Myeloid Lineage Leucocytes Research Articles

P727 Clinical efficacy of apheresis in Ulcerative Colitis. The experience of four tertiary centers

Abstract Background Selective depletion of myeloid lineage leucocytes by adsorptive granulocyte and monocyte apheresis (GMA) with Adacolumn ® was introduced as a nonpharmacologic treatment for ulcerative colitis (UC) in 2000. It has been reported that GMA may be effective in combination with immunosuppressive treatment in a subset of patients. Τhe purpose of our study is the evaluation of the effectiveness and safety of GMA as a complementary treatment in patients with refractory ulcerative colitis. Methods Prospective data collection of a patient cohort with refractory UC receiving Adacolumn ® as an adjunct to their medical treatment. The therapeutic protocol has 2 phases: The induction phase entails two sessions per week for at least 3 weeks. The maintenance includes one weekly session for one month, one session every 15 days for one the next month, and monthly sessions thereafter. The patients’ medical treatment was maintained during the sessions. As a failure to GMA was considered the need for colectomy, the switch to a different treatment and inability to discontinue steroids. Response was evaluated after completion of at least 6 sessions of GMA. Results Ten patients with refractory UC were offered Adacolumn® between February 2021 and September 2023. Mean age was 39.6 years (22-61years). All patients had failed at least one biologic treatment and two-thirds two biologics. Their treatment which was maintained during GMA was: tofacitinib 10mg bid for 4 patients, ustekinumab 90mg sc every 8 weeks for 3, vedolizumab 300 mg every 8 weeks for 2, and corticosteroids 16mg for one. The median duration of treatment was 5.1 months (2-13 months), while the median number of sessions was 16 (6-45). Clinical and endoscopic remission was achieved in two cases (20%), after 13 sessions for both (in brackets in the Table) whereas two patients (20%) responded clinically according to partial Mayo score. Treatment failure was documented for 6 patients (60%) after 6-45 sessions. Patient number 4 performed 45 sessions in different hospitals because he was reluctant to be operated. Three underwent colectomy and three discontinued due to non-response. No adverse effects were observed. The initial median of partial Mayo score was 6 (5-9) while at the end of the evaluation was 4.5 (0-9). Table 1 summarizes the results of our study. Conclusion 1) GMA may be beneficial as an adjunct to biologics in refractory to medical treatment UC patients. 2) Interestingly, all patients on tofacitinib showed a favorable response after the addition of GMA. This observation may help define a subset of UC patients who may benefit the most.

Therapeutic Granulomonocytapheresis as a Non-pharmacologic Treatment Option for Inflammatory Bowel Disease: Efficacy Reports on a Wide Age Range and Disease Profile.

The major phenotypes of inflammatory bowel disease(IBD) include ulcerative colitis (UC) and Crohn's disease (CD), which cause debilitating symptoms, including bloody diarrhea, abdominal discomfort, and fever. Patients require life-long immunosuppressive medications, which cause adverse side effects as additional morbidity factors. However, IBD is initiated and perpetuated by inflammatory cytokines, and given that in patients with IBDmyeloid lineage leukocytes are elevated with activation behaviorand release inflammatory cytokines, selective depletion of elevated granulocytes and monocytes by granulomonocytapheresis is a relevant therapeutic option for IBD patients. Therefore, a column filled with specially designed beads as granulomonocytapheresiscarriers for selective adsorption of myeloid lineage leukocytes (Adacolumn) has been applied to treat patients with active IBD. Patients receive up to 10 granulomonocytapheresis sessions at one or two sessions per week. During each session, the carriers adsorb up to 60% of the myeloid leukocytes from the blood that passes through the granulomonocytapheresis column. Efficacy rates in the UC setting have been as high as 85% in steroid-naïve patients, and 100% in drug-naïve, first-episode cases, but patients with a long duration of active IBD and extensive colonic lesions that have become refractory to pharmacological treatmenthave not responded well. However, granulomonocytapheresis has a favorable safety profile. Given that immunosuppressive medications used to treat IBDpotentially may increase the risk of severe viral infection, non-drug granulomonocytapheresisshould be a favorable treatment strategy. Further, by targeting granulomonocytapheresisto patients with background features and identifying a patient as a likely responder, futile use of medical resources is avoided.

Abstract P3061: A Monoclonal Antibody Blocking Interleukin-1 Receptor Accessory Protein Reduces Acute Viral Myocarditis Severity

IL-1, IL-33 and IL-36 have complementary, pro-inflammatory roles during the immune response that promote autoimmune diseases, particularly myocarditis. While antibodies that neutralize circulating cytokines exist, we hypothesized that blockade of their shared co-receptor, IL-1 receptor accessory protein (IL1RAP), would exhibit a more potent and broader anti-inflammatory profile. The CAN10 antibody blocks IL1RAP and is currently under development for treating severe autoimmune and inflammatory diseases. To investigate if IL1RAP blockade is an effective treatment of cardiac inflammation, we induced autoimmune viral myocarditis in 8-week-old Balb/c male mice with Coxsackievirus B3 and treated them with mCAN10, an anti-mouse IL1RAP monoclonal antibody. Mice were euthanized at day 10, the peak of acute inflammation in the heart. IL1RAP blockade reduced the severity of myocarditis at this timepoint when compared to isotype, saline or IL-1 receptor antagonist (IL1RA) treatment (the gold standard in IL-1 receptor blockade), without affecting viral clearance from the heart. Spectral flow cytometry of heart immune populations revealed that mCAN10 significantly reduced the number of infiltrating leukocytes of broad populations, especially effector CD4 + and CD8 + T cells, inflammatory Ly6C + CCR2 + monocytes, neutrophils and eosinophils. We also observed early echocardiographical parameters suggesting improved heart function, including ejection fraction, fractional shortening and interventricular septum diameter. Interestingly, mCAN10-treated mice demonstrated reduced proliferation of bone marrow precursors of inflammatory myeloid and lymphoid lineage leukocytes. Splenic immune cell populations were not affected, indicating that mCAN10 does not cause global immune suppression in these animals. Altogether, our data show that a single monoclonal antibody targeting three inflammatory cytokine systems, IL-1, IL-33 and IL-36, potently reduces acute viral myocarditis severity in a broader fashion that is not recapitulated by IL-1α/β blockade, and shows translational promise for therapeutics of inflammatory disease. Phase I clinical studies of the CAN10 antibody are in preparation.

Use of granulocyte and monocyte adsorption apheresis in dermatology (Review).

Adsorptive granulocyte and monocyte apheresis (GMA) is an extracorporeal treatment that selectively removes activated myeloid lineage leukocytes from peripheral blood. This technique consists of a column with cellulose acetate beads as absorptive leukocytapheresis carriers, and was initially used to treat ulcerative colitis. A literature search was conducted to extract recently published studies about the clinical efficacy of GMA in patients with different skin disorders, reporting information on demographics, clinical symptoms, treatment and clinical course. Dermatological diseases, in which GMA has been performed, include generalized pustular psoriasis, pyoderma gangrenosum, palmoplantar pustular psoriasis, Behcet's disease, Sweet's syndrome, adult-onset Still's disease, impetigo herpetiformis, reactive arthritis, acne and hidradenitis suppurativa syndrome, cutaneous allergic vasculitis and systemic lupus erythematosus. In most patients, GMA was started after the failure of conventional therapeutic options and it was helpful in the majority of cases. Based on the information summarized, GMA could be considered a valid non-pharmacological treatment option for patients with several dermatological conditions, which are difficult to treat with other pharmacological preparations.

Regulation of Inflammatory Response by Transmembrane Adaptor Protein LST1.

LST1 is a small adaptor protein expressed in leukocytes of myeloid lineage. Due to the binding to protein tyrosine phosphatases SHP1 and SHP2 it was thought to have negative regulatory function in leukocyte signaling. It was also shown to be involved in cytoskeleton regulation and generation of tunneling nanotubes. LST1 gene is located in MHCIII locus close to many immunologically relevant genes. In addition, its expression increases under inflammatory conditions such as viral infection, rheumatoid arthritis and inflammatory bowel disease and its deficiency was shown to result in slightly increased sensitivity to influenza infection in mice. However, little else is known about its role in the immune system homeostasis and immune response. Here we show that similar to humans, LST1 is expressed in mice in the cells of the myeloid lineage. In vivo, its deficiency results in alterations in multiple leukocyte subset abundance in steady state and under inflammatory conditions. Moreover, LST1-deficient mice show significant level of resistance to dextran sodium sulphate (DSS) induced acute colitis, a model of inflammatory bowel disease. These data demonstrate that LST1 regulates leukocyte abundance in lymphoid organs and inflammatory response in the gut.

Adsorptive Granulocyte and Monocyte Apheresis Is Effective in Ulcerative Colitis Patients Both with and without Concomitant Prednisolone

Background: The number of ulcerative colitis (UC) patients is increasing in Japan and other countries. Selective depletion of myeloid lineage leucocytes by adsorptive granulocyte and monocyte apheresis (GMA) with an Adacolumn (JIMRO, Takasaki, Japan) was introduced as a nonpharmacologic treatment strategy in UC patients in 2000. GMA has been reported to be effective in clinical trials; however, the effect of concomitant prednisolone (PSL) on GMA needs to be clarified. Methods: Thirty-nine patients with active UC were treated with GMA at our institute between June 2009 and September 2018. All patients received GMA therapy once or twice a week with the Adacolumn. Conventional medication was to be continued during the whole GMA treatment course. The clinical response was retrospectively evaluated. Results: According to the partial Mayo score, remission was 33.3%, significant efficacy 25.6%, effective 25.6%, and no response 15.4%. The average partial Mayo score was 6.2 ± 1.4 at entry and significantly declined to 1.8 ± 1.8 after GMA sessions (p < 0.0001). The average number of bowel movements was 9.5 ± 5.6 at entry and significantly declined to 3.0 ± 2.8 after GMA sessions (p < 0.0001). In a comparison between the group treated with concomitant PSL and the group without PSL, the change in partial Mayo score or the number of bowel movements from entry to after GMA sessions was not significantly different. Among 24 patients treated by GMA with concomitant PSL, 75% (18/24) became steroid free. Conclusions: The effect of GMA with concomitant PSL and that of GMA without PSL were not different, and GMA was effective irrespective of PSL administration. The present study showed that GMA had efficacy and led many UC patients treated by PSL to be steroid free with no safety concern in the real world, although there is the possibility of recruitment bias due to the retrospective nature of the study.

Granulomonocytapheresis as a cell-dependent treatment option for patients with inflammatory bowel disease: Concepts and clinical features for better therapeutic outcomes.

Ulcerative colitis (UC) and Crohn's disease (CD) are major phenotypes of the chronic inflammatory bowel disease (IBD), which afflicts millions of individuals throughout the world with debilitating symptoms. The chronic nature of IBD means that patients require life-long medications, and this may lead to drug dependency, loss of response together with adverse side effects as additional morbidity factors. The efficacy of antitumour necrosis factor (TNF)-α biologics has validated the role of inflammatory cytokines notably TNF-α in the exacerbation and perpetuation of IBD. However, cytokines are released by myeloid lineage leucocytes like the CD14+ CD16+ monocyte phenotype. Additionally in IBD, myeloid leucocytes are elevated with activation behavior, while lymphocytes are compromised. Therefore, patients' leucocytes appear logical targets of therapy. Adsorptive granulomonocytapheresis (GMA) with an Adacolumn uses carriers, which interact with the Fcγ receptor expressing leucocytes and deplete the elevated myeloid leucocytes, while the neutrophils, which re-enter the circulation via the Adacolumn outflow (≥40%) are phagocytosed by CD19 B-cells to become interleukin (IL)-10 producing Bregs or CD19high CD1Dhigh B-cells. IL-10 is an anti-inflammatory cytokine. GMA has been applied to treat patients with IBD. The efficacy outcomes have been impressive as well as disappointing, the clinical response to GMA defines the patients' disease course and severity at entry. Efficacy outcomes in patients with deep ulcers together with extensive loss of the mucosal tissue are not encouraging, while patients without these features respond well and attain a favorable long-term disease course. Accordingly, for responder patients, GMA fulfills a desire to be treated without drugs.

Clinical and immunological effects of adsorptive myeloid lineage leukocyte apheresis in patients with immune disorders.

Adsorptive granulocyte and monocyte apheresis (GMA) with the Adacolumn® is an extracorporeal treatment, which uses cellulose acetate (CA) beads as adsorptive leukocytapheresis carriers designed to remove elevated and potentially activated myeloid lineage leukocytes. Reports on the clinical efficacy of GMA in patients with skin lesions have appeared in the published work. Dermatological diseases, which are known to respond to GMA, include pyoderma gangrenosum, skin lesions of Behçet's disease, rheumatoid arthritis, pustular psoriasis, psoriatic arthritis, adult-onset Still's disease, Sweet's syndrome, cutaneous allergic vasculitis and systemic lupus erythematosus rashes. In association with clinical studies, efforts to understand the mechanisms of GMA have made significant progress. GMA selectively depletes elevated myeloid lineage leukocytes through binding between blood immunoglobulin G or complement iC3b, which form on the surface of CA beads and the Fcγ receptors or complement receptors expressed on the myeloid lineage cells. However, GMA has immunomodulatory effects including down-modulation of inflammatory cytokine profile, changes in leukocyte surface receptors and induction of regulatory T cells. These actions render GMA a unique non-pharmacological treatment option for patients with chronic dermatoid conditions, which are difficult to treat with pharmacological preparations.

Myeloid Dendritic Cells Repress Human Cytomegalovirus Gene Expression and Spread by Releasing Interferon-Unrelated Soluble Antiviral Factors.

Cytomegalovirus (CMV) is a betaherpesvirus that latently infects most adult humans worldwide and is a major cause of morbidity and mortality in immunocompromised hosts. Latent human CMV (HCMV) is believed to reside in precursors of myeloid-lineage leukocytes and monocytes, which give rise to macrophages and dendritic cells (DC). We report here that human monocyte-derived DC (mo-DC) suppress HCMV infection in coculture with infected fibroblast target cells in a manner dependent on the effector-to-target ratio. Intriguingly, optimal activation of mo-DC was achieved under coculture conditions and not by direct infection with HCMV, implying that mo-DC may recognize unique molecular patterns on, or within, infected fibroblasts. We show that HCMV is controlled by secreted factors that act by priming defenses in target cells rather than by direct viral neutralization, but we excluded a role for interferons (IFNs) in this control. The expression of lytic viral genes in infected cells and the progression of infection were significantly slowed, but this effect was reversible, indicating that the control of infection depended on the transient induction of antiviral effector molecules in target cells. Using immediate early or late-phase reporter HCMVs, we show that soluble factors secreted in the cocultures suppress HCMV replication at both stages of the infection and that their antiviral effects are robust and comparable in numerous batches of mo-DC as well as in primary fibroblasts and stromal cells.IMPORTANCE Human cytomegalovirus is a widespread opportunistic pathogen that can cause severe disease and complications in vulnerable individuals. This includes newborn children, HIV AIDS patients, and transplant recipients. Although the majority of healthy humans carry this virus throughout their lives without symptoms, it is not exactly clear which tissues in the body are the main reservoirs of latent virus infection or how the delicate balance between the virus and the immune system is maintained over an individual's lifetime. Here, for the first time, we provide evidence for a novel mechanism of direct virus control by a subset of human innate immune cells called dendritic cells, which are regarded as a major site of virus latency and reactivation. Our findings may have important implications in HCMV disease prevention as well as in development of novel therapeutic approaches.

Toll-Like Receptor 4 on both Myeloid Cells and Dendritic Cells Is Required for Systemic Inflammation and Organ Damage after Hemorrhagic Shock with Tissue Trauma in Mice.

Trauma combined with hemorrhagic shock (HS/T) leads to systemic inflammation, which results in organ injury. Toll-like Receptor 4 (TLR4)-signaling activation contributes to the initiation of inflammatory pathways following HS/T but its cell-specific roles in this setting are not known. We assessed the importance of TLR4 on leukocytes of myeloid lineage and dendritic cells (DCs) to the early systemic inflammatory response following HS/T. Mice were subjected to HS/T and 20 inflammatory mediators were measured in plasma followed by Dynamic Bayesian Network (DBN) Analysis. Organ damage was assessed by histology and plasma ALT levels. The role of TLR4 was determined using TLR4−/−, MyD88−/−, and Trif−/− C57BL/6 (B6) mice, and by in vivo administration of a TLR4-specific neutralizing monoclonal antibody (mAb). The contribution of TLR4 expressed by myeloid leukocytes and DC was determined by generating cell-specific TLR4−/− B6 mice, including Lyz-Cre × TLR4loxP/loxP, and CD11c-Cre × TLR4loxP/loxP B6 mice. Adoptive transfer of bone marrow-derived TLR4+/+ or TLR4−/− DC into TLR4−/− mice confirmed the contribution of TLR4 on DC to the systemic inflammatory response after HS/T. Using both global knockout mice and the TLR4-blocking mAb 1A6 we established a central role for TLR4 in driving systemic inflammation. Using cell-selective TLR4−/− B6 mice, we found that TLR4 expression on both myeloid cells and CD11chigh DC is required for increases in systemic cytokine levels and organ damage after HS/T. We confirmed the capacity of TLR4 on CD11chigh DC to promote inflammation and liver damage using adoptive transfer of TLR4+/+ conventional (CD11chigh) DC into TLR4−/− mice. DBN inference identified CXC chemokines as proximal drivers of dynamic changes in the circulating levels of cytokines/chemokines after HS/T. TLR4 on DC was found to contribute selectively to the elevations in these proximal drivers. TLR4 on both myeloid cells and conventional DC is required for the initial systemic inflammation and organ damage in a mouse model of HS/T. This includes a role for TLR4 on DC in promoting increases in the early inflammatory networks identified in HS/T. These data establish DC along with macrophages as essential to the recognition of tissue damage and stress following tissue trauma with HS.

Adsorptive Depletion of Myeloid Lineage Leucocytes as Remission Induction Therapy in Patients with Ulcerative Colitis after Failure of First-Line Medications: Results from a Three-Year Real World, Clinical Practice

Background/Aims: In patients with active ulcerative colitis (UC), pharmacologics, although initially effective in most patients, are associated with refractoriness, loss of response or unfavourable side effects as additional morbidity factors. Depletion of myeloid lineage leucocytes like the CD14(+)CD16(+) monocyte phenotype, which is a major source of tumour necrosis factor-α, by granulocyte/monocyte apheresis (GMA) if effective, is also known to be free from side effects. Methods: In clinical practice setting, 77 consecutive patients with moderate to severe UC, who failed to respond to first-line medications received GMA with the Adacolumn as remission induction therapy. Patients who achieved remission were followed for 3 years. Results: Among the 77 patients, 46.8% were corticosteroids-naïve, 26% corticosteroid-dependent and 27.3% corticosteroid-refractory. The overall clinical remission rate was 79.2%, and the overall mucosal healing (MH) rate according to the Mayo endoscopic subscore ≤1 was 58.5%. MH rates in corticosteroid-naïve, corticosteroid-dependent and corticosteroid-refractory subgroups were 70.8, 56.3, and 38.5%, respectively. The 3-year sustained clinical remission rates in corticosteroid-naïve, corticosteroid-dependent and corticosteroid-refractory subgroups were 83.3, 68.8, and 23.1%, respectively. Conclusion: Corticosteroid-naïve patients appeared to benefit the most from the Adacolumn GMA, and attain a favourable long-term clinical course. Accordingly, GMA should be a first-line therapy in this clinical setting.

Immunological Mechanisms of Adsorptive Cytapheresis in Inflammatory Bowel Disease.

Ulcerative colitis and Crohn's disease are the two main forms of inflammatory bowel disease (IBD). The study of immunological pathways involved in the onset of IBD is of fundamental importance to identify potential biological markers of disease activity and specific targets for therapy. Removing excess and activated circulating leukocytes with adsorptive cytapheresis has been shown to be a potentially effective treatment for patients with an inflamed bowel. Adsorptive cytapheresis is a non-pharmacological approach for active IBD, in which known sources of inflammatory cytokines such as activated myeloid lineage leucocytes are selectively depleted from the circulatory system. The decrease in inflammatory load caused by removing these cells is thought to enhance drug therapy and thereby promote disease remission. The benefit of cytapheresis appears to rest upon its ability to reduce levels of certain immune cell populations; however, whether this depletion results in further changes in lymphocyte populations and cytokine production needs further clarification. In this review, we aim to summarize existing evidence on the role of cytapheresis in patients with IBD, its effect on cytokine levels and cellular populations, and to discuss its potential impact on disease activity.

P565 Assessments of clinical efficacy and mucosal healing in ulcerative colitis patients undergoing granulomonocytapheresis at different treatment frequencies

Background: Patients with active ulcerative colitis (UC) are known to have elevated myeloid lineage leucocytes including the CD14+CD16+ monocyte phenotype known to release tumour necrosis factor-α. Accordingly granulomonocytapheresis (GMA) with an Adacolumn has been applied to deplete inflammatory cytokine releasing leucocytes as a remission induction therapy. In general, patients who respond well continue responding and favour GMA over pharmacologics. However, published data indicate that patients with extensive deep ulcers and loss of the mucosal tissue at the affected sites may not respond well to GMA, while steroid naïve patients respond well. We have focused on GMA frequency and long term efficacy as supported by endoscopic findings. Methods: In a retrospective setting, and with interest on long term mucosal healing, we assessed the efficacy of the Adacolumn GMA in patients with active UC treated at different GMA frequencies in the past 10 years. In our data base, we found 99 corticosteroid naive patients who had received GMA at one session per week (n=18, group 1), at 2 to 4 sessions per week (n=31, group 2) or daily (intensive) GMA (n=50, group 3). Each patient could have received up to 11 GMA sessions. Initial efficacy evaluations were undertaken within 10 days following the last GMA session. Clinical activity index (CAI) ≤4 meant remission, while Mayo 0 or 1 meant mucosal healing. The included patients had been followed for ≥12 months on maintenance mesalamine. Results: The average baseline CAI in groups 1 to 3 were 7.9, 7.8, and 8.4, respectively; the number of GMA sessions were 9.1, 9.7 and 10.1 sessions, respectively; the GMA treatment periods were 55.1, 26.5 and 15.5 days, respectively. The mean CAI after the conclusion of GMA treatment courses were 2.5±2.7, 3.4±3.1 and 3.5±2.7, respectively. The rates of mucosal healing were 76.9%, 60.% and 61.8%, respectively. At 12 months, 40.0% in group 1, 57.1% in group 2 and 61.9% in group 3 had maintained mucosal healing. No GMA related serious adverse event was observed. Conclusions: This efficacy evaluation undertaking in steroid naïve patients with active UC showed that for an equal number of GMA sessions, the clinical efficacy was not significantly affected by the frequency of GMA sessions, but the time to remission and the rate of mucosal healing at 12 months were significantly better for intensive GMA. However, the efficacy outcomes in our 99 patients are higher than reported for GMA in patients with severe UC refractory to the current pharmacologicals, reflecting the fact that GMA is more effective in steroid naïve patients who have mild or moderately active UC, but not so effective in patients with severe UC in whom drug therapy has failed.

Factors associated with treatment outcome, and long-term prognosis of patients with ulcerative colitis undergoing selective depletion of myeloid lineage leucocytes: a prospective multicenter study

BackgroundPatients with ulcerative colitis (UC) have elevated/activated myeloid lineage leucocytes and may respond favorably to adsorptive granulocyte/monocyte apheresis (GMA). However, there are patients who respond well to GMA, and patients who do not benefit. Therefore, predictive factors of GMA efficacy need to be defined. MethodsIn a prospective multicenter setting, 200 UC patients at 32 institutes received one GMA session per week over 10 weeks. Patients who achieved remission were followed for 12 months. The Clinical Activity Index (CAI) ≤3 meant remission, and response meant CAI decreased by ≥3. Quality of life was evaluated by the Inflammatory Bowel Disease Questionnaire (IBDQ). ResultsAfter final GMA, remission, response and no response rates were 67.0%, 15.0% and 18%, respectively. The remission group had a significant decrease in myeloid leucocytes and platelets. Corticosteroid dose decreased (P < 0.001); 49 of 97 patients on corticosteroids became steroid-free. Baseline CAI was lower in the remission group versus non-remission (P < 0.01), whereas IBDQ was higher in the remission group versus non-remission (P < 0.05). After 12 months, 52 of 134 patients had maintained remission. Disease duration was longer in the relapsed group versus maintained remission group (P = 0.041). Male gender, first UC episode and corticosteroid responder were significant factors for maintaining remission, whereas corticosteroid dependent UC was associating with relapse. DiscussionSelective myeloid leucocyte depletion was effective for remission induction and improving patients' quality of life. Baseline demographics such as disease activity level, duration and corticosteroid dependency appear to predict response to GMA. Additionally, patients with a first UC episode who were drug naive responded well to GMA and achieved a favorable long-term disease course by avoiding pharmacologics from an early stage of their inflammatory bowel disease. These findings should help to end unnecessary use of medical resources by targeting GMA to patients who may respond well.

ST3Gal-4 is the primary sialyltransferase regulating the synthesis of E-, P-, and L-selectin ligands on human myeloid leukocytes

AbstractThe precise glycosyltransferase enzymes that mediate selectin-ligand biosynthesis in human leukocytes are unknown. This knowledge is important because selectin-mediated cell tethering and rolling is a critical component of both normal immune response and various vascular disorders. We evaluated the role of 3 α(2,3)sialyltransferases, ST3Gal-3, -4, and -6, which act on the type II N-Acetyllactosamine structure (Galβ1,4GlcNAc) to create sialyl Lewis-X (sLeX) and related sialofucosylated glycans on human leukocytes of myeloid lineage. These genes were either silenced using lentiviral short hairpin RNA (shRNA) or functionally ablated using the clustered regularly interspaced short palindromic repeat/Cas9 technology. The results show that ST3Gal-4, but not ST3Gal-3 or -6, is the major sialyltransferase regulating the biosynthesis of E-, P-, and L-selectin ligands in humans. Reduction in ST3Gal-4 activity lowered cell-surface HECA-452 epitope expression by 75% to 95%. Glycomics profiling of knockouts demonstrate an almost complete loss of the sLeX epitope on both leukocyte N- and O-glycans. In cell-adhesion studies, ST3Gal-4 knockdown/knockout cells displayed 90% to 100% reduction in tethering and rolling density on all selectins. ST3Gal-4 silencing in neutrophils derived from human CD34+ hematopoietic stem cells also resulted in 80% to 90% reduction in cell adhesion to all selectins. Overall, a single sialyltransferase regulates selectin-ligand biosynthesis in human leukocytes, unlike mice where multiple enzymes contribute to this function.

Crohn's disease complicated by hepatitis B virus successfully treated with the use of adsorptive depletion of myeloid lineage leucocytes to suppress inflammatory cytokine profile

Background aimsIn patients with inflammatory bowel disease infected with hepatitis B virus (HBV), immunosuppressive therapy required to suppress active inflammatory bowel disease may promote HBV reactivation. MethodsA 27-year-old corticosteroid-naive woman with Crohn's disease (CD) activity index of 249.8 complicated by HBV infection was offered Entecavir to control HBV reactivation during immunosuppressive therapy for CD. The patient refused Entecavir, fearing that it might adversely affect her pregnancy outcome. Instead, we applied intensive granulocyte/monocyte adsorptive apheresis (GMA) at two sessions per week to deplete inflammatory cytokine-producing leucocytes as an immunosuppressive therapy in this case. ResultsGMA induced stable remission (CD activity index, I 105) and endoscopic improvement without HBV reactivation or safety concern. Furthermore, CD remission was paralleled by suppression of tumor necrosis factor and interleukin as measured in serum samples. ConclusionsImmunosuppressive therapy required to treat an active CD potentially can promote HBV reactivation and worsen liver function. In this study involving a CD case complicated by chronic HBV infection, intensive GMA as a non-pharmacologic treatment intervention was associated with clinical remission and endoscopic improvement without HBV reactivation. Furthermore, GMA was well-tolerated and was without any safety concern. However, suppression of tumor necrosis and interleukin-6by GMA in this clinical setting is potentially very interesting.

P318 Therapeutic depletion of myeloid lineage leucocytes in patients with ulcerative colitis: Demographic features of responders and non-responders to this non-pharmacological treatment option

P318 Therapeutic depletion of myeloid lineage leucocytes in patients with ulcerative colitis: Demographic features of responders and non-responders to this non-pharmacological treatment option

P308 Treatment of corticosteroid naive children and adolescents with ulcerative colitis by adsorptive depletion of myeloid lineage leucocytes as monotherapy or in combination with low dose prednisolone after failure of first-line medications

Results: 201 patients recruited by 19 Spanish gastroenterologists were included. 55.7% were male and mean (SD) age was 38.9 (12.3) years. The mean (SD) disease duration was 8.6 (8.1) years. Most of the patients had disease in the terminal ileum (L1: 42.3%), with a non-structuring, non-penetrating behaviour (B1: 54.7%). Perianal disease was present in 41 (20.4%) patients. 102 patients (50.7%) were in clinical remission. Scenarios E and F were the most preferred (57.3% and 53.7% respectively). The least preferred was scenario A (19.9%). Treatment administered by healthcare personnel (0.155), treatment administered at home (0.485) and subcutaneous treatments (0.053) were considered as the most useful. These scores indicate the value of each characteristic has been perceived by patients [from 1 (high) to 0 (low)]. And the result of the most influence factor when choosing a CD therapy is the place where the treatment is administered with an importance of 50.7%. Conclusions: A validated questionnaire to evaluate patient’s preferences has been applied to CD patients, enabling involvement of the patient in treatment making decisions, which could have the benefit of improving adherence and effectiveness. The results demonstrated that treatment administered at home had the greatest impact on preferences.

Treating inflammatory bowel disease by adsorptive leucocytapheresis: a desire to treat without drugs.

Ulcerative colitis and Crohn's disease are the major phenotypes of the idiopathic inflammatory bowel disease (IBD), which afflicts millions of individuals throughout the world with debilitating symptoms, impairing function and quality of life. Current medications are aimed at reducing the symptoms or suppressing exacerbations. However, patients require life-long medications, and this can lead to drug dependency, loss of response together with adverse side effects. Indeed, drug side effects become additional morbidity factor in many patients on long-term medications. Nonetheless, the efficacy of anti-tumour necrosis factors (TNF)-α biologics has validated the role of inflammatory cytokines notably TNF-α in the exacerbation of IBD. However, inflammatory cytokines are released by patients' own cellular elements including myeloid lineage leucocytes, which in patients with IBD are elevated with activation behaviour and prolonged survival. Accordingly, these leucocytes appear logical targets of therapy and can be depleted by adsorptive granulocyte/monocyte apheresis (GMA) with an Adacolumn. Based on this background, recently GMA has been applied to treat patients with IBD in Japan and in the European Union countries. Efficacy rates have been impressive as well as disappointing. In fact the clinical response to GMA seems to define the patients' disease course, response to medications, duration of active disease, and severity at entry. The best responders have been first episode cases (up to 100%) followed by steroid naïve and patients with a short duration of active disease prior to GMA. Patients with deep ulcers together with extensive loss of the mucosal tissue and cases with a long duration of IBD refractory to existing medications are not likely to benefit from GMA. It is clinically interesting that patients who respond to GMA have a good long-term disease course by avoiding drugs including corticosteroids in the early stage of their IBD. Additionally, GMA is very much favoured by patients for its good safety profile. GMA in 21st century reminds us of phlebotomy as a major medical practice at the time of Hippocrates. However, in patients with IBD, there is a scope for removing from the body the sources of pro-inflammatory cytokines and achieve disease remission. The bottom line is that by introducing GMA at an early stage following the onset of IBD or before patients develop extensive mucosal damage and become refractory to medications, many patients should respond to GMA and avoid pharmacologics. This should fulfill the desire to treat without drugs.

Treatment of children and adolescents with ulcerative colitis by adsorptive depletion of myeloid lineage leucocytes as monotherapy or in combination with low dose prednisolone after failure of first-line medications

BackgroundCurrently available drugs for the treatment of ulcerative colitis (UC) include salicylates, thiopurines, corticosteroids and new anti-tumour necrosis factor (TNF)-α biologics. Among these medications, corticosteroids in children and adolescents may adversely affect the patients’ growth and development. Further, UC patients have elevated and activated myeloid lineage leucocytes including the CD14 + CD16+ monocytes, which release TNF-α as a significant exacerbating factor. Accordingly, depletion of these cells by granulocyte/monocyte adsorption (GMA) should alleviate inflammation and promote UC remission. The objective of this study was to evaluate the efficacy of GMA in children and adolescents in whom conventional first-line medications had failed to induce remission.MethodsIn a single centre setting, between 2007 and 2012, a total of 24 consecutive children and adolescents, age 11–19 years were given mesalazine or sulphasalazine as a first-line medication. Seventeen patients relapsed or did not respond to the first-line medications, and received GMA with the Adacolumn, 2 sessions in the first week, and then weekly, up to 11 sessions. Patients who achieved a decrease of ≥5 in the clinical activity index (CAI) were to continue with GMA, while non-responders were to receive 0.5 to 1.0 mg/kg/day prednisolone (PSL) plus additional GMA sessions similar to GMA responder cases. At entry and week 12, patients were clinically and endoscopically evaluated, allowing each patient to serve as her/his own control.ResultsSeven patients achieved remission with the first-line medications and did not receive GMA. Five patients did not respond to the first 5 GMA sessions and received PSL plus GMA, while 12 patients responded to the first 5 GMA sessions and received additional sessions. At entry, the average CAI was 12.7 ± 2.5, range 8–17, and the average endoscopic index was 8.5 ± 1.5, range 7–11. The corresponding values at week 12 were 2.1 ± 0.2, range 1–4 (P < 0.001) and 2.4 ± 0.2, range 1–4 (P < 0.001). PSL was tapered to 0 mg within 3 months.ConclusionsWith the strategy we applied in this study, all 24 consecutive patients achieved remission. In growing patients with active UC refractory to first-line medications, GMA was associated with clinical remission and mucosal healing, while in non-responders to GMA monotherapy, addition of a low dose PSL enhanced the efficacy of GMA and tapering of the PSL dose soon after remission was not associated with UC relapse. Therefore, the majority of young corticosteroid naive UC patients in whom first-line salicylates have failed may respond to GMA and be spared from additional drug therapy. Avoiding corticosteroids at an early stage of UC should ensure better long-term clinical course.