Immunomodulation of peritoneal macrophages by granulocyte-macrophage colony-stimulating factor in humans

Shorter Total Length of Stay After Intraperitoneal Fosfomycin, Metronidazole, and Molgramostim for Complicated Appendicitis: A Pivotal Quasi-Randomized Controlled Trial

Background: We aimed to investigate the difference in the total length of hospital stay (LOS) after intraperitoneal vs. intravenous antibiotic treatment in patients with complicated appendicitis.

Methods: We conducted a quasi-randomized prospective clinical trial. The intervention group received 4 g fosfomycin, 1 g metronidazole, and 50 μg recombinant human granulocyte-macrophage colony-stimulating factor intraperitoneally, which was left in the abdominal cavity, immediately after laparoscopic appendectomy. Postoperatively, this group received antibiotics orally. The control group received intravenous antibiotics both during surgery and postoperatively. We primarily evaluated total LOS within 30 days. Furthermore, we evaluated harms and adverse events, Gastrointestinal Quality of Life Index, postoperative complications, and convalescence. Participants were followed for 30 days postoperatively.

Results: A total of 12 participants concluded the trial. The total LOS was significantly shorter in the intervention group (six participants, median 13 h; range 2–21 h) than in the control group (six participants, median 84 h; range 67–169 h), p = 0.017. Comparable harms and Gastrointestinal Quality of Life Index scores were found in the two groups. The time to return to normal activities was median 6 and 10 days for the intervention and the control group, respectively. There were no serious adverse events related to the trial nor any complications in the intervention group. In the control group, two patients developed intraabdominal abscesses.

Conclusions: The intervention group had a significantly shorter total LOS. The study was not powered to assess differences in complications, but the results indicate that the intervention seems to be a safe regimen, which can be investigated further to treat patients with complicated appendicitis.

Identifiers: EudraCT no. 2017-004753-16.

ClinicalTrials:https://clinicaltrials.gov/ct2/show/NCT03435900?term=NCT03435900&draw=2&rank=1">draw=2&rank=1.

Intraperitoneal administration of fosfomycin, metronidazole, and granulocyte-macrophage colony-stimulating factor in patients undergoing appendectomy is safe: a phase II clinical trial

We aimed to investigate the safety of intraperitoneal administration of the combination of fosfomycin, metronidazole, and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in patients undergoing appendectomy. We conducted a prospective phase II clinical trial in 14 otherwise healthy men suffering from uncomplicated appendicitis. After appendectomy, the trial treatment was administered intraperitoneally and left in the abdominal cavity. Trial treatment consisted of 4 g fosfomycin, 1 g metronidazole, and 50 µg rhGM-CSF in a total volume of 500 ml. Safety was evaluated through white blood cell count where a toxic effect was predefined. We evaluated harms and adverse events, repeated biochemical markers, vital signs, and length of stay. White blood cell count did not drop below the toxic range. The recorded harms were dizziness, discomfort when breathing deeply, no flatus, and bloating. Adverse events included three patients with diarrhoea after discharge and one patient with a hypotensive episode. No serious adverse events or infectious complications occurred. Intraperitoneal administration of fosfomycin, metronidazole, and rhGM-CSF was safe in otherwise healthy men undergoing laparoscopic appendectomy. There were some possible harms and adverse events but we were unable to assess if they were related to anaesthesia, surgery, or the trial treatment.

Is There a Role for Hematopoietic Growth Factors During Sepsis?

Sepsis is a complex syndrome characterized by simultaneous activation of pro- and anti-inflammatory processes. After an inflammatory phase, patients present signs of immunosuppression and possibly persistent inflammation. Hematopoietic growth factors (HGFs) are glycoproteins that cause immune cells to mature and/or proliferate. HGFs also have a profound effect on cell functions and behavior. HGFs play crucial role in sepsis pathophysiology and were tested in several clinical trials without success to date. This review summarizes the role played by HGFs during sepsis and their potential therapeutic role in the Management of sepsis-related immune disturbances.

Identification of Gene Transcripts Implicated in Peritoneal Membrane Alterations

♦ BACKGROUND: Permanent stimulation of the peritoneum during peritoneal dialysis (PD) is likely to result in increased expression of genes encoding proteins involved in inflammation and tissue remodeling. Peritoneal fibrosis and neoangiogenesis may develop. ♦ OBJECTIVE: To assess highly expressed genes potentially in volved in peritoneal alterations during PD treatment using an animal model. ♦ METHODS: A PD catheter was implanted in 36 male Wistar rats after 70% nephrectomy. The rats were divided into 3 groups, exposed to dialysis solution for 8 weeks, and sacrificed 2 weeks later. Group B was exposed to a buffer, group D was exposed to a 3.86% glucose-based dialysis solution, and in group D+H, a second hit of intraperitoneal blood on top of the dialysis solution was given to induce the development of peritoneal sclerosis. Before sacrifice, peritoneal function was assessed. Omental tissue was obtained for analysis of gene expression using RT-qPCR. ♦ RESULTS: Fibrosis scores, vessel counts, and peritoneal function parameters were not different between the groups. Genes involved in the transforming growth factor beta signaling pathway, cell proliferation, angiogenesis, and inflammation were more expressed (p < 0.05) in the D+H group. Almost no differences were found between the control groups. We identified 4 genes that were related to peritoneal transport. ♦ CONCLUSION: Already a mid-term peritoneal exposure, when no microscopical and functional alterations are present, provokes activation of gene pathways of cell proliferation, fibrosis, neoangiogenesis, and inflammation.

A Review of GM-CSF Therapy in Sepsis

Determine what clinical role, if any, GM-CSF may have in the clinical treatment of sepsis in the adult patient. Advancements in the management of sepsis have led to significant decreases in early mortality; however, sepsis remains a significant source of long-term mortality and disability which places strain on healthcare resources with a substantial growing economic impact. Historically, early multiple organ failure (MOF) and death in patients with severe sepsis was thought to result from an exaggerated proinflammatory response called the systemic inflammatory response syndrome (SIRS). Numerous prospective randomized controlled trials (PRCTs) tested therapies aimed at decreasing the organ injury associated with an exaggerated inflammatory response. With few exceptions, the results from these PRCTs have been disappointing, and currently no specific therapeutic agent is approved to counteract the early SIRS response in patients with severe sepsis. It has long been recognized that there is a delayed immunosuppressive state that contributes to long-term morbidity. However, recent findings now support a concurrent proinflammatory and anti-inflammatory response present throughout sepsis. Multiple immunomodulating agents have been studied to combat the immunosuppressive phase of sepsis with the goal of decreasing secondary infection, reducing organ dysfunction, decreasing ICU stays, and improving survival. Granulocyte-macrophage colony stimulating factor (GM-CSF), a myelopoietic growth factor currently used in patients with neutropenia secondary to chemotherapy-induced myelosuppression, has been studied as a potential immune-activating agent. The applicability of GM-CSF as a standard therapy for generalized sepsis is still largely understudied; however, small-scale studies available have demonstrated some improved recovery from infection, decreased hospital length of stay, decreased days requiring mechanical ventilation, and decreased medical costs.

A potential role of macrophage activation in the treatment of cancer

One of the functions of macrophages is to provide a defense mechanism against tumor cells. In the last decades the mechanism of tumor cell killing by macrophages have been studied extensively. The tumor cytotoxic function of macrophages requires stimulation either with bacterial cell wall products such as lipopolysaccharide (LPS) or muramyldipeptide (MDP) or with cytokines such as interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Activated macrophages secrete several substances that are directly involved in tumor cell killing i.e. tumor necrosis factor (TNF) and nitric oxide (NO). On the other hand, substances are secreted that are able to stimulate tumor cell growth, depending on the stage and the nature of the tumor. Several clinical trials have been performed aiming at the activation of macrophages or dendritic cells, a subpopulation of the macrophages. In this review we will summarize and discuss experimental studies and clinical trials based on the activation of macrophages.

Activation of peritoneal cells upon in vivo transfection with a recombinant alphavirus expressing GM-CSF

In this study we determined the in vivo localization of recombinant proteins expressed by intraperitoneally (i.p.) injected recombinant Semliki Forest virus (SFV) particles. Subsequently, we investigated the influence of i.p. administered SFV particles encoding recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on intraperitoneal recruitment and activation of cells. Finally, the therapeutic effect of SFV-GM-CSF treatment on an i.p. growing ovarian tumor was determined. Intraperitoneal injections of recombinant SFV particles encoding the reporter protein luciferase resulted in a high level of luciferase activity in cells of the peritoneal lining and tumor cells in the peritoneal cavity. Low levels of luciferase activity were found in liver, spleen and lungs. Injection of SFV-GM-CSF particles resulted in a slight increase in the number of peritoneal macrophages and in a significant increase in the number of neutrophils. In contrast to multiple i.p. injections with commercially available recombinant GM-CSF, i.p. injected SFV-GM-CSF particles activated the macrophages to tumor cytotoxicity. Although treatment of tumor-bearing mice with SFV-GM-CSF particles did not result in prolonged survival, tumor growth was inhibited for 2 weeks. Our findings indicate that macrophage-activating cytokines expressed by the efficient and safe recombinant SFV system when administered i.p. may provide an immunotherapeutic treatment modality additional to current chemotherapeutic treatment of intraperitoneally growing cancers.

Effect of intraperitoneally administered recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on the cytotoxic potential of murine peritoneal cells

We studied the effect of recombinant murine granulocyte-macrophage colony-stimulating factor (rmGM-CSF) on the cytotoxic potential of murine peritoneal cells. Mice received rmGM-CSF intraperitoneally using different dosages and injection schemes. At different time points after the last injection, mice were sacrificed, peritoneal cells isolated and their tumour cytotoxicity was determined by a cytotoxicity assay using syngeneic [methyl-3H]thymidine-labelled colon carcinoma cells. Also, the cytotoxic response to a subsequent in vitro stimulation with lipopolysaccharide was determined. Upon daily injection of 6000-54,000 U rmGM-CSF over a 6-day period, the number of peritoneal cells increased over ten fold with the highest rmGM-CSF dose. Increases in cell numbers was mainly due to increases in macrophage numbers. Upon injection of three doses of 3000 U rmGM-CSF per day for 3 consecutive days, the number of macrophages remained elevated for minimally 6 days. Although the peritoneal cells from rmGM-CSF-treated mice were not activated to a tumoricidal state, they could be activated to high levels of cytotoxicity with an additional in vitro stimulation of lipopolysaccharide. Resident cells isolated from control mice could be activated only to low levels of tumour cytotoxicity with lipopolysaccharide. Tumour cytotoxicity strongly correlated with nitric oxide secretion. When inhibiting nitric oxide synthase, tumour cell lysis decreased. Thus, the expanded peritoneal cell population induced by multiple injections of rmGM-CSF has a strong tumour cytotoxic potential and might provide a favourable condition for immunotherapeutic treatment of peritoneal neoplasms.

Granulocyte stimulating factor in patients on peritoneal dialysis and LPS stimulated peripheral blood mononuclear cells

Dialysate and serum levels of granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage colony stimulating factor (GM-CSF) and leukemia inhibitory factor (LIF) were analyzed in patients with continuous ambulatory peritoneal dialysis (CAPD). Samples from the peritoneal effluent and from serum were obtained during the first months of dialysis and during peritonitis from the first three dialysate bags drained on the day of admittance and form nightbags on days three and ten. Serum samples were drawn on days one and ten. On the first day of infection G-CSF was detected in twelve out of fifteen samples in the dialysate and reached its peak median level, 443 pg/ml, in the first drained bag and thereafter decreased significantly. Also in serum a peak, 190 pg/ml, was observed on the first day. LIF was found in six of ten analyzed dialysate samples, with a peak median level of 77 pg/ml on day one, while only four of ten patients had detectable GM-CSF. Peripheral blood mononuclear cells from non-infected CAPD patients were stimulated with lipopolysaccharide and G-CSF levels in the supernatants increased significantly (P < 0.05) after 6 h stimulation. We conclude that G-CSF is produced locally in the dialysate during the acute stage of peritonitis and to a lesser extent also systemically. These findings are in line with G-CSF production after LPS stimulation of peripheral blood mononuclear cells.