Relevance of the Processed Blood Volume per Granulocyte and Monocyte Apheresis Session to its Clinical Efficacy in Patients With Ulcerative Colitis

Granulocyte/monocyte adsorption (GMA) has been introduced as an adjunct intervention for active ulcerative colitis (UC) patients. The processed blood volume (PV) per GMA session is an important factor for its efficacy because depletion of elevated/activated myeloid leukocytes is its main action. Hitherto, this aspect of GMA has been largely ignored. Thirty‐three patients were enrolled for remission induction therapy with five weekly GMA sessions at a standard PV of 1800 mL, regardless of patients' bodyweight (BW). The patients were divided into three groups: high (H)BW (≥65 kg, n = 11), 50 kg ≤ medium (M)BW