Physical activity and renal function in the Italian kidney transplant population.

BACKGROUND: The well-documented benefits of physical activity (PA) are still poorly characterized in long-term kidney transplant outcome. This study analyzed the impact over a 10-year follow-up of PA on graft function in Italian kidney transplant recipients (KTRs). METHODS: Since 2002, the Italian Transplant-Information-System collected donor and recipient baseline and transplant-related parameters in KTRs. In 2015, 'penchant for PA' (PA ≥ 30-min, 5 times/week) was added. Stable patients aged ≥18 years at the time of first-transplantation were eligible. KTRs with at least 10-year follow-up were also analyzed. Mixed-effect regression models were used to compare eGFR changes over time in active versus non-active patients. RESULTS: PA information was available for 6,055 KTRs (active 51.6%, non-active 48.4%). Lower penchant for PA was found in overweight and obese patients (OR = 0.84; OR = 0.48, respectively), in those with longer dialysis vintage (OR = 0.98 every year of dialysis), and older age at transplant. Male subjects showed greater penchant for PA (OR = 1.25). A slower decline of eGFR over time was observed in active KTRs compared to non-active, and this finding was confirmed in the subgroup with at least 10-year follow-up (n = 2,060). After applying the propensity score matching to reduce confounding factors, mixed-effect regression models corroborated such better long-term trend of graft function preservation in active KTRs. CONCLUSIONS: Penchant for PA is more frequent among male and younger KTRs. Moreover, in our group of Italian KTRs, active patients revealed higher eGFR values and preserved kidney function over time, up to 10-years of follow-up.

Longitudinal Analysis of Cardiovascular Risk Factors in Active and Sedentary Kidney Transplant Recipients.

Background: Despite the benefits of physical activity on cardiovascular risk in kidney transplant recipients (KTRs), the long-term effects of exercise have been poorly investigated. This is a three-year observational study comparing graft function and cardiovascular risk factors in active KTRs (AKTRs) vs. sedentary KTRs (SKTRs). Methods: KTRs with stable renal function were assigned to active or sedentary group in relation to the level of daily physical activity based on World Health Organization (WHO) recommendations (<150 or >150 minutes/week, respectively). Complete blood count, renal function indices, lipid profile, blood pressure and anthropometric measures were collected yearly for an observation period of three years. The comparisons between the two groups were performed by repeated measures analyses of covariance (ANCOVAs), with age as a covariate. Results: Fifty-four subjects were included in the study. Thirty of them were identified as AKTRs (M/F 26/4, aged 45 ± 12 years) and 24 as SKTRs (M/F 18/6, aged 51 ± 14 years). Baseline characteristics were similar between the groups except body mass index (BMI) that was significantly higher in SKTRs (p = 0.043). Furthermore, over the three-year observation period, BMI decreased in AKTRs and increased in SKTRs (p = 0.006). Graft function was stable in AKTRs, while it showed a decline over time in SKTRs, as indicated by the rise in serum creatinine levels (p = 0.006) and lower eGFR (p = 0.050). Proteinuria, glucose and uric acid levels displayed a decrease in AKTRs and an increase in SKTRs during the three-year period (p = 0.015, p = 0.004 and p = 0.013, respectively). Finally, concerning lipid profiles, AKTRs had a significant reduction over time of triglycerides levels, which conversely showed a clinically relevant increase in SKTRs (p = 0.014). Conclusions: Our findings indicate that regular weekly exercise training may counteract the increased cardiovascular risks and also prevent graft function decline in KTRs.

Vitamin D in Kidney Transplant Recipients: Mechanisms and Therapy.

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is common in kidney transplant recipients (KTRs), where secondary hyperparathyroidism (HPTH) and post-transplantation bone disease (PTBD) are potential effectors of both graft and vascular aging. Reduced 25(OH)D levels are highly prevalent in KTRs. Experimental and clinical evidence support the direct involvement of deranged vitamin D metabolism in CKD-MBD among KTRs. This review analyzes the pathophysiology of vitamin D derangement in KTRs and its fall out on patient and graft outcome, highlighting the roles of both nutritional and active vitamin D compounds to treat PTBD, cardiovascular disease (CVD) and graft dysfunction. Fibroblast growth factor-23-parathyroid hormone (PTH)-vitamin D axis, immunosuppressive therapy and previous bone status have been associated with PTBD. Although several studies reported reduced PTH levels in KTRs receiving nutritional vitamin D, its effects on bone mineral density (BMD) remain controversial. Active vitamin D reduced PTH levels and increased BMD after transplantation, but paricalcitol treatment was not accompanied by benefits on osteopenia. Vitamin D is considered protective against CVD due to the widespread pleiotropic effects, but data among KTRs remain scanty. Although vitamin deficiency is associated with lower glomerular filtration rate (GFR) and faster estimated GFR decline and data on the anti-proteinuric effects of vitamin D receptor activation (VDRA) in KTRs sound encouraging, reports on related improvement on graft survival are still lacking. Clinical data support the efficacy of VDRA against HPTH and show promising evidence of VDRA's effect in counteracting post-transplant proteinuria. New insights are mandatory to establish if the improvement of surrogate outcomes will translate into better patient and graft outcome.

Importance of vascular calcification in kidney transplant recipients.

BACKGROUND: Kidney transplantation is the treatment of choice for chronic kidney disease (CKD), but in kidney transplant recipients (KTRs) cardiovascular events are the first cause of death with a functioning graft, ranging from 36 to 55%. The impact of vascular calcification (VC) on morbidity and mortality of KTRs is not appreciated enough nowadays. SUMMARY: This review summarizes 13 important studies on VC in KTRs, comparing the results with CKD and dialysis populations. We focused on VC evaluation and use of coronary artery calcification (CAC) and aorta calcification (AoC) scores. We also evaluated the influence of traditional and non-traditional progression risk factors. KEY MESSAGES: VC strongly predicts cardiovascular events and all-cause mortality in KTRs. VC assessment is important in KTRs and based essentially on multislice computed tomography or electron beam computed tomography recognition of lesions. Quantitative measurement of CAC and AoC scores is essential for a correct definition of the calcium burden before and after kidney transplant. Progression of CAC slows down but does not halt after kidney transplant. A variable association of both traditional and non-traditional risk factors is shown. There is a strong association between baseline CAC score and CAC progression. A significant improvement in secondary hyperparathyroidism after transplantation favorably affects the progression of CAC. Low 25(OH)D3 levels are an independent determinant of CAC progression. Diabetes is a risk factor for the presence of CAC in KTRs, but has not been independently associated with CAC progression. The data published on the use of immunosuppressive drugs as progression factors are few and inconclusive.

Emerging drugs for chronic kidney disease.

INTRODUCTION: Chronic kidney disease (CKD) is a worldwide health problem. Despite remarkable headway in slowing the progression of kidney diseases, the incidence of end-stage renal disease (ESRD) is increasing in all countries with a severe impact on patients and society. The high incidence of diabetes and hypertension, along with the aging population, may partially explain this growth. Currently, the mainstay of pharmacological treatment for CKD, aiming to slow progression to ESRD are ACE inhibitors and angiotensin II receptor blockers for their hemodynamic/antihypertensive and anti-inflammatory/antifibrotic action. However, novel drugs would be highly desirable to effectively slow the progressive renal function loss. AREAS COVERED: Through the search engines, PubMed and ClinicalTrial.gov, the scientific literature was reviewed in search of emerging drugs in Phase II or III trials, which appear to be the most promising for CKD treatment. EXPERT OPINION: The great expectations for new drugs for the management of CKD over the last decade have unfortunately not been met. Encouraging results from preliminary studies with specific agents need to be tempered with caution, given the absence of consistent and adequate data. To date, several agents that showed great promise in animal studies have been less effective in humans.

Effect of vitamin D receptor activator therapy on vitamin D receptor and osteocalcin expression in circulating endothelial progenitor cells of hemodialysis patients.

BACKGROUND: The effects of vitamin D receptor (VDR) and osteocalcin (OC) expression as well as VDR agonist (VDRA) therapy on circulating endothelial progenitor cells (EPCs) has not been elucidated yet. METHODS: We therefore analyzed EPCs in 30 healthy controls and 82 patients undergoing dialysis (no VDRA therapy: 28; oral calcitriol: 30, and intravenous paricalcitol, PCTA: 24). The percentage of EPCs (CD34+/CD133-/KDR+/CD45-) expressing VDR or OC, and VDR and OC expression defined by mean fluorescence intensity (MFI) were analyzed using flow cytometry. The in vitro effect of VDRAs was evaluated in EPCs isolated from each patient group. RESULTS: The percentage of VDR+ EPCs correlated positively with VDRA therapy and 25(OH)D, and negatively with diabetes, C-reactive protein, hemoglobin and osteopontin. VDR-MFI correlated positively with VDRA therapy, parathyroid hormone (PTH) and 25(OH)D, and negatively with diabetes and osteopontin. The percentage of OC+ EPCs correlated positively with the calcium score, PTH and phosphate, and negatively with 25(OH)D. OC-MFI correlated positively with calcium score, PTH, phosphate and hemoglobin, and negatively with albumin, 25(OH)D and osteopontin. Cell cultures from patients without VDRA therapy had the highest levels of calcium deposition and OC expression, which both significantly decreased following in vitro VDRA administration: in particular extracellular calcium deposition was only reduced by adding PCTA. CONCLUSIONS: Our data suggest that 25(OH)D serum levels and VDRA therapy influence VDR and OC expression on circulating EPCs. Since OC expression may contribute to vascular calcification, we hypothesize a putative protective role of VDRA therapy.

[New Perspectives in Post-Surgical Acute Kidney Injury During Sepsis].

Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. Sepsis is a common complication in patients undergoing surgery and is a major risk factor for the development of acute kidney injury (SA-AKI). Prevention of AKI in surgery patients is largely based on identification of high baseline risk, monitoring, and reduction of nephrotoxic insults. Early identification of patients at risk of AKI, or at risk of progressing to severe and/or persistent AKI, is crucial to the timely initiation of adequate supportive measures, including limiting further insults to the kidney. Although specific therapeutic options are limited, several clinical trials have evaluated the use of care bundles and extracorporeal techniques as potential therapeutic approaches.

[Discovering uncommon nephropathies: a case of acute kidney damage from malaria].

Malaria is one of the most common infectious diseases in the world with a high prevalence in developing countries. Renal impairment occurs in 40% of Plasmodium falciparum infections; glomeruli, tubules or interstitium can be involved with different pathophysiological mechanisms. We describe a case of severe acute renal failure caused by P. falciparum malaria in a young woman from the Ivory Coast. Renal biopsy revealed severe and widespread acute tubular necrosis and the presence of blackish pigment granules in the glomerular and peritubular capillaries, negative for iron histochemical staining; in electron microscopy we found rounded-oval-shaped structures containing cytoplasmic organelles, electrondensic granules and cellular debris, likely of infectious origin, within monocyte-macrophages located in the tubular lumen. Specific Antigen for P. falciparum and malarial parasite in blood were positive, with very rare trophozoites and gametocytes compatible with Plasmodium falciparum. Steroid therapy and specific antiparasitic therapy were set up with progressive functional improvement until complete recovery. This case highlights the importance of paying maximum attention to low incidence pathologies in our country, considering the continuous migratory movements of these years that can cause an increase in these diseases; anamnestic data are essential for a timely diagnosis which can contribute to a rapid remission avoiding severe complications.

Renal Thrombotic Microangiopathy in Concurrent COVID-19 Vaccination and Infection.

We report on the development of nephrotic proteinuria and microhematuria, with histological features of renal thrombotic microangiopathy (TMA), following the first dose of BNT162b2 COVID-19 vaccine (Pfizer-BioNTech) and COVID-19 diagnosis. A 35-year-old previously healthy man was admitted at our hospital due to the onset of foamy urine. Previously, 40 days earlier, he had received the first injection of the vaccine, and 33 days earlier, the RT-PCR for SARS-CoV-2 tested positive. Laboratory tests showed nephrotic proteinuria (7.9 gr/day), microhematuria, serum creatinine 0.91 mg/dL. Kidney biopsy revealed ultrastructural evidence of severe endothelial cell injury suggestive of a starting phase of TMA. After high-dose steroid treatment administration, complete remission of proteinuria was achieved in a few weeks. The association of COVID-19 with renal TMA has been previously described only in patients with acute renal injury. Besides, the correlation with COVID-19 vaccine has not been reported so far. The close temporal proximity (7 days) between the two events opens the question whether the histological findings should be ascribed to COVID-19 itself or to vaccine injection.

[Resilience in COVID-19 times: general considerations on the recovery of a 93-year-old patient on haemodialysis treatment].

We report the case of a 93-year-old woman on haemodialysis treatment for more than 30 months and with multiple comorbidities who recovered from a Covid-19 infection without any significant clinical problems. The patient has shown a delay in viral clearance with swab test negativization (confirmed) after 33 days; after testing positive again, she has resulted persistently negative, (confirmed after 49 days). After the first negative swab, IgG and IgM antibodies have been found; these have remained persistently positive after a month. As well as highlighting an unexpected resilience in an extremely fragile context, the analysis of this case draws attention to patients' management and, potentially, to the need to arrange dialysis treatments in isolation for some time after their "laboratory recovery".

Promotion of Pre- and Post-Transplant Physical Exercise in the Emilia-Romagna Region: The Network of the Program "Transplantation, Physical Activity, and Sport".

BACKGROUND: Following the positive experience of the national project "A transplant...and now it's time for sport," the Transplant Reference Center of the Emilia-Romagna Region has pursued the promotion of pre- and post-transplant physical exercise by developing a network. METHODS: The path involved the transplant centers and operative units (UU.OO) who wanted to target transplant and waiting list patients, who are clinically stable, to perform personalized exercise through a program (supervised or not) prescribed by a specialist in sports medicine. With the collaboration of the Collective Prevention and Public Health Service, the network was established, consisting of the sports medicine centers and the gyms that promote health for adapted physical activity (PS-AMA). To implement the network, training courses for all the professionals involved (doctors, nurses, exercise specialists) and operational meetings in the transplant centers-nephrology units with patients' associations have been organized. RESULTS: To date, there are 14 transplant centers and UU.OO, 9 sports medicine centers, and 45 PS-AMA involved in this network. Seven training courses were organized with the participation of 193 health professionals. Since January 2016, there have been 65 transplanted patients and 5 patients on the waiting list who practice the prescribed exercise. Of these, 45 carry out supervised exercise in PS-AMA; 25 perform autonomous exercise. Each patient is monitored every 6 months. No problems related to the exercise performance were recorded. CONCLUSIONS: The development of a network of professionals and associations is the key element to raise awareness of physical activity among transplanted and waiting-for-transplant patients, reducing the pathologies associated with a sedentary lifestyle.

[The accuracy of hospital discharge records and their use in identifying and staging chronic kidney disease].

Administrative databases contain precious information that can support the identification of specific pathologies. Specifically, chronic kidney disease (CKD) patients could be identified using hospital discharge records (HDR); these should contain information on the CKD stage using subcategories of the ICD9-CM classification's 585 code (subcategories can be expressed just by adding a fourth digit to this code). To verify the accuracy of HDR data regarding the coding of CKD collected in the Italian region Emilia-Romagna, we analyzed the HDR records of patients enrolled in the PIRP project, which could easily be matched with eGFR data obtained through laboratory examinations. The PIRP database was used as the gold standard because it contains data on CKD patients followed up since 2004 in thirteen regional nephrology units and includes data obtained from reliable and homogeneous laboratory measurement. All HDR of PIRP patients enrolled between 2009 and 2017 were retrieved and matched with available laboratory data on eGFR, collected within 15 days before or after discharge. We analyzed 4.168 HDR, which were classified as: a) unreported CKD (n=1.848, 44.3%); b) unspecified CKD, when code 585.9 (CKD, not specified) or 586 was used (n=446, 10.7%); c) wrong CKD (n=833, 20.0%); d) correct CKD (n=1041, 25.0%). We noticed the proportion of unreported CKD growing from 32.9% in 2009 to 56.6% in 2017, and the correspondent proportion of correct CKDs decreasing from 25.4% to 22.3%. Across disciplines, Nephrology showed the highest concordance (69.1%) between the CKD stage specified in the HDRs and the stage reported in the matched laboratory exam, while none of the other disciplines, except for Geriatrics, reached 20% concordance. When the CKD stage was incorrectly coded, it was generally underestimated; among HDRs with unreported or unspecified CKD at least half of the discharges were matched with lab exams reporting CKD in stage 4 or 5. We found that the quality of CKD stage coding in the HDR record database was very poor, and insufficient to identify CKD patients unknown to nephrologists. Moreover, the growing proportion of unreported CKD could have an adverse effect on patients' timely referral to a nephrologist, since general practitioners might remain unaware of their patients' illness. Actions aimed at improving the training of the operators in charge of HDRs compilation and, most of all, at allowing the exploitation of the informative potential of HDRs for epidemiological research are thus needed.

Renal function and physical fitness after 12-mo supervised training in kidney transplant recipients.

AIM: To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations. METHODS: Ninety-nine kidney transplant recipients (KTRs) were assigned to interventional exercise (Group A; n = 52) and a usual care cohort (Group B; n = 47). Blood and urine chemistry, exercise capacity, muscular strength, anthropometric measures and health-related quality of life (HRQoL) were assessed at baseline, and after 6 and 12 mo. Group A underwent a supervised training three times per week for 12 mo. Group B received only general recommendations about home-based physical activities. RESULTS: Eighty-five KTRs completed the study (Group A, n = 44; Group B, n = 41). After 12 mo, renal function remained stable in both groups. Group A significantly increased maximum workload (+13 W, P = 0.0003), V'O2 peak (+3.1 mL/kg per minute, P = 0.0099), muscular strength in plantar flexor (+12 kg, P = 0.0368), height in the countermovement jump (+1.9 cm, P = 0.0293) and decreased in Body Mass Index (-0.5 kg/m2, P = 0.0013). HRQoL significantly improved in physical function (P = 0.0019), physical-role limitations (P = 0.0321) and social functioning scales (P = 0.0346). No improvements were found in Group B. CONCLUSION: Twelve-month of supervised aerobic and resistance training improves the physiological variables related to physical fitness and cardiovascular risks without consequences on renal function. Recommendations alone are not sufficient to induce changes in exercise capacity of KTRs. Our study is an example of collaborative working between transplant centres, sports medicine and exercise facilities.

[Dyslipidemia in Kidney transplant recipients]. / Dislipidemia post-trapianto.

The kidney transplant recipients' population shows pronounced alterations of the lipidic profile, with hypercholesterolemia (total cholesterol, LDL, VLDL), normal HDL and hypertriglyceridemia. Multiple factors contribute to the development of dyslipidemia, towards these, immunosuppressive therapy plays an important role. The impact on cardiovascular outcomes is less well defined than in general population. This work is a revaluation of the clinical approach to dyslipidemia in kidney transplant based on the more recent Guide Lines and literature. The use of statins in an adult transplanted population (eventually associated with ezetimibe) is safe and is a good compromise in terms of a cost/benefit analysis. Other hypolipidemic drugs are not usually suggested for the high incidence of side effects. Lifestyle changes are taking more and more relevance, and in the pediatric population is the only therapeutic act suggested.

Hepatorenal syndrome: Update on diagnosis and treatment.

Acute kidney injury (AKI) is a common complication in patients with end-stage liver disease and advanced cirrhosis regardless of the underlying cause. Hepatorenal syndrome (HRS), a functional form of kidney failure, is one of the many possible causes of AKI. HRS is potentially reversible but involves highly complex pathogenetic mechanisms and equally complex clinical and therapeutic management. Once HRS has developed, it has a very poor prognosis. This review focuses on the diagnostic approach to HRS and discusses the therapeutic protocols currently adopted in clinical practice.