Association of HLA-G Polymorphisms in the 3'UTR Region and Soluble HLA-G with Kidney Graft Outcome.

Background: Human leukocyte antigen G (HLA-G) belongs to nonclassical HLA I molecule involving in the suppression of immune response. Besides its profound effect to induce fetal tolerance, HLA-G expression has been associated with allograft acceptance. For the regulation of HLA-G levels, polymorphic sites within the 3' untranslated region (3'UTR) are of crucial importance. The aim of the study was to analyze the association between several HLA-G 3'UTR variants (+3003T/C, +3010C/G, +3027C/A, +3035C/T, +3142G/C, +3187A/G, and +3196C/G), soluble HLA-G (sHLA-G) level, and kidney graft outcome in the Slovak Caucasian population. Methods: We investigated 69 kidney transplant recipients (45 males, 24 females) of age 27-65 years. Out of this group, 37 recipients developed acute rejection that was biopsy proven. Recipient's plasma was obtained at 1 day before transplantation and analyzed by ELISA. The HLA-G 3'UTR polymorphisms were typed by direct sequencing. Results: In the recipients with stable allograft function, significantly higher values of sHLA-G were found in the homozygous +3010GG, +3142CC, +3187GG, and +3196CC carriers in comparison to the acute rejection recipients (P = 0.01-0.05). Conclusion: The study demonstrated genetic association between HLA-G 3'UTR variants and sHLA-G level in kidney recipients leading to graft acceptance. We suggest to monitor the pretransplantation sHLA-G level as additional marker to predict kidney graft outcome. Abbreviations: AMR: Antibody-mediated rejection; APC: antigen-presenting cell; CD: cluster of designation; del: deletion; HLA: human leukocyte antigen; ILT: immunoglobulin-like transcript; ins: insertion; KIR: killer-cell immunoglobulin-like receptor; NK: natural killer; sHLA-G: soluble HLA-G; SNP: single nucleotide polymorphism; TCMR: T cell-mediated rejection; URR: upstream regulatory region; UTR: untranslated region.

Should Enteroviruses Be Monitored in Natural Recreational Waters?

Enteroviruses (EVs) infections occur worldwide. Although, infections by these viruses are often asymptomatic and go unnoticed, they can be shed in stool for several weeks. The EVs are associated with sporadic outbreaks and a wide range of clinical symptoms, occasionally accompanied with fatal consequences. Presently in the Slovak Republic (SR) recreational waters are tested only for bacterial indicators. Our aim was to monitor EVs in recreational waters. Water samples were collected during the years 2012-2014 from different recreational natural lakes in Central and West regions of SR. The samples were concentrated by centrifugation using the two-phase separation method recommended by the World Health Organization (WHO) used for EVs surveillance in the treated sewage waste water. Each of the two phases collected from the samples was analysed by polymerase chain reaction for detection of EVs and primary sequencing was done. Our study demonstrated presence of EVs in three localities consecutively for three years, indicating a probability of constant local source of faecal contamination. This is the first monitoring report on the occurrence of EVs in the natural recreational waters in SR.

Expression of HLA-G transcripts in graft biopsy samples of renal transplant recipients.

BACKGROUND: The HLA-G molecule has a high potential to modulate immune response towards the improvement of graft survival after transplantation. In this work, we have analyzed the total HLA-G mRNA expression in graft tissues of dysfunctional transplanted kidneys. MATERIAL AND METHODS: We examined 84 kidney biopsy samples obtained from 65 renal transplant recipients with dysfunctional graft (50 males, 15 females; average age 46.8 ± 11.9 years). 52 specimens were with signs of acute rejection and 32 without any rejection characteristics (diagnosed as glomerulonephritis, ATN and IFTA). Patients with acute rejection were divided into three groups: antibody-mediated rejection (AMR; n = 23), T cell mediated rejection (TCMR; n = 16) and combined antibody and T cell-mediated rejection (AMR + TCMR; n=13). The biopsy samples were taken from a dysfunctional graft at different time periods after kidney transplantation. The relative expression of total HLA-G mRNA in biopsy specimens was determined by real time RT-PCR. The correlation between HLA-G mRNA expression and dysfunctional graft state was investigated. The impact of different factors (post-transplantation interval, gender,mismatch, induction therapy and cold ischemia time) on relative expression of total HLA-G mRNA was also studied. RESULTS: We have found that the levels of HLA-G transcripts in kidneys with rejection were higher than those in non-rejected but dysfunctional grafts (P = 0.0003). The highest levels of HLA-G mRNA were detected at combined AMR + TCMR rejection (P= 0.005). The time-course analysis of total HLA-G mRNA expression was also studied. In both dysfunctional graft groups (rejected and non-rejected) the lower levels of HLA-G transcripts were detected during early post-transplant period (1­3 months), however a substantial increase of HLA-G mRNA expression was observed after an extended period of time(N3 months). It was also revealed that antibody induction therapy may reduce HLA-G expression (P=0.0004) and in female samples were higher levels of HLAG transcripts than those in male recipients (P=0.003). It was found no significant impact of age, cold ischemic time, PRA (Panel Reactive Antibody) score, and a number of HLA-mismatches on HLA-G mRNA expression. CONCLUSIONS: We have demonstrated that the expression of total HLA-GmRNA in renal grafts can be influenced by different factors such as clinical state of transplanted kidney, elapsed time after transplantation, gender and antibody induction therapy. We have proved that HLA-G mRNA expression was significantly higher in recipients with acute rejection in comparison to patients with dysfunctional but non-rejected grafts.

Donor non-specific MICA antibodies in renal transplant recipients.

Despite recent advances in solid organ transplantations, an antibody mediated rejection caused by donor specific antibodies is still a major problem in kidney graft survival. Besides HLA-induced humoral response, antibodies against MICA antigens have recently attracted attention because of their possible role in graft rejection. The aim of our study was to establish whether renal recipients produce antibodies against MICA molecules due to the transplantation and if they are specific for MICA antigens of the donors. MICA antibody screening was performed in 124 kidney recipient sera. 22 sera, that were found to be MICA antibody positive, were further examined for MICA antibody profiles and compared with donor MICA alleles. The analysis of MICA antibody positive sera showed mostly more complex reactivity patterns. A significant fraction of patient sera (59%) reacted not only with the donor MICA antigens, but also with other MICA patterns. A match between antibody specificities and MICA antigens was observed in 41% of renal recipients only. On the other hand, as much as in 36% of recipient sera were detected antibodies against their own MICA molecules. We did not prove a complete correlation between the recipient MICA antibody specificities and MICA antigens of the donor. We assume that MICA antibody induction occurs not only due to the allogeneic stimulation itself but also due to other factors that need to be elucidated.