A combination of the anti-B-cell drug rituximab and intravenous immune globulin (IVIG) therapy led to long-standing remission and prevented recurrence of pemphigus vulgaris, the autoimmune disease that blisters the skin and mucous membranes, according to new study findings.
The study, led by , a dermatologist who heads the Center for Blistering Diseases in Boston, tracked 10 pemphigus vulgaris patients from 2006 to 2015. Every patient who received the novel treatment combination went into remission in 2006 and stayed that way for the duration of follow-up.
The study results were reported in a letter to the editor in the Dec. 31 issue of the New England Journal of Medicine.
Immunoglobulin G autoantibodies, which were a biomarker for pemphigus vulgaris, were undetectable in patients after treatment began and remained so throughout the course of the study. Counts of CD19+ B cells revealed normal levels throughout the 10 years that were observed. Skin-biopsy specimens taken 5 years after the last dose of rituximab was administered, from sites on the body previously affected by pemphigus vulgaris, showed no indication of the disease on direct immunofluorescence assay.
Why the treatment worked is not certain, Ahmed and colleagues stated in the letter.
"The mechanisms by which this combination of treatments produced 10-year remissions are not known," Ahmed and colleagues wrote. "Whereas rituximab destroyed pathogenic B cells, intravenous immune globulin may have helped to restore lost immune regulation and normal physiology."
Clinicians have typically treated pemphigus vulgaris with a combination of rituximab, systemic glucocorticoids, and immunosuppressive agents. Most patients who receive this blend of treatments experience remission within a few weeks, Ahmed and colleagues noted, but relapses are common. Up to 80% of patients treated in this fashion see a return of symptoms, according to case study data.
What's more, the overall immunosuppression caused by the traditional protocol can have serious side effects, which can in some cases be fatal.
"The prolonged period of immunosuppression from rituximab and concomitant therapy can produce several side effects, notably infection, which may proceed to septicemia and death," Ahmed and colleagues wrote.
During the investigation, Ahmed and colleagues observed no short- or long-term adverse effects in the patients who received rituximab and IVIG therapy.
Follow-up in the 10 patients ranged from 111 to 136 months (mean, 131.7 months) after discontinuation of rituximab. (An 11th patient was lost to follow-up for unspecified reasons.)
Pemphigus vulgaris is classified as a type II hypersensitivity reaction, with the immune system producing antibodies that weaken and break bonds between skin cells. The exact cause of the chronic condition is not known.
Disclosures
The study authors declared they had no relevant financial interests.
Primary Source
New England Journal of Medicine
Ahmed A, et al "Long-term remissions in recalcitrant pemphigus vulgaris" N Engl J Med 2015; 373: 2693-94.