have combined stretching and strengthening exercises, this study has provided a clear picture of the effects of stretching alone in this population. However, to gain a more obvious change in function in subjects with OA of the knee joint, the combination of stretching with other exercises such as strengthening, may be required in future studies.

"January 2003" Errata slip inserted inside front cover. Includes bibliographical references (leaves 282-313)

"October 2001" Amendments (4 leaves) inserted inside back cover. Includes bibliographical references (leaves 215-266)

"January 2003" / Errata slip inserted inside front cover. / Includes bibliographical references (leaves 282-313) / xxx, 313 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 2003

Background: Patients and clinicians report pain and fatigue as key outcome measures in rheumatoid arthritis. Fatigue and pain are a major concern to patients. Aim: The objective of this study was to examine fatigue and pain in adult patients with rheumatoid arthritis (RA) and to investigate the association between pain and fatigue with body awareness, demographic, disease-related, emotional and psychosocial factors. Method: Data were collected from a sample of patients with RA (n= 120) recruited from a Rheumatology clinic in a large university hospital in Stockholm, Sweden. Eligible for inclusion were patients between 20 -80 years of age and with a confirmed diagnosis of RA. Fatigue was measured using the Multidimensional Assessment of Fatigue (MAF) scale, while the Visual Analogue Scale (VAS) was used to assess components of pain. A multiple stepwise regression analysis was performed to evaluate factors related to fatigue and pain. In the first step a univariate analysis of variance (ANOVA) was used for all relevant independent factors. In the next step backwards stepwise regression was applied. Result: Fatigue was significantly associated with the Disease Activity Score 28-joints (DAS 28) (p = 0.049), the Body Awareness Questionnaire (BAQ) (p = 0.006), the Positive Affect (PA) scale (p = 0.008) and no smoking (p = 0.021). Pain was significantly associated with the EuroQol EQ-5D (p = 0.008) and the DAS 28 (p = 0.001). The adjusted R-square was 28.6% for fatigue and 50.0% for pain. Conclusion: This study clearly demonstrates that fatigue and pain in patients with RA appear to be associated with disease-related factors. Furthermore, fatigue was related to body awareness and emotional factors, and pain was related to health related quality of life.

Rheumatoid Arthritis (RA) is an autoimmune disease characterized by inflammation and eventual destruction of the synovial joints. The role of platelets in the pathophysiology of arthritis has only recently been established. Because antibodies to CD44 can deplete platelets, we hypothesized that these antibodies might be effective in arthritis through a platelet-depletion mechanism. We examined the K/BxN passive transfer mouse model of arthritis and found that most antibodies against CD44 were capable of depleting platelets. However, anti-CD44 treatment is effective when administered during developing arthritis, while anti-platelet treatment was not. While CD44 antibodies may be therapeutic through platelet-dependant and independent mechanisms, the ability of CD44 antibodies to decrease platelet counts does not seem to be the critical factor in resolving arthritis in the K/BxN model.

Zugl.: Giessen, Univ., Diss., 2009

Zugl.: Giessen, Universiẗat, Diss., 2009.

Leptin, a protein hormone encoded by obese (ob) gene, is mainly produced by adipocytes. Leptin plays an important role in regulating neuroendocrine function and energy metabolism. As a cytokine, leptin is involved in modulating the hematopoiesis and lymphopoiesis. Although leptin has been found to promote T cells activation, it is largely unclear whether and how leptin regulates T cell differentiation and function. Leptin has been associated with disease severity in rheumatoid arthritis (RA). Elevated leptin levels have been detected in the sera and synovial fluid of active RA patients. Th17 cells play key roles in synovitis and joint damage during arthritis development. However, the role of leptin on Th17 cells has not been investigated so far. In culture, leptin promoted Th17 cells differentiationfrom naïve 〖CD4〗^+ T cells via upregulating ROR-γt expression. Moreover, Th17 cells and IL-17 levels were significantly increased in leptin-treated naïve CD4+ T cells. Moreover, this study found that synoviocytes and chondrocytes produced large amounts of leptin especially during acute and chronic stages of mice with collagen-induced arthritis (CIA). Furthermore, leptin levels, Th17 cells in the joint and IL-17 levels in the synovial fluid were closely related to disease activity. Leptin intraarticular injection led to earlier onset of disease, higher clinical score, and more severe joint destruction compared with PBS-treated control mice. Importantly, leptin-injected mice had higher percentages of Th17 cells and cell numbers, elevated IL-17 levels in the synovial fluid, and increased infiltration of Th17 cells in the inflamed joint tissues compared with PBS-treated mice. T follicular helper (Tfh) cells are indispensible for pathogenic autoantibodies production. However, whether leptin receptor (ObR) signaling has a role on Tfh cells and its implication in CIA remain elusive. Upon a T cell-dependent antigen TNP-KLH immunization, germinal center (GC) response, plasma cells (PCs) and memory B cells formation were impaired in db/db mice compared with wild-type (WT) controls. In coculture of Tfh cells from db/db and WT mice with WT GC B cells, anti-TNP IgGs titers in supernatants of db/db Tfh cells were significantly reduced. Intravenously transfer of naïve CD4+ T cells from db/db and WT mice to BoyJ recipient mice, donor CD4+ T cells from db/db mice showed impaired Tfh cells generation in spleens of BoyJ recipient mice compared with mice received with WT CD4+ T cells. These data indicated that ObR-mediated signaling intrinsically modulate Tfh cells generation. In culture, leptin promoted Tfh cells differentiation via inducing Bcl6 expression, and increased IL-21 production in Tfh cells in a dose-dependent manner. Leptin significantly enhanced the phosphorylation of STAT3, upregulated Bcl6 expression, and increased p-STAT3 binding to the Il21 promoter in CD4+ T cells with leptin receptor b (Ob-Rb) overexpression. Upon CIA induction, db/db mice exhibited ameliorated disease severity with impaired Tfh cells response. However, WT Tfh cells transfer to db/db mice restored GC responses, PCs formation, antibody production, and exacerbated synovium inflammation and joint damage in db/db recipient mice. Together, these findings demonstrate that leptin modulates arthritis development via enhancement of Th17 and Tfh cells responses. / published_or_final_version / Pathology / Doctoral / Doctor of Philosophy