Prognostic impact of inter-metastatic heterogeneity of viable tumour cells in colorectal liver metastases.

BACKGROUND: Heterogenous response to neoadjuvant chemotherapy in patients with multiple colorectal liver metastases (CRLM) has been associated with an acquired resistance to systemic therapy. This study evaluated the occurrence of a heterogenous inter-metastatic tumour response with regards to the proportion of viable tumour cells, and its prognostic impact. METHODS: A retrospective cohort study was conducted, including all patients with CRLM surgically treated at Karolinska University Hospital, Stockholm, Sweden, from 2013 to 2018. Factors associated with the proportion of viable tumour cells and inter-metastatic heterogeneity were analysed with regression and survival analyses. RESULTS: Out of 640 surgically treated patients, 405 patients (1357 CRLM), received neoadjuvant chemotherapy. Multiple CRLM were present in 314 patients (78%), out of whom 72 patients (23%) presented with a heterogenous tumour response. The median overall survival (OS) for patients with a heterogenous inter-metastatic tumour response was 36 months, compared to 57 months for patients with a homogenous inter-metastatic tumour response (p < .001). Poor OS in patients receiving preoperative chemotherapy was significantly associated with a heterogenous inter-metastatic tumour response (hazard ratio (HR) 1.68 (1.02-2.78)), right-sided primary tumour (HR 2.01 (1.29-3.43)) and CRLM diameter >5 cm (HR 1.83 (1.06-3.17)). CONCLUSION: Outcome in patients with a heterogenous inter-metastatic tumour response, illustrated by the proportion of viable tumour cells, is inferior to that of patients with a homogenous response. These results suggest that heterogeneity in treatment response is an important marker of aggressive disease and could be of clinical value for decisions on post-operative therapy.

Conversion therapy in patients with colorectal liver metastases.

BACKGROUND: The occurrence of colorectal liver metastases (CRLM) impairs prognosis, yet long-term survival can be achieved by enabling liver resection. This study aims to describe factors associated with conversion therapy leading to liver surgery and treatment outcome. METHODS: A retrospective cohort study was conducted including all patients with CRLM discussed at multidisciplinary team conference at Karolinska University Hospital, Stockholm, Sweden, from 2013 to 2018. Factors associated with conversion therapy and outcome following conversion therapy were analysed with logistic regression and survival analyses. RESULTS: Out of 1023 patients with CRLM, 100 patients (10%) received conversion chemotherapy, out of whom 31 patients (31%) subsequently underwent liver resection. Patients in whom conversion chemotherapy resulted in liver resection were younger (median age 61 vs. 66 years, p = .024), less likely to have a KRAS/NRAS-mutated primary tumours (25% vs. 53%, p = .039) and more likely to have received anti-EGFR agents (32% vs. 4%, p = .001) than patients progressing during conversion chemotherapy. The median OS for patients treated with conversion chemotherapy leading to liver resection was 24 months, compared to 14 months for patients progressing during conversion chemotherapy, p < .001. The OS for patients progressing during conversion chemotherapy was similar to patients given palliative chemotherapy, approximately 13 months. CONCLUSION: Conversion therapy offers a survival benefit in selected patients. Despite treatment advances, the majority of patients undergoing conversion chemotherapy never become eligible for curative treatment.

Ex Vivo Generation of Donor Antigen-Specific Immunomodulatory Cells: A Comparison Study of Anti-CD80/86 mAbs and CTLA4-lg Costimulatory Blockade.

Adoptive transfer of alloantigen-specific immunomodulatory cells generated ex vivo with anti-CD80/CD86 mAbs (2D10.4/IT2.2) holds promise for operational tolerance after transplantation. However, good manufacturing practice is required to allow widespread clinical application. Belatacept, a clinically approved cytotoxic T-lymphocyte antigen 4-immunoglobulin that also binds CD80/CD86, could be an alternative agent for 2D10.4/IT2.2. With the goal of generating an optimal cell treatment with clinically approved reagents, we evaluated the donor-specific immunomodulatory effects of belatacept- and 2D10.4/IT2.2-generated immunomodulatory cells. Immunomodulatory cells were generated by coculturing responder human peripheral blood mononuclear cells (PBMCs) (50 × 106 cells) with irradiated donor PBMCs (20 × 106 cells) from eight human leukocyte antigen-mismatched responder-donor pairs in the presence of either 2D10.4/IT2.2 (3 µg/106 cells) or belatacept (40 µg/106 cells). After 14 days of coculture, the frequencies of CD4+ T cells, CD8+ T cells, and natural killer cells as well as interferon gamma (IFN-γ) production in the 2D10.4/IT2.2- and belatacept-treated groups were lower than those in the control group. The percentage of CD19+ B cells was higher in the 2D10.4/IT2.2- and belatacept-treated groups than in the control group. The frequency of CD4+CD25+CD127lowFOXP3+ T cells increased from 4.1±1.0% (preculture) to 7.1±2.6% and 7.3±2.6% (day 14) in the 2D10.4/IT2.2- and belatacept-treated groups, respectively (p<0.05). Concurrently, delta-2 FOXP3 mRNA expression increased significantly. Compared with cells derived from the no-antibody treated control group, cells generated from both the 2D10.4/IT2.2- and belatacept-treated groups produced lower IFN-γ and higher interleukin-10 levels in response to donor-antigens, as detected by enzyme-linked immunospot. Most importantly, 2D10.4/IT2.2- and belatacept-generated cells effectively impeded the proliferative responses of freshly isolated responder PBMCs against donor-antigens. Our results indicate that belatacept-generated donor-specific immunomodulatory cells possess comparable phenotypes and immunomodulatory efficacies to those generated with 2D10.4/IT2.2. We suggest that belatacept could be used for ex vivo generation of clinical grade alloantigen-specific immunomodulatory cells for tolerance induction after transplantation.

De Novo Donor-Specific HLA Antibody Formation in Two Patients With Crigler-Najjar Syndrome Type I Following Human Hepatocyte Transplantation With Partial Hepatectomy Preconditioning.

Clinical hepatocyte transplantation is hampered by low engraftment rates and gradual loss of function resulting in incomplete correction of the underlying disease. Preconditioning with partial hepatectomy improves engraftment in animal studies. Our aim was to study safety and efficacy of partial hepatectomy preconditioning in clinical hepatocyte transplantation. Two patients with Crigler-Najjar syndrome type I underwent liver resection followed by hepatocyte transplantation. A transient increase of hepatocyte growth factor was seen, suggesting that this procedure provides a regenerative stimulus. Serum bilirubin was decreased by 50%, and presence of bilirubin glucuronides in bile confirmed graft function in both cases; however, graft function was lost due to discontinuation of immunosuppressive therapy in one patient. In the other patient, serum bilirubin gradually increased to pretransplant concentrations after ≈600 days. In both cases, loss of graft function was temporally associated with emergence of human leukocyte antigen donor-specific antibodies (DSAs). In conclusion, partial hepatectomy in combination with hepatocyte transplantation was safe and induced a robust release of hepatocyte growth factor, but its efficacy on hepatocyte engraftment needs to be evaluated with additional studies. To our knowledge, this study provides the first description of de novo DSAs after hepatocyte transplantation associated with graft loss.

Serum apolipoprotein E as a marker to monitor graft function after hepatocyte transplantation in a clinically relevant mouse model.

INTRODUCTION: Hepatocyte transplantation, a promising treatment for patients with acute hepatic failure or metabolic liver diseases, requires improvement in engraftment as well as long-term function of the liver cells. We established a hepatocyte transplantation model in apolipoprotein E (ApoE) knockout mice, evaluating serum ApoE and lipoprotein profiles as markers of engraftment of transplanted wild-type hepatocytes. Herein we have described a method to monitor the function of transplanted hepatocytes at low levels of engraftment, corresponding to those reported in clinical cases. We also investigated whether pretreatment with anakinra, an anti-interleukin-1 antagonist, methylprednisolone, or a combination of the two agents improved engraftment. METHODS: ApoE (-/-) mice were transplanted with hepatocytes isolated from wild-type C57/bl6 mice. A total of 6 × 10(6) hepatocytes were transplanted by 3 separate intrasplenic injections. Animals were treated before transplantation and daily thereafter for 7 days with anakinra, methylprednisolone, or a combination of both. Graft function was monitored by lipoprotein analysis and quantification of ApoE by enzyme-linked immunosorbent assay. Expression of hepatic ApoE mRNA was quantitated by reverse-transcriptase polymerase chain reaction. RESULTS: Treatment with anakinra with or without methylprednisolone did not significantly increase serum or hepatic mRNA ApoE expression. The low level of hepatocyte engraftment did not normalize lipoprotein profiles, but produced a significant decline in very low-density lipoprotein and total cholesterol. Repeated transplantations significantly enhanced liver repopulation; serum ApoE levels increased with each infusion, correlating well with hepatic mRNA expression. CONCLUSIONS: The model of serum ApoE, a sensitive marker of engraftment and transplanted hepatocyte function, allowed us to study hepatocyte transplantation in a clinically relevant manner, that is, without pretreatments such as retrorsine or carbon tetrachloride.

Hepatocyte transplantation for inherited metabolic diseases of the liver.

Inherited metabolic diseases of the liver are characterized by deficiency of a hepatic enzyme or protein often resulting in life-threatening disease. The remaining liver function is usually normal. For most patients, treatment consists of supportive therapy, and the only curative option is liver transplantation. Hepatocyte transplantation is a promising therapy for patients with inherited metabolic liver diseases, which offers a less invasive and fully reversible approach. Procedure-related complications are rare. Here, we review the experience of hepatocyte transplantation for metabolic liver diseases and discuss the major obstacles that need to be overcome to establish hepatocyte transplantation as a reliable treatment option in the clinic.

Microdialysis monitoring for evaluation of the influence exerted by pneumoperitoneum on the kidney: an experimental study.

BACKGROUND: Laparoscopic donor nephrectomy has become the first choice for living donor kidney transplantation, offering advantages over open donor nephrectomy. This study aimed to evaluate kidney tissue metabolism during and after pneumoperitoneum using a microdialysis technique. METHODS: Eight pigs underwent laparotomy and implantation of two microdialysis catheters: one in the cortex and one in the medulla of the left kidney. After laparotomy, the abdominal wall was closed, and pneumoperitoneum was induced with a constant standard pressure of 16 to 18 mmHg for 4 h, followed by rapid desufflation. In microdialysis samples collected from intrarenal catheters, markers of ischemia (glucose, lactate, pyruvate, and lactate-pyruvate ratio) and the marker of cell membrane injury (glycerol) were monitored. RESULTS: There were no changes in glucose, lactate, or pyruvate level before, during, or after pneumoperitoneum, either in the cortex or in the medulla. Additionally, the calculated lactate-pyruvate ratio did not show signs of ischemia during or after pneumoperitoneum. However, with regard to the marker of cell injury, glycerol increased in the medulla after decompression from 22.57 +/- 3.76 to 35.67 +/- 5.43 mmol/l (p < 0.01). This release of glycerol in the medulla was significantly higher than in the cortex (area under the curve [AUC], 22.18 +/- 4.87 vs 34.79 +/- 7.88 mmol/l; p < 0.01). CONCLUSIONS: The pattern of metabolic changes monitored in the kidney during and after pneumoperitoneum indicates some kind of cell injury predominant in the medulla without any signs of kidney ischemia. This nonischemic injury could be related to hyperperfusion of the kidney after decompression or injury to cells attributable to mechanical cell expansion at the point of rapid decompression.