Influence of MDR1 gene polymorphisms on calcineurin inhibitors' metabolism and kidney graft function

Transplantacija bubrega je najbolji način lečenja bolesnika u terminalnoj fazi hronične bolesti bubrega. Uvođenje kalcineurinskih inhibitora (KNI) u imunosupresivne protokole je jedan od najznačajnijih koraka u razvoju transplantacione medicine koji je značajno poboljšao preživljavanje kako alografta, tako i bolesnika sa presađenim bubregom. Ovi lekovi blokiraju sintezu citokina potrebnih za aktivaciju T-limfocita (interleukina-2, interleukina-4, interferona-γ i faktora nekroze tumora-α) i tako ostvaruju svoj imunosupresivni efekat. Imaju vrlo uzak terapijski opseg, izraženu interidividaulnu i intraindividualnu varijabilnost, kao i veliki broj neželjenih efekata koji utiču na funkciju alografta. Samo neki od neželjenih efekata mogu se objasniti neadektavnom koncentracijom leka u krvi. Brojna istraživanja bavila su se ispitivanjem povezanosti genskih polimorfizama i farmakokinetske i farmakodinamske varijabilnosti KNI. Jedan od najznačajnijih gena za metabolizma KNI je MDR1 gen koji kodira sintezu P-glikoproteina koji je proteinski nosač KNI iz intracelularnog u ekstracelularni prostor. Ciljevi istraživanja: Osnovni cilj našeg istraživanja bio je da se ispita učestalost genotipova pojedinačnih nukleotidnih polimorfizama (C1236T, G2677T/A i C3435T) MDR1 gena i njihovih haplotipova. Pored toga, ispitivali smo i uticaj genotipova i haplotipova MDR1 gena na farmakokinetiku KNI, učestalost akutnog odbacivanja (AO), učestalost odložene funkcije alografta (OFA) i funkciju alografta. Imajući u vidu mnogobrojne neželjene efekte KNI, ispitivali smo i uticaj genotipova i haplotipova MDR1 gena na koncentraciju glukoze, kalijuma, mokraćne kiseline, holesterola, triglicerida i aminotransferaza u serumu. Metode: Studija je dizajnirana kao neinterventno retrospektivno opservaciono ispitivanje, sprovedeno u Klinici za nefrologiju Kliničkog centra Srbije i Institutu za mikrobiologiju i imunologiju Medicinskog fakulteta Univerziteta u Beogradu. U ispitivanje su uključena 152 bolesnika sa presađenim bubregom koji su imali CYP3A5*3*3 genotip. Izolacija molekula DNK vršena je iz uzoraka pune krvi standardnom metodom kolonica. Podaci o dozama i koncentracijama KNI, funkciji alografta, AO i OFA, kao i vrednosti glikemije, hemoglobina, hematokrita, mokraćne kiseline, kalijuma, aspartat- i alaninaminotransferaze, ukupnog holesterola i triglicerida, dobijeni su iz ambulantnog kartona bolesnika sa presađenim bubregom...Kidney transplantation is the best treatment option for patients with end stage chronic kidney disease. The introduction of calcineurin inhibitors (CNI) in immunosuppressive protocols have played an important role in improving the outcome of kidney transplantation. These drugs block the cytokine synthesis needed to activate T-lymphocytes and thereby achieve their immunosuppressive effect. They have a narrow therapeutic range, interindividual and intraindividual variability, and a large number of side effects that affect the function of the allograft. However, only some of the side effects can be explained by an inadequate drug concentration in the blood. Numerous studies have investigated the relationship between gene polymorphisms and pharmacokinetic and pharmacodynamic variability of CNI. One of the most significant genes for CNI metabolism is the MDR1 gene that encodes the synthesis of the protein carrier CNI. Objective: The primary aim of our study was to examine the frequency of genotypes of SNPs (C1236T, G2677T/A and C3435T) of the MDR1 gene and their haplotypes. In addition, we examined the influence of genotypes and haplotypes of the MDR1 gene on the CNI pharmacokinetics, the frequency of acute rejection (AR), the frequency of delayed function (DGF) and the allograft function. Also, we examined the influence of SNPs and haplotypes of the MDR1 gene on the serum level of glucose, potassium, uric acid, cholesterol, triglyceride and aminotransferase. Methods: This study was designed as a retrospective observation study conducted at the Clinical Center of Serbia, Clinic of Nephrology and the Institute of Microbiology and Immunology at the University of Belgrade, Medical Faculty. This study included 152 patients who were kidney transplant recipients with a CYP3A5 * 3 * 3 genotype. DNA molecules were extracted from whole blood samples using a standard colonic method. The patient charts revealed data about the CNI dosage and concentration, allograft function, frequency of AR and DGF, as well as the serum level of glucose, hemoglobin, hematocrit, uric acid, potassium, aspartate and alanine aminotransferase, total cholesterol and triglyceride. AR was diagnosed by allograft biopsy or on the basis of allograft function deterioration that has improved after high-dose of corticosteroid therapy. DGF was defined as a need for hemodialysis during the first two weeks after kidney transplantation..

The prevalence of the most important viral infections in renal transplant recipients in Serbia

Viruses are the main cause of opportunistic infections after kidney transplantation. The aim of this study was to determine the prevalence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), B. K. virus (BKV) and John Cunningham virus (JCV) infections in renal transplant recipients (RTR). This retrospective study of 112 RTR investigated the presence of CMV, EBV and polyomaviruses DNA in plasma and/or urine by PCR. The visualization of PCR products was performed by electrophoresis on 2% agarose gel stained with ethidium bromide and photographed under a UV light. The chi-square test was used for statistical analysis. CMV DNA was detected in 14/112 (12.5%), EBV DNA in 4/49 (8.16%), BKV DNA in 10/31 (32.26%) and JCV DNA in 3/31 (9.68%) RTR. These results show that CMV infection is more often present in RTR compared to other investigated viral infections. In the light of these results, molecular testing could be useful in identifying recipients at high risk of symptomatic post-transplant viral infection. [Projekat Ministarstva nauke Republike Srbije, br. 175073, br. 175038 and br. 175089

Uloga holesterola u malim, gustim LDL česticama u progresiji hronične bubrežne bolesti

Dyslipidemia is a common metabolic disorder in chronic kidney disease (CKD) and is largely responsible for development of cardiovascular complications in these patients. It has been noticed that characteristics of lipid disorders vary according to the degree of renal failure. In this study, we investigated concentrations of cholesterol and apolipoprotein B in small, dense low-density lipoproteins (sdLDL-C and sdLDL-apoB) in pre-dialysis (PD) and hemodialysis (HD) stage of CKD. In addition, we explored independent contribution of sdLDL-C and sdLDL-apoB to progression of CKD. We recruited 38 PD and 41 HD patients in this study. Concentrations of sdLDL-C and sdLDL-apoB were determined by heparin-magnesium precipitation method. Other biochemical parameters were measured by routine laboratory methods. Concentrations of sdLDL-C and sdLDL-apoB were significantly higher in PD than in HD patients (P lt 0,001). SdLDL-C (OR=0,122; P lt 0,001) and sdLDL-apoB (OR=0,109; P lt 0,001) were identified as predictors of progression of CKD towards HD stage. Both of examined parameters were independently associated with the disease progression after adjustment for other lipid and non-lipid risk markers, with an exception for adjustment for urea concentration. Assessment of sdLDL-C and sdLDL-apoB in different stages of CKD could be beneficial in term of prediction of risk for cardiovascular disease development and prediction of progression of CKD itself.Dislipidemija je uobičajen metabolički poremećaj u hroničnoj bubrežnoj bolesti (HBB) i u velikoj meri je odgovorna za nastanak kasnijih kardiovaskularnih komplikacija kod ovih pacijenata. Uočeno je da karakteristike dislipidemije variraju u zavisnosti od stadijuma HBB. U ovom radu ispitivali smo koncentracije holesterola i apolipoproteina B u malim, gustim česticama lipoproteina niske gustine (sdLDL-h i sdLDL-apoB) u predijaliznom (PD) i hemodijaliznom (HD) stadijumu HBB, kao i njihov nezavisni potencijal u predviđanju progresije HBB. U studiji je učestvovalo 38 PD i 41 HD pacijent. Koncentracije sdLDL-h i sdLDL-apoB određene su nakon selektivne precipitacije sa heparinom i Mg-solima, a koncentracije ostalih biohemijskih parametara rutinskim metodama. Koncentracije sdLDL-h i sdLDL-apoB bile su značajno više kod PD u odnosu na HD pacijente (P lt 0,001). SdLDL-h (OR=0,122; P lt 0,001) i sdLDL-apoB (OR=0,109; P lt 0,001) identifikovani su kao značajni prediktori progresije bolesti od PD do HD stadijuma, a nezavisan prediktivni potencijal zadržali su i u prisustvu drugih lipidnih i nelipidnih faktora rizika, osim uree. Određivanje sdLDL-h i sdLDL-apoB kod pacijenata u različitim stadijumima HBB može biti korisno u smislu predviđanja rizika za nastanak aterosklerotskih promena, kao i predviđanja progresije same HBB

Influence of MDR1 gene polymorphisms on calcineurin inhibitors' metabolism and kidney graft function

Transplantacija bubrega je najbolji način lečenja bolesnika u terminalnoj fazi hronične bolesti bubrega. Uvođenje kalcineurinskih inhibitora (KNI) u imunosupresivne protokole je jedan od najznačajnijih koraka u razvoju transplantacione medicine koji je značajno poboljšao preživljavanje kako alografta, tako i bolesnika sa presađenim bubregom. Ovi lekovi blokiraju sintezu citokina potrebnih za aktivaciju T-limfocita (interleukina-2, interleukina-4, interferona-γ i faktora nekroze tumora-α) i tako ostvaruju svoj imunosupresivni efekat. Imaju vrlo uzak terapijski opseg, izraženu interidividaulnu i intraindividualnu varijabilnost, kao i veliki broj neželjenih efekata koji utiču na funkciju alografta. Samo neki od neželjenih efekata mogu se objasniti neadektavnom koncentracijom leka u krvi. Brojna istraživanja bavila su se ispitivanjem povezanosti genskih polimorfizama i farmakokinetske i farmakodinamske varijabilnosti KNI. Jedan od najznačajnijih gena za metabolizma KNI je MDR1 gen koji kodira sintezu P-glikoproteina koji je proteinski nosač KNI iz intracelularnog u ekstracelularni prostor. Ciljevi istraživanja: Osnovni cilj našeg istraživanja bio je da se ispita učestalost genotipova pojedinačnih nukleotidnih polimorfizama (C1236T, G2677T/A i C3435T) MDR1 gena i njihovih haplotipova. Pored toga, ispitivali smo i uticaj genotipova i haplotipova MDR1 gena na farmakokinetiku KNI, učestalost akutnog odbacivanja (AO), učestalost odložene funkcije alografta (OFA) i funkciju alografta. Imajući u vidu mnogobrojne neželjene efekte KNI, ispitivali smo i uticaj genotipova i haplotipova MDR1 gena na koncentraciju glukoze, kalijuma, mokraćne kiseline, holesterola, triglicerida i aminotransferaza u serumu. Metode: Studija je dizajnirana kao neinterventno retrospektivno opservaciono ispitivanje, sprovedeno u Klinici za nefrologiju Kliničkog centra Srbije i Institutu za mikrobiologiju i imunologiju Medicinskog fakulteta Univerziteta u Beogradu. U ispitivanje su uključena 152 bolesnika sa presađenim bubregom koji su imali CYP3A5*3*3 genotip. Izolacija molekula DNK vršena je iz uzoraka pune krvi standardnom metodom kolonica. Podaci o dozama i koncentracijama KNI, funkciji alografta, AO i OFA, kao i vrednosti glikemije, hemoglobina, hematokrita, mokraćne kiseline, kalijuma, aspartat- i alaninaminotransferaze, ukupnog holesterola i triglicerida, dobijeni su iz ambulantnog kartona bolesnika sa presađenim bubregom...Kidney transplantation is the best treatment option for patients with end stage chronic kidney disease. The introduction of calcineurin inhibitors (CNI) in immunosuppressive protocols have played an important role in improving the outcome of kidney transplantation. These drugs block the cytokine synthesis needed to activate T-lymphocytes and thereby achieve their immunosuppressive effect. They have a narrow therapeutic range, interindividual and intraindividual variability, and a large number of side effects that affect the function of the allograft. However, only some of the side effects can be explained by an inadequate drug concentration in the blood. Numerous studies have investigated the relationship between gene polymorphisms and pharmacokinetic and pharmacodynamic variability of CNI. One of the most significant genes for CNI metabolism is the MDR1 gene that encodes the synthesis of the protein carrier CNI. Objective: The primary aim of our study was to examine the frequency of genotypes of SNPs (C1236T, G2677T/A and C3435T) of the MDR1 gene and their haplotypes. In addition, we examined the influence of genotypes and haplotypes of the MDR1 gene on the CNI pharmacokinetics, the frequency of acute rejection (AR), the frequency of delayed function (DGF) and the allograft function. Also, we examined the influence of SNPs and haplotypes of the MDR1 gene on the serum level of glucose, potassium, uric acid, cholesterol, triglyceride and aminotransferase. Methods: This study was designed as a retrospective observation study conducted at the Clinical Center of Serbia, Clinic of Nephrology and the Institute of Microbiology and Immunology at the University of Belgrade, Medical Faculty. This study included 152 patients who were kidney transplant recipients with a CYP3A5 * 3 * 3 genotype. DNA molecules were extracted from whole blood samples using a standard colonic method. The patient charts revealed data about the CNI dosage and concentration, allograft function, frequency of AR and DGF, as well as the serum level of glucose, hemoglobin, hematocrit, uric acid, potassium, aspartate and alanine aminotransferase, total cholesterol and triglyceride. AR was diagnosed by allograft biopsy or on the basis of allograft function deterioration that has improved after high-dose of corticosteroid therapy. DGF was defined as a need for hemodialysis during the first two weeks after kidney transplantation..

High rate of native arteriovenous fistulas: How to reach this goal?

The types of vascular accesses for hemodialysis (HD) include the native arteriovenous fistula (AVF), arteriovenous graft (AVG) and central venous catheter (CVC). Adequately matured native AVF is the best choice for HD patients and a high percentage of its presence is the goal of every nephrologist and vascular surgeon. This paper analyses the number and type of vascular accesses for HD performed over a 10-year period at the Clinical Center of Serbia, and presents the factors of importance for the creation of such a high number of successful native AVF (over 80%). Such a result is, inter alia, the consequence of the appointment of the Vascular Access Coordinator, whose task was to improve the quality of care of blood vessels in the predialysis period as well as of functional vascular accesses, and to promote the cooperation among different specialists within the field. Vascular access is the “lifeline” for HD patients. Thus, its successful planning, creation and monitoring of vascular access is a continuous process that requires the collaboration and cooperation of the patient, nephrologist, vascular surgeon, radiologist and medical personnel