Background: Hitherto, therapeutic depletion of granulocytes and monocytes by adsorption (GMA) has been associated with significant and insignificant efficacy in patients with ulcerative colitis (UC). Further, the processed blood volume in one GMA session has been fixed at 30 mL/min × 60 min, regardless of patients' body weight (BW). We were interested to see the efficacy and safety of GMA when administered in relation to patients' BW.

Methods: Sixty patients were randomly assigned to the routine GMA (n = 30) and to GMA adjusted to patients' BW, 60 mL/kg (n = 30). GMA was done with the Adacolumn, up to 10 sessions over 10 weeks. At entry and 1 week post last GMA, patients were clinically and endoscopically evaluated. Remission was defined as clinical activity index (CAI) ≤4, whereas mucosal remission was defined as endoscopic index (EI) ≤3.

Results: In the BW group, the processed volume/session was 3,260 ± 581 versus 1,800 mL in the routine group (P < 0.001). In the BW group, 25 of 30 patients (83.3%) achieved remission versus 19 of 30 patients (63.3%) in the routine group. The average CAI in the BW group fell from 9.6 ± 2.6 to 2.3 ± 2.1 versus from 9.1 ± 2.4 to 4.0 ± 2.1 (P < 0.05) in the routine group. Similarly, the EI in the BW group fell from 9.4 ± 1.3 to 2.1 ± 2.1 versus from 9.2 ± 1.8 to 4.5 ± 2.3 (P < 0.01).

Conclusions: GMA adjusted to patients' BW and at a vastly greater processed volume produces significantly higher efficacy as compared with the routine GMA protocol. Further, in this study, up to twofold higher processed volume caused no safety concern.