Page 96 - Recognizing axial spondyloarthritis - Janneke de Winter

CHAPTER SIX
(GESPIC) versus 135,168 healthy German potential stem cell donors, and c) an early back pain cohort with 94 early axSpA patients versus 216 chronic back pain (CBP) patients from the SPondyloArthritis Caught Early (SPACE) cohort. All patients and controls gave their written informed consent prior to any study procedures. All studies were approved by the local ethics committees of the Academic Medical Center/University of Amsterdam (exploratory cohort), the Medical University of Berlin (exploratory cohort/GESPIC) and the Leiden University Medical Center (the SPACE cohort).
Exploratory cohort
DNA from patients with AS was collected in the Academic Medical Center/ University of Amsterdam (n=9) and the Medical University of Berlin (n=15). All AS patients were diagnosed by a rheumatologist and fulfilled the modified New York (mNY) criteria (9). DNA from healthy controls was collected in the Academic Medical Center/University of Amsterdam (n=10) and the Medical University of Berlin (n=30).
GESPIC
GESPIC is described in detail elsewhere (10). In short, GESPIC is an ongoing, prospective, longitudinal cohort study that started in 2000. Patients with definite axSpA diagnosed by their treating rheumatologist were included. Patients were further classified as AS or nr-axSpA based on the fulfillment of the radiographic criterion of the modified New York criteria according to the judgement of the central readers (11). The cervical and lumbar spine was scored according to the modified Stoke AS Spine Score (mSASSS) (12). AS patients fulfilled the modified New York criteria (9), the duration of symptoms was restricted to ≤10 years at the time of inclusion. Nr-axSpA patients fulfilled the European Spondylarthropathy Study Group (ESSG) criteria (13), the duration of symptoms was restricted to ≤5 years at the time of inclusion.
We included 196 patients of GESPIC for which DNA for HLA typing was available, including 113 patients with AS (57.7%) and 83 patients with nr-axSpA (42.3%). Of the 196 axSpA patients, 158 were HLA-B*27 positive (80.6%) and 100 were male (51.0%). Data were complete, except for ‘duration of back pain (missing in n=16) and HLA-B*27 (missing in n=1). The results of GESPIC were compared with 135,160 randomly selected potential stem cell donors (in short: donors) from the German Bone Marrow Donor Center (DKMS). Donors were matched with GESPIC patients according to their place of residence. Of the 135,160 donors, 13,120 were HLA-B*27 positive (9.7%) and 50,454 were male (37.3%). Donors were not allowed to have a diagnosis of axSpA.
SPACE
The SPACE cohort is an ongoing, prospective, multicenter, longitudinal cohort that started in 2009 and is described in detail earlier (14). In short, the SPACE
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