Chronic kidney disease mineral and bone disorder may persist after successful kidney transplantation. Persistent hyperparathyroidism has been identified in up to 80% of patients throughout the first year after kidney transplantation. International guidelines lack strict recommendations about the management of persistent hyperparathyroidism. However, it is associated with adverse graft and patient outcomes, including higher fracture risk and an increased risk of all-cause mortality and allograft loss. Secondary hyperparathyroidism may be treated medically (vitamin D, phosphate binders and calcimimetics) or surgically (parathyroidectomy). Guideline recommendations suggest medical therapy first but do not clarify optimal parathyroid hormone targets or indications and timing of parathyroidectomy. There are no clear guidelines or long-term studies about the impact of hyperparathyroidism therapy. Parathyroidectomy is more effective than medical treatment, although it is associated with increased short-term risks. Ideally parathyroidectomy should be performed before kidney transplantation to prevent persistent hyperparathyroidism and improve graft outcomes. We now propose a roadmap for the management of secondary hyperparathyroidism in patients eligible for kidney transplantation that includes the indications and timing (pre- or post-kidney transplantation) of parathyroidectomy, the evaluation of parathyroid gland size and the integration of parathyroid gland size in the decision-making process by a multidisciplinary team of nephrologists, radiologists and surgeons.

Vitamin D belongs to the group of liposoluble steroids mainly involved in bone metabolism by modulating calcium and phosphorus absorption or reabsorption at various levels, as well as parathyroid hormone production. Recent evidence has shown the extra-bone effects of vitamin D, including glucose homeostasis, cardiovascular protection, and anti-inflammatory and antiproliferative effects. This narrative review provides an overall view of vitamin D’s role in different settings, with a special focus on chronic kidney disease and kidney transplant.

Background: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a monogenic disease having a prevalence of 1:400–1000 live births. Depending on kidney imaging, patients can be subdivided into Class 1 (typical) and Class 2 (atypical). The present study aims to provide better assessment of Class 2 patients to help define their family history, together with their clinical and radiological characteristics. Methods: One hundred twenty-four PKD patients with abdominal Magnetic Resonance Imaging (MRI) for the staging of ADPKD, were retrospectively analyzed, aiming to focus on Class 2 ADPKD patients. Total kidney volume and total cyst volume were evaluated, while also assessing their clinical and genetic characteristics. Results: Twelve patients fulfilled the Mayo criteria for Class 2 ADPKD (two Class 2B and ten Class 2A). Extrarenal involvement was observed in 66.7% of cases, but only two subjects presented an estimated Glomerular Filtration Rate (eGFR) < 60 mL/min/1.73 m ² . A positive family history for cystic disease was more frequent compared to other published cohorts. Only 8.3% tested positive for a likely pathogenic mutation in the PKD 1 gene. Class 2B patients showed a lower height-adjusted total kidney volume, with a lower percentage of total cyst volume. Conclusion: Based on our results, atypical ADPKD does not represent an uncommon condition, being present in about 10% of MRI-evaluated patients diagnosed with ADPKD. Genetic tests are frequently negative for PKD1/PKD2 , and total cyst volume and residual tissue volume do not increase the prognostic value of MRI in patients with these radiological characteristics. Other tools are needed to better characterize their kidney prognosis. Graphical

Introduction IgA Nephropathy (IgAN) is the prevalent glomerular disease worldwide. Complement system activation is crucial in its pathogenesis. Few studies correlated serum C3 and C4 with disease activity and prognosis. Methods This retrospective monocentric study investigated the prognostic value of serum complement in patients with IgAN. Primary outcome was defined as 40% decline in eGFR or onset of kidney failure. The aim was to evaluate whether the addition of serum C3 and C4 to established predictive models, including one based on variables related to chronic kidney disease (CKD) progression and another incorporating variables from the International IgA Prediction Tool (IntIgAPT), enhances the accuracy of outcome prediction. Results 101 patients were stratified according to baseline C3 levels in three groups (Low, Medium and High). During a median 54.28 months follow-up, the Low group exhibited higher primary outcome incidence (16.3 events vs 2.9 and 1.7 events x 100 pts/year, p = 0.0026). Model-1 (M1), consisting of CKD progression variables, and Model-3 (M3), comprising IntIgANPT variables, were implemented with baseline C3 and C4 to form Model-2 (M2) and Model-4 (M4), respectively. M2 demonstrated improved predictive performance over M1 showing higher discrimination (lower AIC and BIC, higher C-index and NR2). Similarly, M4 outperformed M3 showing enhanced outcome prediction when adding C3 and C4. Conclusion Inclusion of serum C3 and C4 can enhance prediction accuracy of already existing prognostic models. Specifically, lower C3 and higher C4 levels were associated with poorer prognosis in IgAN, characterizing a more 'Complement-Pathic' subset of patients.