Page 76 - Fertility in Women with Rheumatoid Arthritis Vruchtbaarheid van vrouwen met reumatoïde artritis

Chapter 5
PATIENTS AND METHODS
Patients
Patient data were derived from the Rotterdam Early Arthritis Cohort (REACH), a prospective cohort study in the greater Rotterdam area which was started in July 2004 and is still ongoing.6 Enrolled patients had joint complaints for less than 12 months, which were not explained by trauma or overexertion. They did not use any anti- rheumatic medication before enrolment. The Erasmus MC medical ethical review board approved the study protocol and a written informed consent was acquired before inclusion. Patients were examined at several visits, including the rst visit (T0) and 6 months later (T6). Patient characteristics, general history, disease activity scores and drugs prescribed were registered. When available, serum samples for each visit were stored. X-rays of hands and feet were made at baseline and assessed for bony erosions.
For the current study, all women aged 18 to 42 years ful lling the 2010 ACR/EULAR RA classi cation criteria were included.7 Serum samples from T0 and T6 visits were used.
Controls
An existing control population of healthy females was used.8 From this population, all women aged 18 to 42 years were selected (n=509). All controls had regular menstrual cycles ranging between 25 and 35 days or were proven fertile. Twenty-nine percent of controls had ever been pregnant, for 60% this is unknown. No additional fertility assessments were available. Controls did not use any hormones or oral contraceptives during the three months prior to blood sampling. In case of proven fertility, blood sampling was at least six months after delivery. Sampling was performed randomly during the menstrual cycle.8
Measurements
Disease activity was scored using the Disease Activity Score with a 28 joint count (DAS28). Serum samples were stored at -80° Celsius. Laboratory measurements included IgM-rheumatoid factor (RF) (enzyme-linked immunosorbent assay (ELISA)), anti-cyclic citrullinated peptide (anti-CCP), (Elia CCP on immunoCAP 250; Phadia Freiburg, Germany), C reactive protein (CRP) levels (mg/L) (local standards) and AMH levels (μg/L) (in-house double-antibody ELISA (commercially available as GenII Beckman Coulter, Beckman Coulter, Inc., Webster, Texas)). The range of the AMH standards used in the in-house AMH assay was 0.037-5 ng/mL.8
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