Association of UDP-glucuronosyltransferase 1A9 (UGT1A9) gene polymorphism with kidney allograft function.

BACKGROUND: UDP-glucuronosyltransferases (UGTs) are a group of enzymes involved in the detoxification and excretion of xeno- and endobiotics. Polymorphic variants of the UGT1A9 gene were shown to influence exposition to mycophenolate mophetil (MMF), a common immunosuppressive drug used in kidney allograft recipients. Therefore, the aim of this study was to evaluate an association between key clinical features of kidney post-transplant course in patients receiving MMF therapy and UGT1A9-2152C>T and -275 T>A SNPs, known to induce UGT1A9 gene expression and UGT1A9 98T>C, resulting in reduced enzyme activity. MATERIAL/METHODS: DNA was isolated from peripheral blood of kidney allograft recipients (n=103) and a control group representing the background population of Poland (n=450). Presence of the analyzed SNP was detected using the PCR restriction fragment length polymorphism (RFLP) method. Accuracy of the applied method was confirmed by DNA sequencing. RESULTS: In patients carrying the UGT1A9-2152T and -275A minor alleles we observed a trend of increased risk of acute allograft rejection within 3 months after transplantation, but this difference was at the border of significance. However, the UGT1A9 98C allele was found to be associated with diminished estimated glomerular filtration rate (eGFR) during the first year after engraftment and transient proteinuria in the first and second month post-transplantation. This association was not observed for UGT1A9-2152C>T and -275 T>A. Our data show that transplanted kidney function may be affected in patients carrying UGT1A9 98C allele and receiving MMF. CONCLUSIONS: Genotyping of the functional UGT1A9 SNP may be of practical use in kidney transplant recipients.

[Platelet-mediated regulation of immunity]. / Plytki krwi jako regulatory procesów odpornosciowych.

Platelets, essentially non-nucleated blood cells, are highly reactive components of the circulatory system. They have long been consigned solely to a role in thrombosis and hemostasis. Platelets release platelet-derived microvesicles (PMV), also known as platelet-derived microparticles (PMP). They are important but still under-appreciated mediators of intracellular cross-talk between platelets and other cells and modulate their function. They are formed after stimulation of platelets by an agonist, such as thrombin, collagen, and many others. Platelets can carry biological mediators; they can modulate immune responses and inflammatory events. Microparticles can be released from activated platelets and leukocytes in inflammatory events, but in atherosclerosis they can be released from apoptotic endothelial cells, lymphocytes, and monocytes. The markers of innate immunity expressed by platelets are Toll-like receptors (TLRs). The role of platelets in tumor progression and metastasis has been recognized, but the mechanism of their action remains still unclear.

Bacteriophage translocation.

The occurrence of phages in the human body, especially in the gastrointestinal tract, raises the question of their potential role in the physiology and pathology of this system. Especially important is the issue of whether phages can pass the intestinal wall and migrate to lymph, peripheral blood, and internal organs and, if so, the effects such a phenomenon could have (such passage by bacteria, known as bacterial translocation, has been shown to cause various disturbances in humans, from immune defects to sepsis). Available data from the literature support the assumption that phage translocation can take place and may have some immunomodulatory effects. In addition, phages of the gut may play a protective role by inhibiting local immune reactions to antigens derived from gut flora.

[Bacterial translocation and its clinical significance]. / Translokacja bakterii i kliniczne znaczenie tego zjawiska.

Bacterial translocation (BT) is defined as the passage of indigenous bacteria colonizing the intestine through the epithelial mucosa to the mesenteric lymph nodes and other sites. It can even cause the development of lethal sepsis. BT is being studied extensively, most research being conducted on animal, mostly murine, models. The cause of BT is not well known. Despite advances in antimicrobial therapy, the mortality rate associated with bacteremia is still high, and sepsis can often originate from the patient's own intestinal flora. Consequently, a better understanding of the mechanisms of BT as well as mechanisms operating to prevent bacteria from translocating from the gastrointestinal tract may provide more logical treatment of particular patients. BT may be promoted by immunosuppression (probably one of the most important factors causing the increase in BT), disturbances in the normal ecology of the gastrointestinal tract, allowing some indigenous bacteria to overgrow others, and by mucosal injuries. This article discusses the potential role of various factors responsible for BT and the relationship between BT and neoplastic disease. It also emphasizes the significance of the immune system, which appears to play a role in the ontogeny of gut-associated lymphoid tissue (GALT), including the role of IL-2 (which induces an increase in BT) and the macrophage, which participates in the transport of bacteria from the intestinal lumen to mesenteric lymph nodes. A better understanding of the immunopathology of BT may contribute to the development of novel means of therapy for sepsis and other serious complications of bacterial infection.