Published Online: March 15, 2013
Wiskott–Aldrich syndrome (WAS), a rare primary immunodeficiency disorder, is characterized by an increased risk of autoimmunity. There are no previously documented cases which developed autoimmune thrombotic thrombocytopenic purpura (TTP). Autoimmune TTP is a rare but severe disease of small vessels that is associated with autoantibody-mediated deficiency of a plasma metalloprotease, ADAMTS13. While plasma exchange and the anti-CD20 chimeric antibody rituximab have been used successfully for autoimmune TTP, a considerable number of patients relapse.
In a Letter to the Editor published recently in The Journal of Allergy & Clinical Immunology (JACI), Toyoda et al theorized that repeated courses of rituximab treatment may be effective in preventing a relapse of autoimmune TTP. They administered rituximab monthly to a 20-month-old boy with WAS who presented with recurrent autoimmune TTP and refractory cytomegalovirus (CMV) infection. The patient experienced several potentially fatal episodes and had a poor general condition prior to monthly treatment with rituximab. With this treatment, the patient showed improved clinical condition with stable ADAMTS13 activity and no signs of autoimmune TTP. The patient then underwent allogenic hematopoietic cell transplantation (HCT), the only known curative approach for WAS. The clinical course of post-cord blood transplantation (CBT) was uneventful, and the patient has been in good condition with no recurrence of autoimmunity for the last 25 months.
The researchers reported a previously unknown complication of autoimmune TTP in a patient with WAS, who was successfully treated with CBT combined with rituximab before and after transplantation. Repeated courses of rituximab used as pre-emptive treatment may be effective in maintaining a remission of autoimmunity in cases presenting primary immunodeficiency.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.