1. Department of Rheumatology, Stellenbosch University and Tygerberg Academic Hospital, Tygerberg, South Africa,
2. Department of Psychiatry, Stellenbosch University and Tygerberg Academic Hospital, Tygerberg, South Africa
3. Department of Psychology, Stellenbosch University and Tygerberg Academic Hospital, Tygerberg, South Africa
4. Department of Microbiology and Immunology, Stellenbosch University and Tygerberg Academic Hospital, Tygerberg, South Africa