A randomised controlled unblinded multicentre non-inferiority trial with activated vitamin D and prednisolone treatment in patients with minimal change nephropathy (ADAPTinMCN)

Background Minimal change nephropathy (MCN) is a common cause of nephrotic syndrome in both adults and children. International guidelines recommend treatment with prednisolone 1 mg/kg/day to adults. This dose is derived from an empirically established dose in children, although children generally attain remission faster and relapse more rapidly than adults. Prednisolone is associated with multiple and serious adverse events. Activated vitamin D has been shown to reduce albuminuria in other glomerular renal diseases with a minimum of adverse events. This study tests the hypothesis that a new treatment regimen in MCN combining reduced dose prednisolone and active vitamin D is as efficient in inducing remission and has fewer and less severe adverse events than standard prednisolone. Furthermore, we aim to establish models allowing for more personalized medicine based on assessment of the individual’s prednisolone metabolism. Methods A randomised controlled multicentre non-inferior unblinded trial including 96 adult, incident patients with biopsy-proven MCN, albuminuria > 3 g/day, and an estimated glomerular filtration rate (eGFR) > 30 ml/min from renal departments in Denmark. Patients are randomised to standard prednisolone (1 mg/kg/day) or reduced prednisolone (0.5 mg/kg/day) and alfacalcidol (0.5 μg/day). The primary outcome is the rate of remissions after 16 weeks and the time from diagnosis to remission. The study will include a saliva test to characterise prednisolone pharmacokinetics and compare them to genetic variations in specific liver enzymes responsible for prednisolone metabolism. Discussion Reducing the prednisolone dose is expected to reduce the number of severe adverse events. This study will examine if reduced prednisolone dose with active vitamin D but without additional immunosuppression is feasible in the treatment of MCN and will reduce the number of adverse events. The findings can potentially change current guidelines for treatment of MCN in adults. Additional outcomes on inter-individual pharmacokinetic and metabolic variations may allow for a more personalised treatment strategy. Trial registration EudraCT 2017-001206-16, ClinicalTrials.gov NCT03210688. Registered on June 3, 2017.

Patterns of renal pathology in Chinese patients with systemic sclerosis undergoing renal biopsy at a tertiary medical center

Objective We investigated renal injury characteristics in Chinese patients with systemic sclerosis (SSc) who had undergone renal biopsy. Methods We searched the medical records of patients with SSc who were hospitalized at Peking Union Medical College Hospital between January 1990 and August 2019. We analyzed the clinical characteristics and pathological results of these patients. Results We identified 25 patients who had undergone renal biopsy. Of these patients, 10 had scleroderma renal crisis (SRC); one underwent renal biopsy twice (for diffuse mesangial proliferative glomerulonephritis and for SRC); two had antineutrophil cytoplasmic antibody-associated glomerulonephritis; one had immunoglobulin M nephropathy; one had minimal change nephropathy; seven had lupus nephritis; one had scleroderma renal crisis with comorbid lupus nephritis; and two had drug-related kidney injury (caused by aristolochic acid in one and D-penicillamine in the other). Acute tubular necrosis was observed in the patient taking oral aristolochic acid, while minimal change nephropathy was observed in the patient with D-penicillamine-induced renal injury. Conclusions SRC was the most commonly encountered renal damage in patients with SSc. We recommend biopsy for patients undergoing treatment for SRC who have persistent renal injury with proteinuria, regardless of hematuria. Rheumatologists in Eastern countries should be aware of aristolochic acid nephropathy.

Identification of a Novel ACTN4 Gene Mutation Which Is Resistant to Primary Nephrotic Syndrome Therapy

ACTN4, a gene which codes for the protein α-actinin-4, is critical for the maintenance of the renal filtration barrier. It is well known that ACTN4 mutations can lead to kidney dysfunction, such as familial focal segmental glomerulosclerosis (FSGS), a common cause of primary nephrotic syndrome (PNS). To elucidate whether other mutations of ACTN4 exist in PNS patients, we sequenced the ACTN4 gene in biopsies collected from 155 young PNS patients (≤16 years old). The patients were classified into five groups: FSGS, minimal change nephropathy, IgA nephropathy, membranous nephropathy, and those without renal puncture. Ninety-eight healthy people served as controls. Samples were subjected to Illumina’s next generation sequencing protocols using FastTarget target gene capture method. We identified 5 ACTN4 mutations which occurred only in PNS patients: c.1516G > A (p.G506S) on exon 13 identified in two PNS patients, one with minimal change nephropathy and another without renal puncture; c.1442 + 10G > A at the splice site in a minimal change nephropathy patient; c.2191-4G > A at the cleavage site, identified from two FSGS patients; and c.1649A > G (p.D550G) on exon 14 together with c.2191-4G > A at the cleavage sites, identified from two FSGS patients. Among these, c.1649A > G (p.D550G) is a novel ACTN4 mutation. Patients bearing the last two mutations exhibited resistance to clinical therapies.