Clinical efficacy of α4 integrin block with natalizumab in ankylosing spondylitis

We describe the impact of α4-β1/7 blockade with natalizumab, a recombinant humanised immunoglobulin (Ig) G4κ monoclonal antibody (mAb) targeted to the α4 subunit of the α4β1 and α4β7 integrins, on the gut and spine inflammation in a patient with ankylosing spondylitis (AS) who developed multiple sclerosis after treatment with tumour necrosis factor (TNF)-blocking agents. A 45-year-old man with human leucocyte antigen (HLA)-B27-positive AS was admitted in January 2007. He had been diagnosed with AS 4 years earlier based on the presence of inflammatory back pain, peripheral arthritis, radiographic bilateral grade 2 sacroiliitis, HLA-B27 positivity. At that time, he had evidence of chronic intestinal inflammation upon histological evaluation of the gut. He was treated with adalimumab for 2 years, achieving a good clinical response. In March 2009, MRI of the brain was performed for the occurrence of …