TLR9gene polymorphism (rs187084, rs352140): association with acute rejection and estimated glomerular filtration rate in renal transplant recipients

Biomarkers for Kidney-Transplant Rejection: A Short Review Study

Kidney transplantation is the preferred treatment for end-stage renal failure, but the limited availability of donors and the risk of immune rejection pose significant challenges. Early detection of acute renal rejection is a critical step to increasing the lifespan of the transplanted kidney. Investigating the clinical, genetic, and histopathological markers correlated to acute renal rejection, as well as finding noninvasive markers for early detection, is urgently needed. It is also crucial to identify which markers are associated with different types of acute renal rejection to manage treatment effectively. This short review summarizes recent studies that investigated various markers, including genomics, histopathology, and clinical markers, to differentiate between different types of acute kidney rejection. Our review identifies the markers that can aid in the early detection of acute renal rejection, potentially leading to better treatment and prognosis for renal-transplant patients.

Association of TLR2 and TLR9 gene polymorphisms with atopic dermatitis: a systematic review and meta-analysis with trial sequential analysis

Atopic dermatitis (AD) is a chronic, inflammatory skin disease. The mechanism was complex. Genetic mutations of Toll-like receptor (TLR) may be associated with AD, yet still unclear. We aim to provide specific evidence of the association of TLR2, TLR9 gene polymorphisms with AD. Publications were selected according to the criteria. Newcastle-Ottawa Scale was applied to evaluate the quality. The value of ORs and 95%CIs were applied to measure the associations. According to the heterogeneity, the effects model of fixed or random was selected in data combination. For TLR2 gene rs5743708 polymorphism, under allele and recessive contrasts, the pooled data showed a significant correlation, which was A vs a, OR = 0.51 (95%CI: 0.30, 0.86); AA vs Aa + aa, OR = 0.54 (95%CI: 0.33, 0.88). For TLR2 gene rs4696480 polymorphism, under allele, homozygous, heterozygous, and dominant contrasts, the pooled data showed a significant correlation, which was A vs a, OR = 0.79 (95%CI: 0.64, 0.97), AA vs aa, OR = 0.65 (95%CI: 0.43, 0.97), Aa vs aa, OR = 0.68 (95%CI: 0.48, 0.97), AA + Aa vs aa, OR = 0.67 (95%CI: 0.49, 0.93). There are significant associations of TLR2 gene rs5743708, rs4696480 polymorphisms with atopic dermatitis, while no associations are found in TLR9 gene rs5743836, rs187084 polymorphisms.

The TLR9 2848C/T Polymorphism Is Associated with the CMV DNAemia among HIV/CMV Co-Infected Patients

Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns and are essential components of the host’s innate immune response. The aim of this study was to determine the TLR9 genotype frequency and investigate the association between TLR9 polymorphisms and cytomegalovirus (CMV) DNAemia in human immunodeficiency virus (HIV)/CMV co-infected patients. A total of 205 HIV/CMV co-infected adults were screened for the presence of the four TLR9 polymorphisms (−1237T/C, −1486T/C, 1174G/A, and 2848C/T) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Mutation presented in at least one allele of the TLR9 2848C/T single nucleotide polymorphism (SNP) was associated with the occurrence of CMV DNAemia among HIV-infected patients with CMV co-infection (p = 0.004). The level of CMV DNA was higher in patients who were homozygous recessive or heterozygous for the 2848C/T polymorphism compared with those who had a wild-type genotype for this polymorphism (p = 0.005). Mutation detected in at least one allele of this SNP was also associated with a lower interferon type β (IFN-β) concentration (p = 0.048), while no relationships between TLR9 −1237T/C, −1486T/C, and 1174G/A SNPs and CMV DNAemia were observed. Our findings suggest that the mutation present in at least one allele of the TLR9 2848C/T SNP may be associated with the active CMV infection in HIV/CMV co-infected subjects.

An Insight Into the Immunologic Events and Risk Assessment in Renal Transplantation

Organ transplantation has always been considered to be the optimal therapeutic intervention in patients with end-stage organ failure. In the US, approximately 615,000 patients are diagnosed with end-stage renal disease and less than 30% have received a kidney transplant. One of the crucial drawbacks in successful renal transplantation is allograft rejection. Survival rates among transplant recipients have greatly improved due to better understanding of transplant biology and more effective immunosuppressive agents. Post-transplant immune monitoring and optimization of the immunosuppressive therapy using non-invasive biomarkers can effectively predict impending graft rejection and may spare the need for renal biopsy. This article provides an insight into the immunomodulations of renal transplant recipients. It depicts the immune system including several types of kidney rejection and reviews the biomarkers that may serve in near future, as surveillance tools for graft monitoring. Finally, a summary on the main immunosuppressive drugs used in kidney transplant both in the induction and maintenance phases is also covered.

Toll-Like Receptor Family Polymorphisms Are Associated with Primary Renal Diseases but Not with Renal Outcomes Following Kidney Transplantation

Toll-like receptors (TLRs) play a crucial role in innate- and adaptive immunity. The TLR pathways were shown to play key functional roles in experimental acute and chronic kidney injury, including the allo-immune response after experimental renal transplantation. Data about the precise impact of TLRs and their negative regulators on human renal transplant outcomes however are limited and contradictory. We studied twelve non-synonymous single nucleotide polymorphisms (SNPs) of which eleven in TLR1-8 and one in SIGIRR in a final cohort comprising 1116 matching donors and recipients. TLR3 p.Leu412Phe and SIGIRR p.Gln312Arg significantly deviated from Hardy-Weinberg equilibrium and were excluded. The frequency distribution of the minor alleles of the remaining 10 TLR variants were compared between patients with end-stage renal disease (recipients) and controls (kidney donors) in a case-control study. Secondly, the associations between the minor allele frequency of the TLR variants and delayed graft function, biopsy-proven acute rejection and death-censored graft failure after transplantation were investigated with Cox regression. Carrier frequencies of the minor alleles of TLR1 p.His305Leu (OR = 4.79, 95% CI = 2.35–9.75, P = 0.0002), TLR1 p.Asn248Ser (OR = 1.26, 95% CI = 1.07–1.47, P = 0.04) and TLR8 p.Met1Val (OR = 1.37, 95% CI = 1.14–1.64, P = 0.008) were significantly higher in patients with ESRD, with little specificity for the underlying renal disease entity (adjusted for age, gender and donor-recipient relatedness). The minor allele frequency of none of the TLR variants significantly associated with the surrogate and definite outcomes, even when multivariable models were created that could account for TLR gene redundancy. In conclusion, genetic variants in TLR genes were associated with the prevalence of ESRD but not renal transplant outcomes. Therefore, our data suggests that specific TLR signaling routes might play a role in the final common pathway of primary renal injury. A role for TLR signaling in the context of renal transplantation is probably limited.

Effect of delayed graft function, acute rejection and chronic allograft dysfunction on kidney allograft telomere length in patients after transplantation: a prospective cohort study

BACKGROUND

The outcome of kidney allograft transplantation is associated with numerous donor-dependent and recipient-dependent immunological and non-immunological factors. Studies on genetic factors affecting the non-immunological aspects, like ageing of the kidney allograft and patient outcome are still lacking. The aim of this study was the analysis of relative telomere length (RTL; T/S ratio) in the biopsy specimens of the transplanted kidney allograft and its correlation with the delayed graft function (DGF), acute rejection (AR) and chronic allograft dysfunction (CAD).

METHODS

The study enrolled 119 Caucasian kidney allograft recipients (64 M/55 F, mean age 47.32 ± 14.03; transplantation performed between 2001 and 2012). Organs were harvested from cadaveric donors (59.8 M/40.2 F, mean age 45.99 ± 14.62).

RESULTS

There were significant differences in RTL assessed in kidney allograft biopsy specimens collected 3-6 months after transplantation between patients with DGF and without DGF (181.8 ± 82.0 vs. 284.6 ± 149.6; p < 0.05) and in RTL of kidney allograft biopsy specimens collected 18-60 months after transplantation between patients with AR and without AR (188.1 ± 162.1 vs. 263.3 ± 134.7; p = 0.047). There were significant differences in RTL assessed in kidney allograft biopsy specimens collected 12-24 months after transplantation between patients with CAD and without CAD (168.0 ± 120.0 vs. 282.1 ± 158.4; p = 0.038).

CONCLUSIONS

Duration of dialysis before transplantation and PRA influence the kidney allograft ageing. Telomere length assessed in biopsy specimens collected in the peri-transplant period predicts the long-term kidney allograft function. Complications of kidney transplantation, like DGF, AR and CAD are linked with the telomere length and thus, graft ageing.

Xenogenic (porcine) Acellular Dermal Matrix Promotes Growth of Granulation Tissues in the Wound Healing of Fournier Gangrene

This article investigates the application values of Xenogenic (porcine) acellular dermal matrix (XADM) in preparation of a Fournier gangrene wound bed. Thirty-six consecutive cases of patients with Fournier gangrene between 2002 and 2012 were enrolled in our department of our hospital. The patients were divided into two groups according to different methods of wound bed preparation after surgical débridement, including the experimental group (17 cases) and the control group (19 cases). The wounds in the experimental group were covered with XADM after surgical wound débridement, whereas the wounds were cleaned with hydrogen peroxide and sodium hypochlorite solution (one time/day) in the control group. The wound bed preparation time and hospital stay were then compared in the two groups. The wound preparation time was 13.64 ± 1.46 days and hospitalization period was 26.06 ± 0.83 days in the experimental XADM group. In the control group, the wound bed preparation time and hospitalization period were 22.37 ± 1.38 and 38.11 ± 5.60 days, respectively. The results showed statistical differences between these two groups. When used in wound débridement after Fournier gangrene, XADM protects interecological organizations, promotes the growth of granulation tissues, and maximally retains function and morphology of the perineum and penis.

TLR4 and TLR9 Polymorphisms Effect on Inflammatory Response in End-Stage Renal Disease Patients

Toll-like receptors (TLRs) play a key role in the response of innate and adaptive immune system to microbial and endogenous ligands. Inflammation is a common feature in end-stage renal disease (ESRD) patients; however, the mechanisms/factors triggering the inflammatory process are still poorly clarified. Our aim was to analyze the impact of the c.-1486T>C and c.896A>G polymorphisms in TLR9 and TLR4 genes, respectively, on the inflammatory response of ESRD patients. Clinical and laboratory evaluation was carried out on 184 ESRD patients. Polymerase chain reaction followed by restriction fragmens length polymorphisms (PCR-RFLP) was employed for genotyping of TLR-4 c.896A>G and TLR-9 c.-1486T>C polymorphisms. The prevalence of AA and AG of TLR4 c.896A>G polymorphism in ESRD patients was 97.8% and 2.2%, respectively. None of the individuals showed a homozygous TLR4 polymorphism. Concerning the TLR9 c.-1486T>C polymorphism, we found that ESRD patients showed a prevalence of TC and CC genotypes of 57.1% and 20.6%, respectively. We found that the heterozygous patients for the TLR4 c.896A>G polymorphism presented an increased level in lymphocyte count, a decrease in neutrophil/lymphocyte ratio and in serum levels of hepcidin. Regarding the TLR9 c.-1486T>C polymorphism, we found that it is associated with decreased white blood cell and neutrophil counts, ferritin and CRP serum levels, and with an increase in serum levels of creatinine. Our data suggest that the presence of the studied polymorphisms is associated with a decreased inflammatory response in ESRD patients under hemodialysis, and, thus its presence might have beneficial effects in ESRD patients. Moreover, our data provide new insights in the role of TLR polymorphisms in renal disease, which might have impact in the near future for the development of innovative therapies.