Activated granulocytes and monocytes may contribute to the pathogenesis of inflammatory bowel disease (IBD). Granulocyte and monocyte apheresis (GMA) is a novel nonpharmacologic approach for active IBD, in which granulocytes and monocytes are mechanically removed from the circulatory system. Recently, two randomized, double-blind, sham-controlled studies were conducted to evaluate the efficacy of GMA for ulcerative colitis (UC)1 and Crohn's disease (CD).2 In both studies, the response and remission rates were not significantly different between the GMA and sham controlled groups.
Clinical response and remission rates in the two randomized studies1,2 were much lower than those in uncontrolled studies conducted in Japan. The response and remission rates during GMA should be cautiously interpreted because they are affected by patient and disease characteristics. In our experience, the outcomes of GMA for UC are affected by a previous history of corticosteroid therapy.3 Steroid-naïve patients and patients on low dose steroid and short duration of exposure respond well to GMA. The efficacy of GMA for UC is also affected by macroscopic features of mucosal inflammation.4 Patients with erythema, friability and erosions respond to GMA. In contrast, patients with deep ulceration do not respond to GMA. Thus, previous exposure to corticosteroids and severe mucosal inflammation (deep ulceration) lower the efficacy of GMA. In a study with a higher proportion of patients with these deleterious factors, GMA may be less effective.
Clinical response and remission are major endpoints of GMA studies. It is also important to evaluate steroid-sparing effects of GMA. Long-term and high-dose steroid treatment usually produces serious side effects which impair the patients' quality of life. If GMA can spare patients from exposure to corticosteroids, the risk of steroid-induced adverse events should be minimized.
Our recent study5 was conducted to see if early introduction of GMA for new-onset UC reduces corticosteroid administration and steroid dependency in the long-term. Twenty patients were treated with GMA, with or without corticosteroids (GMA group), and 20 patients were given corticosteroids without GMA (steroid group). During five-year follow-up, five patients in the GMA group did not require corticosteroids. The mean dose of steroid administered during the five years was significantly lower in the GMA group than in the steroid group (2141 mg vs 5443 mg). Furthermore, the incidence of steroid-dependence was significantly lower in the GMA group (5% vs 35%). In patients with the first UC episode, GMA therapy at an early stage significantly reduces steroid administration and steroid-dependency in the long-term. The cost of GMA (approximately €1400 for one session) is much higher as compared with corticosteroids. However, if GMA can spare patients from corticosteroids, and reduce the incidence of steroid-dependency, hospitalization and surgery, it should be cost-effective.
Conflict of interest statement