Granulocyte and monocyte adsorptive apheresis induces apoptosis of neutrophils and release of a novel chemoattractant for desensitization of interleukin-8 response - In vitro and in vivo results.

OBJECTIVE: Apoptotic cells participate in maintenance of homeostasis of the adaptive immune system. Granulocyte/monocyte adsorptive apheresis (GMA) performed with an Adacolumn has been shown to have clinical efficacy together with immunomodulatory effects for immune-mediated disorder cases, such as inflammatory bowel disease (IBD) or psoriatic arthritis. Although induction of apoptosis in neutrophils by GMA has been observed, the detailed mechanism remains unclear. METHODS: To focus on phagocytosis-induced cell death (PICD) that induces apoptotic neutrophils, a comparative study utilizing a GMA-carrier (leukocyte adsorbing carrier for Adacolumn) and yeast particles was performed with in vitro and in vivo examinations. RESULTS: L-selectin was significantly (P = 0.0133) shed, reactive oxygen species (ROS) production was promoted (P = 0.0019), and apoptosis induction was enhanced (P = 0.0087) by peripheral blood co-cultured with the GMA-carrier or yeast particles as compared to incubated blood alone. Furthermore, degranulation of myeloperoxidase, elastase, and lactoferrin was increased by both treatments, while the highest level of interleukin-1 receptor antagonist release was found with GMA-carrier treatment (P = 0.0087) as compared to the yeast particles. Plasma from blood treated with the GMA-carrier showed chemotactic activity, and suppressed neutrophil migration to IL-8 and LTB4. In vivo results demonstrated that neutrophil chemotaxis to IL-8 was desensitized (P = 0.0078) in rabbits following GMA apheresis, while CXCR1 and CXCR2 expressions in neutrophils were reduced by exposing peripheral blood to the GMA-carrier. CONCLUSIONS: GMA may regulate the immune system in patients with an immune-mediated disorder by inducing a biological response of neutrophils with a PICD-like reaction.

Efficacy of Granulocyte and Monocyte Adsorptive Apheresis in Patients With Inflammatory Bowel Disease Showing Lost Response to Infliximab.

BACKGROUND AND AIMS: In inflammatory bowel disease [IBD] patients, antibody-to-infliximab [ATI] generation is responsible for loss of response [LOR] and infusion reaction [IR] to infliximab. An immuno-therapeutic approach is considered an option to overcome LOR. Granulocyte/monocyte adsorptive apheresis [GMA] using an Adacolumn has been shown to have clinical efficacy together with immunomodulatory effects in IBD patients. METHODS: We developed an ATI-CAI assay utilizing a C1q immobilized plate and applied it to measure ATI in patients who were receiving infliximab, including 56 with sustained response, 76 with LOR and six with IR. Furthermore, 14 patients with LOR and two with paradoxical skin reactions who received infliximab + GMA combination therapy were analysed. RESULTS: Fourteen patients with LOR, seven with Crohn's disease and seven with ulcerative colitis, showed significantly improved clinical indices [p = 0.0009], and decreased ATI [p = 0.0171] and interleukin-6 [p = 0.0537] levels at week 8 following initiation of infliximab + GMA therapy. Nine patients who received combination therapy achieved remission, which was maintained to week 24 with infliximab alone. Additionally, cutaneous lesions in two patients with IR were improved. ATI-CAI assay efficiency was not influenced by infliximab concentration during the test. Pre- and post-infliximab infusion ATI levels were not different. Patients with ATI greater than the 0.153 µg/mL cut-off value were likely to experience LOR [odds ratio 3.0]. CONCLUSIONS: Patients who received infliximab + GMA therapy appeared to regain clinical response to infliximab by a decrease in ATI level. Furthermore, the concentration of infliximab in the test did not influence ATI measurement, but was associated with clinical response.

Development of a C1q-immobilized (Cim) assay to measure total antibodies to infliximab and its clinical relevance in patients with inflammatory bowel disease.

OBJECTIVE: Determination of antibodies to infliximab (ATI) is desirable for the management of patients with inflammatory bowel disease (IBD) who receive infliximab. Conventional ligand-binding ATI-assays detect only free-form of ATI, potentially increasing the proportion of patients with undetectable ATI, but with adequate trough infliximab (TRI) level who experience loss of response (LOR) to infliximab. We investigated this assertion using a novel ATI-Cim assay. METHODS: An ATI-Cim assay was developed by utilizing a C1q-immobilized plate, detecting free-form and ATI-infliximab complexes. Plasma ATI in 137 consecutive IBD patients, 56 with sustained clinical response (SCR), 76 with LOR and 5 with infusion reactions was measured. RESULTS: ATI levels reached a plateau following addition of up to 25 µg/mL infliximab to different concentrations of free-form ATI. ATI concentration did not significantly change during infliximab infusion (P = 0.4316). ATI concentration > 0.153 µg/mL was associated with LOR (odds ratio 3.0: 95%, confidence interval 1.5 to 6.1, P = 0.0029). The number of patients with undetectable ATI was higher in SCR than in LOR, 53.6% vs 22.4% (P = 0.0004). Patients with SCR and LOR were divided into 4 subgroups by combined cut-off ATI and TRI values. (A) ATI > 0.153 µg/mL and TRI ≤ 2 µg/mL; (B) ATI > 0.153 µg/mL and TRI > 2 µg/mL; (C) ATI ≤ 0.153 µg/mL and TRI ≤ 2 µg/mL; (D) ATI ≤ 0.153 µg/mL and TRI > 2 µg/mL. The frequency of LOR showed a decreasing trend from subgroup A to D, 80.8%, 64.1%, 55.2% and 36.8%, respectively (P = 0.0003). CONCLUSIONS: The measured ATI level appeared to define the patients' response to infliximab. Combining ATI and trough infliximab levels should help to understand the mechanism of LOR and make therapeutic algorithms.

An open-label prospective randomized multicenter study of intensive versus weekly granulocyte and monocyte apheresis in active crohn's disease.

BACKGROUND: Granulocyte and monocyte adsorptive apheresis (GMA) has shown efficacy in patients with active Crohn's disease (CD). However, with routine weekly therapy, it may take several weeks to achieve remission. This study was performed to assess clinical efficacy and safety of intensive GMA in patients with active CD. METHODS: In an open-label, prospective, randomized multicentre setting, 104 patients with CD activity index (CDAI) of 200 to 450 received intensive GMA, at two sessions per week (n = 55) or one session per week (n = 49). Clinical remission was defined as a CDAI score <150. Patients in each arm could receive up to 10 GMA sessions. However, GMA treatment could be discontinued when CDAI decreased to <150 (clinical remission level). RESULTS: Of the 104 patients, 99 were available for efficacy evaluation as per protocol, 45 in the weekly GMA group, and 54 in the intensive GMA group. Remission was achieved in 16 of 45 patients (35.6 %) in the weekly GMA and in 19 of 54 (35.2 %) in the intensive GMA (NS). Further, the mean time to remission was 35.4 ± 5.3 days in the weekly GMA and 21.7 ± 2.7 days in the intensive GMA (P = 0.0373). Elevated leucocytes and erythrocyte sedimentation rate were significantly improved by intensive GMA, from 8005/µL to 6950/µL (P = 0.0461) and from 54.5 mm/hr to 30.0 mm/hr (P = 0.0059), respectively. In both arms, GMA was well tolerated and was without safety concern. CONCLUSIONS: In this study, with respect to remission rate, intensive GMA was not superior to weekly GMA, but the time to remission was significantly shorter in the former without increasing the incidence of side effects. UMIN registration # 000003666.

Apoptotic cells ameliorate chronic intestinal inflammation by enhancing regulatory B-cell function.

Apoptosis is a programmed physiological death of unwanted cells, and handling of apoptotic cells (ACs) is thought to have profound effects on immune-mediated disorders. However, there is scant information regarding the role of ACs in intestinal inflammation, in which immune homeostasis is a major concern. To investigate this, we injected ACs into a severe combined immunodeficiency adoptive transfer model of chronic colitis in the presence and absence of cotransferred whole B or regulatory B cell (Breg)-depleted B cells. We also injected syngeneic ACs into AKR/N mice as a control and into milk fat globule-epidermal growth factor 8 knockout mice deficient of phagocytic function. Chronic colitis severity was significantly reduced in the AC as opposed to the phosphate-buffered saline group with cotransferred whole B cells. The AC-mediated effect was lost in the absence of B cells or presence of Breg-depleted B cells. In addition, ACs induced splenic B cells to secrete significantly increased levels of interleukin 10 in AKR/N mice but not milk fat globule-epidermal growth factor 8 knockout mice. Apoptotic leukocytes were induced by reactive oxygen species during granulocyte/monocyte apheresis therapy in rabbits and H2O2-induced apoptotic neutrophils ameliorated mice colitis. Our results indicate that ACs are protective only in the presence of B cells and phagocytosis of ACs induced interleukin 10 producing Bregs. Thus, the ameliorative effect seen in this study might have been exerted by AC-induced Bregs through increased production of the immunosuppressive cytokine interleukin 10, whereas an AC-mediated effect may contribute to the anti-inflammatory effect of granulocyte/monocyte apheresis as a novel therapeutic mechanism for inflammatory bowel disease.

Correlation of neutrophil and monocyte derived interleukin-1 receptor antagonist and interleukin-8 with colitis severity in the rabbit.

Activated neutrophils and monocytes produce interleukin (IL)-8, a pro-inflammatory chemokine, but also IL-1 receptor antagonist (IL-1ra), which is an anti-inflammatory cytokine. We were interested to see the profiles of IL-8 and IL-1ra in the colonic tissue and in the peripheral blood leukocytes (PBL) during the development of immune complex induced colitis in rabbits. IL-1ra and IL-8 in PBL were measured in 26 rabbits at time 0 h, 24 h, and 48 h after induction of colitis. The colons were removed at 48 h for measuring myeloperoxidase (MPO), ulcer area, IL-1ra and IL-8. Epithelial damage, crypt abscess formation and leukocyte infiltration of the colonic tissue were major features of this colitis model. During the development of colitis, there was an increase in circulating neutrophils and monocytes (P<0.0001), but not lymphocytes. Likewise, elevated amounts of IL-1ra (P=0.0001) and IL-8 (P=0.0219) production by PBL were observed following induction of colitis. Flow cytometry revealed major source of IL-1ra was monocytes, while the main sources of IL-8 were neutrophils and monocytes. There was correlation between MPO and ulcer area (Rs=0.6327, P<0.0001). At 24 h, PBL from MPOHigh group (n=11) showed increased IL-1ra (P=0.027) and IL-8 (P=0.0128) levels vs MPOLow group (n=15). IL-8 production by PBL showed correlation with tissue MPO (Rs=0.4273, P=0.0295). The colitis in this model was associated with an increase in circulating monocytes and neutrophils, which released increased amounts of IL-8 and IL-1ra. Further, IL-8 and IL-1ra showed correlation with the severity of colitis. These observations should significantly further understandings on the role of neutrophils and monocytes in the immunopathogenesis of ulcerative colitis.

Assessment of rabbit spleen size using ultrasonography.

Assessment of spleen size using the ultrasonography has become a standard practice in human. However, the assessment is not established method in experimental animals. To establish the index to assess the spleen size using ultrasonography, we measured the cross-section image of rabbit spleen during endotoxin shock. The image of the cross-section was appeared as triangle, and the height of the triangular image was defined as the spleen index. This spleen index showed strong correlation with the spleen weight. In conclusion, this method is suitable for observation of changes in rabbit spleen size and may reduce the number of rabbit in the longitudinal studies.

Pilot clinical study of Adacolumn cytapheresis in patients with systemic lupus erythematosus.

The aim of this study is to investigate the clinical effects of cytapheresis using the Adacolumn system (selective removal of circulating monocytes and granulocytes by means of an extracorporeal type column) in patients with active systemic lupus erythematosus (SLE). An open uncontrolled multicenter pilot study was conducted in 18 SLE patients who were showing a SLEDAI score of 8 or more under conventional medication. Patients with lupus nephritis (>class 1, WHO classification) were excluded. Extracorporeal cytapheresis with the Adacolumn system was administered once a week for five consecutive weeks. The efficacy of the treatment was evaluated using the SLEDAI for 10 weeks after the first cytapheresis session. The median SLEDAI decreased from 16 at baseline to six at week 11 (10 weeks after the first apheresis) (p<0.001). Significant improvements in musculoskeletal and dermal systems were observed. Arthritis and alopecia were present in 14 and nine patients at baseline and this number decreased to five and one patients, respectively by week 11. Three mild and one moderate adverse events out of the 42 reported events were judged 'probably related' to the treatment; no serious adverse events were reported. Selective removal of monocytes and granulocytes from the blood in an extracorporeal circulation system was associated with clinical improvement in this small series of patients with SLE. Since this approach seems not to have the disadvantages of pharmacological immunosuppression, further controlled studies of Adacolumn cytapheresis are warranted in SLE.

Leucocytapheresis with Adacolumn enhances HCV-specific proliferative responses in patients infected with hepatitis C virus genotype 1.

The most important aim in controlling virus infections is to destroy infected cells. Impaired cellular immunity in HIV and HCV infection leads to chronic infection. This study examined the effect of cytapheresis on the subsequent response to interferon/ribavirin treatment in patients infected with HCV. Adacolumn cytapheresis was carried out once a day for 5 consecutive days in patients who relapsed or did not respond to previous peginterferon and ribavirin combination treatment (n = 14: relapsers = 3, non-responders = 11). Peginterferon and ribavirin combination treatment was started after cytapheresis. During combination treatment, the proliferative response of peripheral blood mononuclear cells to HCV proteins (core, NS3, NS4, and NS5), tetanus toxoid, and phytohemagglutinin was measured, and compared to the early virological response. After treatment by leucocytapheresis, the proliferative response of peripheral blood mononuclear cells to HCV-core and tetanus toxoid increased significantly over the baseline (P < 0.05). A marked increase in the phytohemagglutinin response was observed after peginterferon and ribavirin combination treatment was started (P < 0.01 at week 5 and P < 0.005 at week 13). There were, however, no clear changes in the proliferative response to other antigens. Among the 14 patients, 12 (85.7%) achieved an early virological response by week 13 (12 weeks after the start of combination treatment). After treatment, nine patients (64.3%) had a significant proliferative response to HCV core antigen. Among the nine patients, eight patients (88.9%) achieved early virological response. The results indicate that activation of cellular immunity by leucocytapheresis facilitates an early virological response rate in HCV patients. This new therapy may, therefore, become an additional therapeutic measure for HCV.

In vitro and in vivo evaluation of Adacolumn cytapheresis in healthy subjects.

Adacolumn is a medical device for adsorptive cytapheresis. It has been developed for selective adsorption of granulocytes and monocytes from peripheral blood of patients with immune disorders, such as autoimmune diseases and chronic inflammatory diseases. A double blind sham-controlled crossover study design was used in order to evaluate in vivo biological responses of leukocytes as well as biocompatibility during and after Adacolumn cytapheresis in healthy volunteers. In addition, experiments were undertaken to further evaluate leukocyte reactions to Adacolumn carrier (G-1: cellulose diacetate) beads in vitro. Six healthy volunteers, 4 males and 2 females, with a mean age of 26.7 years were randomly assigned to one of the two treatment arms in a crossover fashion. Three subjects received a single Adacolumn treatment, followed by a single sham treatment at an interval of 7 days. The other three subjects received the two treatments in reverse order. All subjects were followed up 7 days after the last treatment. Additionally, in vitro investigations were carried out using blood from the healthy donors to examine the effect of G-1 beads on granulocyte functions. In vitro exposure of human peripheral blood to G-1 beads caused downregulation of L-selectin expression and upregulation of Mac-1 expression on granulocytes, leading to a marked reduction of adhesive capacity of granulocytes to endothelial cells. The exposure also led to decreased granulocyte chemotactic activity to IL-8. The number of granulocytes and monocytes clearly decreased during Adacolumn cytapheresis. Granulocytes showed marked phenotypic changes of L-selectin(Low) and Mac-1(Hi) after passing through Adacolumn in vivo. Expression of TNF-alpha and chemokine receptors was downregulated. In addition, TNF-alpha and IL-1beta producing capacity of peripheral blood leukocytes was decreased after Adacolumn cytapheresis and these changes lasted even one week after the cytapheresis. The level of complement fragments, C3a and C5a, increased, while bradykinin concentration did not change during Adacolumn cytapheresis. Exposure of human peripheral blood to G-1 beads, both in vitro and in vivo, caused a significant reduction of adhesive capacity and proinflammatory cytokine producing capacity of peripheral blood leukocytes. Such changes were not observed after sham apheresis. Despite complement activation, tolerability of Adacolum cytapheresis was not influenced. These findings may at least partly explain the beneficial effect of Adacolumn cytapheresis in the treatment of autoimmune diseases.

Relationship between fecal calprotectin, intestinal inflammation, and peripheral blood neutrophils in patients with active ulcerative colitis.

Active ulcerative colitis (UC) is associated with elevated granulocytes and monocytes/macrophages (GM) which show activation behavior and increased survival time. Further, fecal calprotectin (a stable neutrophil protein) level parallels intestinal inflammation and can predict UC relapse. Since GM are major sources of inflammatory cytokines and chemokines, they are suspected to have roles in the initiation and perpetuation of UC. Our objective was to investigated relationships between peripheral blood (PB) neutrophils, calprotectin, and UC disease activity. Full PB and calprotectin were determined in 69 healthy controls and 31 patients with UC, then 7 randomly selected patients received GM adsorptive apheresis (GMA) with Adacolumn, 10 sessions of 60-min duration each. Patients with UC had higher neutrophil counts (P < 0.001), but lower lymphocyte counts (P < 0.001) compared with controls. Further, fecal calprotectin levels showed a correlation with UC clinical activity index (CAI; P < 0.001) and mucosal inflammation (P < 0.001). Following GMA, there were falls in neutrophils (P < 0.02), CAI (P < 0.02) and calprotectin (P < 0.02). In conclusion, GM appear to contribute to intestinal inflammation and UC activity and reduction of these cells by GMA should benefit patients with active UC. Further, the correlations among calprotectin, UC activities, and PB neutrophils should serve as the basis for preemptive actions to control this disease.

Studies on the mechanisms of leukocyte adhesion to cellulose acetate beads: an in vitro model to assess the efficacy of cellulose acetate carrier-based granulocyte and monocyte adsorptive apheresis.

Granulocyte and monocyte adsorptive apheresis (GMA) using a column filled with cellulose acetate (CA) beads (carriers) has been associated with a significant clinical efficacy in patients with rheumatoid arthritis and ulcerative colitis. To obtain further understanding on the mechanisms of disease modification by cellulose acetate-carrier-based GMA, in the present study, we investigated the mechanisms of granulocyte and monocyte adhesion to CA beads following exposure of human peripheral blood to the carriers at 37 degrees C for up to 60 min under controlled conditions. Cellulose acetate beads selectively adsorbed granulocytes, monocytes. CD19+ (B cells) and CD56+ (NK cells) lymphocyte subpopulations. The granulocyte and monocyte adsorption was inhibited by heat-inactivated plasma and EDTA, indicating that the adsorption was plasma protein (immunoglobulin, complement) and calcium dependent. Accordingly, granulocyte and monocyte adsorption was markedly enhanced by coating the carriers with IgG. Similarly, C3b was adsorbed onto the CA beads as a marker of complement activation. The results indicated that IgG and active complement fragments mediated leukocyte adhesion to CA beads via the FcgammaR and/or leukocyte complement receptor like CR3. Additionally, CA beads induced loss of expression of TNF receptors on CD16- granulocytes and CD14+ monocytes, but not on CD3+ lymphocytes In conclusion, CA beads might be an appropriate biomaterial for inducing extracorporeal immunomodulation as a treatment for auto-immune diseases which are associated with pathological leukocyte activity.

Anti-inflammatory effect of granulocyte and monocyte adsorption apheresis in a rabbit model of immune arthritis.

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.

Immunomodulatory effects of granulocyte and monocyte adsorption apheresis as a treatment for patients with ulcerative colitis.

Our aim was to understand the mechanism of immunological changes associated with the use of an adsorptive-type extracorporeal device (Adacolumn) that has been developed for selective adsorption of granulocytes and monocytes/macrophages from peripheral blood of patients with active ulcerative colitis. The column is filled with carriers (G-1 beads) that have a diameter of 2 mm and are made of cellulose diacetate. In peripheral blood treated with the G-1 beads or peripheral blood from patients with active ulcerative colitis following granulocyte and monocyte adsorption apheresis, a significant suppression of proinflammatory cytokines (tissue necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-8) production by leukocytes, neutrophil chemotaxis, down-regulation of leukocyte adhesion molecule (L-selectin) and neutrophil adhesion to interleukin-1beta-activated endothelial cells were observed. Furthermore, after granulocyte adsorption therapy, the number of CD10-negative premature granulocytes increased, indicating increased turnover of these cells in the circulation. Our observations suggest that selective granulocyte and monocyte adsorption is associated with modified peripheral blood leukocyte function favorable to patients with ulcerative colitis and possibly other autoimmune disorders which reflect leukocyte hyperactivity.