Renal Involvement in Systemic Sclerosis

Scleroderma renal crisis (SRC) is classical renal disease in systemic sclerosis (SSc). SRC is a relatively rare manifestation, approximately in 5% of patients. In terms of severity, manifestation in the form of SRC is the most common cause of acute organ failure. In SSc patients, SRC is defined as a new onset of accelerated arterial hypertension and rapidly progressive anuric or oliguric renal failure. SRC is primarily vascular injury with increased activity of the renin-angiotensin activity. These events lead to release or activation of cytokines and growth factors that result in the typical proliferative vascular lesions. Successful approach is routine use of angiotensin-converting enzyme inhibitors in the treatment of SRC (except prevention) and other advances in renal replacement therapy in SSc management. It is crucial to detect manifestations of SRC early and to manage appropriately in collaboration with intensive care medicine, cardiologists, and nephrologists. In contrast to SRC, clinical presentation of interstitial renal disease is poor, often without evidence of renal abnormality. Interestingly, other renal manifestations are glomerulonephritis and vasculitis. These manifestations are associated with overlapping mechanisms. The objective of this chapter is to focus on actual knowledge about the renal involvement in SSc and current treatment principles and possibilities

Vitamin D Binding Protein Is Not Involved in Vitamin D Deficiency in Patients with Chronic Kidney Disease

Objective. This study was designed to evaluate vitamin D status with separate determination of 25-OH D2 and 25-OH D3 and its relationship to vitamin D binding protein (VDBP) in patients with chronic kidney disease (CKD) and long-term haemodialysis patients (HD). Methods. 45 CKD patients, 103 HD patients, and 25 controls (C) were included. Plasma vitamin D concentrations were determined using chromatography and VDBP in serum and urine in CKD using enzyme immunoassay. Results. Plasma vitamin D levels were lower in CKD (30.16 ± 16.74 ng/mL) and HD (18.85 ± 15.85 ng/mL) versus C (48.72 ± 18.35 ng/mL), P<0.0001. 25-OH D3 was the dominant form of vitamin D. Serum VDBP was higher in CKD (273.2 ± 93.8 ug/mL) versus C (222 ± 87.6 ug/mL) and HD (213.8 ± 70.9 ug/mL), P=0.0003. Vitamin D/VDBP ratio was the highest in C and the lowest in HD; however, there was no correlation between vitamin D and VDBP. Urinary concentration of VDBP in CKD (0.25 ± 0.13 ug/mL) correlated with proteinuria (r=0.43, P=0.003). Conclusions. Plasma levels of vitamin D are decreased in CKD patients and especially in HD patients. 25-OH D3 was the major form of vitamin D. Despite urinary losses of VDBP, CKD patients had higher serum VDBP concentrations, indicating compensatory enhanced production. Vitamin D binding protein is not involved in vitamin D deficiency

Effects of hemodialysis on serum fetuin-A levels

Fetuin-A is a calcification inhibitor, negative acute phase response marker and cardiovascular mortality predictor in hemodialysis patients. Low levels of fetuin-A are associated with malnutrition, inflammation, decreased bone mass density, low-turnover bone and use of high calcium concentration dialysate. Hemodialysis procedure (HD) has been shown to decrease fetuin-A levels by 20%, probably due to HD-induced inflammation or acute changes in calcium metabolism. The aim of our study was to investigate effects of HD on serum fetuin-A levels. Forty clinically and hemodynamically stable hemodialysis patients (21 females, 68 (38-85) years) underwent routine bicarbonate hemodialysis or hemodiafiltration with polysulfone dialyzer. On consecutive HD dialysis solution with different calcium concentration with/without citric acid was used to assess influence of calcium shifts and parathyroid activity on fetuin-A changes during HD. All other parameters of HD were kept constant. Serum fetuin-A, calcium, phosphorus, iPTH, CRP and other biochemical parameters were measured before and after each HD. Our data show that predialysis serum fetuin-A levels have positive correlation with iPTH levels (p<0.05) and tendency to decrease with higher CRP levels. There was no change in fetuin-A levels during HD: 206 (167.1; 231.9) ug/ml before and 208.9 (170.3; 246.3) ug/ml after HD; respectively. When corrected for haemoconcentration, decrease in fetuin-A was only 2.8% (p<0.05). There was also no difference between effect of hemodialysis and hemodia-filtration procedure. The use of different calcium dialysate concentrations had distinct effect on iPTH levels during and after HD, however, we observed no associated changes in fetuin-A levels. The use of dialysate solution with citric acid had no effect on fetuin-A levels. In conclusion, standard bicarbonate HD with polysulfone dialyser and ultrapure dialysate induces only minor changes in fetuin-A and no changes in hsCRP levels. iPTH levels correlate positively with predialysis fetuin-A, but distinct acute changes in iPTH secretion induced by different dialysate calcium concentrations have no effect on serum fetuin-A levels after a single HD

Results from part A of the multi-center, double-blind, randomized, placebo-controlled NefIgArd trial, which evaluated targeted-release formulation of budesonide for the treatment of primary immunoglobulin A nephropathy

The therapeutic potential of a novel, targeted-release formulation of oral budesonide (Nefecon) for the treatment of IgA nephropathy (IgAN) was first demonstrated by the phase 2b NEFIGAN trial. To verify these findings, the phase 3 NefigArd trial tested the efficacy and safety of nine months of treatment with Nefecon (16 mg/d) versus placebo in adult patients with primary IgAN at risk of progressing to kidney failure (ClinicalTrials.gov: NCT03643965). NefIgArd was a multicenter, randomized, double-blind, placebo-controlled two-part trial. In Part A, 199 patients with IgAN were treated with Nefecon or placebo for nine months and observed for an additional three months. The primary endpoint for Part A was 24-hour urine protein-to-creatinine ratio (UPCR) after nine months. Secondary efficacy outcomes evaluated included estimated glomerular filtration rate (eGFR) at nine and 12 months and the UPCR at 12 months. At nine months, UPCR was 27% lower in the Nefecon group compared with placebo, along with a benefit in eGFR preservation corresponding to a 3.87 ml/min/1.73 m2 difference versus placebo (both significant). Nefecon was well-tolerated, and treatment-emergent adverse events were mostly mild to moderate in severity and reversible. Part B is ongoing and will be reported on later. Thus, NefIgArd is the first phase 3 IgA nephropathy trial to show clinically important improvements in UPCR and eGFR and confirms the findings from the phase 2b NEFIGAN study