Autoimmune neutropenia (AIN) is characterized by antibody mediated peripheral destruction of neutrophils. Since there is no effective treatment, antibiotics have to be used frequently for recurrent infections. Five selected patients with serologically proven AIN were treated with r-metHuG- CSF at 5-8 μg/kg body weight (300-480 μg) daily: the dose and frequency of r-metHuG-CSF was reduced after neutrophil counts above 1.0 x 109/l were obtained. R-metHuG-CSF is effective in AIN and causes a sustained rise in ANC which can he maintained on a low dose administered twice or thrice weekly.

Candida albicans is an increasingly important pulmonary fungal pathogen. Resident alveolar macrophages are important in host defense against opportunistic fungal infections. Activation of Group IVA cytosolic phospholipase A2α (cPLA2α) in macrophages initiates arachidonic acid (AA) release for production of eicosanoids, which regulate inflammation and immune responses. We investigated the ability of C. albicans to activate cPLA2α in unprimed alveolar macrophages and after priming with granulocyte macrophage colony-stimulating factor (GM-CSF), which regulates alveolar macrophage maturation. AA was released within minutes by GM-CSF-primed but not unprimed alveolar macrophages in response to C. albicans, and was blocked by soluble glucan phosphate (S-GP). The expression of the β-glucan receptor dectin-1 was increased in GM-CSF-primed macrophages, and AA release from GM-CSF-primed dectin-1-/- alveolar macrophages was reduced to basal levels. The enhanced activation of extracellular signal-regulated kinases and phosphorylation of cPLA2α on Ser-505 that occurred in GM-CSF-primed macrophages were reduced by MEK1 and Syk inhibitors, which also suppressed AA release. At later times after C. albicans infection (6 h), unprimed and GM-CSF-primed macrophages released similar levels of AA. The expression of cyclooxygenase 2 and prostanoid production at 6 hours was higher in GM-CSF-primed macrophages, but the responses were not dependent on dectin-1. However, dectin-1 contributed to the C. albicans-stimulated increase in TNF-α production that occurred in GM-CSF-primed macrophages. The results demonstrate that dectin-1 mediates the acute activation of cPLA 2α in GM-CSF-primed alveolar macrophages, but not in the more delayed phase of AA release and GM-CSF-dependent prostanoid production.

Granulocyte colony-stimulating factor (GCSF) is currently the most widely used cytokine for stem cell mobilization. There are few studies suggesting GCSF administration may induce activation of both coagulation and endothelial cells that could favor the developing of thrombotic events. We report a 58-year-old female with vasculitis and renal impairment. She was found to have an underlying monoclonal gammopathy of unknown significance (MGUS). The monoclonal protein was felt to play a role in her underlying renal disease and peripheral neuropathy. She was considered a candidate for peripheral blood stem cell transplantation to manage the monoclonal protein. During stem cell mobilization with GCSF, she developed worsening of anemia; thrombocytopenia and worsening of renal function. She was diagnosed with thrombotic microangiopathy (TMA) which was successfully treated with therapeutic plasma exchange and rituximab. It is possible that GCSF may have directly (activating endothelial cells) or indirectly (activation of underlying autoimmune disorder) contributed to TMA in this patient.

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Une des stratégies pour limiter les neutropénies induites par la chimiothérapie est l’utilisation de granulocyte-colony stimulating factor (G-CSF). Nous avons développé, par une approche de population, un nouveau modèle pharmacocinétique/pharmacodynamique capable de décrire la cinétique des neutrophiles des patients traités au carboplatine, qu’ils aient ou non reçu du G-CSF. Les simulations réalisées à partir de ce modèle ont montré que le G-CSF n’était pas bénéfique chez tous les patients et que la formulation à action longue semblerait plus efficace que les autres formulations. Nous avons également établi des règles de décision permettant d’une part de prédire le risque de neutropénie sévère, et d’autre part d’identifier précocement les patients pour lesquels le G-CSF peut avoir un effet bénéfique. / Granulocyte colony-stimulating factor (G-CSF) is often used in cancer patients receiving cytotoxic drugs to prevent or reduce high grade neutropenia. We developed a new population pharmacokinetic/pharmacodynamic model to describe neutrophil time-course in carboplatin-treated patients, whether or not they received G-CSF. Model simulations showed that G-CSF was not as beneficial as expected in some patients and that the onceper- cycle formulation was more efficient than other formulations. Model-based decision rules were also built to anticipate prolonged high grade neutropenia and early identify patients for whom G-CSF was beneficial.

L’immunologie de la reproduction englobe les principes de l’immunologie générale et les aspects spécifiques de la reproduction et du développement. Les Colony Stimulating Factors (CSFs) sont une illustration de l'application médicale de ce domaine. Dans la famille des CSFs, le Granulocyte-Colony Stimulating Factor (G-CSF) apparaît aujourd'hui comme une thérapie innovante dans divers cas d'échec de la reproduction, bien que ses cibles et ses effets ne soient pas encore clairement établis. Dans ce travail, à travers une revue sur les CSFs dans la reproduction, une étude consacrée aux gènes cibles du G-CSF dans l'endomètre humain, et une étude consacrée aux effets de la supplémentation systémique en G-CSF sur l’implantation embryonnaire murine, nous avons essayé d'approcher certains mécanismes d'action possibles pour cette cytokine. Dans les modèles murins fertiles et pro-abortifs, la supplémentation systémique en G-CSF, ciblant spécifiquement l’endomètre préimplantatoire, modifie les taux d’implantation embryonnaire. Dans l’endomètre humain, certaines dérégulations préimplantatoires de gènes cibles du G-CSF ont également été observées chez les patients infertiles. L'influence du G-CSF sur ces gènes cibles a été également illustrée dans un modèle ex-vivo de culture endométriale. Ces cibles dont l’expression est influencée par le G-CSF sont décrites comme des molécules clés dans le processus implantatoire, intervenant sur l’adhésion embryonnaire, la migration cellulaire, le remodelage des tissus et l'angiogenèse locale. Ces données suggèrent des possibilités de diagnostic préventif et pré-conceptionnel de certains échecs de reproduction, considérés jusqu’à maintenant comme idiopathiques, et de thérapies innovantes orientées, afin d’optimiser la réceptivité du biosenseur endométrial afin de permettre une implantation embryonnaire harmonieuse et une grossesse évolutive. / Reproductive Immunology involves general immunology principles and special aspects of reproduction and development. Colony Stimulating Factors (CSFs) are an illustration of the medical application of this domain. In the CSF family, Granulocyte-Colony Stimulating Factor (G-CSF) appears today as a promising therapy in various cases of reproductive failure although its targets and effects are not clearly established. In this work, through a review on CSFs in reproduction, a study dedicated to human endometrial targets of G-CSF, and a study dedicated to systemic G-CSF supplementation effects on murine embryo implantation, we tried to approach some possible mechanisms of action of this cytokine. In the considered non-abortive and abortion-prone murine models, the timed systemic G-CSF supplementation, targeting specifically the pre implantation endometrium, influenced the embryo implantation process. Some pre conceptual human endometrial dysregulations of G-CSF target genes were also observed in infertile patients. The endometrial influence of G-CSF on these target genes was also illustrated in an ex-vivo model. These molecules under G-CSF influence are described as critically involved in embryo implantation process, by influencing embryo adhesion, cell migration, tissue remodelling and angiogenesis. These data suggest possible pre-conceptual preventive diagnosis of such reproductive failures and future orientated therapies to optimise the endometrial biosensor and the further embryo implantation and ongoing pregnancy.

In under a century, melioidosis, the infection due to Burkholderia pseudomallei, has emerged from Whitmore’s series of glanders-like infections amongst the morphia addicts in Burma to a major cause of mortality in northeastern Thailand and northern Australia. Also endemic in other parts of south-east Asia, melioidosis may have varied presentations ranging from severe, overwhelming infection to chronic, low grade disease. Observational evidence had suggested that granulocyte colony stimulating factor (G-CSF), a naturally occurring substance produced by the body in response to infection, may have been useful in reducing the high mortality associated with the more severe forms of this infection. Other observations linked the occurrence of this disease to various environmental factors, such as contamination of drinking water and the annual rainfall. This thesis explores and attempts to quantify these associations. There are three parts to this thesis. In the first part, I reviewed the epidemiology and management of patients with melioidosis. The use of G-CSF and meropenem was associated with a fall in mortality, although other factors may have at least partially contributed to this effect. In the second part, I progressed towards a clinical trial of G-CSF. There was no other evidence supporting the use of G-CSF in severe sepsis and ethical issues precluded a trial in Darwin. There was not evidence from laboratory models of G-CSF action in melioidosis to support the use of G-CSF in patients, although there remained some doubt regarding the applicability of such models to human disease. I examined clinical methods to identify patients at high risk of death from melioidosis. A simple scoring system based on clinical and laboratory parameters was developed and externally validated. However, clinical definitions of severe sepsis appeared to be better predictors of mortality. A clinical trial based on clinical definitions was commenced in Thailand. In the final part, I explored the question of whether different strains or B. pseudomallei or different environmental conditions caused different patterns of infection. There was no evidence that strain types of this bacterium determine the pattern or severity of disease, but weather conditions appeared to influence the distribution of disease in northern Australia.

<p>Clinical islet transplantation is an emerging procedure to cure type 1 diabetes. The graft is implanted by infusion into the liver through the portal vein. A major obstacle that still needs to be overcome is the requirement for islets from multiple donors to achieve insulin independence. </p><p>An innate inflammatory reaction, the IBMIR, is elicited when islets are exposed to blood. The IBMIR has been described as a clotting reaction culminating in disruption of islet morphology and is a plausible cause for loss of tissue during the early post-transplant period. </p><p>In this thesis, the underlying mechanisms of the IBMIR were characterized. The IBMIR was for the first time demonstrated in patients undergoing an islet transplant, and a number of clinically applicable strategies to limit this reaction were identified.</p><p>The thrombin inhibitor melagatran completely blocked the IBMIR in an <i>in vitro</i> tubing blood loop system, indicating that thrombin is the driving force in the reaction. Interestingly, islets were shown to produce and secrete tissue factor (TF), the physiological trigger of coagulation. Inactivated FVIIa, a specific inhibitor of TF, successfully blocked initiation of the IBMIR. An alternative approach to limit the IBMIR was to pre-treat islets in culture prior to transplantation. Nicotinamide added to the culture medium effectively decreased the level of TF in human islets. Infiltration of immune cells, also a part of the IBMIR, was characterized in detail. The predominant cell types infiltrating the islets were neutrophilic granulocytes and, to a lesser degree, monocytes. Both cell types may exert direct cytotoxic effects, and the antigen-presenting monocytes may also be important for directing the specific immune system to the site of inflammation. </p><p>These findings have provided new insight into the nature of the IBMIR and offer several new strategies to improve the outcome of clinical islet transplantation.</p>