Donor Klotho KL-VS Polymorphism Predicts Allograft Glomerulosclerosis and Early Post-Transplant Kidney Function.

BACKGROUND: The Klotho protein, encoded by the KL (Klotho) gene, exerts antiaging and antifibrotic effects. The KL-VS genotype diminishes Klotho expression and correlates with cardiovascular death, heart failure, and chronic kidney disease progression. The aim of this study was to analyze the contribution of donor Klotho rs9536314 and rs9527025 polymorphisms (KL-VS genotype) to renal allograft morphology and function in the early post-transplant period. METHODS: Clinical data and biopsy reports of 170 deceased donor transplantations were retrieved from standard medical files. Donor DNA was genotyped for rs9527025 and rs9536314 SNPs using custom TaqMan assays. RESULTS: As rs9527025 remained in full linkage with rs9536314, we report results for the latter. The analyses were performed for G dominant model (GG+GT vs TT). We found an association between reported SNP alleles, morphologic changes in the peritransplant biopsy, and kidney function 3 months after engraftment. A chronic glomerulopathy score of >0 was found in 12.2% of GG+GT cases and in 3.2% of TT cases (P = .023). For G allele carriers, the third month's median estimated glomerular filtration rate value was 35.0 (range, 20.4-76.6 mL/min), while for TT haplotype, the value was 46.3 (range, 15.5-96.8 mL/min), P = .001. At the third post-transplant month, proteinuria incidence was higher for organs with G allele than with TT haplotype (24.4% vs 9.5%; P = .030; odds ratio 3.09; 95% confidence interval 1.22-7.69). CONCLUSION: Deceased donor KL-VS polymorphism, altering protein dimerization and coreceptor function, predicts early renal transplant glomerular lesions and function. Further analyses for mentioned effect durability are necessary. ETHICS STATEMENT: This study complies with the Helsinki Congress and the Istanbul Declaration regarding donor source. Donors were not prisoners, and were not paid or coerced.

Diagnostic utility of monitoring cytomegalovirus-specific immunity by QuantiFERON-cytomegalovirus assay in kidney transplant recipients.

BACKGROUND: Despite universal prophylaxis, late cytomegalovirus (CMV) infection occurs in a high proportion of kidney transplant recipients. We evaluated whether a specific viral T-cell response allows for the better identification of recipients who are at high risk of CMV infection after prophylaxis withdrawal. METHODS: We conducted a prospective study in 19 pretransplant anti-CMV seronegative kidney graft recipients R- (18 from seropositive donors [D+] and one from a seronegative donor [D-]) and 67 seropositive recipients R(+) (59 from seropositive donors and eight from seronegative donors) who received antiviral prophylaxis with valganciclovir. The QuantiFERON-CMV (QF-CMV) assay was performed within the first and third months after transplantation. Blood samples were monitored for CMV DNAemia using a commercial quantitative nucleic acid amplification test (QNAT) that was calibrated to the World Health Organization International Standard. RESULTS: Twenty-one of the 86 patients (24%) developed CMV viremia after prophylaxis withdrawal within 12 months posttransplantation. In the CMV R(+) group, the QF-CMV assay yielded reactive results (QF-CMV[+]) in 51 of 67 patients (76%) compared with 7 of 19 patients (37%) in the CMV R(-) group (p = 0.001). In the CMV R(+) group, infection occurred in seven of 16 recipients (44%) who were QF-CMV(-) and eight of 51 recipients (16%) who were QF-CMV(+). In the CMV R(-) group, infection evolved in five of 12 recipients (42%) who were QF-CMV(-) and one of 7 recipients (14%) who were QF-CMV(+). No difference was found in the incidence of CMV infection stratified according to the QF-CMV results with regard to the recipients' pretransplant CMV IgG serology (p = 0.985). Cytomegalovirus infection occurred in 15 of 36 patients (42%) with hypogammaglobulinemia (HGG) 90 days posttransplantation compared with two of 34 patients (6%) without HGG (p = 0.0004). Cytomegalovirus infection occurred in seven of 13 patients (54%) with lymphocytopenia compared with 14 of 70 patients (20%) without lymphocytopenia (p = 0.015). The multivariate analysis revealed that the nonreactive QuantiFERON-CMV assay was an independent risk factor for postprophylaxis CMV infection. CONCLUSIONS: In kidney transplant recipients who received posttransplantation prophylaxis, negative QF-CMV results better defined the risk of CMV infection than initial CMV IgG status after prophylaxis withdrawal. Hypogammaglobulinemia and lymphocytopenia were risk factors for CMV infection.

Effect of Over 10-Year Cryopreserved Encapsulated Pancreatic Islets Of Langerhans.

OBJECTIVES: Immunoisolation of pancreatic islets of Langerhans performed by the encapsulation process may be a method to avoid immunosuppressive therapy after transplant. The main problem related to islet transplant is shortage of human pancreata. Resolution of this obstacle may be cryopreservation of encapsulated islets, which enables collection of sufficient numbers of isolated islets required for transplant and long-term storage. Here, we assessed the ability of encapsulated islets to function after long-term banking at low temperature. MATERIALS AND METHODS: Islets of Langerhans isolated from rat, pig, and human pancreata were encapsulated within alginate-poly-L-lysine-alginate microcapsules. Cryopreservation was carried out using a controlled method of freezing (Kriomedpol freezer; Kriomedpol, Warsaw, Poland), and samples were stored in liquid nitrogen. After 10 years, the samples were thawed with the rapid method (with 0.75 M of sucrose) and then cultured. RESULTS: We observed that microcapsules containing islets maintained their shape and integrity after thawing. During culture, free islets were defragmented into single cells, whereas encapsulated islets were still round in shape and compact. After 1, 4, and 7 days of culture of encapsulated islets, the use of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests showed increased mitochondrial activity. After they were thawed, the insulin secretion capacity was comparable with that obtained with fresh islets. CONCLUSIONS: Cryopreservation and storage of free and microencapsulated islets were possible for about 10 years, although only encapsulated islets retained viability and secretory properties.

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.

Isolation, banking, encapsulation and transplantation of different types of Langerhans islets.

INTRODUCTION: The discovery of a cure for diabetes is a dream of many medical researchers. The transplantation of Langerhans islets is a potential treatment of choice for patients with type 1 diabetes as a source of endogenous insulin for the recipient. OBJECTIVES: The aim of the experiment was to transplant Langerhans islets without immunosuppression. To protect the grafts against transplant rejection, semipermeable membranes could be used. MATERIAL AND METHODS: Langerhans islets were isolated from rats and pigs and immunoisolated by encapsulation in alginate-protamine-heparin (APH) or alginate-poly-L-lysine-alginate (APA) membranes. Islets were pooled in a controlled manner. Tests for cryopreservation and biocompatibility were also performed. RESULTS: The capsules coated with APH are more resistant than the capsules coated with APA. After transplantation of the islets immunoisolated with APA, euglycemia is maintained longer than after transplantation of the islets immunoisolated with APH. Microencapsulation protects the islets from destruction by the host. CONCLUSIONS: It is feasible to treat experimental diabetes by transplantation of encapsulated Langerhans islets without immunosuppression.

The influence of intraperitoneal transplantation of free and encapsulated Langerhans islets on the second set phenomenon.

To protect the allografts or xenografts against transplant rejection special semipermeable membranes are applied. So far, there are only a few studies on the influence of an immunoisolated graft on the recipient immune system. Therefore, the possibility that an intraperitoneally grafted alginate/poly L-lysine/alginate (APA) coated pancreatic islets graft can effectively sensitize the recipient and provoke second set phenomenon was studied. C3H male mice and male WAG rats were used as donors of full-thickness skin and of free or encapsulated islet intraperitoneal grafts. Male BALB/c mice served as recipients. Skin grafts were performed following the method of Billingham and Medawar. The length of the second skin graft survival time served as the criterion for the sensitizing capacity of the primary graft. APA encapsulation of islets delayed but has not prevented the development of the second set phenomenon. However, the second skin graft rejection time was significantly longer after grafting of encapsulated islets than after free islets transplantation. APA microencapsulation of intraperitoneally transplanted islets delayed but did not prevent the development of the second set phenomenon. Encapsulation does not ensure complete immunoisolation, but only creates "an artificially immunoprivileged site of transplantation."