Thesis (M.S.)--University of Michigan, 1991.

Thesis (Ph. D.)--University of Minnesota, 1999. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 80-96).

Thesis (Ph. D.)--University of Minnesota, 1999. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1991.

An in vitro cell and organ culture system for the study of human arthrotropic viruses was established to determine the permissiveness of joint cells and tissue to five strains of rubella virus (RV), adenovirus type 2 (Ad) and human parvovirus (B19). A semi-continuous line of fetal chondrocytes (FC) and primary synovial membrane/cartilage (SMC) cells were used to investigate virus/joint cell interactions. In addition, the SMC cells were used to determine the ability of a virus to establish a persistent infection in cells of joint origin. Intact joint tissue containing both synovial membrane and cartilage was also infected to determine the ability of the viruses to replicate in non-dividing cells and also their invasive capability in the presence of an extracellular matrix. Results showed that all RV strains and Ad were able to replicate in FC, SMC cells and intact joint tissue. The only exception to this was that replication of RV strain Cendehill was not detected in joint tissue. In contrast, there was no indication, by either DNA-DNA hybridization or immunoperoxidase staining, that B19 was able to replicate in SMC cells. Most importantly, the behaviour of the rubella strains in this model was found to correlate with the clinical data concerning the incidence of complications associated with rubella infection or vaccination. This suggests that arthritogenicity is related to the ability of a particular virus to infect and persist in joint tissue and establishes the in vitro model as a useful system to evaluate the arthrotropicity of future rubella vaccines. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

Biological disease-modifying anti-rheumatic drugs (DMARDs) for the treatment of Rheumatoid Arthritis, particularly TNF-α inhibitors, have been shown to improve patient outcome by slowing or halting radiographic damage. However, similar to most immunemodulators, there is an increased risk of infections co-incident with Tumour necrosis factor (TNF)-α inhibitor use, particularly the risk of activated latent tuberculosis infection (LTBI). Therefore, local and international guidelines recommend pre-screening for tuberculosis (TB) prior to the initiation of TNF-α therapy in rheumatoid arthritis (RA) patients. Also of critical importance in South Africa is the need for clinicians to be aware of environmental risk factors such as TB being highly endemic. Thus, a qualitative analysis was performed to investigate rheumatologists’ perceptions of TB co-incident with TNF-α inhibitors. Method: Physicians (n=18) practising rheumatology in the private and public healthcare sectors in Gauteng were interviewed to obtain their perceptions and attitudes related to TB co-incident with TNF-α inhibitor use. Interviews were audio-recorded and the transcripts analysed using thematic content analysis. Results: The determinants of health equity: Affordability, accessibility and availability of medicines (specifically TNF-α inhibitors) was reported to be different for the public care versus the private care patient. The high cost of TNF-α inhibitors warranted funding predominantly by the private medical schemes. A higher occurrence of latent TB infection was reported by physicians practising in the public or combined practice compared to the occurrence of LTBI in the private sector (21.4%versus 1.5%). The majority of study participants advocated pre-screening of TB, prior to the initiation of TNF-α inhibitors, in RA. However, it was suggested that because of the high occurrence of LTBI in the public sector, Isoniazid preventative therapy (IPT) should be compulsory, irrespective of the patient’s TB status, for the duration of TNF-α therapy. Most study participants supported local South African Rheumatism and Arthritis Association (SARAA) guideline recommendation to re-screen for TB by chest x-ray (CXR), every 6 months. However, the value of re-screening using diagnostic tools, purified protein derivative (PPD) skin test or interferon-gamma release assays (IGRAs) was queried due to the possibility of false readings. The occurrence of associated active TB in RA patients on TNF-α inhibitors was reported to be 0.07% in the private or combined practice versus 3.00% in the public sector. Forty percent of TB cases were reported to be extra-pulmonary. Despite active vigilance, some physicians reported that active TB month occurred months after the cessation of TNF-α inhibitor therapy. [Similar findings were observed from the British Society for Rheumatology Biologics Register (BSRBR)]. The majority of patients that developed TB co-incident with TNF-α inhibitors were treated successfully with TB chemotherapy. Only 1 of 12 patients died of extra-pulmonary TB, following compassionate use of infliximab in public care. Conclusion: Physicians practising rheumatology in Gauteng were of the opinion that there is a TB risk associated with the use of TNF-α inhibitors for the management of rheumatoid arthritis, as South Africa is a TB endemic country. Most acknowledged that these biological DMARDs were efficacious in slowing or halting radiographic progression in rheumatoid arthritis, but emphasised the need to take steps to prevent TB reactivation in the immuno - compromised RA patients and to remain overtly vigilant for active TB. In clinical practice, physicians mentioned that the monitoring and management of TB associated with TNF-α inhibitors appears to follow the socio-economic status of the RA patient and that distinct recommendations should be made for the public healthcare as well as the private healthcare sectors. Different opinions emanated from different physicians relating to the adequacy of local SARAA guidelines for the prevention of TB associated with TNF-α inhibitors. Some physicians mentioned that local guidelines were sufficient, whilst other physicians mentioned that the diagnostic tools were inadequate in the South African setting and that additional precautions should be taken in the form of IPT for the full duration of TNF-α therapy for all candidates, irrespective of TB status determined during pre-screening. As the science of biological DMARDs evolves with the rapid development of new medicinal therapies, physicians showed a preference to consider alternative non TNF-α biological DMARDs that had a lower risk of associated TB, specifically in high-risk RA patients. Physicians’ overall perception of the management of RA with TNF-α inhibitor therapy was that the risk-benefit assessment of these interventions, as well as patient preference and economic considerations should be taken into account.

Tumor necrosis factor (TNF) antagonists are biologic response modifiers that have significantly improved functional outcomes in patients with rheumatoid arthritis (RA). RA is a progressive disease in which structural joint damage can continue to develop even in the face of symptomatic relief. Before the introduction of biologic agents, the management of RA involved the use of disease-modifying antirheumatic drugs (DMARDs) early in the course of disease. This focus on early treatment, combined with the availability of the anti-TNF agents, has contributed to a shift in treatment paradigms favoring the early and timely use of DMARDs with biologic therapies. Improvement in symptom control does not always equate to a reduction in disease progression or disability. With the emergence of structure-related outcome measures as the primary means for assessing the effectiveness of antirheumatic agents, the regular use of X-rays is recommended for the continued monitoring and evaluation of patients. In addition to the control of symptoms and improvement in physical function, a reduction in erosions and joint-space narrowing should be considered among the goals of therapy, leading to a better quality of life. Adherence to therapy is an important element in optimizing outcomes. Durability of therapy with anti-TNF agents as reported from clinical trials can also be achieved in the clinical setting. Concomitant methotrexate therapy might be important in maintaining TNF antagonist therapy in the long term. Overall, the TNF antagonists have led to improvements in clinical and radiographic outcomes in patients with RA, especially those who have failed to show a complete response to methotrexate.

Background: Fatigue is a prevalent burden in RA and a key management priority for patients, but current treatment is lacking because its mechanisms are unknown. Although pain has been identified as a possible cause of fatigue, the link between these symptoms is unclear. This project aimed to examine the prognosis of fatigue and determine the role of pain in symptom outcomes. Methods: Two disease registries were used to address these aims in early – the Norfolk Arthritis Register (NOAR) – and severe RA – the British Society for Rheumatology Biologics Register for RA (BSRBR-RA). In both registries, fatigue and pain were measured along with a variety of demographic, clinical and psychosocial data. The prevalence of high symptoms was determined in both cohorts and the prognosis of fatigue delineated in NOAR using group-based trajectory modelling (GBTM). Descriptive statistics and structural equation modelling (SEM) determined the magnitude and pathways of fatigue change following commencement of anti-TNF therapies in the BSRBR-RA. Results: High fatigue was reported by 56% of 413 eligible early-RA patients. Of those, 68% reported persistent high fatigue at year one, but GBTM showed the progression of fatigue to vary over 4 years. Key sex differences in trajectories were observed. Of 6835 eligible participants commencing anti-TNF therapies, 39% reported high fatigue at baseline, but 66% improved to a low fatigue status by six-months. SEM indicated that the effect of disease activity on changes in fatigue was indirect and that improvements were largely driven by pain. The particular importance of mental health and disability were also highlighted throughout analysis. Discussion/Conclusions: Fatigue is a common and often chronic burden in RA. The symptom is amenable to treatment by anti-TNF therapies, but improvements are not driven by reductions in disease activity. Instead pain is a mediator of improvement and likely a suitable treatment target, along with mental health and disability.

published_or_final_version / Community Medicine / Master / Master of Public Health