Soluble CD30, the Immune Response, and Acute Rejection in Human Kidney Transplantation: A Systematic Review and Meta-Analysis

Non-invasive biomarkers of acute rejection in pediatric kidney transplantation: New targets and strategies

Kidney transplantation is the preferred treatment for pediatric end-stage renal disease. However, pediatric recipients face unique challenges due to their prolonged need for kidney function to accommodate growth and development. The continual changes in the immune microenvironment during childhood development and the heightened risk of complications from long-term use of immunosuppressive drugs. The overwhelming majority of children may require more than one kidney transplant in their lifetime. Acute rejection (AR) stands as the primary cause of kidney transplant failure in children. While pathologic biopsy remains the "gold standard" for diagnosing renal rejection, its invasive nature raises concerns regarding potential functional impairment and the psychological impact on children due to repeated procedures. In this review, we outline the current research status of novel biomarkers associated with AR in urine and blood after pediatric kidney transplantation. These biomarkers exhibit superior diagnostic and prognostic performance compared to conventional ones, with the added advantages of being less invasive and highly reproducible for long-term graft monitoring. We also integrate the limitations of these novel biomarkers and propose a refined monitoring model to optimize the management of AR in pediatric kidney transplantation.

Donor-Derived Cell-Free DNA (dd-cfDNA) in Kidney Transplant Recipients With Indication Biopsy-Results of a Prospective Single-Center Trial

Donor-derived cell-free DNA (dd-cfDNA) identifies allograft injury and discriminates active rejection from no rejection. In this prospective study, 106 kidney transplant recipients with 108 clinically indicated biopsies were enrolled at Heidelberg University Hospital between November 2020 and December 2022 to validate the clinical value of dd-cfDNA in a cohort of German patients. dd-cfDNA was quantified at biopsy and correlated to histopathology. Additionally, dd-cfDNA was determined on days 7, 30, and 90 post-biopsy and analyzed for potential use to monitor response to anti-rejection treatment. dd-cfDNA levels were with a median (IQR) % of 2.00 (0.48-3.20) highest in patients with ABMR, followed by 0.92 (0.19-11.25) in patients with TCMR, 0.44 (0.20-1.10) in patients with borderline changes and 0.20 (0.11-0.53) in patients with no signs of rejection. The AUC for dd-cfDNA to discriminate any type of rejection including borderline changes from no rejection was at 0.72 (95% CI 0.62-0.83). In patients receiving anti-rejection treatment, dd-cfDNA levels significantly decreased during the 7, 30, and 90 days follow-up compared to levels at the time of biopsy (p = 0.006, p = 0.002, and p < 0.001, respectively). In conclusion, dd-cfDNA significantly discriminates active rejection from no rejection. Decreasing dd-cfDNA following anti-rejection treatment may indicate response to therapy. Clinical Trial Registration: https://drks.de/search/de/trial/DRKS00023604, identifier DRKS00023604.

EPHX1 and GSTP1 polymorphisms are associated with COPD risk: a systematic review and meta-analysis

Background: Chronic obstructive pulmonary disease (COPD) affects approximately 400 million people worldwide and is associated with high mortality and morbidity. The effect of EPHX1 and GSTP1 gene polymorphisms on COPD risk has not been fully characterized. Objective: To investigate the association of EPHX1 and GSTP1 gene polymorphisms with COPD risk. Methods: A systematic search was conducted on 9 databases to identify studies published in English and Chinese. The analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines (PRISMA). The pooled OR and 95% CI were calculated to evaluate the association of EPHX1 and GSTP1 gene polymorphisms with COPD risk. The I² test, Q test, Egger's test, and Begg's test were conducted to determine the level of heterogeneity and publication bias of the included studies. Results: In total, 857 articles were retrieved, among which 59 met the inclusion criteria. The EPHX1 rs1051740 polymorphism (homozygote, heterozygote, dominant, recessives, and allele model) was significantly associated with high risk of COPD risk. Subgroup analysis revealed that the EPHX1 rs1051740 polymorphism was significantly associated with COPD risk among Asians (homozygote, heterozygote, dominant, and allele model) and Caucasians (homozygote, dominant, recessives, and allele model). The EPHX1 rs2234922 polymorphism (heterozygote, dominant, and allele model) was significantly associated with a low risk of COPD. Subgroup analysis showed that the EPHX1 rs2234922 polymorphism (heterozygote, dominant, and allele model) was significantly associated with COPD risk among Asians. The GSTP1 rs1695 polymorphism (homozygote and recessives model) was significantly associated with COPD risk. Subgroup analysis showed that the GSTP1 rs1695 polymorphism (homozygote and recessives model) was significantly associated with COPD risk among Caucasians. The GSTP1 rs1138272 polymorphism (heterozygote and dominant model) was significantly associated with COPD risk. Subgroup analysis suggested that the GSTP1 rs1138272 polymorphism (heterozygote, dominant, and allele model) was significantly associated with COPD risk among Caucasians. Conclusion: The C allele in EPHX1 rs1051740 among Asians and the CC genotype among Caucasians may be risk factors for COPD. However, the GA genotype in EPHX1 rs2234922 may be a protective factor against COPD in Asians. The GG genotype in GSTP1 rs1695 and the TC genotype in GSTP1 rs1138272 may be risk factors for COPD, especially among Caucasians.

Decreased expression of ADAM10 on monocytes is associated with chronic allograft dysfunction in kidney transplant recipients

BACKGROUND

Chronic allograft dysfunction (CAD) is a common cause of allograft loss in kidney transplant recipients (KTRs). Our previous study found that elevated serum soluble T cell immunoglobulin mucin-3 (sTim-3) was positively associated with the severity of CAD in KTRs. sTim-3 was reported to be generated from ADAM10/ADAM17-mediated ectodomain shedding of membrane Tim-3 (mTim-3) in humans. However, whether mTim-3 shedding-related molecules participate in the progression of CAD remains unknown. Here, we explored the relationships between different forms of Tim-3, including mTim-3 on different peripheral blood cell subsets, serum and urine sTim-3, and ADAM10/17 expression and active status to investigate their roles in CAD.

METHODS

63 KTRs with stable grafts, 91 KTRs with CAD and 42 healthy controls (HCs) were enrolled. Total Tim-3, pADAM10/17 and mADAM10/17 proteins were semiquantified by western blot. Serum and urine sTim-3 concentrations were determined by ELISA. mTim-3 and ADAM10/17 expression on leukocyte subpopulations was determined by flow cytometry.

RESULTS

The KTR groups displayed significantly higher levels of urine sTim-3 pg/μmol creatinine than the HC group, while no difference was found between the two KTR groups. KTRs with CAD presented reduced nonactive pADAM10 protein but unaltered active mADAM10 when compared to the Stable group; no difference was found between the KTR groups regarding total Tim-3 and p/m ADAM17 protein levels. In addition, the CAD group showed lower mTim-3 expression on BDCA3⁺ DC than the Stable group; no other difference was observed in its expression on B, T, NK, NKT, monocyte subsets and other DC subsets among groups. With the deterioration of allograft function, ADAM10 expression densities on classical, intermediate, and non-classical monocytes were significantly decreased. Correlation analyses revealed that eGFR and serum sTim-3 exhibited weak to modest correlations with ADAM10 on monocyte and DC subsets.

CONCLUSIONS

Our data indicated that ADAM10, especially its decreased expression on monocytes, may play an important role in the progression of CAD in KTRs. However, whether there is an interaction between ADAM10 and mTim-3 in the pathogenesis of CAD in KTRs needs to be further studied.

Expression of Wnt signaling agonists and antagonists in periodontitis and healthy subjects, before and after non-surgical periodontal treatment: A systematic review

Periodontitis is a preventable and treatable multifactorial chronic inflammatory disease that can lead to irreversible periodontal destruction and tooth loss. Wnt signaling and its regulators play an important role in periodontal inflammation, destruction, regeneration, and reconstruction. This systematic review aimed at investigating the involvement of Wnt signaling agonists and antagonists in periodontitis and healthy subjects, before and after periodontal treatment. Electronic searches were carried out using MEDLINE/PubMed, EMBASE, and Cochrane Library databases in addition to hand searches. Studies having different designs assessing the levels of Wnt signaling antagonist and agonist levels in gingival crevicular fluid, serum, and tissue in patients diagnosed with periodontitis or gingivitis, compared with healthy individuals were included. In addition, studies compared these levels in periodontitis patients before and after non-surgical periodontal therapy were also eligible. Sixteen studies met the eligibility criteria. Sclerostin (SOST) has been mainly investigated in the literature (8 publications). Sclerostin (5 studies), Wnt-5a (2 studies), secreted frizzled-related protein 1 (SFRP1) (3 studies), and β-catenin (3 studies) show increased levels in periodontitis compared with periodontal health. Strong correlations between marker levels and periodontal clinical parameters were identified for SOST (5 studies), SFRP1 (2 studies), and β-catenin (2 studies). SOST (3 studies) and SFRP1 (1 study) levels significantly decrease following non-surgical periodontal treatment. The present systematic review demonstrated an association between Wnt signaling agonist and antagonist levels and periodontitis. Wnt agonists and antagonists may serve as valuable diagnostic and prognostic markers for periodontitis onset and progression. Further case-control and longitudinal studies should be conducted for different Wnt signaling agonists and antagonists.

Prognostic significance of CD30 expression in diffuse large B-cell lymphoma: A systematic review with meta-analysis

BACKGROUND

CD30 is variably expressed in diffuse large B-cell lymphoma (DLBCL), but its prognostic potential for the affected patients remains debatable and unclear. Therefore, we aimed to determine the frequency of CD30 expression in DLBCL and its potential for prognostic determination.

METHODS

An electronic systematic review was performed using multiple databases, followed by a quantitative meta-analysis to assess the frequency of CD30 expression with positivity cut-off values of >0% and >20%, and to determine its association with clinicopathological features and patients' survival.

RESULTS

Using a cut-off value >0%, we observed that 3.5%-59.1% of the cases were considered positive for CD30. There was a significant association of the protein expression with a lower number of extra-nodal sites affected by the neoplasm, with Ann Arbor advanced stage, the absence of B-symptoms, the lack of MYC and BCL2 translocations, and a lower ECOG performance. Using a cut-off value >20%, we observed that 2.5%-36.7% of the cases were considered positive for CD30, being significantly associated with a lower number of extra-nodal sites affected by the neoplasm, Ann Arbor stages III/IV, non-GCB tumours, the lack of MYC and BCL2 translocations, and a lower ECOG value. CD30 expression was significantly associated with a better survival rate, regardless of what cut-off parameter was used.

CONCLUSION

Despite variations in the cut-off values used to determine CD30 positivity in DLBCL, the expression of this protein seems to be associated with a higher survival rate and better prognosis.

The association between vitamin D and acute rejection in human kidney transplantation: A systematic review and meta-analysis study

BACKGROUND

Vitamin D (VitD) deficiency is associated with several diseases such as multiple sclerosis, rheumatoid arthritis, respiratory infection, and so forth. In the field of transplantation (kidney transplantation), some studies reported that patients with VitD deficiency are of increased chance of acute rejection, but other studies did not show such a chance. On the other hand, since VitD is a modulatory factor and can reduce the inflammatory response, understanding the exact role of it in transplantation may contribute to tolerance condition in these patients.

METHODS

The electronic databases, including PubMed, Scopus, Embase, ProQuest, Web of Science, and Google Scholar, were searched for eligible studies. In general, 14 studies with a total of 4770 patients were included in this meta-analysis. Regarding the methodological heterogeneity, we selected a random-effects combination model. Moreover, OR was chosen as an effect size for this study.

RESULTS

After the combination of 14 studies, we showed that patients in the VitD-deficient group had an 82% increased chance of acute rejection compared with patients in the VitD-sufficient group, and this effect was significant (OR 1.82; 95% confidence interval [CI] [1.29, 2.56]; I² = 52.3%). This result was significant, and, regarding the narrow CI, it can be a conclusive result. Study quality and gender variables were the main sources of inconsistent results in the primary studies. Moreover, using meta-regression, we showed that VitD deficiency (independent from the estimated glomerular filtration rate (eGFR) of patients) increased the chance of acute rejection.

CONCLUSION

The normal VitD status of patients a few days before and after transplantation can reduce the chance of acute rejection.

Innate immunity: Trained immunity and innate allorecognition against the allograft

The immune system response of transplant recipients is the main cause of allograft rejection; therefore, its suppression seems crucial. Nevertheless, immunosuppressive agents are largely ineffective against innate immune response. Innate immunity is immediately activated after transplantation and contribute to allograft inflammation and rejection. In this regard, understanding the mechanism of activation and targeting the components of innate immunity could improve allograft survival time. In this review, we discuss two scenarios in the innate immunity, i.e., danger and allogeneic signals in the context of both allogeneic and syngeneic graft. Moreover, the mechanisms of innate allorecognition (i.e., signal regulatory protein α-CD47 and paired immunoglobulin-like receptors-MHC I axis) are described, which can improve our clinical decisions to use a better therapeutic strategy.

Recent Advances on Biomarkers of Early and Late Kidney Graft Dysfunction

New biomarkers of early and late graft dysfunction are needed in renal transplant to improve management of complications and prolong graft survival. A wide range of potential diagnostic and prognostic biomarkers, measured in different biological fluids (serum, plasma, urine) and in renal tissues, have been proposed for post-transplant delayed graft function (DGF), acute rejection (AR), and chronic allograft dysfunction (CAD). This review investigates old and new potential biomarkers for each of these clinical domains, seeking to underline their limits and strengths. OMICs technology has allowed identifying many candidate biomarkers, providing diagnostic and prognostic information at very early stages of pathological processes, such as AR. Donor-derived cell-free DNA (ddcfDNA) and extracellular vesicles (EVs) are further promising tools. Although most of these biomarkers still need to be validated in multiple independent cohorts and standardized, they are paving the way for substantial advances, such as the possibility of accurately predicting risk of DGF before graft is implanted, of making a “molecular” diagnosis of subclinical rejection even before histological lesions develop, or of dissecting etiology of CAD. Identification of “immunoquiescent” or even tolerant patients to guide minimization of immunosuppressive therapy is another area of active research. The parallel progress in imaging techniques, bioinformatics, and artificial intelligence (AI) is helping to fully exploit the wealth of information provided by biomarkers, leading to improved disease nosology of old entities such as transplant glomerulopathy. Prospective studies are needed to assess whether introduction of these new sets of biomarkers into clinical practice could actually reduce the need for renal biopsy, integrate traditional tools, and ultimately improve graft survival compared to current management.