Rituximab Treatment And Immunoglobulin Levels Monitoring

Background Rheumatoid arthritis is a well-known inflammatory condition with a prevalence around 1% in females and 0.5% in males in UK (as per NOAR study). In the past decade use of biologic therapy has helped clinicians to treat rheumatoid arthritis more effectively. Rituximab is one of the biologics which is used commonly for treating rheumatoid arthritis. Rituximab is chimeric monoclonal antibody targeting CD20 molecule of B cells. First trial of rituximab in treating rheumatoid arthritis was published in 2004 and since then it has shown promising results in trials. In order to guide clinicians British society of rheumatology proposed recommendations in March 2010. An audit is required to ensure adherence to clinical guidelines at Haywood hospital. Objectives To assess whether patients receiving Rituximab are appropriately monitored with pretherapy evaluation of immunoglobulin levels To assess the effects of rituximab on immunoglobulin levels and incidence of infection among patients on rituximab Methods Data was collected of all (N=105) patients who received Rituximab between May 2014 until April 2015 at the Haywood Hospital where patients attend for Rituximab injections. Data was collected retrospectively from the Diamond System, Medisec system and Clinical Information System and entered onto an excel spread sheet which included following details Start date of Rituximab IgG levels prior to Rituximab and current IgG levels Total doses of rituximab and frequency of IgG monitoring Intermittent infections and type of infections. Results We observed that 82 out of 105 patients were started on rituximab after February 2011 when the BSR guidance was published and 53 out of 105 patients had their immunoglobulin levels checked prior to commencing rituximab 35/76 (46%) patients had 1 or more episodes of infections whilst on Rituximab which required treatment. Of these, 16 (46%) had recurrent infections. 39 patients had dropped their IgG levels after starting rituximab 18 (46%) of these suffered from infections. 17 patients had a drop in IgG ≥20% and 6 of these (36%) had recurrent infections and 1 patient had 1 episode of infection. None of the patients had dropped their IgG levels below 5 Conclusions A significant number of patients (35/76 =46%) had 1 or more episodes of infections despite IgG levels being above lower normal limit Among patients who dropped their IgG levels had increased number infections. Also they had more than 1 episodes of infection Patients who dropped IgG levels ≥20% suffered with recurrent infections References BSR and BHPR guidelines on the use of rituximab in rheumatoid arthritis doi:10.1093/rheumatology/ker106b. Disclosure of Interest None declared