Contrast-induced encephalopathy in patients with advanced chronic kidney disease: What the nephrologist needs to know.

Contrast-induced encephalopathy is a neurological complication related to contrast used in endovascular procedures or computed tomography (CT). The main risk factors are arterial hypertension, diabetes mellitus, chronic kidney disease (CKD), hyperosmolar contrasts, the amount of infused contrast and its direct infusion in the posterior cerebral territory, or pathologies with blood-brain barrier damage. Symptomatology is non-specific and may present as altered level of consciousness, neurological focality or seizures. Diagnosis is done by exclusion after ischemic or hemorrhagic stroke has been ruled out; CT or MRI are useful for differentiation. Generally, it appears shortly after exposure and the symptoms lasts 48-72h with complete recovery, although cases with persistence of symptoms or longer duration have been described. Treatment consists of monitoring, supportive measures and kidney replacement therapy (KRT) with hemodialysis (HD) in patients in chronic KRT program. It is important for the nephrologist to be aware of this entity given the susceptibility of the patient on HD as well as its potential therapeutic role in these patients.

Management of Postthyroidectomy Hypoparathyroidism and Its Effect on Hypocalcemia-Related Complications: A Meta-Analysis.

OBJECTIVE: The aim of this Meta-analysis is to evaluate the impact of different treatment strategies for early postoperative hypoparathyroidism on hypocalcemia-related complications and long-term hypoparathyroidism. DATA SOURCES: Embase.com, MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and the top 100 references of Google Scholar were searched to September 20, 2022. REVIEW METHODS: Articles reporting on adult patients who underwent total thyroidectomy which specified a treatment strategy for postthyroidectomy hypoparathyroidism were included. Random effect models were applied to obtain pooled proportions and 95% confidence intervals. Primary outcome was the occurrence of major hypocalcemia-related complications. Secondary outcome was long-term hypoparathyroidism. RESULTS: Sixty-six studies comprising 67 treatment protocols and 51,096 patients were included in this Meta-analysis. In 8 protocols (3806 patients), routine calcium and/or active vitamin D medication was given to all patients directly after thyroidectomy. In 49 protocols (44,012 patients), calcium and/or active vitamin D medication was only given to patients with biochemically proven postthyroidectomy hypoparathyroidism. In 10 protocols (3278 patients), calcium and/or active vitamin D supplementation was only initiated in case of clinical symptoms of hypocalcemia. No patient had a major complication due to postoperative hypocalcemia. The pooled proportion of long-term hypoparathyroidism was 2.4% (95% confidence interval, 1.9-3.0). There was no significant difference in the incidence of long-term hypoparathyroidism between the 3 supplementation groups. CONCLUSIONS: All treatment strategies for postoperative hypocalcemia prevent major complications of hypocalcemia. The early postoperative treatment protocol for postthyroidectomy hypoparathyroidism does not seem to influence recovery of parathyroid function in the long term.

Assessment of Individualized Mean Perfusion Pressure Targets for the Prevention of Cardiac Surgery-Associated Acute Kidney Injury-The PrevHemAKI Randomized Controlled Trial.

BACKGROUND: Retrospective studies support that mean perfusion pressure (MPP) deficit in cardiac surgery patients is associated with a higher incidence of acute kidney injury (CS-AKI). The aim of our study was to apply an algorithm based on MPP in the postoperative period to determine whether management with an individualized target reduces the incidence of CS-AKI. METHODS: Randomized controlled trial of patients undergoing cardiac surgery with extracorporeal circulation. Adult patients submitted to valve replacement and/or bypass surgery with a high risk of CS-AKI evaluated by a Leicester score >30 were randomized to follow a target MPP of >75% of the calculated baseline or a standard hemodynamic management during the first postoperative 24 h. RESULTS: Ninety-eight patients with an eGFR of 54 mL/min were included. There were no differences in MAP and MPP in the first 24 h between the randomized groups, although a higher use of noradrenaline was found in the intervention arm (38.78 vs. 63.27, p = 0.026). The percentage of time with MPP < 75% of measured baseline was similar in both groups (10 vs. 12.7%, p = 0.811). MAP during surgery was higher in the intervention group (73 vs. 77 mmHg, p = 0.008). The global incidence of CS-AKI was 36.7%, being 38.6% in the intervention group and 34.6% in the control group (p = 0.40). There were no differences in extrarenal complications between groups as well. CONCLUSION: An individualized hemodynamic management based on MPP compared to standard treatment in cardiac surgery patients was safe but did not reduce the incidence of CS-AKI in our study.

Impact of cardiac surgery associated acute kidney injury on 1-year major adverse kidney events.

Background: The incidence of acute kidney injury following cardiac surgery (CSA-AKI) is up to 30%, and the risk of chronic kidney disease (CKD) has been found to be higher in these patients compared to the AKI-free population. The aim of our study was to assess the risk of major adverse kidney events (MAKE) [25% or greater decline in estimated glomerular filtration rate (eGFR), new hemodialysis, and death] after cardiac surgery in a Spanish cohort and to evaluate the utility of the score developed by Legouis D et al. (CSA-CKD score) in predicting the occurrence of MAKE. Methods: This was a single-center retrospective study of patients who required cardiac surgery with cardiopulmonary bypass (CPB) during 2015, with a 1-year follow-up after the intervention. The inclusion criteria were patients over 18 years old who had undergone cardiac surgery [i.e., valve substitution (VS), coronary artery bypass graft (CABG), or a combination of both procedures]. Results: The number of patients with CKD (eGFR < 60 mL/min) increased from 74 (18.3%) to 97 (24%) within 1 year after surgery. The median eGFR declined from 85 to 82 mL/min in the non-CSA-AKI patient group and from 73 to 65 mL/min in those with CSA-AKI (p = 0.024). Fifty-eight patients (1.4%) presented with MAKE at the 1-year follow-up. Multivariate logistic regression analysis showed that the only variable associated with MAKE was CSA-AKI [odds ratio (OR) 2.386 (1.31-4.35), p = 0.004]. The median CSA-CKD score was higher in the MAKE cohort [3 (2-4) vs. 2 (1-3), p < 0.001], but discrimination was poor, with a receiver operating characteristic curve (AUC) value of 0.682 (0.611-0.754). Conclusion: Any-stage CSA-AKI is associated with a risk of MAKE after 1 year. Further research into new measures that identify at-risk patients is needed so that appropriate patient follow-up can be carried out.

Proteomic analysis of small intestinal neuroendocrine tumors and mesenteric fibrosis.

Mesenteric metastases in small intestinal neuroendocrine tumors (SI-NETs) are associated with mesenteric fibrosis (MF) in a proportion of patients. MF can induce severe abdominal complications, and an effective preventive treatment is lacking. To elucidate possible novel therapeutic targets, we performed a proteomics-based analysis of MF. The tumor cell and stromal compartment of primary tumors and paired mesenteric metastases of SI-NET patients with MF (n = 6) and without MF (n = 6) was analyzed by liquid chromatography-mass spectrometry-based proteomics. Analysis of differential protein abundance was performed. Collagen alpha-1(XII) (COL12A1) and complement component C9 (C9) expression was evaluated by immunohistochemistry (IHC) in mesenteric metastases. A total of 2988 proteins were identified. Unsupervised hierarchical clustering showed close clustering of paired primary and mesenteric tumor cell samples. Comparing MF to non-MF samples, we detected differentially protein abundance solely in the mesenteric metastasis stroma group. There was no differential abundance of proteins in tumor cell samples or primary tumor stroma samples. Analysis of the differentially abundant proteins (n = 36) revealed higher abundance in MF samples of C9, various collagens and proteoglycans associated with profibrotic extracellular matrix dysregulation and signaling pathways. Proteins involved in fatty acid oxidation showed a lower abundance. COL12A1 and C9 were confirmed by IHC to have significantly higher expression in MF mesenteric metastases compared to non-MF. In conclusion, proteome profiles of SI-NETs with and without MF differ primarily in the stromal compartment of mesenteric metastases. Analysis of differentially abundant proteins revealed possible new signaling pathways involved in MF development. In conclusion, proteome profiles of SI-NETs with and without MF differ primarily in the stromal compartment of mesenteric metastases. Analysis of differentially abundant proteins revealed possible new signaling pathways involved in MF development.

Extracorporeal Photopheresis Improves Graft Survival in a Full-Mismatch Rat Model of Kidney Transplantation.

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy based on the infusion of autologous cellular products exposed to ultraviolet light (UV) in the presence of a photosensitizer. The study evaluates the ECP efficacy as induction therapy in a full-mismatch kidney transplant rat model. Dark Agouti to Lewis (DA-L) kidney transplant model has been established. ECP product was obtained from Lewis rat recipients after DA kidney graft transplantation (LewDA). Leukocytes of those LewDA rats were exposed to 8-methoxy psoralen, and illuminated with UV-A. The ECP doses assessed were 10 × 106 and 100 × 106 cells/time point. Lewis recipients received seven ECP infusions. DA-L model was characterized by the appearance of donor-specific antibodies (DSA) and kidney function deterioration from day three after kidney transplant. The dysfunction progressed rapidly until graft loss (6.1 ± 0.5 days). Tacrolimus at 0.25 mg/kg prolonged rat survival until 11.4 ± 0.7 days (p = 0.0004). In this context, the application of leukocytes from LewDA sensitized rats accelerated the rejection (8.7 ± 0.45, p = 0.0012), whereas ECP product at high dose extended kidney graft survival until 26.3 ± 7.3 days, reducing class I and II DSA in surviving rats. ECP treatment increases kidney graft survival in full-mismatch rat model of acute rejection and is a suitable immunomodulatory therapy to be explored in kidney transplantation.

Creatine Kinase Elevation in Autosomal Dominant Polycystic Kidney Disease Patients on Tolvaptan Treatment.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary cause of end-stage kidney disease. Currently, tolvaptan is the only treatment that has proven to delay disease progression. The most notable side effect of this therapy is drug-induced liver injury; however, recently, there have been two reports of creatine kinase (CK) elevation in ADPKD patients on tolvaptan treatment. We set out to monitor and determine the actual incidence of CK elevation and evaluate its potential association with other clinical factors. METHODS: This is an observational retrospective multicenter study performed in rapidly progressive ADPKD patients on tolvaptan treatment from Barcelona, Spain. Laboratory tests, demographics, treatment dose, and reported symptoms were collected from October 2018 to March 2021. RESULTS: Ninety-five patients initiated tolvaptan treatment during follow-up. The medication had to be discontinued in 31 (32.6%) patients, primarily due to aquaretic effects (12.6%), elevated liver enzymes (8.4%), and symptomatic or persistently elevated CK levels (3.2%). Moreover, a total of 27 (28.4%) patients had elevated CK levels, with most of them being either transient (12.6%), mild and asymptomatic (4.2%), or resolved after dose reduction (3.2%) or temporary discontinuation (2.1%). CONCLUSION: We pre-sent the largest cohort that has monitored CK levels in a real-life setting, finding them elevated in 28.4% of patients. More research and monitoring will help us understand the clinical implications and the pathophysiological mechanism of CK elevation in this population.

Immune Profiling of Peripheral Blood Mononuclear Cells at Pancreas Acute Rejection Episodes in Kidney-Pancreas Transplant Recipients.

Profiling of circulating immune cells provides valuable insight to the pathophysiology of acute rejection in organ transplantation. Herein we characterized the peripheral blood mononuclear cells in simultaneous kidney-pancreas transplant recipients. We conducted a retrospective analysis in a biopsy-matched cohort (n = 67) and compared patients with biopsy proven acute rejection (BPAR; 41%) to those without rejection (No-AR). We observed that CD3+ T cells, both CD8+ and CD4+, as well as CD19+ B cells were increased in patients with BPAR, particularly in biopsies performed in the early post-transplant period (<3 months). During this period immune subsets presented a good discriminative ability (CD4+ AUC 0.79; CD8+ AUC 0.80; B cells AUC 0.86; p < 0.05) and outperformed lipase (AUC 0.62; p = 0.12) for the diagnosis of acute rejection. We further evaluated whether this could be explained by differences in frequencies prior to transplantation. Patients presenting with early post-transplant rejection (<3 months) had a significant increase in T-cell frequencies pre-transplant, both CD4+ T cells and CD8+ T cells (p < 0.01), which were associated with a significant inferior rejection-free graft survival. T cell frequencies in peripheral blood correlated with pancreas acute rejection episodes, and variations prior to transplantation were associated with pancreas early acute rejection.

Persistent post-thyroidectomy hypoparathyroidism: A multicenter retrospective cohort study.

BACKGROUND AND OBJECTIVE: The reported incidence of persistent hypoparathyroidism varies widely, and consensus on a definition is lacking. The objective was to evaluate the real-life incidence of persistent hypoparathyroidism by investigating a new pragmatic definition. METHODS: This retrospective multicenter cohort study evaluated the effect of different definitions for persistent hypoparathyroidism on the incidence of hypoparathyroidism. In addition, risk factors for hypoparathyroidism were analyzed. RESULTS: In total, 749 patients were included. Using the new pragmatic definition, we report an incidence of 7.9% of persistent hypoparathyroidism. When applying other commonly used definitions, incidence varied between 11.8% and 22.1%. Risk factors were parathyroid autotransplantation, presence of another surgical complication, and low postoperative serum calcium. CONCLUSIONS: Our data show that the incidence of persistent hypoparathyroidism in the literature may vary through the use of different definitions. This study indicates that a new pragmatic definition of persistent hypoparathyroidism has the potential to enable unbiased comparison between studies.

Aberrant tryptophan metabolism in stromal cells is associated with mesenteric fibrosis in small intestinal neuroendocrine tumors.

Background: Increased levels of serotonin secretion are associated with mesenteric fibrosis (MF) in small intestinal neuroendocrine tumors (SI-NETs). However, the profibrotic potential of serotonin differs between patients, and in this study, we aimed to gain an understanding of the mechanisms underlying this variability. To this end, we analyzed the proteins involved in tryptophan metabolism in SI-NETs. Methods: Proteomes of tumor and stroma from primary SI-NETs and paired mesenteric metastases of patients with MF (n = 6) and without MF (n = 6) were identified by liquid chromatography-mass spectrometry (LC-MS). The differential expression of proteins involved in tryptophan metabolism between patients with and without MF was analyzed. Concurrently, monoamine oxidase A (MAO-A) expression was analyzed in the tumor and stromal compartment by immunohistochemistry (IHC) and reported as intensity over area (I/A). Results: Of the 42 proteins involved in tryptophan metabolism, 20 were detected by LC-MS. Lower abundance of ten proteins was found in mesenteric metastases stroma in patients with MF. No differential expression was found in primary SI-NETs. In patients with MF, IHC showed lower MAO-A expression in the stroma of the primary SI-NETs (median 4.2 I/A vs 6.5 I/A in patients without MF, P = 0.003) and mesenteric metastases (median 2.1 I/A vs 2.8 I/A in patients without MF, P= 0.019). Conclusion: We found a decreased expression of tryptophan and serotonin-metabolizing enzymes in the stroma in patients with MF, most notably in the mesenteric stroma. This might account for the increased profibrotic potential of serotonin and explain the variability in the development of SI-NET-associated fibrotic complications.

Risk Factors for Acute Kidney Injury Following Cardiac Surgery and Performance of Leicester Score in a Spanish Cohort.

The incidence of acute kidney injury following cardiac surgery (CSA-AKI) is up to 30%, and it places patients at an increased risk of death. The Leicester score (LS) is a new score that predicts CSA-AKI of any stage with better discrimination compared to previous scores. The aim of this study was to identify risk factors for CSA-AKI and to assess the performance of LS. A unicentric retrospective study of patients that required cardiac surgery with cardio-pulmonary bypass (CPB) in 2015 was performed. The inclusion criteria were patients over 18 years old who were operated on for cardiac surgery (valve substitution (VS), Coronary Artery Bypass Graft (CABG), or a combination of both procedures and requiring CPB). CSA-AKI was defined with the Kidney Disease Improving Global Outcomes (KDIGO) criteria. In the multivariate analysis, hypertension (odds ratio 1.883), estimated glomerular filtration rate (EGFR) <60 mL/min (2.365), and peripheral vascular disease (4.66) were associated with the outcome. Both discrimination and calibration were better when the LS was used compared to the Cleveland Clinic Score and Euroscore II, with an area under the curve (AUC) of 0.721. In conclusion, preoperative hypertension in patients with CKD with or without peripheral vasculopathy can identify patients who are at risk of CSA-AKI. The LS was proven to be a valid score that could be used to identify patients who are at risk and who could benefit from intervention studies.

Radiofrequency Ablation for Benign Symptomatic Thyroid Nodules in the Netherlands: Successful Introduction of a Minimally Invasive Treatment Option Improving Quality of Life.

PURPOSE: To determine whether adoption of radiofrequency (RF) ablation in patients with symptomatic benign thyroid nodules (SBTNs) in a Dutch regional thyroid network resulted in clinical success and improvement in health-related and thyroid-related quality of life (QoL). MATERIALS AND METHODS: The eligibility criteria for RF ablation were as follows: (a) nodule size between 2.0 and 5.0 cm, (b) solid component >20%; (c) benign cytology in 2 separate cytological assessments, and (d) symptoms unequivocally related to mechanical compression. The primary end point of this study was volume reduction 1 year after ablation. The secondary outcomes were health-related and thyroid-related QoL, measured using the short form health survey questionnaire (SF-36) and thyroid-specific patient-reported outcome questionnaire (ThyPRO-39), respectively, as well as adverse event rates. RESULTS: A total of 72 SBTNs in 67 patients were included. Median age was 50.0 (interquartile range, 41.0-56.0) years, and 91.0% were women. The median volume reduction at 6 weeks, 6 months, 1 year, 2 years, and 3 years was 51.0%, 63.9%, 65.2%, 81.3%, and 90.3%, respectively. The patients showed a significant improvement on the SF-36 physical component scale and ThyPRO-39 overall QoL-impact scale. An absolute improvement was seen in goiter and cosmetic complaints, determined using ThyPRO-39. The overall adverse event rate was 9.0%, of which 4.5% were considered major. CONCLUSIONS: RF ablation is an effective treatment option for SBTNs, with a significant volume reduction and improvement in health-related and thyroid-related QoL.

New Insights Into Diuretic Use to Treat Congestion in the ICU: Beyond Furosemide.

Diuretics are commonly used in critically ill patients with acute kidney injury (AKI) and fluid overload in intensive care units (ICU), furosemide being the diuretic of choice in more than 90% of the cases. Current evidence shows that other diuretics with distinct mechanisms of action could be used with good results in patients with selected profiles. From acetazolamide to tolvaptan, we will discuss recent studies and highlight how specific diuretic mechanisms could help to manage different ICU problems, such as loop diuretic resistance, hypernatremia, hyponatremia, or metabolic alkalosis. The current review tries to shed some light on the potential use of non-loop diuretics based on patient profile and give recommendations for loop diuretic treatment performance focused on what the intensivist and critical care nephrologist need to know based on the current evidence.

Outcomes in older kidney recipients from older donors: A propensity score analysis.

Background: The age of patients referred for kidney transplantation has increased progressively. However, the precise influence of age on transplant outcomes is controversial. Methods: Etrospective study in which graft and recipient survival were assessed in a cohort of ≥75 years old kidney recipients and compared with a contemporary younger one aged 60-65 years through a propensity score analysis. Results: We included 106 recipients between 60-65 and 57 patients of ≥75 years old with a median follow-up of 31 [13-54] months. Unadjusted one- and five-year recipient survival did not significantly differ between the older (91% and 74%) and the younger group (95% and 82%, P=0.06). In the IPTW weighted Cox regression analysis, recipient age was not associated with an increased risk of death (HR 1.88 95%CI [0.81-4.37], P=0.14). Unadjusted one- and five-year death-censored graft survival did not significantly differ between both groups (96% and 83% for the older and 99% and 89% for the younger group, respectively, P=0.08). After IPTW weighted Cox Regression analysis, recipient age ≥75 years was no associated with an increased risk of graft loss (HR 1.95, 95%CI [0.65-5.82], P=0.23). Conclusions: These results suggest that recipient age should not be considered itself as an absolute contraindication for kidney transplant.

Immunogenic and immunotolerogenic effects of extracorporeal photopheresis in high immunological risk kidney recipients. A single center case series.

The immunomodulatory effects of extracorporeal photopheresis (ECP) have been used for the treatment of T-cell mediated disorders, such as rejection in organ transplantation. Currently, it is an established therapy for heart and lung rejection, but not for kidney transplantation (KT), where experience is limited. In addition, some data suggest that ECP could generate an immune response against infections, thus being an alternative for the treatment of rejection in case of active or high-risk of infection. In the present study, we analyze four cases of use of ECP as concomitant therapy in patients with KT and high risk of opportunistic infections due to the high burden of immunosuppression throughout their renal diseases. Two patients had concomitant viral infection (cytomegalovirus and BK virus, respectively) and three patients were on treatment for graft rejection. In the two patients with active viral infection, the infection was successfully controlled during ECP treatment. In all cases, ECP has been shown to be a safe procedure, without complications.

Influence of Persistent Inflammation in Follow-Up Biopsies After Antibody-Mediated Rejection in Kidney Transplantation.

Background: Despite recent advances in immunosuppression treatment, antibody-mediated rejection (ABMR) remains the leading cause of kidney graft loss. Information about prognostic markers and the efficacy of treatment is scarce. Methods: Retrospective study with kidney recipients diagnosed an active ABMR from January 1, 2004 to December 31, 2019 to explore the influence of persistent inflammation in follow-up biopsies on graft survival after ABMR treatment. Results: About 116 patients were included. Active ABMR were treated with a combination of plasma exchange (PE), intravenous immunoglobulin (IVIg), rituximab, and steroids. At 6 months of treatment, 63 (54.3%) patients presented a stabilization or improvement in kidney-graft function. The effectiveness varied depending on the timepoint of the presentation between transplantation and rejection, which is lower for those with late ABMR (63 vs. 21% for early vs. late ABMR, respectively). Ninety patients (77%) underwent a control biopsy after ABMR treatment, from which 46 (51%) responded to the treatment. Microvascular inflammation (MVI) persisted in 64 (71%) biopsies, whereas tubulitis persisted in 17 (19%) biopsies. Death-censored graft survival at 1 year was significantly lower in patients with persistent MVI (86% vs. 95% without persistent MVI, P = 0.002), or with persistent tubulitis (44% vs. 66% without tubulitis, P = 0.02). In the Cox Regression analysis, the persistence of MVI [hazard ratio (HR), 4.50 (95%CI, 1.35-14.96), P = 0.01] and tubulitis [HR 2.88 95%CI (1.24-6.69), P = 0.01) in follow-up biopsies significantly increased the risk of graft failure. Conclusion: Persistent inflammation in follow-up biopsies after ABMR treatment was associated with an increased risk of graft loss, even without meeting Banff rejection criteria. Study Registration: Agencia Española de Medicamentos y Productos Sanitarios (AEMPS): 14566/RG 24161. Study code: UTRINM-2017-01.

Advantages of plasmatic CXCL-10 as a prognostic and diagnostic biomarker for the risk of rejection and subclinical rejection in kidney transplantation.

This study evaluate the potential of plasmatic CXCL-10 (pCXCL-10) as a pre&post transplantation prognostic and diagnostic biomarker of T-cell-mediated rejection (TCMR), antibody-mediated rejection (ABMR) and subclinical rejection (SCR) risk in adult kidney recipients considering BKV and CMV infections as possible clinical confounder factors. Twenty-eight of 100 patients included experienced rejection (TCMR:14; ABMR:14); 8 SCR; 13 and 16 were diagnosed with BKV and CMV infection, respectively. Pre-transplantation pCXCL-10 was significantly increased in TCMR and ABMR and post-transplantation in TCMR, ABMR and SCR compared with nonrejectors. All CMV+ patients showed pCXCL-10 levels above the cutoff values established for rejection whereas the 80% of BKV+ patients showed pCXCL-10 concentration < 100 pg/mL. pCXCL-10 could improve pre-transplantation patient stratification and immunosuppressive treatment selection according to rejection risk; and after kidney transplantation could be a potential early prognostic biomarker for rejection. Clinical confounding factor in BKV+ and particularly in CMV+ patients must be discarded.