Detlef Meyer

Morbidity of Temporary Loop Ileostomy in Patients With Colorectal Cancer

PurposeThis study was designed to quantify the temporary loop ileostomy-related morbidity in patients with colorectal cancer and contrast the morbidity rates after ileostomy closure before, during, and after the start of adjuvant therapy.MethodsBetween 1997 and 2004, 120 patients with colorectal carcinoma underwent colorectal resection and creation of a temporary loop ileostomy to protect the low anastomosis. Stoma-related complications and perioperative morbidity after ileostomy closure were assessed retrospectively by reviewing the medical records.ResultsSixteen of the 120 patients (13.3 percent) suffered stoma-related complications, requiring early ileostomy closure in three. After ileostomy closure, anastomotic leakage of the ileoileostomy occurred in 3 of the 120 patients (2.5 percent), 2 of them died postoperatively (1.7 percent). The rate of minor complications (16.7 percent in all patients) was much higher in patients undergoing adjuvant chemotherapy or radiochemotherapy (25.5 percent) than in patients receiving no additional therapy (9.2 percent). In the former patients, there was a trend toward fewer complications when ileostomy closure was performed before (12.5 percent), rather than during (42.9 percent) or after (21.2 percent), the start of adjuvant therapy.ConclusionsThe morbidity following closure of a temporary loop ileostomy in colorectal cancer patients is much higher in patients receiving adjuvant chemotherapy or radiochemotherapy. The morbidity, however, might possibly be lowered to the level of patients receiving no additional therapy if ileostomy closure is performed before the start of adjuvant therapy.

Apoptosis of T lymphocytes in liver and/or small bowel allografts during tolerance induction.

BACKGROUND Apoptosis of parenchymal cells has been described during allograft rejection. Immunologically privileged tissue in the mouse has been found to prevent rejection by initiating apoptosis of infiltrating lymphocytes. The aim of this study was to investigate whether apoptosis may play a role in T-cell regulation during rejection and subsequent tolerance induction after liver transplantation (LTx) and combined liver/small bowel transplantation (LSBTx). METHODS LTx and LSBTx (Brown Norway-->Lewis) were performed without immunosuppression. Cell migration, activation, and apoptosis were investigated by means of sequential histology, immunohistochemistry, and the terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labeling assay. Donor (Brown Norway) and third-party (Dark Agouti) cardiac allografts were transplanted into LSBTx recipients to determine specific tolerance. RESULTS Transient acute cellular rejection occurred after LTx and LSBTx and was followed by specific tolerance. The kinetics of apoptosis were similar in liver allografts after LTx and LSBTx, but differed from the processes in small bowel allografts after LSBTx. Apoptosis of parenchymal cells in the grafted livers correlated directly with interleukin-2 receptor expression of the infiltrating T cells. During the late phase of rejection, a peak of apoptosis in the lymphocyte infiltrate was demonstrated, characterized as predominantly apoptotic CD8+ T lymphocytes. CONCLUSIONS These results demonstrate that specific tolerance is achieved in both LTx and LSBTx after a transient rejection crisis. Apoptosis is involved in graft rejection and tolerance induction. Activation of T lymphocytes correlates with parenchymal cell apoptosis in the allograft. T-cell inactivation seems to result in apoptosis of cytotoxic T cells and tolerance, which appears to be unique to the liver allograft.

Band Erosion and Passage, Causing Small Bowel Obstruction

A rare complication of adjustable gastric banding is reported. A 65-year-old man developed recurrent vomiting, epigastric pain, and small-bowel obstruction 13 months after laparoscopic adjustable gastric banding for morbid obesity. Investigation revealed that the band had migrated completely into the gastric lumen and had passed far down the jejunum. The band was still connected by the tubing to the port chamber. By laparoscopy, the band was cut at the stomach, and removed via a jejunotomy. Postoperative course was uneventful. Complete band migration requires early removal of the band.

Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases

BackgroundThe local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth.MethodsCT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired t test when appropriate.ResultsIntraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-β and TNF-α were increased during tumor growth whereas IFN-γ showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location.ConclusionsThis study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the situation in human cancer.

Tolerance of rat liver allografts induced by short-term selective immunosuppression combining monoclonal antibodies directed against CD25 and CD54 with subtherapeutic cyclosporine.

BACKGROUND Our purpose was to develop and evaluate protocols for selective immunosuppression after liver transplantation using the monoclonal antibodies (mAbs) NDS-61, directed against the interleukin-2 receptor (CD25), and 1A29, directed against the intercellular adhesion molecule-1 (CD54), in combination with subtherapeutic cyclosporine (CsA). METHODS Orthotopic rat liver transplantation (ORLT) was performed in a DA-to-LEW strain combination. Immunosuppression was administered from day 0 to +13. Functional parameters such as survival time, body weight, and serum bilirubin levels were measured and the liver grafts were evaluated histologically. RESULTS A stepwise tapering of CsA from 3 to 0.25 mg/kg/day reduced the long-term survival rate. All animals died at a CsA dosage of 0.25 mg/kg/day, which was therefore defined as subtherapeutic. Monotherapy with the anti-CD25 mAb was performed at dosages of 600 and 1800 microg/kg/day. The lower mAb dosage resulted in a long-term survival rate of 12% and was defined as subtherapeutic. The combination therapy of CsA (0.25 mg/kg/day) and anti-CD25 mAb (600 microg/kg/day) produced a synergistic effect and led to a long-term survival rate of 84%. This survival rate was significantly higher than those after either CsA (P<0.005) or anti-CD25 mAb (P<0.001) monotherapy. Both dosages (10 and 30 microg/kg/day) of anti-CD54 mAb monotherapy as well as anti-CD54 mAb combined with a subtherapeutic dosage of CsA were ineffective in preventing acute allograft rejection. The addition of anti-CD54 mAb (30 microg/kg/day) to combined CsA plus anti-CD25 mAb therapy (triple therapy), however, increased the long-term survival rate to 100%. In the triple therapy group there was no rejection process in the liver allografts at any time, and donor-specific tolerance could be shown by donor-specific and third-party heterotopic heart transplantation. CONCLUSIONS The synergistic action of subtherapeutic CsA plus anti-CD25 mAb NDS-60 could be demonstrated, whereas anti-CD54 mAb only had a positive effect in a triple therapy group. Triple therapy prevented both acute and chronic rejection and induced donor-specific tolerance.

Familial gastrointestinal stromal tumors caused by the novel KIT exon 17 germline mutation N822Y.

Gastrointestinal stromal tumors (GISTs) are most often associated with oncogenic mutations of the KIT gene resulting in activation of the tyrosine kinase receptor KIT. Familial GIST syndrome based on a hereditary predisposition to develop GIST owing to a germline mutation is exceedingly rare. We describe a kindred with familial GIST displaying a novel germline mutation in exon 17. Three siblings (2 females, 1 male; 42 to 49 y) underwent surgery for multiple intra-abdominal tumors within a 3-year period. Their father had been operated on for gastric and jejunal tumors 20 years previously. The GIST was confirmed by immunohistochemistry in each sibling. Tumor and blood samples of the family members were analyzed for mutations in KIT and platelet-derived growth factor receptor (PDGFRα) genes. All examined lesions were of spindle cell type with expression of CD117. The tumor material exhibited a novel point mutation in codon 822 in exon 17 resulting in the replacement of asparagine by tyrosine (N822Y). The same mutation was detected in the fathers blood sample. One healthy brother of the 3 siblings showed a wild-type sequence of the KIT gene. The germline mutation in exon 17 of the KIT gene identified in this kindred is very different from previously reported mutations of the KIT gene in familial GIST. Although the penetrance of KIT mutations is as yet unknown, assessment of the unaffected kindred of GIST patients for the presence of this mutation could help to distinguish individuals at high risk from those at virtually no risk.

The intraportal injection model: A practical animal model for hepatic metastases and tumor cell dissemination in human colon cancer

BackgroundThe development of new therapeutic strategies for treatment of metastasized colorectal carcinoma requires biologically relevant and adequate animal models that generate both reproducible metastasis and the dissemination of tumor cells in the form of so-called minimal residual disease (MRD), an expression of the systemic character of neoplastic disease.MethodsWe injected immunoincompetent nude mice intraportally with different numbers (1 × 105, 1 × 106 and 5 × 106 cells) of the human colon carcinoma cell lines HT-29 and SW-620 and investigated by histological studies and CK-20 RT-PCR the occurrence of hematogenous metastases and the dissemination of human tumor cells in bone marrow.ResultsOnly the injection of 1 × 106 cells of each colon carcinoma cell line produced acceptable perioperative mortality with reproducible induction of hepatic metastases in up to 89% of all animals. The injection of 1 × 106 cells also generated tumor cell dissemination in the bone marrow in up to 63% of animals with hepatic metastases.ConclusionThe present intraportal injection model in immunoincompetent nude mice represents a biologically relevant and adequate animal model for the induction of both reproducible hepatic metastasis and tumor cell dissemination in the bone marrow as a sign of MRD.

Mechanisms of Tolerance Induction After Rat Liver Transplantation: Intrahepatic CD4+ T Cells Produce Different Cytokines During Rejection and Tolerance in Response to Stimulation☆☆☆

Increasing evidence supports the existence of regulatory T cells that may inhibit the allogeneic immune response after transplantation by secreting regulatory cytokines. To determine whether rat liver tolerance is associated with intrahepatic regulatory T cells secreting a characteristic cytokine profile, we analyzed the cytokine production of freshly isolated intragraft CD4+ T cells at different times postoperatively by semiquantitative reverse transcription-polymerase chain reaction and by enzyme-linked immunosorbent assay before and after in vitro stimulation. Orthotopic arterialized liver transplantation was performed in two allogeneic rat strain combinations, one with fatal acute rejection (DA-to-LEW) and one with long-lasting tolerance (LEW-to-DA) without immunosuppression despite a complete major histocompatibility complex mismatch (spontaneous liver tolerance). Liver allografts of both groups showed continuously increasing cellular infiltration between day 3 and day 7 after transplantation. In this inflammatory situation, very low levels of interleukin-13 were detectable directly after cell isolation, as well as after in vitro stimulation. However, after 30 days, intrahepatic CD4+T cells in the tolerance group were then able to express elevated messenger RNA levels of the anti-inflammatory cytokine interleukin-13 in response to stimulation. This result indicates the presence of an intragraft Th2-like CD4+T cell population, which may have a regulatory function in the induction of liver tolerance.

Transfusion-related acute lung injury (TRALI) —an important, severe transfusion-related complication

BackgroundTransfusion-related acute lung injury (TRALI) is an immune-mediated transfusion reaction that can cause severe complications or even death. It is now the leading cause of transfusion-related death in the United States.MethodsThe TRALI syndrome is presented in two cases in a surgical intensive care unit and discussed against the background of the present literature. In both cases, concomitant diseases led to an extremely difficult course of TRALI.ConclusionsKnowledge of the TRALI syndrome is necessary to enable early diagnosis and treatment. It should be taken into consideration at any time when cardiopulmonary instability occurs after transfusion of blood products, which is a frequent event on surgical Intensive Care Units. TRALI remains a clinical diagnosis supported by serologic studies if these are available. Against the background of this potentially life-threatening complication, every single indication to transfuse blood products needs to be scrutinized carefully.

Regulatory Allospecific T Cell Clones Abrogate Chronic Allograft Rejection

True alloantigen-specific tolerance is the ultimate goal of solid organ transplantation, eliminating the need for long-term immunosuppression. Recent evidence suggests that Th1-derived cytokines are associated with rejection and Th2-derived cytokines with long-term allograft survival, but the roles of these subsets in rejection and tolerance are incompletely understood. Here, we analyzed the functional and regulatory capacities of T cell clones derived from tolerant and rejecting rats (Wistar rat donors, Lewis rat recipients). We generated and subcloned T cell lines from lymphocytes derived from either acutely rejecting grafts or from the grafts of CTLA4-Ig-treated tolerant rats. Pretransplantation adoptive transfer of T cell clones generated from rejected grafts (Th1 clones) accelerated acute rejection or promoted development of chronic rejection, whereas transfer of T cell clones generated from tolerized grafts (Th2 clones) protected rats from acute rejection and progressive organ dysfunction. When Th1 and Th2 clones were injected simultaneously, Th2 clones specifically regulated activation of Th1 clones. Rats that received injections of Th2 clones accepted long-term donor-specific skin grafts but acutely rejected third-party skin grafts. Tolerant rats treated with Th2 clones demonstrated an increased number of regulatory CD4+CD25+Foxp3+ cells and strong mononuclear cell staining for IL-10 but negligible IFN-gamma, IL-17, and IL-23 compared with untreated rats or those treated with Th1 clones. In summary, these results demonstrate the regulatory functions of Th2 cells in a clinically relevant allogeneic transplant model and provide new insight into the functional role of Th2 cells in preventing the process of chronic rejection.