Inclusion Criteria

INCLUSION CRITERIA FOR RHEUMATOID ARTHRITIS PATIENTS (5 PATIENTS)

- Age between 18 and 70 years-old with documented diagnosis (clinical evaluation,
x-ray hands and feet minimum 2 months before inclusion) of rheumatoid arthritis
minimum 3 months and maximum 15 years according to ACR criteria 1987. At least 8
tender and 8 swollen joints with inadequate response to at least 2 disease-modifying
antirheumatic drugs (DMARDs) of which one is Methotrexate (MTX). Methotrexate must
have been administered at least 3 months before baseline and doses and route must be
stable for at least 2 months before baseline. Minimum dosage of MTX is 10 mg weekly
and maximum dosage is 25 mg weekly. HAQ (Health assessment Score) score at least 25
at baseline and DAS 28(Disease Activity Score) > 3.7 at baseline.

- All patients are biological naïve patients.

- Negative for Tuberculosis (TB) (also in history) and negative screening for TB
(Mantoux test / x-ray thorax)

- Female patients must be post-menopausal for at least 1 year or must underwent
surgery so that they cannot become pregnant. Women of child bearing potential must
use adequate contraception throughout the study and 12 weeks after the last dose of
certolizumab pegol.

- Patient need to understand the study and sign an informed consent form approved by
the ethics committee before participation in this study.

INCLUSION CRITERIA FOR PATIENTS WITH AXIAL SPONDYLARTHROPATY (15 PATIENTS)

- Age between 18 and 70-years old with presence of a documented diagnosis of
spondylarthropathy according to current ASAS criteria valid for all of the 3
sub-groups (early axial, early peripheral and established axial)

- 10 patients with axial SpA must fulfill current ASAS criteria for AxSpA and 5 of them
need to fulfill the current modified New York criteria:

- Chronic low back pain > 3 months and onset of age < 45 years

- Active inflammatory injury on sacro-iliac joints on MRI. Active inflammatory
injuries are defined as oedema of bone in or around the sacro-iliac joints,
compatible with active injuries seen on axial SpA with STIR (short tau inversion
recovery) MRI

- Inadequate response on previously, optimal use of min 2 Non-Steroidal
Anti-Inflammatory Drugs (NSAIDS) in a anti-inflammatory dosage during 3 months
or a medical contra-indication for use of NSAIDs

- BASDAI score ≥ 4

- 5 patients with peripheral SpA must have presence of clinical peripheral arthritis or
enthesitis or dactylitis with active disease activity, even under a stable dose of
sulfasalazine during 3 months AND presence of one of the following:

- Psoriasis of skin

- Inflammatory bowel disease

- Positive HLA B27

- sacro-iliitis on image (X-ray or MRI of the sacro-iliac joints)

- all patients are anti-TNF naive

- No active tuberculosis (in medical history as current) and negative screening for
latent TB (Mantoux test and X-ray thorax).

- Female patients must be post-menopausal for at least 1 year or must underwent
surgery so that they cannot become pregnant. Women of child bearing potential must
use adequate contraception throughout the study and 12 weeks after the last dose of
certolizumab pegol.

- Patient need to understand the study and sign an informed consent form approved by
the ethics committee before participation in this study.

EXCLUSION CRITERIA FOR RHEUMATOID ARTHRITIS AND SPONDYLOARTHROPATHY PATIENTS

- Patients cannot have treatment with experimental biological and non-biological
therapy in the last 3 months or 5-times the half-live prior to baseline visit

- Patients who had previously treatment with anti-TNF

- Patients who had previously treatment with rituximab and/or abatacept

- Known hypersensitivity to certolizumab pegol (Cimzia®) or one of it compounds

- Current or recent medical history of progressive uncontrolled renal, hepatic,
hematological, gastro-intestinal, endocrine, pulmonary, cardial, neurological or
cerebral diseases.

- Severe or life threatening infections in the last 6 months; signs of current or
recent infection

- Active or latent tuberculosis: in case one or more of the 3 criteria are positive:
medical history of TB, recent (< 6 months) X-ray chest or recent positive PPD skin

- Known history or current viral hepatitis B of hepatitis C

- Known HIV infection

- Malignancy or history of a malignancy

- History of lymph-proliferative disease or signs/symptoms suggestive fort his disease.

- Moderate to severe hart failure (NYHA-class III/IV)