Ioannis N. Boletis

Sepsis is a life-threatening condition characterized by a dysregulated host response to infection, leading to multi-organ dysfunction. Toll-like receptor signaling via MYD88- and TRIF-dependent pathways plays a central role in this process; however, its temporal and tissue-specific dynamics remain incompletely understood. The aim of this study was to investigate time-dependent transcriptional changes in MYD88- and TRIF-dependent signaling pathways across multiple organs in a murine model of sepsis. mRNA expression of MYD88, IRAK1, IRAK4, NF-kB, CCL4, CCL20, CCR2, IFN-β, IFN-γ, TNF-α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-18, Klotho, KLF4, HOXA5, NANOG and HIF1α was quantified using qRT-PCR in intestinal, kidney, liver and lung tissues at 24, 48, and 72 h following cecal ligation and puncture-induced sepsis in male C57BL/6J mice. Significant upregulation of innate immune signaling molecules, cytokines, chemokines, and interferon-related genes was observed in all tissues compared with controls. Genes associated with hypoxia and cellular regulation were also increased. These responses were tissue-specific and progressively intensified over time. Sepsis represents a dynamic, time-dependent, and tissue-specific process characterized by sustained activation of immune and hypoxic pathways, providing potential targets for time-stratified therapeutic strategies.

Living kidney transplantation yields better outcomes for recipients than deceased donation, though it may present long-term challenges for donors. This study assessed the quality of life (QoL) of living kidney donors in Greece using the SF-36 questionnaire and examined associated sociodemographic and clinical factors. This cross-sectional study included 242 clinically stable kidney donors from Laiko General Hospital’s Kidney Donor Outpatient Clinic in Athens. Data on demographics, comorbidities, laboratory parameters, and QoL were collected. Spearman’s correlation coefficients were used to identify associations between QoL scores and influencing factors. The majority of donors were female (73.55%). Donors reported high QoL, with median PCS and MCS scores of 55.27 (49.08–57.73) and 54.17 (46.64–59.93), respectively. Male donors had higher PCS and MCS scores than females (p = 0.028 and p = 0.004). Laparoscopic nephrectomy was associated with better mental health and physical outcomes compared to open surgery (p < 0.001). Higher education and eGFR correlated with better PCS scores, while older age negatively affected QoL (p < 0.05). Living kidney donors reported a satisfactory level of overall QoL post-donation. Lower QoL scores were correlated with the female gender, older age, and open nephrectomy. These findings may further reinforce support for our current organ donation policy. Non-modifiable factors appear to influence donor quality of life. These findings reinforce the current organ donation policy while emphasizing the need for careful pre-transplant counseling and ongoing monitoring post-donation.

Background/Objectives: Glucocorticoids are commonly used for maintenance immunosuppressive therapy in kidney transplant recipients (KTRs). We aimed to investigate the prevalence of hypothalamic-pituitary-adrenal (HPA) axis suppression and its association with metabolic disorders in stable KTRs on low-dose glucocorticoids. Methods: This cross-sectional study included adult KTRs on low-dose glucocorticoids. HPA axis suppression was defined as baseline morning cortisol < 5 μg/dL. Adrenocorticotropic hormone (ACTH), dehydroepiandrosterone-sulphate (DHEAS) and 24 h urinary free cortisol (UFC) levels were also assessed. Examined metabolic disorders included hypertension, dyslipidemia, central obesity and post-transplant diabetes mellitus (PTDM). Results: Eighty adult KTRs with a median 57 months (IQR 24–102) since transplantation were included in the study. The mean prednisolone dose was 5.0 ± 1.3 mg/day. Baseline cortisol < 5.0 μg/dL was observed in 27.5% of the KTRs. Participants with baseline cortisol < 5.0 μg/dL were older (55.1 vs. 47.4 years, p = 0.023) and had had a transplant for a longer time (101.4 vs. 67.0 months, p = 0.043), compared with the rest of the cohort. Baseline cortisol correlated positively with ACTH (rho = 0.544, p < 0.001), DHEAS (rho:0.459, p < 0.001) and UFC (rho: 0.377, p = 0.002). The area under the receiver-operating characteristic curve for ACTH as a predictor of baseline cortisol > 5.0 μg/dL was 0.79 [95% confidence interval (CI): 0.68–0.89]. After adjustment for covariates, HPA axis suppression was not associated with the examined metabolic disorders. Conclusions: Our study showed that stable KTRs on chronic low-dose glucocorticoids exhibited an increased prevalence of HPA axis suppression. ACTH may serve as a surrogate biomarker for HPA axis activity in this population. Further research could evaluate the association of glucocorticoid-induced HPA axis inhibition with metabolic disorders.

Acute kidney injury is a common complication following cardiac surgery (CSA-AKI). Serum creatinine levels require a minimum of 24–48 h to indicate renal injury. Nevertheless, early diagnosis remains critical for improving patient outcomes. A PRISMA-compliant systematic review of the PubMed and CENTRAL databases was performed to assess the role of Klotho as a predictive biomarker for CSA-AKI (end-of-search date: 17 February 2024). An evidence quality assessment of the four included studies was performed with the Newcastle–Ottawa scale. Among the 234 patients studied, 119 (50.8%) developed CSA-AKI postoperatively. Serum Klotho levels above 120 U/L immediately postoperatively correlated with an area under the curve (AUC) of 0.806 and 90% sensitivity. Additionally, a postoperative serum creatinine to Klotho ratio above 0.695 showed 94.7% sensitivity and 87.5% specificity, with an AUC of 92.4%, maintaining its prognostic validity for up to three days. Urinary Klotho immunoreactivity was better maintained in samples obtained via direct catheterization rather than indwelling catheter collection bags. Storage at −80 °C was necessary for delayed testing. Optimal timing for both serum and urine Klotho measurements was from the end of cardiopulmonary bypass to the time of the first ICU lab tests. In conclusion, Klotho could be a promising biomarker for the early diagnosis of CSA-AKI. Standardization of measurement protocols and larger studies are needed to validate these findings.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) stands as the most prevalent hereditary renal disorder in humans, ultimately culminating in end-stage kidney disease. Animal models carrying mutations associated with polycystic kidney disease have played an important role in the advancement of ADPKD research. The Han:SPRD rat model, carrying an R823W mutation in the Anks6 gene, is characterized by cyst formation and kidney enlargement. The mutated protein, named Samcystin, is localized in cilia of tubular epithelial cells and seems to be involved in cystogenesis. The homozygous Anks6 mutation leads to end-stage renal disease and death, making it a critical factor in kidney development and function. This review explores the utility of the Han:SPRD rat model, highlighting its phenotypic similarity to human ADPKD. Specifically, we discuss its role in preclinical trials and its importance for investigating the pathogenesis of the disease and developing new therapeutic approaches.

This meta-analysis aims to assess current evidence regarding sociodemographic disparities among adults with kidney failure. Medline, Scopus, Web of Science, CENTRAL, and Google Scholar were systematically searched from inception to 20 February 2022. Overall, 165 cohort studies were included. Compared to White patients, dialysis survival was significantly better among Black (hazard ratio—HR: 0.68; 95% CI: 0.61–0.75), Asian (HR: 0.67; 95% CI: 0.61–0.72) and Hispanic patients (HR: 0.80; 95% CI: 0.73–0.88). Black individuals were associated with lower rates of successful arteriovenous fistula use, peritoneal dialysis and kidney transplantation, as well as with worse graft survival. Overall survival was significantly better in females after kidney transplantation compared to males (HR: 0.87; 95% CI: 0.84–0.90). Female sex was linked to higher rates of central venous catheter use and a lower probability of kidney transplantation. Indices of low SES were associated with higher mortality risk (HR: 1.22, 95% CI: 1.14–1.31), reduced rates of dialysis with an arteriovenous fistula, peritoneal dialysis and kidney transplantation, as well as higher graft failure risk. In conclusion, Black, Asian and Hispanic patients present better survival in dialysis, while Black, female and socially deprived patients demonstrate lower rates of successful arteriovenous fistula use and limited access to kidney transplantation. PROSPERO registration: CRD42022300839.

Complement activation by HLA antibodies is a key component of immune-mediated graft injury. We examined the clinical outcomes of kidney transplant recipients with complement-fixing de novo donor-specific antibodies (dnDSA) who were followed in our center. The C1q-binding ability was retrospectively assessed in 69 patients with dnDSA and mean fluorescence intensity (MFI) values > 2000 out of the 1325 kidney transplant recipients who were screened for DSA between 2015 and 2019. Luminex IgG single antigen beads (SAB)and C1q-SAB assays (One Lambda) were used. C1q-binding dnDSA was identified in 32/69 (46.4%) of the patients. Significantly higher MFI values were observed in C1q-positive DSA (18,978 versus 5840, p < 0.001). Renal graft biopsies were performed in 43 of the kidney transplant recipients (62.3%) with allograft dysfunction. Antibody-mediated rejection (ABMR) was detected in 29/43 (67.4%) of the patients. The incidence of ABMR was similar among patients with C1q-binding and non-C1q-binding DSA (51.7% vs. 48.3%, p = 0.523). Graft loss occurred in 30/69 (43.5%) of the patients at a median time of 82.5 months (IQR 45–135) from DSA detection. C1q-binding DSA was present in more patients who experienced graft loss (53.1% vs. 35.1%, p = 0.152). Higher MFI values and inferior clinical outcomes occurred in most of the kidney transplant recipients with C1q-binding dnDSA.

Background and Objectives: Solid organ transplant (SOT) recipients have a higher risk of suffering from severe Coronavirus (COVID-19) compared to the general population. Studies have shown impaired immunogenicity of mRNA vaccines in this high-risk population; thus, SOT recipients have been prioritized globally for primary and booster doses. Materials and Methods: We analyzed 144 SOT recipients who had previously received two doses of BNT162b2 or mRNA1273 vaccine, and who were subsequently vaccinated with a booster dose of the mRNA1273 vaccine. Humoral and cellular immune responses were measured 1 and 3 months after the second dose, and 1 month after the third dose. Results: One month after the second dose, 33.6% (45/134) of patients displayed a positive antibody response with a median (25th, 75th) antibody titer of 9 (7, 161) AU/mL. Three months after the second dose, 41.8% (56/134) tested positive with a median (25th, 75th) antibody titer of 18 (7, 251) AU/mL. After the booster dose, the seropositivity rate increased to 69.4% (93/134), with a median (25th, 75th) titer of 966 (10, 8027) AU/mL. The specific SARS-CoV-2 T-cell response was assessed in 44 randomly selected recipients 3 months after the second dose, and 11.4% (5/44) of them had a positive response. Following the third dose, 42% (21/50) tested positive. Side effects after the third dose were mild, with pain at the injection site being the most frequent adverse effect, reported by 73.4% of the recipients. Conclusion: Our study shows a mild delayed increase in antibody titer, three months after primary vaccination compared to one month after. It also shows a robust augmentation of humoral and specific T-cell responses after the booster dose, as well as the safety and tolerability of the mRNA vaccines in SOT recipients.

Kidney injury due to medications is a well-known clinical entity. Although drug-induced tubulointerstitial disease is commonly encountered, there are few reports in the literature associated with glomerular injury due to medications. The recognition of this type of kidney injury is crucial, as rapid discontinuation of the offending agent is critical to maximizing the likelihood of quick and effective renal function recovery. In this article, we present four cases that presented with nephrotic syndrome and were diagnosed with biopsy-proven podocytopathies, associated with exposure to a certain medication. All of them experienced complete resolution of nephrotic syndrome within days or weeks after discontinuation of the offending drug. We also present the data, which were found in a Medline search from the year 1963 until the present, regarding cases with podocytopathies associated with penicillamine, tamoxifen and the combination of pembrolizumab-axitinib, including only adult cases from the English literature. The Medline search revealed nineteen cases of penicillamine-induced minimal-change disease (MCD), one case of tamoxifen-induced MCD, and none associated with pembrolizumab-axitinib therapy. We also searched for the largest studies and meta-analyses regarding drug-induced podocytopathies after a Medline search from 1967 to the present of the English literature.

Allo- and autoimmune mechanisms are involved in kidney allograft rejection and loss. This study investigates the impact of anti-angiotensin II type-1 receptor antibodies (anti-AT1RAbs) detected alone or in association with HLA donor-specific antibodies (HLA-DSAs) on the outcome of kidney transplantation (KTx). Anti-AT1RAbs and HLA-DSAs were detected in 71 kidney transplant (KT) recipients who developed biopsy-proven acute or chronic active T-cell rejection (TCMR) (n = 51) or antibody-mediated rejection (ABMR) (n = 20), forming the rejection group (RG). The control group (CG) included 71 KTx recipients with comparable characteristics without rejection. All patients had been transplanted with negative T/B flow crossmatch (T/BFCXM). The median follow-up period was 3.7 years. Antibodies were determined pre- and periodically post-KTx by Luminex method for HLA-DSAs and enzyme-linked immunosorbent assay for anti-AT1RAbs. Before KTx, twenty-three (32.4%) patients in the RG, sixteen with TCMR and seven with ABMR, were found anti-AT1Rabs-positive (≥10 U/mL) versus eleven (15.5%) patients in the CG (p = 0.031). Simultaneous detection of preformed anti-AT1RAbs and HLA-DSAs was found in five patients of the RG versus two of the CG (p = 0.355). At the time of transplant biopsy, fifteen (21.1%) patients, four with ABMR and eleven with TCMR, were positive for anti-AT1RAbs. Anti-AT1RAbs and HLA-DSAs were detected simultaneously in 7/15 (46.7%) cases, three with ABMR and four with TCMR. During the follow-up, thirteen (18.3%) patients in the RG, eight with ABMR and five with TCMR, lost their graft compared to one patient (1.4%) in the CG (p = 0.001). Six out of thirteen (46.2%) RG patients who lost the graft were found positive for anti-AT1RAbs pretransplant. Patient survival with functioning graft did not differ significantly between anti-AT1Rabs-positive and negative KT recipients (log-rank p = 0.88). Simultaneous detection of anti-ATR1Abs and HLA-DSAs did not have a significant influence on patient survival with functioning graft (log-rank p = 0.96). Graft function at the end of the follow-up was better, but not significantly, in anti-AT1Rabs-negative patients, with serum creatinine 1.48 [1.20–1.98] mg/dL and eGFR (CKD-EPI) 48.5 [33.5–59.0] mL/min/1.73 m², compared to anti-AT1Rabs-positive ones who had serum creatinine 1.65 [1.24–2.02] mg/dL (p = 0.394) and eGFR (CKD-EPI) 47.0 [34.8–60.3] mL/min/1.73 m² (p = 0.966). Anti-AT1RAbs detection pretransplant characterizes KT recipients at increased risk of cellular or antibody-mediated rejection. Furthermore, anti-AT1RAbs, detected alone or simultaneously with HLA-DSAs, appear to be associated with impaired graft function, but their role in graft survival has not been documented in this study. Screening for these antibodies appears to complement pretransplant immunological risk assessment.