Abstract C027: A Phase I, dose finding study of BI 754111, an anti-LAG-3 antibody, in combination with BI 754091, an anti-PD-1 antibody, in patients with advanced solid tumors: preliminary results from the microsatellite stable (MSS) metastatic colorectal cancer (mCRC) cohort

Background: Inhibition of the PD-1 pathway is an effective immunotherapeutic approach in a subset of patients with various solid tumors and hematologic malignancies. Blockade of the PD-1 pathway leads to overexpression of other checkpoint receptors, including LAG3, potentially providing an escape pathway for tumor cells. LAG-3 signaling contributes to immune cell exhaustion, preventing T-cell proliferation. Dual blockade of PD-1 and LAG-3 has the potential to synergistically restore T-cell functionality and therefore enhance antitumor immune responses. This Phase I trial is evaluating the combination of BI 754111, an anti-LAG-3 monoclonal antibody (mAb), and BI 754091, an anti-PD-1 mAb, in patients with advanced solid tumors. Methods: This open-label, Phase I study is being conducted in two parts. Part 1 (dose-escalation) enrolled patients with advanced solid tumors; no dose limiting toxicities were reported and BI 754111 600 mg intravenous (iv) every 3 weeks (q3w) in combination with BI 754091 (240 mg iv q3w) was selected for further assessment in part 2 (dose expansion). In part 2, patients are being enrolled in 4 cohorts: 1) anti-PD-(L)1 pretreated non-small cell lung cancer (NSCLC) that progressed after having achieved benefit on previous PD-(L)1; 2) previously treated (anti-PD-[L]1 naïve) MSS mCRC; 3) anti-PD-(L)1 pretreated TMB >10 and/or MSI-h and/or dMMR solid tumors; 4) treatment-naive NSCLC with EGFR and ALK wild type tumors. Primary endpoint for the expansion cohorts is objective response. Safety and pharmacokinetics of the combination were secondary endpoints. The mCRC cohort is fully recruited; other cohorts are open to recruitment. This abstract presents data from the MSS CRC cohort. Results. 40 patients with MSS mCRC were enrolled (27 male [67.5%]; median age 56.5 years [range 25–85]; median of 3.0 prior regimens [range 1–10]) and received BI 754111 600 mg q3w in combination with BI 754091 240 mg q3w. Treatment-related AEs (TRAEs) were reported in 18 patients (45%); most commonly infusion-related reactions (10.0%), myalgia (10.0%), hypothyroidism (7.5%), diarrhea (7.5%) and arthralgia (7.5%). Grade 3/4 TRAEs occurred in 4 patients (grade 3 colitis, grade 3 maculo-papular rash, grade 4 diabetic ketoacidosis [n=2]). Treatment-emergent immune-related AEs occurred in 9 patients; of these, 4 had grade 3/4 events (colitis and maculo-papular rash [grade 3] and diabetic ketoacidosis [grade 4; n=2]). To date, 2 (5%) patients achieved a partial response, and 12 (30%) achieved stable disease. Updates will be presented. Conclusion. BI 754111 + BI 754091 was well-tolerated and showed preliminary activity in patients with previously treated MSS mCRC. Assessment of the combination in other cohorts is ongoing.

Citation Format: Johanna Bendell, Susanna V Ulahannan, Quincy Chu, Manish Patel, Ben George, Renee Landsberg, Mabrouk Elgadi, Christine Duffy, Ralph Graeser, Wenbo Tang, Michael Merger, Miaomiao Ge, Melissa Johnson. A Phase I, dose finding study of BI 754111, an anti-LAG-3 antibody, in combination with BI 754091, an anti-PD-1 antibody, in patients with advanced solid tumors: preliminary results from the microsatellite stable (MSS) metastatic colorectal cancer (mCRC) cohort [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr C027. doi:10.1158/1535-7163.TARG-19-C027

Final results from GCIG/ENGOT/AGO-OVAR 12, a randomised placebo-controlled phase III trial of nintedanib combined with chemotherapy for newly diagnosed advanced ovarian cancer

AGO-OVAR 12 investigated the effect of adding the oral triple angiokinase inhibitor nintedanib to standard front-line chemotherapy for advanced ovarian cancer. At the primary analysis, nintedanib demonstrated significantly improved progression-free survival (PFS; primary endpoint) compared with placebo. We report final results, including overall survival (OS). Patients with primary debulked International Federation of Gynaecology and Obstetrics (FIGO) stage IIB-IV newly diagnosed ovarian cancer were randomised 2:1 to receive carboplatin (area under the curve 5 or 6) plus paclitaxel (175 mg/m² ) on day 1 every 3 weeks for six cycles combined with either nintedanib 200 mg or placebo twice daily on days 2-21 every 3 weeks for up to 120 weeks. Between December 2009 and July 2011, 1,366 patients were randomised (911 to nintedanib, 455 to placebo). Disease was considered as high risk (FIGO stage III with >1 cm residuum, or any stage IV) in 39%. At the final analysis, 605 patients (44%) had died. There was no difference in OS (hazard ratio 0.99, 95% confidence interval [CI] 0.83-1.17, p = 0.86; median 62.0 months with nintedanib vs. 62.8 months with placebo). Subgroup analyses according to stratification factors, clinical characteristics and risk status showed no OS difference between treatments. The previously reported PFS improvement seen with nintedanib did not translate into an OS benefit in the nonhigh-risk subgroup. Updated PFS results were consistent with the primary analysis (hazard ratio 0.86, 95% CI 0.75-0.98; p = 0.029) favouring nintedanib. The safety profile was consistent with previous reports.

The prognostic value of tumor residuals indicated by surgeon, by radiology or an integrated approach by surgeons' assessment and pre-chemotherapy CT-scan in patients with advanced ovarian cancer: An exploratory analysis of the AGO Study led Intergroup trial AGO-OVAR 12

5521

Background: Post-OP TR is a strong prognostic factor in AOC; the best prognosis is observed after complete resection (TR0). TR assessment is performed at the end of the surgery and may be exposed to personal bias. Pre-Chemo CT may improve post-OP assessment, however, it may also be prone to findings by post-OP tumor re-growth, tissue repair or scarring. Methods: Pts with FIGO IIB-IV AOC recruited into the double-blind randomized frontline AGO-OVAR12 trial were scheduled for baseline CT before the 1st chemo cycle. SA and RA of TR were compared. Additionally, a measurement of TR integrating both approaches were assessed (IA). For this IA information of surgical and path reports were reviewed by two of the authors. Results: 1355 pts had complete data for all 3 assessment methods. Of 689 pts with TR0 in SA, 497 (72%) and 539 (78%) had also TR0 pre-Chemo (RA and IA), but showed TR>0 in 192 (28%) and 150 pts (22%), respectively. Pts with SA defined TR0 had a similar median PFS of 27.6 mos compared to TR0 defined by RA (27.8 mos) and IA (28.9 mos). Pts with concordant TR0 (SA/ IA and SA/ RA) had a median PFS of 28.9 mos. In contrast, pts with discordant SA TR0 - RA TR>0 or SA TR0 - IA TR>0 showed inferior median PFS of 19.2 mos (HR: 1.89, 95%CI: 1.48-2.40; p<0.0001) and 16.9 mos (HR: 2.02, 95% CI: 1.57- 2.59; p<0.0001), respectively. Pts with concordant TR>0 had an even lower median PFS of 13.5 (SA and IA) and 12.9 mos (SA and RA). PFS of the experimental therapy or placebo dependent if SA, RA or IA were used, will be presented. Conclusions: Pre-Chemo CT provides information separating the group of pts with post-OP TR0 in pts with TR0 and pts with TR> 0 pre-Chemo. The latter group showed PFS values in between those with surgically assessed post-OP TR0 and those with post-OP TR> 0, forming a third prognostic group. Detailed analysis should evaluate to what extend tumor biology, surgical bias, or imperfect imaging contribute to the discrepancies. Integrating all this may lead to better definition of prognostic groups and the need for specific treatment strategies.

Standard first-line chemotherapy with or without nintedanib for advanced ovarian cancer (AGO-OVAR 12): a randomised, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Angiogenesis is a target in the treatment of ovarian cancer. Nintedanib, an oral triple angiokinase inhibitor of VEGF receptor, platelet-derived growth factor receptor, and fibroblast growth factor receptor, has shown activity in phase 2 trials in this setting. We investigated the combination of nintedanib with standard carboplatin and paclitaxel chemotherapy in patients with newly diagnosed advanced ovarian cancer.

METHODS

In this double-blind phase 3 trial, chemotherapy-naive patients (aged 18 years or older) with International Federation of Gynecology and Obstetrics (FIGO) IIB-IV ovarian cancer and upfront debulking surgery were stratified by postoperative resection status, FIGO stage, and planned carboplatin dose. Patients were randomly assigned (2:1) via an interactive voice or web-based response system to receive six cycles of carboplatin (AUC 5 mg/mL per min or 6 mg/mL per min) and paclitaxel (175 mg/m(2)) in addition to either 200 mg of nintedanib (nintedanib group) or placebo (placebo group) twice daily on days 2-21 of every 3-week cycle for up to 120 weeks. Patients, investigators, and independent radiological reviewers were masked to treatment allocation. The primary endpoint was investigator-assessed progression-free survival analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01015118.

FINDINGS

Between Dec 9, 2009, and July 27, 2011, 1503 patients were screened and 1366 randomly assigned by nine study groups in 22 countries: 911 to the nintedanib group and 455 to the placebo group. 486 (53%) of 911 patients in the nintedanib group experienced disease progression or death compared with 266 (58%) of 455 in the placebo group. Median progression-free survival was significantly longer in the nintedanib group than in the placebo group (17·2 months [95% CI 16·6-19·9] vs 16·6 months [13·9-19·1]; hazard ratio 0·84 [95% CI 0·72-0·98]; p=0·024). The most common adverse events were gastrointestinal (diarrhoea: nintedanib group 191 [21%] of 902 grade 3 and three [<1%] grade 4 vs placebo group nine [2%] of 450 grade 3 only) and haematological (neutropenia: nintedanib group 180 [20%] grade 3 and 200 (22%) grade 4 vs placebo group 90 [20%] grade 3 and 72 [16%] grade 4; thrombocytopenia: 105 [12%] and 55 [6%] vs 21 [5%] and eight [2%]; anaemia: 108 [12%] and 13 [1%] vs 26 [6%] and five [1%]). Serious adverse events were reported in 376 (42%) of 902 patients in the nintedanib group and 155 (34%) of 450 in the placebo group. 29 (3%) of 902 patients in the nintedanib group experienced serious adverse events associated with death compared with 16 (4%) of 450 in the placebo group, including 12 (1%) in the nintedanib group and six (1%) in the placebo group with a malignant neoplasm progression classified as an adverse event by the investigator. Drug-related adverse events leading to death occurred in three patients in the nintedanib group (one without diagnosis of cause; one due to non-drug-related sepsis associated with drug-related diarrhoea and renal failure; and one due to peritonitis) and in one patient in the placebo group (cause unknown).

INTERPRETATION

Nintedanib in combination with carboplatin and paclitaxel is an active first-line treatment that significantly increases progression-free survival for women with advanced ovarian cancer, but is associated with more gastrointestinal adverse events. Future studies should focus on improving patient selection and optimisation of tolerability.

FUNDING

Boehringer Ingelheim.

Randomized phase II study of nintedanib in metastatic castration-resistant prostate cancer postdocetaxel

This open-label, phase II trial assessed the efficacy and safety of two doses of nintedanib, a triple angiokinase inhibitor targeting vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor signaling, in patients with metastatic castration-resistant prostate cancer (mCRPC) following progression on docetaxel-based regimens. Patients were randomized to nintedanib 150 mg (arm A, n=40) or 250 mg (arm B, n=41) twice daily for 6 months unless disease progression or adverse events (AEs) led to discontinuation. The primary endpoint was the prostate-specific antigen (PSA) response rate (confirmed PSA decline of ≥20% from baseline). Eighty-one patients were enrolled. The PSA response rate was 0% (0/32) in arm A versus 11.1% (4/36) in arm B (P=0.12); 5.6% of patients (2/36) in arm B showed a PSA reduction of at least 50%. In arm B, the rate of PSA increase was significantly decelerated on treatment versus before treatment (P=0.002). The median progression-free survival was 73.5 and 76.0 days for arm A and arm B, respectively (P=0.3). AEs included gastrointestinal disorders, asthenia, hypertension, and reversible elevated transaminases. The incidence of drug-related serious AEs (no drug-related deaths) was 20.0% (arm A) and 24.4% (arm B). The primary endpoint was not met. Nintedanib (250 mg) showed only modest activity with manageable AEs in patients with mCRPC post-docetaxel.

Prolonged response of relapsed high grade serous ovarian carcinoma to the oral angiokinase inhibitor nintedanib in a patient with a germline BRCA1 mutation

► Nintedanib is an anti-angiogenic agent that has demonstrated activity in relapsed ovarian cancer. ► Our patient had prolonged response to nintedanib, allowing her to have potentially curative surgery 6 years after her diagnosis. ► The relationship between angiogenesis and BRCA mutation is worth exploring in ovarian cancer.

A randomised phase II trial of the Polo-like kinase inhibitor BI 2536 in chemo-naïve patients with unresectable exocrine adenocarcinoma of the pancreas - a study within the Central European Society Anticancer Drug Research (CESAR) collaborative network

BACKGROUND

BI 2536, a novel Polo-like kinase 1 inhibitor, was assessed in patients with unresectable advanced exocrine adenocarcinoma of the pancreas.

METHODS

The study employed a two-stage design. Randomised first-line patients received BI 2536 200 mg on day 1 (n=43) or 60 mg on days 1-3 (n=43) every 21 days. Recruitment of second-line patients was planned for a second stage dependent on an interim analysis demonstrating ≥ 2 responses in the first 18 evaluable patients following 12 weeks of treatment and/or tumour control ≥ 12 weeks in 5 patients per schedule. Primary end point was objective response rate (ORR).

RESULTS

By independent review, ORR was 2.3% (all partial) and 24.4% had stable disease as confirmed best response. The second stage was not initiated. Median overall and progression-free survivals were 149 (95% confidence interval (CI), 91-307) and 46 days (95% CI, 44-56). Most common drug-related adverse events were neutropenia (37.2%), leukopenia (29.1%), fatigue (29.1%) and nausea (22.1%); most common grade 3/4-related events were neutropenia (36.0%), leukopenia (27.9%) and thrombocytopenia (8.1%).

CONCLUSION

Given the low ORR and poor survival, further development of BI 2536 monotherapy is not warranted in this population.

Randomized phase II placebo-controlled trial of maintenance therapy using the oral triple angiokinase inhibitor BIBF 1120 after chemotherapy for relapsed ovarian cancer

PURPOSE

Inhibiting angiogenesis is one of the most promising avenues for new therapies for ovarian cancer. We investigated the efficacy and safety of a novel agent, BIBF 1120, a triple angiokinase inhibitor, after chemotherapy for relapsed disease.

PATIENTS AND METHODS

We conducted a randomized, double-blind, controlled phase II trial in 83 patients who had just completed chemotherapy for relapsed ovarian cancer, with evidence of response, but at high risk of further early recurrence. The patients were randomly assigned to receive maintenance therapy using BIBF 1120 250 mg or placebo, twice per day, continuously for 36 weeks. End points were progression-free survival (PFS), toxicity, and overall survival.

RESULTS

Thirty-six-week PFS rates were 16.3% and 5.0% in the BIBF 1120 and placebo groups, respectively (hazard ratio, 0.65; 95% CI, 0.42 to 1.02; P = .06). Four patients continued on BIBF 1120, including two patients for another year or more. The proportion of patients with any grade 3 or 4 adverse events was similar between the groups (34.9% for BIBF 1120 v 27.5% for placebo; P = .49; mostly grade 3). However, more patients on BIBF 1120 experienced diarrhea, nausea, or vomiting (mainly grade 1 or 2 and no grade 4). There was a higher rate of grade 3 or 4 hepatotoxicity in patients on BIBF 1120 (51.2%) compared with patients on placebo (7.5%; P < .001), but this was rarely of clinical significance, and patients continued with the trial treatment. A single-level dose reduction to 150 mg was made in 15 patients, all on active drug.

CONCLUSION

BIBF 1120 is well tolerated and associated with a potential improvement in PFS. The observed treatment effect is sufficient to justify further study within a large phase III trial.

Phase II trial of weekly alternating sequential BIBF 1120 and afatinib for advanced colorectal cancer

AIM

The feasibility of an alternating regimen of BIBF 1120, a potent, oral, triple angiokinase inhibitor, and afatinib (BIBW 2992), a potent ErbB family blocker, was explored in patients with advanced pretreated colorectal cancer (CRC).

PATIENTS AND METHODS

Patients received repeated courses of alternating 7-day treatment periods, first with BIBF 1120 250 mg twice daily and then afatinib 50 mg once daily. The primary endpoint was the objective response rate; the incidence/severity of adverse events (AEs) and pharmacokinetics (PK) were determined.

RESULTS

Forty-six patients (≥4 prior lines, most anti-VEGF and/or -EGFR pretreated) received BIBF 1120 and afatinib. No objective responses were observed; the best response was stable disease in 20 patients (43.5%). Seven patients (15.2%) remained progression-free for ≥16 weeks. Median progression-free survival was 1.9 months; median overall survival was 5.5 months. The most frequent drug-related AEs were diarrhoea (80.4%), asthenia (47.8%), nausea (43.5%) and rash (41.3%). PK assessments did not show obvious alterations for either drug.

CONCLUSION

Weekly alternating administration of BIBF 1120 and afatinib is feasible; however, its efficacy was limited in this highly palliative patient population.

Prolactin stimulates proliferation of the glucose-dependent beta-cell line INS-1 via different IRS-proteins

CONTEXT

Prolactin is one of the most potent growth stimulating growth hormones of pancreatic beta cells.

OBJECTIVE

We investigated the role of prolactin on the proliferation of the beta-cell line INS-1.

DESIGN

In particular, we investigated the involvement of intracellular signal transduction molecules in prolactin-dependent upregulation of INS-1 growth.

SETTING

The effect of prolactin on the growth of INS-1 cells was assessed in vitro under various feeding conditions.

MAIN OUTCOME MEASURES

Cell proliferation was measured in the pancreatic beta-cell line INS-1 using 3H-thymidine incorporation. The activation of mitogenic signaling proteins was assessed by co-immunoprecipitation, immunoblot analysis and in proliferation assays using specific protein inhibitors.

RESULTS

Prolactin (0.5-2 nM) increased INS-1 cell proliferation in the presence of 3-24 mM glucose up to 48 fold, having a maximum in the presence of physiological glucose concentrations (6 mM). Prolactin activated the JAK2/STAT5 pathway and phosphatidylinositol-3'-kinase (PI3'K) in the presence of all the glucose concentrations used (3-15 mM). At low glucose concentrations (3 mM), PI3'K activation occurred through IRS-2 phosphorylation whereas, in the presence of physiological glucose concentration IRS4 and at high glucose concentrations (15 mM), IRS-1 triggered a proliferative effect. PI3'K activation was essential for prolactin and glucose stimulated INS-1 cell proliferation. Co-stimulation with different growth factors (IGF-I, growth hormone) in addition to prolactin and glucose had no additive effects.

CONCLUSION

These results define prolactin as an important hormone. mediating glucose-dependent pancreatic beta-cell proliferation primarily by the activation of PI3'K-dependent signaling pathways.

Retroperitoneal gas gangrene after colonoscopic polypectomy without bowel perforation in an otherwise healthy individual: report of a case

BACKGROUND

Abdominal gas gangrene caused by clostridia species is rare and usually associated with organ perforation, immune suppression, or advanced malignoma.

CASE REPORT

A 61-year-old man was admitted with severe back pain 1 day after uncomplicated colonoscopic polypectomy. With the exception of preexisting minor depression, the patient had been previously in excellent health. The computed tomography scan showed retroperitoneal emphysema in the left psoas muscle. During exploratory laparotomy, a spreading retroperitoneal phlegmon with pneumoretroperitoneum and a secondary peritonitis were found. A macroscopic perforation of the gut, particularly at the polypectomy sites was excluded. After the operation, the patient evolved in a septic shock condition and had pulmonary failure. Before hyperbaric oxygen therapy could be employed, the patient died. The autopsy showed a massive gas gangrene of the retroperitoneum caused by Clostridium perfringens, but no macroscopic bowel perforation was detected.

RESULTS

This is the first report of a case of gas gangrene after uncomplicated polypectomy without macroscopic perforation in an otherwise healthy individual. A microperforation due to mucosal defect after polypectomy was most likely the entry point for the bacteria.

CONCLUSION

We conclude that clostridial myonecrosis should be considered in unclear abdominal infections, even if the patient's history is not typical as in the present case.

Defining the roles of perforin, Fas/FasL, and tumour necrosis factor alpha in T cell induced mucosal damage in the mouse intestine

BACKGROUND AND AIMS

Mucosal flattening and epithelial cell apoptosis are typical features of T cell induced inflammatory diseases of the bowel, such as coeliac disease and graft versus host disease. Mice injected with a T cell activating anti-CD3 antibody develop a severe diarrhoeal illness. We describe the histological features of this enteropathy and define the effector mechanisms involved in T cell induced mucosal injury in this in vivo model.

METHODS

Wild-type and genetically modified mice were injected with the anti-CD3 antibody 3C11 (50 microg). Changes in the murine intestine were characterised by light microscopy analysis and terminal uridine nick-end labelling (TUNEL) assay. The role of perforin, Fas/Fas ligand (FasL), tumour necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) in T cell induced mucosal damage was assessed using selected immunodeficient mouse strains.

RESULTS

T cell activation caused severe damage, including small intestinal mucosal flattening and apoptosis of crypt epithelial cells. Mucosal damage was unaltered in anti-CD3 treated mice lacking IFN-gamma, Fas, or TNF-alpha receptors. In mice lacking TNF-alpha receptors and Fas (TNF-R1xR2 lpr/lpr strain), enterocyte apoptosis was diminished but there was no significant reduction in tissue damage. Apoptosis and mucosal injury were significantly reduced in perforin knockout mice. Abrogation of both FasL and perforin (perforin KOxgld mice) further significantly reduced tissue damage and apoptotic bodies.

CONCLUSIONS

T cell induced mucosal injury is mediated by the combined effect of multiple pathways but predominantly by perforin. The redundancy of the mechanisms of tissue damage will have significant impact on therapeutic strategies aimed at specific and targeted inhibition of inflammatory processes.

Hepatocyte growth factor stimulates proliferation of pancreatic beta-cells particularly in the presence of subphysiological glucose concentrations

We investigated the role of hepatocyte growth factor (HGF) in beta-cell growth and its complex intracellular signal transduction pathways. Cell proliferation was measured in the beta-cell line INS-1 using [3H]thymidine incorporation. Activation of mitogenic signaling proteins was assessed using co-immunoprecipitation, immunoblot analysis and specific protein activity inhibitors in proliferation assays. HGF (1 x 375 nM) increased INS-1 cell proliferation in the presence of 3-24 mM glucose up to 45-fold vs unstimulated controls. HGF exceeded the effect of glucose alone (2 x 2-fold at 3 mM glucose and 1 x 7-fold in the presence of 15 mM glucose). The HGF-induced INS-1 cell proliferation was further increased by addition of IGF-I or GH. Stimulation with HGF activated the JAK-2/STAT-5 pathway with a subsequent activation of phosphatidylinositol-3'-kinase (PI3'K). PI3'K activation was necessary for HGF- and glucose-stimulated INS-1 cell proliferation. The effect of PI3'K was mediated via 70 kDa S6 kinase and protein kinase B, which showed maximum activation in the presence of 3-6 mM glucose. Protein kinase C was essential for HGF-induced INS-1 cell proliferation. The HGF effect was also mediated at low glucose concentrations via insulin receptor substrate 4 (IRS-4) whereas other IRS proteins did not show any activation. High glucose concentrations also showed an increased IRS-4/PI3'K binding and therefore activation. In conclusion, beta-cell proliferation is mediated via complex interacting signal transduction pathways. HGF, in contrast to other growth factors, seems to be of importance particularly in the presence of low glucose concentrations and therefore takes a special role in this complex concert.

Intestinal macrophages lack CD14 and CD89 and consequently are down-regulated for LPS- and IgA-mediated activities

The intestinal mucosa normally displays minimal inflammation despite the close proximity between mucosal macrophages and lumenal bacteria. Macrophages interact with bacteria and their products through CD14, a surface receptor involved in the response to LPS, and CD89, the receptor for IgA (FcalphaR). Here we show that resident macrophages isolated from normal human intestine lack CD14 and CD89. The absence of CD14 and CD89 was not due to the isolation procedure or mucosal cell products, but was evident at the transcriptional level, as the macrophages expressed neither CD14- nor CD89-specific mRNAs, but did express Toll-like receptor 2 and 4 transcripts. Consistent with their CD14(-) phenotype, lamina propria macrophages displayed markedly reduced LPS-induced cytokine production and LPS-enhanced phagocytosis. In addition, IgA-enhanced phagocytosis was sharply reduced in lamina propria macrophages. Thus, the absence of CD14 and CD89 on resident intestinal macrophages, due to down-regulated gene transcription, causes down-modulated LPS- and IgA-mediated functions and probably contributes to the low level of inflammation in normal human intestinal mucosa.

[Giant fecaliths in habitual constipation]

HISTORY AND FINDINGS

A 17-year old adolescent with chronic constipation developed fecal incontinence with liquid, fetid stool. He had had variable bowel symptoms since early childhood, but not in his infancy. Since several years he had undergone psychotherapeutic treatment for depression due to a familial conflict situation. Abdominal palpation revealed the presence of a large, hard mass in the lower abdomen, measuring about 20 cm in diameter.

INVESTIGATIONS

A defecography verified the presence of a huge obstructing fecalith in the rectum, with massive dilation and elongation of the antecedent rectum and colon (megarectum and megacolon). Neither endoscopy nor radiological imaging revealed a narrow bowel segment. In sequential biopsies, no indication of aberrant innervation was found. The recto-anal inhibitory reflex could be elicited.

TREATMENT AND COURSE

Restoration of the rectal passage was achieved by manual disimpaction in numerous sessions, supported by repeated rectal enemas. Subsequently, the patient had normal daily bowel movements for a few days. However, he had to be readmitted three weeks later because again a fecalith had formed, measuring 15 cm in diameter. A few days after discharge the patient hat not followed the exhortation to void ad least once per day. After renewed disimpaction he was referred to a psychosomatic clinic.

CONCLUSION

Voluntary withholding of defecation can eventuate massive coprostasis and the development of megacolon and megarectum. In theses instances the major complaint may not be constipation but paradoxical diarrhea. A number of conditions have to be excluded before the diagnosis idiopathic megacolon can be confirmed. Treatment ist difficult and often necessitates prolonged and repetitious interventions.

[Gastrointestinal diseases in pregnancy]

Abdominal complaints during pregnancy are frequent. In most instances, nausea and vomiting are a consequence of pregnancy and are considered indicators of a well-developing pregnancy. The growing uterus and hormonal changes during pregnancy often lead to gastroesophageal reflux and constipation. Serious gastrointestinal diseases such as intestinal obstruction or the exacerbation of a chronic inflammatory bowel disease during pregnancy are rare, but if suspected, often warrant immediate confirmation and aggressive therapy. Unnecessary delays are associated with an increasing mortality and morbidity.

Characterization of enteric functional changes evoked by in vivo anti-CD3 T cell activation

Specific in vivo T cell activation initiated by treatment with anti-CD3 antibodies leads to diarrhea and structural damage of the intestinal mucosa. In this study, the effect of T cell-induced mucosal damage on jejunal epithelial ion transport, muscle contractility, and neuronal ACh release was assessed in Ussing chambers, organ baths, and a specialized perfusion apparatus, respectively. Time-matched control mice received hamster serum containing irrelevant antibodies. Jejunal segments from anti-CD3-treated mice displayed a significantly elevated epithelial baseline short-circuit current (which indicates increased ion transport) and a concomitant reduction in responsiveness to prosecretory stimuli (nerve stimulation, carbachol, and forskolin). Longitudinal smooth muscle displayed altered spontaneous contractile activity, length-tension relationships, and carbachol-stimulated contraction in tissues excised from mice 20 and 40 h posttreatment. Anti-CD3 treatment did not affect stimulated ACh release from myenteric plexus neurons. We conclude that specific T cell activation via anti-CD3 antibody results in dramatic alterations in jejunal epithelial and smooth muscle function. Such T cell-induced changes in intestinal function may contribute to the symptomatology of T cell-mediated enteropathies, including graft-versus-host disease, celiac disease, and idiopathic inflammatory bowel disease.

[Unusual case of disseminated sarcoidosis with prominent gastrointestinal symptoms]

HISTORY AND ADMISSION FINDINGS

A 63-year-old man had for 10 months suffered from marked weight loss, night sweats, diffuse abdominal pain and increased stool frequency. He was admitted to evaluate an ultrasonically abnormal focus in the liver parenchyma and elevated liver function parameters. His sclerae were obviously icteric and he looked under-weight.

INVESTIGATIONS

He had a hypochromic microcytic anemia and abnormal liver and pancreatic function tests: total bilirubin 3.11 mg/dl, direct bilirubin 2.21 mg/dl, GOT21U/l, gamma-GT 422 U/l, alkaline phosphatase 1449 U/l, alpha-amylase 481 U/l, lipase 2827 U/l. The serum creatinine level was elevated to 1.47 mg/dl. Computed tomography revealed enlarged liver and spleen as well as an enlargement of intraabdominal lymph nodes, chest radiogram and endoscopic cholangio-pancreatography were unremarkable. Biopsies from the lower duodenum, large intestine, bone marrow and liver showed inflammatory changes with Langhans-type mononuclear granulomas. Together with these findings an increased activity of the angiotensin-converting-enzyme (ACE) indicated sarcoidosis, other causes having been excluded.

TREATMENT AND COURSE

All signs and symptoms rapidly improved under prednisolone, and 4 weeks after begin of treatment the biochemical abnormalities had clearly regressed. The raised serum levels of soluble IL-2 receptors and of neopterin, measures of sarcoidosis activity, had decreased. Activity of ACE had fallen.

CONCLUSION

Sarcoidosis can present with diverse clinical signs and symptoms. In a case of multi-system disease that cannot be readily classified, sarcoidosis should be included in the differential diagnosis.

Infections in the immunopathogenesis of chronic inflammatory bowel disease

In chronic inflammatory bowel disease, self-destructive, exaggerated inflammation seems to occur in the absence of a well defined pathogen. However, epidemiological data strongly suggests that development of disease does not depend on endogenous factors alone. In this review, we summarize how a possible role for microbial factors can be reconciled with the current understanding of etiology and pathogenesis of IBD. The data presented does not support that IBD is an infectious disease nor that it is a self-antigen-specific autoimmune disease, however, recent findings increasingly suggest that tissue damage might be caused by a non-specific autoaggressive inflammation which is driven by common, ubiquitous microbial agents derived from the bacterial flora in the intestinal lumen.

Isolation and purification of CD14-negative mucosal macrophages from normal human small intestine

Mucosal macrophages play a fundamental role in the regulation of immunological events and inflammation in the small intestine. Because no information is available on normal small intestinal macrophages, we developed a technique for the isolation and purification of jejunal lamina propria macrophages in order to study their phenotype and activity. From sections of normal human jejunum, lamina propria mononuclear cells were isolated by neutral protease digestion and then subjected to counterflow centrifugal elutriation to purify the macrophages. The cells isolated by this procedure contained < 1% CD3+ lymphocytes and displayed the size distribution, morphological features, ultrastructure and phagocytic activity of mononuclear phagocytes. In contrast to blood monocytes, however, mucosal macrophages from the jejunum did not exhibit adherence properties or express CD14, a receptor for the lipopolysaccharide-binding protein. The purification of large numbers of lamina propria macrophages by this procedure offers the opportunity to define the role of this cell in the physiological inflammation characteristic of normal intestinal mucosa and the pathological inflammation associated with small intestinal diseases.

Modulation by 5-HT3 and 5-HT4 receptors of the release of 5-hydroxytryptamine from the guinea-pig small intestine

The effects of agonists and antagonists of 5-hydroxytryptamine (5-HT) receptors on the release of endogenous 5-HT from enterochromaffin cells were studied in the vascularly perfused isolated guinea-pig small intestine. The experiments were done in the presence of tetrodotoxin in order to exclude a neuronally mediated influence on 5-HT release. The 5-HT3 receptor agonist 2-methyl-5-HT increased 5-HT release, and this effect was antagonized by 1 nmol/l tropisetron. Nanomolar concentrations of tropisetron, MDL 72,222 and granisetron decreased 5-HT release. Ondansetron (0.1 and 1 mumol/l) did not modify 5-HT release. 5-Methoxytryptamine, BIMU8 and cisapride concentration-dependently inhibited 5-HT release. BIMU8 was more potent than 5-methoxytryptamine. Micromolar concentrations of tropisetron (1 and 10 mumol/l) enhanced the release, whilst methiothepine (0.1 mumol/l) did not affect the release of 5-HT. The results suggest that enterochromaffin cells of the guinea-pig ileum do not contain 5-HT1 and 5-HT2 receptors, but are endowed with 5-HT3 and 5-HT4 autoreceptors. Activation of the 5-HT3 receptors triggers a positive feedback mechanism leading to an increase of 5-HT release. The 5-HT3 receptors on the enterochromaffin cell differ from neuronal 5-HT3 receptors on guinea-pig myenteric plexus by their high affinity for tropisetron and MDL 72,222, and their very low affinity for ondansetron. Stimulation of 5-HT4 receptors causes inhibition of release; the inhibitory 5-HT4 receptor mechanism appears to predominate.