Development of antinuclear antibodies and its clinical impact in patients with Crohn's disease treated with chimeric monoclonal anti-TNFα antibodies (infliximab)

Background Although the efficacy of infliximab in Crohn's disease (CD) has been demonstrated, its safety profile has yet to be established. Autoimmune adverse events such as human anti-chimeric antibodies and the development of antinuclear antibodies (ANAs) have been notified, but the true incidence and clinical relevance of the latter is still unknown. Objective To evaluate the changes in ANA status in CD patients treated with infliximab and the clinical evolution of those who are ANA positive. Methods The ANA status of 36 CD patients treated with infliximab was determined at baseline and 6 weeks after the initial infliximab infusion. Patients were followed up monthly. In the case of infliximab re-treatment, ANA status was again evaluated. Twenty-eight patients (78%) were treated concomitantly with immunosuppressants. Results Eight patients (22%) were ANA positive at baseline; none developed anti-double-stranded DNA antibodies (aDNAds) at week 6. Three of them were retreated: there were increasing ANA titres in all cases and developing aDNAds in two. Only six of 28 patients who were ANA negative at baseline changed their ANA status at week 6, but none developed aDNAds. One of them was retreated showing a further increase in ANA titre and developing aDNAds at high titre. No patient presented lupus-like syndrome. Conclusions Only a few CD patients treated with infliximab and immunosuppressants develop ANAs. This condition is not associated with aDNAds and/or lupus-like syndrome in the majority of cases.