Page 14 - Recognizing axial spondyloarthritis - Janneke de Winter

CHAPTER ONE
assessing the disease burden of peripheral disease manifestations in axial SpA. To study if radiographic and non-radiographic axial SpA are phenotypically similar, in chapter 3 we compared the prevalence of peripheral and extra-articular disease manifestations in the radiographic (AS) and non-radiographic phenotype of axial SpA by performing a meta-analysis of cohort studies comparing radiographic
and non-radiographic axial SpA.
Part II of the thesis focuses on the identification and validation of promising biomarkers in the axial SpA field.
MRI-SI is increasingly used to support a diagnosis of axial SpA, although the specificity of MRI of the SI joints is not well known. In chapter 4 we assessed the prevalence of sacroiliitis on MRI of the SI joints in healthy Individuals, runners, and women with postpartum back pain when compared to patients with axial SpA and chronic back pain (CBP) controls.
Anti-CD74 antibodies were proposed as a potential biological marker to diagnose axial SpA. To study their diagnostic value in AS and early axial SpA, in chapter 5 we assessed the prevalence and diagnostic value of anti-CD74 antibodies first in AS patients and healthy controls and second in a ‘real life’ cohort of patients with early, chronic back pain: the SPondyloArthritis Caught Early (SPACE) cohort.
In chapter 6 we tested the prevalence of HLA-C*07, an MHC class I gene, of which absence might be linked to susceptibility to axial SpA. We tested HLA-C*07 prevalence in three different settings. First in an exploratory cohort of AS patients and healthy individuals. Second in GESPIC: a German cohort of early AS and non- AS patients that we compared with a large cohort of healthy donors. Third we confirmed our findings in an early chronic back pain cohort, the SPACE cohort.
Part III of the thesis focuses on the preclinical recognition of axial SpA and the desirability of preclinical treatment.
To investigate whether seemingly healthy first-degree relatives of patients with AS have clinical, laboratory, or imaging features of SpA, in chapter 7 we described the baseline data of the Pre-SpA cohort: a cohort of seemingly healthy first-degree relatives of HLA-B*27 positive AS patients, that we prospectively follow over time.
Initiatives as the Pre-SpA cohort might enable to detect the early or pre-clinical phase of SpA. Hereby, early or pre-clinical management of SpA might become feasible, although the desirability for at-risk individuals is yet unknown. In chapter 8 we therefore studied the willingness of first degree relatives of axial SpA patients of the Pre-SpA cohort to start using preventive medication.
Finally, chapter 9 discusses and summarizes the findings of this thesis.
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