Molecular fingerprints of neutrophil-dependent oxidative stress in inflammatory bowel disease
Neutrophil accumulation within epithelial crypts and in the intestinal mucosa directly correlates with clinical disease activity and epithelial injury in inflammatory bowel disease (IBD). Current advances have defined the mechanisms by which neutrophils are activated or migrate across endothelial and mucosal epithelial cells. A better understanding of this process will likely provide new insights into novel treatment strategies for IBD. Especially, activated neutrophils produce reactive oxygen and nitrogen species and myeloperoxidase within intestinal mucosa, which induce oxidative stress. Posttranslational modification of proteins generated by these reactive species serves as a “molecular fingerprint” of protein modification by lipid peroxidation-, nitric oxide-, and myeloperoxidase-derived oxidants. Measurement of these modified proteins may serve both as a quantitative index of oxidative stress and an important new biological marker of clinical relevance to IBD. We have succeeded in the clinical development of a novel granulocyte adsorptive apheresis therapy for IBD. In this review, we discuss current advances in defining the role of neutrophil-dependent oxidative stress in IBD.
Granulocyte and monocyte adsorption apheresis (GCAP) for refractory skin diseases caused by activated neutrophils and psoriatic arthritis: evidence that GCAP removes Mac-1-expressing neutrophils
In the present study, we have shown that granulocyte and monocyte adsorption apheresis (GCAP), an extracorporeal apheresis instrument whose column contains cellulose acetate (CA) beads, is useful for skin diseases attributable to activated granulocytes and psoriatic arthritis (PsA). We assessed the clinical effectiveness of GCAP and investigated the mechanisms underlying the adsorption of pathogenic granulocytes. The effect of GCAP was assessed in 14 patients with neutrophilic dermatoses and 16 with PsA. The mechanisms by which the instrument adsorbs activated granulocytes were investigated using an in vitro mini-column system that mimics the GCAP. Skin lesions and arthropathy improved in 22 of 29 patients (75.9%) and 14 of 18 (77.8%), respectively. Mac-1 (CD11b/CD18) expression on the peripheral neutrophils, increased compared with normal subjects, was reduced by GCAP. In the mini-column system, CA beads adsorbed 50% neutrophils; and adsorption was inhibited significantly by treating plasma with EDTA and blood cells with antihuman CD11b monoclonal antibody. GCAP was useful for treating neutrophilic dermatoses and PsA. GCAP adsorbs Mac-1-expressing neutrophils to the CA beads by the binding of complement component (iC3b) on CA beads and CD11b expressed on activated neutrophils.
Granulocyte and monocyte adsorption apheresis for cutaneous allergic vasculitis
Cutaneous allergic vasculitis (CAV) is characterized clinically by purpuric patches with secondary ulcerations, and histologically by leukocytoclastic vasculitis with neutrophil infiltrates. Granulocyte and monocyte adsorption apheresis (GCAP) is an extracorporeal apheresis instrument using a column containing cellulose acetate beads designed to remove pathogenic granulocytes. Here we report our assessment of the efficacy of GCAP for recurrent leg ulcers in a 49-year-old woman with CAV. She underwent five GCAP treatments at one-week intervals. In each treatment session, 1800 mL of blood was processed. Her leg ulcers responded well and her white blood cell and neutrophil counts and the expression level of CD11b/CD18, a marker for activated neutrophils, on her peripheral neutrophils were reduced from 7500/microL to 6500/microL, 4350/microL to 3315/microL, and 64.9 MFI (mean fluorescence intensity) to 27.0 MFI (normal controls: 10.5 +/- 1.2 MFI) by GCAP, respectively. These results suggest that GCAP is useful for skin disorders with leucocytoclastic vasculitis.
Anti-inflammatory effect of granulocyte and monocyte adsorption apheresis in a rabbit model of immune arthritis
Inflammation 2002 Aug;26(4):199-205. doi: 10.1023/a:1016523914161.
In active rheumatoid arthritis, large numbers of granulocytes and macrophages are found in the inflamed joints. These leucocytes can promote inflammation and tissue injury by releasing inflammatory cytokines, proteinases and oxygen derivatives. To see if granulocyte and monocyte (GM) depletion produces anti-inflammatory effect, GM adsorption apheresis was performed in rabbits with immune arthritis by using a column (Adacolumn) filled with cellulose diacetate beads (G-1 beads) as adsorptive carriers which selectively adsorb CD11b positive GMs. Injection of ovalbumin into the knee joints of ovalbumin-sensitized rabbits caused a marked increase in peripheral blood leucocytes, joint swelling, increased granulocyte adhesion to G-1 beads and elevated TNF-alpha production by peripheral blood mononuclear cells (PBMC). When rabbits received a 60 min adsorption apheresis, there was suppression of CD11b positive leucocyte infiltration into the joint and reduced joint swelling (P < 0.01) compared with controls. Additionally, there was a significant (p < 0.01) suppression of TNF-alpha production by PBMC in the post column blood. These results suggest that GM depletion may serve as a non-pharmacological strategy to modify inflammatory disorders.
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