Clinical Features and Management of Acute and Chronic Radiation-Induced Colitis and Proctopathy.

BACKGROUND: RICAP is a recognized adverse effect of radiation therapy (RT) that can adversely affect cancer patients' quality of life. Data on the clinical characteristics and outcomes of RICAP are scarce. We aimed to analyze the clinical and endoscopic characteristics of acute or chronic radiation-induced colitis and proctopathy (ARICAP and CRICAP) based on symptom onset after RT (≤ or >45 days, respectively). METHODS: This is a retrospective observational study of a single tertiary cancer center, from January 2010 and December 2018, of cancer patients with endoscopically confirmed ARICAP and CRICAP. We conducted univariate and multivariate logistic regression analyses to associate clinical variables with endoscopic and medical outcomes. RESULTS: One hundred and twelve patients were included (84% Caucasian; 55% female; median age of 59 years); 46% had ARICAP with non-bloody diarrhea as the predominant symptom, whereas 55% had CRICAP with mostly bloody diarrhea. Neovascularization was the most frequent finding on endoscopy, followed by bleeding. ARICAP patients more often received medical management (p < 0.001), whereas CRICAP patients with bleeding more often received argon plasma coagulation (APC) (p = 0.002). Female sex and undergoing less-intense RT treatments were more associated with medical treatment; bleeding clinically and during the endoscopy was more associated with APC treatment. However, APC treatment did not significantly reduce bleeding recurrence or RICAP symptoms. CONCLUSION: Patients with ARICAP and CRICAP experience different symptoms. Medical management should be considered before endoscopic therapy. APC may be useful in patients with endoscopically apparent bleeding.

Efficacy and safety of vedolizumab and infliximab treatment for immune-mediated diarrhea and colitis in patients with cancer: a two-center observational study.

BACKGROUND: Current treatment guidelines for immune-mediated diarrhea and colitis (IMDC) recommend steroids as first-line therapy, followed by selective immunosuppressive therapy (SIT) (infliximab or vedolizumab) for refractory cases. We aimed to compare the efficacy of these two SITs and their impact on cancer outcomes. METHODS: We performed a two-center, retrospective observational cohort study of patients with IMDC who received SITs following steroids from 2016 to 2020. Patients' demographic, clinical, and overall survival data were collected and analyzed. RESULTS: A total of 184 patients (62 vedolizumab, 94 infliximab, 28 combined sequentially) were included. The efficacy of achieving clinical remission of IMDC was similar (89% vs 88%, p=0.79) between the two groups. Compared with the infliximab group, the vedolizumab group had a shorter steroid exposure (35 vs 50 days, p<0.001), fewer hospitalizations (16% vs 28%, p=0.005), and a shorter hospital stay (median 10.5 vs 13.5 days, p=0.043), but a longer time to clinical response (17.5 vs 13 days, p=0.012). Longer durations of immune checkpoint inhibitors treatment (OR 1.01, p=0.004) and steroid use (OR 1.02, p=0.043), and infliximab use alone (OR 2.51, p=0.039) were associated with higher IMDC recurrence. Furthermore, ≥3 doses of SIT (p=0.011), and fewer steroid tapering attempts (p=0.012) were associated with favorable overall survival. CONCLUSIONS: Treatment with vedolizumab as compared with infliximab for IMDC led to comparable IMDC response rates, shorter duration of steroid use, fewer hospitalizations, and lower IMDC recurrence, though with slightly longer time to IMDC response. Higher number of SIT doses was associated with better survival outcome, while more steroid exposure resulted in worse patient outcomes.

Clinicopathologic Features, Treatment Response, and Outcomes of Immune Checkpoint Inhibitor-Related Esophagitis.

BACKGROUND: Although immune checkpoint inhibitors (ICIs) have provided practice-changing outcomes in treating many cancers, ICI-related gastrointestinal toxicity can limit their use. Upper gastrointestinal toxicity is not common nor as well described as lower gastrointestinal toxicity. We aimed to characterize the clinical presentation, endoscopic and histologic features, treatment response, and outcomes of ICI-related esophagitis. METHODS: We retrospectively studied patients at The University of Texas MD Anderson Cancer Center in whom esophagitis developed after receiving ICIs from June 2011 through January 2020. We included patients with endoscopic evidence of esophagitis and excluded those with other obvious causes of esophagitis. A chi-square test was used to assess associations between categorical variables. The Mann-Whitney U test was used to compare differences between continuous variables. RESULTS: Of 657 consecutive patients who underwent esophagogastroduodenoscopy (EGD) during or within 6 months of completing ICI-based therapy, 21 (3%) had esophagitis deemed to be from ICIs. Of these patients, 1 (5%) received an inhibitor of CTLA-4 alone, 15 (71%) received anti-PD-1 or PD-L1 monotherapy, and 5 (24%) received a combination of these. Median time from ICI initiation to onset of esophagitis was 4 months. Upon evaluation with EGD, only 3 patients (14%) had isolated esophageal involvement; 18 (86%) had concurrent involvement of the stomach, duodenum, or both. Most patients (67%) were treated with proton pump inhibitors, and 4 (19%) received steroids (prednisone or budesonide). The mortality rate was 38% (median follow-up, 15 months). CONCLUSIONS: Esophagitis associated with ICI use is rare. The diagnosis is one of exclusion because its clinical presentation appears similar to that of inflammation resulting from other causes. It often occurs in conjunction with other upper gastrointestinal toxicity. Symptoms are mild and respond well to nonimmunosuppressive treatment, with few severe complications.

Clinical Characteristics and Outcomes of Eosinophilic Colitis in Patients With Cancer.

BACKGROUND: Eosinophilic colitis (EoC) is a rare form of eosinophilic gastrointestinal disease characterized by diffuse eosinophilic infiltration in the deep lamina propria of colonic mucosa. The pathophysiology is unclear, but EoC has been associated with multiple known risk factors. AIM: The aim of this study was to characterize the clinical characteristics and disease course of patients with EoC at a major cancer center. MATERIAL AND METHODS: We retrospectively reviewed colonic samples obtained between January 2000 and December 2018 from our institutional database and included cases with significant colonic eosinophilia. Baseline clinical data and EoC-related clinical course and outcomes were documented. RESULTS: Forty-one patients were included. One fourth had coexisting autoimmune conditions. Seventy-eight percent had a cancer diagnosis. Half the patients received chemotherapy, with a median duration of 180 days between chemotherapy and EoC onset. Symptoms were present in 76% of patients. Diarrhea was more prevalent in patients who received chemotherapy (85% vs. 42%). Median duration of EoC symptoms was 30 days in patients with cancer and 240 days in those without cancer (P=0.03). Most patients (88%) had normal colonoscopy findings. Fifteen percent of patients required hospitalization. All-cause mortality was 37%, mostly related to underlying malignancy and organ failure. CONCLUSIONS: EoC in cancer patients appears to have more diarrhea-predominant symptoms, particularly in patients receiving chemotherapy, but a shorter disease duration compared with patients without cancer. Hospitalization can be required for serious cases. Treatment may be reserved for patients requiring symptom management, as most patients with EoC have good clinical outcomes regardless of treatment.

CD95L and Anti-Tumor Immune Response: Current Understanding and New Evidence.

The ability of FasL/CD95L to induce apoptosis in various Fas/CD95-expressing cells has been described in the context of hematopoiesis or thymic elimination of self-reactive T cells and resolution of an acute immune response under physiological conditions. At the same time, non-apoptotic CD95 activation is widely described in cancer and shown to stimulate invasiveness of cancer cells, promote cancer progression as well as stemness of cancer cells. This paper puts emphasis on the evolving understanding of expression and the non-apoptotic activities of the CD95/CD95L signaling pathway on the function of tumor cells, tumor microenvironment and immune cells. The emerging evidence to support the role of CD95/CD95L signaling in the anti-tumor immune response will be presented in the context of various malignancies and the modalities of potential therapeutic interventions via selective CD95L inhibition in combination with traditional interventions such as RT, chemotherapy and immune checkpoint inhibitors.

Gastrointestinal Injury Related to Antiangiogenesis Cancer Therapy.

BACKGROUND: Data on gastrointestinal toxicities related antiangiogenesis cancer therapy is very limited. We aim to describe the clinical, endoscopic, and histologic features and outcomes of antiangiogenesis-associated colitis and diarrhea (ACD) at a tertiary-care cancer center. PATIENTS AND METHODS: We performed a retrospective study of cancer patients who received antiangiogenesis therapy (AAT) and underwent endoscopy for ACD symptoms during 2000-2018. RESULTS: A total of 12,045 patients received AAT during the study period. Of these, 552 patients underwent lower gastrointestinal tract endoscopic evaluation after AAT. Among them, we identified 41 patients who developed ACD. The median time from AAT initiation to ACD onset was 20 weeks. Most patients received bevacizumab (83%). The median duration of ACD symptoms was 6 days. On endoscopy, 7 patients (17%) had mucosal ulceration, and 16 (39%) had nonulcerative inflammation. Active histologic inflammation was evident in 8 patients (20%). Thirteen patients (32%) received treatment for ACD: antibiotics in 5 (12%) and antimotility agents in 11 (27%). Sixteen patients (39%) were hospitalized for ACD, and 2 were admitted to the intensive care unit. One colonic perforation (2%) related to underlying malignancy was reported after colonoscopy. Patients with enterocolitis symptoms had more frequent abnormal endoscopic findings (P = .024) and less frequently received antimotility agents (P = .011) compared to those with diarrhea only. Abnormal endoscopic findings were associated with more hospitalizations (P = .063) compared to normal group. CONCLUSION: ACD is a rare adverse event of AAT and is usually mild. Despite its rarity, complications of ACD can be serious, requiring intensive care unit and surgery. Colonic perforation occurred after routine endoscopy after AAT in 2% of our cohort.

Concepts for agonistic targeting of CD40 in immuno-oncology.

TNF Receptor Superfamily (TNF-R-SF) signaling is a structurally well-defined event that requires proper receptor clustering and trimerization. While the TNF-SF ligands naturally exist as trivalent functional units, the receptors are usually separated on the cell surface. Critically, receptor assembly into functional trimeric signaling complexes occurs through binding of the natural ligand unit. TNF-R-SF members, including CD40, have been key immunotherapeutic targets for over 20 years. CD40, expressed by antigen-presenting cells, endothelial cells, and many tumors, plays a fundamental role in connecting innate and adaptive immunity. The multiple investigated strategies to induce CD40 signaling can be broadly grouped into antibody-based or CD40L-based approaches. Currently, seven different antibodies and one CD40L-based hexavalent fusion protein are in active clinical trials. In this review, we describe the biology and structural properties of CD40, requirements for agonistic signal transduction through CD40 and summarize current attempts to exploit the CD40 signaling pathway for the treatment of cancer.

Gastrointestinal Adverse Events Observed After Chimeric Antigen Receptor T-Cell Therapy.

BACKGROUND: Chimeric antigen receptor T-cell (CART) therapy can significantly improve outcomes for patients with certain hematologic malignancies. The most notable drawbacks of CART are cytokine release syndrome and CART-related encephalopathy syndrome. Gastrointestinal adverse events (GI-AEs) have not yet been reported in association with CART. Herein, we describe the incidence and clinical features of GI-AEs observed after CART. MATERIALS AND METHODS: We report a case series of patients with hematologic malignancies who received CART, in a clinical trial or as the standard of care, and subsequently suffered from GI-AEs between 2012 and 2018. RESULTS: In our cohort, 37 of 132 (28%) patients experienced GI-AEs. All 37 experienced diarrhea with a median onset of 7 days (interquartile range, 4 to 25 d) after CART infusion. The median age of these patients was 58 years. Most had diffuse large B-cell lymphoma (51%). Seventeen patients experienced cytokine release syndrome, and 9 experienced CART-related encephalopathy syndrome. The interleukin-6 antagonist was required in 15 patients. Overall, 49% of patients had grade 1 diarrhea, 32% had grade 2, and 15% had grade 3. Other gastrointestinal symptoms in these patients were abdominal pain (41%), nausea and vomiting (49%), fever (8%), bloody stools (3%), and abdominal distension (5%). The median duration of symptoms was 6 days (interquartile range, 3 to 9 d). In 32 patients who underwent imaging, 8 (25%) had findings suggestive of gastrointestinal tract inflammation. Nine (24%) patients experienced GI-AE recurrence after initial improvement. The symptoms were attributed to an alternative cause in 17 (13%) cases and to CART in 20 (15%) cases. One patient developed CART-related refractory colitis that eventually responded to antibiotics for pneumonia. CONCLUSION: CART-related GI-AEs occur in 15% of patients treated with CART. These symptoms are typically mild and self-limiting, requiring only symptomatic treatment. Nevertheless, CART may, in rare cases, lead to refractory colitis.

HERA-GITRL activates T cells and promotes anti-tumor efficacy independent of FcγR-binding functionality.

BACKGROUND: Glucocorticoid-induced TNFR-related protein (TNFRSF18, GITR, CD357), expressed by T cells, and its ligand (TNFSF18, GITRL), expressed by myeloid populations, provide co-stimulatory signals that boost T cell activity. Due to the important role that GITR plays in regulating immune functions, agonistic stimulation of GITR is a promising therapeutic concept. Multiple strategies to induce GITR signaling have been investigated. The limited clinical efficacy of antibody-based GITR agonists results from structural and functional characteristics of antibodies that are unsuitable for stimulating the well-defined trimeric members of the TNFRSF. METHODS: To overcome limitations of antibody-based TNFRSF agonists, we have developed HERA-GITRL, a fully human hexavalent TNF receptor agonist (HERA) targeting GITR and mimicking the natural signaling concept. HERA-GITRL is composed of a trivalent but single-chain GITRL-receptor-binding-domain (scGITRL-RBD) unit fused to an IgG1 derived silenced Fc-domain serving as dimerization scaffold. A specific mouse surrogate, mmHERA-GITRL, was also generated to examine in vivo activity in respective mouse tumor models. RESULTS: For functional characterization of HERA-GITRL in vitro, human immune cells were isolated from healthy-donor blood and stimulated with anti-CD3 antibody in the presence of HERA-GITRL. Consistently, HERA-GITRL increased the activity of T cells, including proliferation and differentiation, even in the presence of regulatory T cells. In line with these findings, mmHERA-GITRL enhanced antigen-specific clonal expansion of both CD4+ (OT-II) and CD8+ (OT-I) T cells in vivo while having no effect on non-specific T cells. In addition, mmHERA-GITRL showed single-agent anti-tumor activity in two subcutaneous syngeneic colon cancer models (CT26wt and MC38-CEA). Importantly, this activity is independent of its FcγR-binding functionality, as both mmHERA-GITRL with a functional Fc- and a silenced Fc-domain showed similar tumor growth inhibition. Finally, in a direct in vitro comparison to a bivalent clinical benchmark anti-GITR antibody and a trivalent GITRL, only the hexavalent HERA-GITRL showed full biological activity independent of additional crosslinking. CONCLUSION: In this manuscript, we describe the development of HERA-GITRL, a true GITR agonist with a clearly defined mechanism of action. By clustering six receptor chains in a spatially well-defined manner, HERA-GITRL induces potent agonistic activity without being dependent on additional FcγR-mediated crosslinking.

Upper gastrointestinal symptoms and associated endoscopic and histological features in patients receiving immune checkpoint inhibitors.

Background: Immune checkpoint inhibitors (ICIs) have demonstrated effectiveness in treating many malignancies. Gastrointestinal (GI) adverse events are commonly reported; however, few reports describe upper GI tract toxic effects. We aimed to describe clinical features of upper GI injury related to ICI. Methods: We studied consecutive patients who received ICIs between April 2011 and March 2018 and developed upper GI symptoms requiring esophagogastroduodenoscopy (EGD). Results: Sixty patients developed upper GI symptoms between ICI initiation and 6 months after the last infusion. Among patients who had both EGD and colonoscopy (n = 38), 21 had endoscopic evidence of inflammation involving both the upper and lower GI tract. Overall, histological signs of inflammation of the stomach were evident in 83% of patients, but inflammation of the duodenum in 38%. Total of 42 patients had other risk factors of gastritis, i.e., chemotherapy, radiotherapy, and non-steroidal anti-inflammatory drugs. Only isolated gastric inflammation was seen on endoscopy in patients without these risk factors. The rates of ulceration were similar in the cohorts with and without other risk factors for gastritis. Isolated upper GI inflammation was related to anti-PD-1/L1 in 47% of patients. Immunosuppressive therapy in our cohort with upper GI toxicity consisted of steroids (42%) and infliximab or vedolizumab (23%). Most isolated upper GI symptoms were treated with proton pump inhibitors (65%) or H2 blockers (35%). Conclusion: We observed a correlation between ICI use and onset of upper GI inflammation even when other risk factors were excluded. Gastric involvement was evident more often than duodenal involvement on endoscopic and histological level.

Can Immune Checkpoint Inhibitors Induce Microscopic Colitis or a Brand New Entity?

Background: Microscopic colitis (MC) has been described as 1 pattern of injury in immune checkpoint inhibitor (ICPI)-induced colitis. The main objective of this study was to characterize ICPI-induced MC by exploring the differences in risk factors, colitis treatments, endoscopic features, and clinical outcomes between cancer and noncancer patients with MC with and without exposure to ICPIs. Methods: A retrospective chart review was conducted among patients diagnosed with MC from our institutional pathology database from January 2012 to January 2018. Patients were categorized into MC in cancer patients with or without ICPI exposure and in noncancer patients. Risk factors (use of tobacco and certain medications), colitis treatments (antidiarrheals and immunosuppressants), endoscopic features (with or without mucosal abnormality), and clinical outcomes (diarrhea recurrence, hospitalization, mortality) were collected and compared among the 3 groups. Results: Of the 65 eligible patients with MC, 15 cancer patients had exposure to ICPI, 39 cancer patients had no exposure to ICPI, and 11 had no cancer diagnosis. Among the risk factors, proton pump inhibitor was more frequently used in the ICPI-induced MC cohort (P = 0.040). Furthermore, in this population, mucosal abnormality was the most common endoscopic feature compared with normal findings in the non-ICPI-induced MC groups (P = 0.106). Patients with ICPI-induced MC required more treatments with oral and intravenous steroids and nonsteroidal immunosuppressive agents (all P < 0.001) and had a higher rate of hospitalization (P < 0.001). Conclusion: This study suggests that despite some similarities between MC with and without exposure to ICPIs, ICPI-induced MC has a more aggressive disease course that requires more potent immunosuppressive treatment regimens and greater need for hospitalization. 10.1093/ibd/izy240_video1izy240.video15828223597001.

Outcomes of vedolizumab therapy in patients with immune checkpoint inhibitor-induced colitis: a multi-center study.

BACKGROUND: Immune-mediated diarrhea and colitis (IMDC) can limit immune checkpoint inhibitors (ICIs) treatment, which is efficacious for advanced malignancies. Steroids and infliximab are commonly used to treat it. These agents induce systemic immunosuppression, with its associated morbidity. We assessed clinical outcomes of vedolizumab as an alternative treatment for IMDC. METHODS: We analyzed a retrospective case series of adults who had IMDC refractory to steroids and/or infliximab and received vedolizumab from 12/2016 through 04/2018. RESULTS: Twenty-eight patients were included. The median time from ICI therapy to IMDC onset was 10 weeks. Fifteen patients (54%) had grade 2 and 13 (46%) had grade 3 or 4 IMDC. Mucosal ulceration was present in 8 patients (29%), and nonulcerative inflammation was present in 13 (46%). All patients had features of active histologic inflammation; 14 (50%) had features of chronicity, and 10 (36%) had features of microscopic colitis concurrently. The mean duration of steroid therapy was 96 days (standard deviation 74 days). Nine patients received infliximab in addition to steroids and their IMDC was refractory to it. Among these, the duration of steroid use was 131 days compared with 85 days in patients who did not receive infliximab. Likewise, patients who failed infliximab before vedolizumab had a clinical success rate of 67% compared to 95% for patients that did not receive infliximab. The median number of vedolizumab infusions was 3 (interquartile range 1-4). The mean duration of follow-up was 15 months. Twenty-four patients (86%) achieved and sustained clinical remission. Repeat endoscopic evaluation was performed in 17 patients. Endoscopic remission was attained in 7 (54%) of the 13 patients who had abnormal endoscopic findings initially; 5/17 patients (29%) reached histologic remission as well. CONCLUSIONS: Vedolizumab can be appropriate for the treatment of steroid-refractory IMDC, with favorable outcomes and a good safety profile.

The Hexavalent CD40 Agonist HERA-CD40L Induces T-Cell-mediated Antitumor Immune Response Through Activation of Antigen-presenting Cells.

CD40 ligand (TNFSF5/CD154/CD40L), a member of the tumor necrosis factor (TNF) superfamily is a key regulator of the immune system. The cognate receptor CD40 (TNFRSF5) is expressed broadly on antigen-presenting cells and many tumor types, and has emerged as an attractive target for immunologic cancer treatment. Most of the CD40 targeting drugs in clinical development are antibodies which display some disadvantages: their activity typically depends on Fcγ receptor-mediated crosslinking, and depletion of CD40-expressing immune cells by antibody-dependent cellular cytotoxicity compromises an efficient antitumor response. To overcome the inadequacies of antibodies, we have developed the hexavalent receptor agonist (HERA) Technology. HERA compounds are fusion proteins composed of 3 receptor binding domains in a single chain arrangement, linked to an Fc-silenced human IgG1 thereby generating a hexavalent molecule. HERA-CD40L provides efficient receptor agonism on CD40-expressing cells and, importantly, does not require FcγR-mediated crosslinking. Strong activation of NFκB signaling was observed upon treatment of B cells with HERA-CD40L. Monocyte treatment with HERA-CD40L promoted differentiation towards the M1 spectrum and repolarization of M2 spectrum macrophages towards the M1 spectrum phenotype. Treatment of in vitro co-cultures of T and B cells with HERA-CD40L-triggered robust antitumor activation of T cells, which depended upon direct interaction with B cells. In contrast, bivalent anti-CD40 antibodies and trivalent soluble CD40L displayed weak activity which critically depended on crosslinking. In vivo, a murine surrogate of HERA-CD40L-stimulated clonal expansion of OT-I-specific murine CD8 T cells and showed single agent antitumor activity in the CD40 syngeneic MC38-CEA mouse model of colorectal cancer, suggesting an involvement of the immune system in controlling tumor growth. We conclude that HERA-CD40L is able to establish robust antitumor immune responses both in vitro and in vivo.

A Single-Chain-Based Hexavalent CD27 Agonist Enhances T Cell Activation and Induces Anti-Tumor Immunity.

Tumor necrosis factor receptor superfamily member 7 (TNFRSF7, CD27), expressed primarily by T cells, and its ligand CD27L (TNFSF7, CD70) provide co-stimulatory signals that boost T cell activation, differentiation, and survival. Agonistic stimulation of CD27 is therefore a promising therapeutic concept in immuno-oncology intended to boost and sustain T cell driven anti-tumor responses. Endogenous TNFSF/TNFRSF-based signal transmission is a structurally well-defined event that takes place during cell-to-cell-based contacts. It is well-established that the trimeric-trivalent TNFSF-receptor binding domain (TNFSF-RBD) exposed by the conducting cell and the resulting multi-trimer-based receptor clustering on the receiving cell are essential for agonistic signaling. Therefore, we have developed HERA-CD27L, a novel hexavalent TNF receptor agonist (HERA) targeting CD27 and mimicking the natural signaling concept. HERA-CD27L is composed of a trivalent but single-chain CD27L-receptor-binding-domain (scCD27L-RBD) fused to an IgG1 derived silenced Fc-domain serving as dimerization scaffold. The hexavalent agonist significantly boosted antigen-specific T cell responses while having no effect on non-specific T cells and was superior over stabilized recombinant trivalent CD27L. In addition, HERA-CD27L demonstrated potent single-agent anti-tumor efficacy in two different syngeneic tumor models, MC38-CEA and CT26wt. Furthermore, the combination of HERA-CD27L and an anti-PD-1 antibody showed additive anti-tumor effects highlighting the importance of both T cell activation and checkpoint inhibition in anti-tumor immunity. In this manuscript, we describe the development of HERA-CD27L, a true CD27 agonist with a clearly defined forward-signaling mechanism of action.

The Contained Self-Reactive Peripheral T Cell Repertoire: Size, Diversity, and Cellular Composition.

Individual self-reactive T cells have been discovered in both humans and mice. It is difficult to assess the entire contained self-reactive peripheral T cell repertoire in healthy individuals because regulatory T cells (Tregs) can render these cells anergic and, therefore, functionally indistinguishable. We addressed this issue by removing regulatory T cells, thereby allowing us to characterize the exposed self-reactive T cells. This resulted in activation of approximately 4% of both CD4(+) and CD8(+) T cells. Activation and division of these cells was not a bystander product of Ag-independent signals but required TCR stimulation. Analysis of TCR sequences showed that these responding cells were polyclonal and encompassed a broad range of structural TCR diversity. Adoptive transfer of naive and effector/memory T cell populations showed that even the naive T cell pool contained self-reactive T cell precursors. In addition, transfer of mature thymocytes showed that this response was an intrinsic T cell property rather than a peripheral adaptation. Finally, we found that the unexpectedly strong contribution of the naive CD5(low) T cell pool showed that the overall self-reactive response has not only a diverse polyclonal TCR repertoire, but also comprises a broad range of affinities for self.

Origin of monocytes and macrophages in a committed progenitor.

Monocytes, macrophages and dendritic cells (DCs) are developmentally related regulators of the immune system that share the monocyte-macrophage DC progenitor (MDP) as a common precursor. Unlike differentiation into DCs, the distal pathways for differentiation into monocytes and monocyte-derived macrophages are not fully elucidated. We have now demonstrated the existence of a clonogenic, monocyte- and macrophage-restricted progenitor cell derived from the MDP. This progenitor was a Ly6C(+) proliferating cell present in the bone marrow and spleen that generated the major monocyte subsets and macrophages, but not DCs or neutrophils. By in-depth quantitative proteomics, we characterized changes in the proteome during monocyte differentiation, which provided insight into the molecular principles of developing monocytes, such as their functional maturation. Thus, we found that monocytes and macrophages were renewed independently of DCs from a committed progenitor.

Percutaneous endoscopic gastrostomy in cancer patients: predictors of 30-day complications, 30-day mortality, and overall mortality.

BACKGROUND: Cancer patients benefit from percutaneous endoscopic gastrostomy (PEG) in many ways including nutritional support and venting in cases of malignant obstruction. Lack of high-quality studies with adequate follow-up has led to limited information regarding risk stratification and predictors of morbidity and mortality. AIMS: Elucidate predictors of complications and mortality with long-term follow-up in cancer patients undergoing PEG. METHOD: Retrospective review of all patients undergoing PEG placement at MD Anderson Cancer Center from January 1, 2004 to December 31, 2006. Statistical analysis included descriptive statistics, Kaplan-Meier survival estimates, and Cox proportional hazards regression analyses. RESULTS: A total of 218 subjects underwent PEG. Those with American Society of Anesthesiology (ASA) scores of 4, 4E, or 5E were at significant risk of a major complication in the first 30 days. Multivariate analysis revealed ASA scores ≥4, elevated WBC count, and advanced tumor stage to be independent predictors of mortality in the first 30 days and INR >1.5 and diversion/venting as an indication for PEG placement to be independent predictors of overall mortality. CONCLUSIONS: Patients with high baseline illness severity are more likely to have complications and are at increased risk of mortality after PEG. Our study results suggest that particular attention be directed to ASA score, INR, WBC counts, transfusion requirements, presence of advanced malignancies, and the indication for PEG placement when determining risk of complications or death. Patients undergoing venting PEG are expected to have short post-PEG survival but improvement in quality of life likely justifies the risks associated with PEG placement.

Monocytes and macrophages in cancer: development and functions.

Monocytes and tumor-associated macrophages are part of the myeloid family, a group of hematopoietic derived cells. Monocytes are direct precursors of hematopoietic stem cell-derived macrophages. After their recruitment into the tumor tissue, they can differentiate into tumor-associated macrophages, a very heterogeneous cell population in terms of phenotype and pro-tumor function, supporting tumor initiation, local progression and distant metastasis. Therefore, targeting monocytes and macrophages is a promising immunotherapeutic approach. This review will focus on the development of monocytes as macrophage precursors, the functions of tumor-associated macrophages and the possibility of interfering with tumor development and progression by targeting these myeloid cells.