Biljana Draskovic-Pavlovic

Peripheral blood granulocyte activity following contact sensitization of rats with dinitrochlorobenzene

Contact hypersensitivity (CHS) reaction is a classic example of a cell-mediated reaction. As the afferent phase of the reaction includes inflammation, CHS is a suitable model for investigating non-specific immunity. Some aspects of granulocyte activity in the afferent phase of experimentally induced CHS to dinitrochlorobenzene (DNCB) in two genetically different rat strains, AO and DA were examined in this study. A shift in the ratio of granulocytes to lymphocytes in favour of granulocytes and an increase in granulocyte survival were noted in DA rats. Granulocytes from both strains demonstrated increased levels of NBT reduction and an increase in their adhesion to plastic. Decreased granulocyte adhesion in the presence of monoclonal antibodies to beta2 integrins (anti-CD11b/c and anti-CD18) points to the contribution of these molecules to granulocyte adhesiveness during the sensitization phase of CHS. Stimulation of adhesion in the presence of anti-CD11a antibody, points to a differential modulation of adhesion molecule activity during the afferent phase of CHS. Changes in functional activity of granulocytes demonstrated in this study might contribute to the development of CHS in rats.

Our first experiences in applying an original method for removal of ABO-isoagglutinins in ABO-incompatible kidney recipients

BACKGROUND/AIM Due to improved methods for removal of ABO isoagglutinins and novel immunosuppressive protocols, short and long-term outcome in blood group incompatible is similar to blood group compatible kidney transplantation. The aim of this study was to determine the efficacy of our original method for removal of ABO isoagglutinins from the blood in ABO-incompatible kidney allograft recipients. METHOD Between 2006 and 2008 twelve patients were transplanted from ABO incompatible living donors. Titers of ABO isoagglutinins were 4-128 (IgG). Immunosuppressive therapy started 14 days before kidney transplantation with rituximab, followed by a triple therapy (prednisone + tacrolimus + mycophenolate mofetil) and the first plasma exchange (PE) procedure, in which one plasma volume was substituted with albumin and saline on day 7 before transplantation. For selective extracorporeal immunoadsorption, the removed plasma was mixed with donor blood type filtered red blood cells, centrifuged and the supernatant separated and preserved. In the next PE procedure, the removed plasma was replaced with immunoadsorbed plasma, and so on. Titers of ABO agglutinins, renal allograft function and survival were followed-up. RESULTS The pre-transplant treatment consisting of 1-5 PE procedures and immunosuppressive therapy resulted in target ABO agglutinins titers below 4. During a 10-24 month follow-up three patients had an early acute rejection, one patient acute rejection and hemolytic anemia, two patients surgical complications and one of them lost his graft. In the post-transplant period, the titers of ABO antibodies remained below 4. All the patients had stable kidney allograft function with mean serum creatinine +/- SD of 129 +/- 45 micromol/l at the end of the study. CONCLUSION Our method for removal of ABO antibodies was effective in a limited series of patients and short-term follow-up.

Renal transplantation promptly restores excretory function but disturbed L-arginine metabolism persists in patients during the early period after surgery.

The synthesis and whole body metabolism of L-arginine (Arg) are disturbed in renal diseases. Renal transplantation represents the best therapy in the end-stage of these diseases. In the present we compared alterations of plasma Arg and related compounds with renal excretory function in patients with end-stage renal disease, before and after kidney transplantation. Arg, asymmetric dimethylarginine (ADMA), citrulline (Cit), glutamine (Gln), ornithine (Orn), phenylalanine (Phe), tyrosine (Tyr), urea, creatinine, albumin, and nitrate were analyzed in patients before, immediately after (0-time) and 1, 2, 3, 7 and 14 days following living donors kidney transplantation. Healthy subjects were controls. Glomerular filtration rate (GFR) and amino acid molar ratios were calculated. Before transplantation creatinine, urea, Cit, Gln, ADMA, and nitrate were above, while GFR and Arg were below controls, confirming disturbed excretory and metabolic renal functions in patients with renal disease. Renal transplantation promptly normalized creatinine, urea, GFR, Cit, and nitrate. However, regardless of increased molar Phe/Tyr ratios, indicating increased net protein catabolism in peripheral tissues, low Arg and elevated ADMA concentrations persisted throughout the examined period. Alterations of other amino acids also suggest similarly disturbed Arg metabolism in patients after kidney transplantation. In conclusion, renal transplant promptly restored its excretory function, but increased net protein catabolism, disturbed Arg metabolism and endothelial dysfunction in entire body of these patients were not improved throughout the early period after the operation. That has to be considered in their therapy.

Functional properties of granulocytes after thermal injury

Thermal injury, as well as other forms of severe trauma, induces simultaneous hyper- and anti-inflammatory response. While data about decreased number and responsiveness of T lymphocytes are largely consistent, reports concerning granulocytes following trauma are contradictory. Contrary to the evidence on the increased accumulation of granulocytes in the lungs or liver, the results from our laboratory demonstrated reduced granulocyte influx in the wound that heals in conditions of thermal injury. We also demonstrated evidence that indicates impaired signal transduction in granulocytes following thermal injury, as well as their divergent response regarding the adhesiveness, oxidative burst and nitric oxide production at the wound site.

A Monoclonal Antibody R-MC 46 Induces Homotypic Adhesion and Activation of Rat Peripheral Blood Neutrophils

Publisher Summary This chapter presents a study in which homotypic adhesion is used to describe that R-MC 46 monoclonal antibody (mAb) triggers homotypic granulocyte aggregation and enhances phorbol ester (PMA)-induced NADPH oxidase activity and hydrogen peroxide production. Female Albino Oxford (AO) rats of 12–16 week old were used as a source of cells, and peripheral blood granulocytes were prepared by centrifugation on a gradient NycoPrep Animal 1007. The study found that the treatment of rat peripheral blood neutrophils by R-MC 46 mAb caused dramatic increase in aggregation, which was only partly dependent on β2 integrins and possibly involves other adhesion molecules. R-MC 46 two- to threefold enhanced the PMA-triggered hydrogen peroxide production and twofold enhanced nitroblue tetrazolium (NBT) reduction capacity. These findings suggest that the surface molecule R-MC 46 is the novel receptor for an activation pathway that leads in neutrophils to activation.