Blog entry by Meguid El Nahas
Rituximab, a chimeric monoclonal anti-CD20 antibody, has now been extensively used in the management of autoimmune diseases including SLE and lupus nephritis as well as AASV (ANCA associated systemic vasculitis).
Concern has been expressed about the association of immunosuppressants, including Rituximab, and the increased risk of Progressive multifocal leukoencephalopathy (PML). The signal and association with Rituximab is of concern and warrants vigilance.
Whilst rare, such an association may be overlooked when considering teh RISK:BENEFIT of rituximab in autoimmune renal disease. However, the devastating nature of PML warrants careful follow-up and vigilance. This, all the more, since the benefit of Rituximab in conditions such as LN (LUNAR study) and ANCA associated vasculitis (RAVE INT & RITUXIVAS studies) is not superior to current therapies!
A recent article in the NEJM, this month, also shows an increased risk of PML with another monoclonal antibody Natalizumab (anti-integrin a4), with increased risk in those who have a positive status in respect to anti-JC virus antibodies, prior use of immunosuppression and duration of treatment.
Perhaps, we should screen the patients we treat willi nilly with Rituximab.. for anti-JC (John Cunningham) antibodies?!
Perhaps, we should use Rituximab less often when evidence supports its indication!?