Complement activation is involved in biological responses to leukocyte adsorptive apheresis

Macrophage differentiation and polarization on a decellularized pericardial biomaterial

The monocyte-derived macrophage (MDM), present at biomaterial implantations, can increase, decrease or redirect the inflammatory and subsequent wound healing process associated with the presence of a biomaterial. Understanding MDM responses to biomaterials is important for improved prediction and design of biomaterials for tissue engineering. This study analyzed the direct differentiation of monocytes on intact, native collagen. Human monocytes were differentiated on decellularized bovine pericardium (DBP), polydimethylsiloxane (PDMS) or polystyrene (TCPS) for 14 d. MDMs on all surfaces released high amounts of MMP-9 compared to MMP-2 and relatively little MMP-1. MDMs differentiated on DBP released more MMP-2, but less acid phosphatase activity. MDMs on all three surfaces released low amounts of cytokines, although substrate differences were found: MDMs on DBP released higher amounts of IL-6, IL-8, and MCP-1 but lower amounts of IL-10 and IL-1ra. This research provides evidence that MDMs on decellularized matrices may not be stimulated towards an activated, inflammatory phenotype, supporting the potential of decellularized matrices for tissue engineering. This study also demonstrated that the differentiation surface affects MDM phenotype and therefore study design of macrophage interactions with biomaterials should scrutinize the specific macrophage culture method utilized and its effects on macrophage phenotype.

Treating ulcerative colitis by Adacolumn therapeutic leucocytapheresis: clinical efficacy and safety based on surveillance of 656 patients in 53 centres in Japan

BACKGROUND/AIM

The Adacolumn selectively depletes granulocytes and monocytes/macrophages, which are thought to be part of the immunopathogenesis of ulcerative colitis. This work aims at evaluating the safety and clinical efficacy of the Adacolumn in patients with ulcerative colitis in large population-based data sets.

METHODS

The Adacolumn post marketing surveillance in Japan was undertaken on 697 patients in 53 medical institutions over 7 years from 29 October 1999 to 28 October 2006. Clinical efficacy and safety data were provided by patients' physicians in the participating institutes.

RESULTS

Safety was evaluated in all the 697 patients and efficacy in 656 patients. At entry, 92% of the patients were on salicylates, 74% on prednisolone and only 9% on immunomodulators. Approximately 40% of patients had severe ulcerative colitis and over 70% had ulcerative colitis that was refractory to conventional medications. There was no serious adverse events; mild to moderate adverse events were seen in 7.7% of the patients. The overall response (remission or significantly improved) was 77.3%; the remission rate based on clinical activity index was 71.1%, while 17.1% remained unchanged and 5.6% worsened. Patients were subgrouped into severe, moderate and mild ulcerative colitis based on clinical activity index (n=578), the response rates were 63.2%, 65.7% and 80.4%, respectively (P<0.001). Endoscopic assessment of efficacy showed very significant mucosal healing, Matts' endoscopic index improved from 3.2+/-0.04 to 2.1+/-0.7 (n=219, P<0.001); reduction in prednisolone dose (P<0.0001); leucocyte count (n=358, P<0.0001) and C-reactive protein (n=314, P<0.0001). Patients who received > or =6 Adacolumn sessions (n=319) did better than patients who received < or =5 sessions (n=188, P=0.004) and multivariate logistic regression analysis revealed that baseline granulocyte count was the strongest predictor of clinical response to Adacolumn (P=0.0191, odds ratio 1.151).

CONCLUSION

This post marketing surveillance provides the largest ever efficacy and safety data on the Adacolumn therapeutic leucocytapheresis in patients with ulcerative colitis. As a non-pharmacologic treatment for patients with active ulcerative colitis most of whom were refractory to conventional drug therapy, the observed efficacy was very significant. Baseline granulocyte count was convincingly an independent predictor of clinical response.