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IgA nephropathy (IgAN) is a progressive form of kidney disease defined by glomerular deposition of IgA. We performed a genome-wide association study involving 10,146 kidney biopsy-diagnosed IgAN cases and 28,751 matched controls across 17 international cohorts. We defined 30 independent genome-wide significant risk loci jointly explaining 11% of disease risk. A total of 16 loci were novel, including TNFSF4, REL, CD28, CXCL8/PF4V1, LY86, LYN, ANXA3, TNFSF8/15, REEP3, ZMIZ1, RELA, ETS1, IGH, IRF8, TNFRSF13B and FCAR. The SNP-based heritability of IgAN was estimated at 23%. We observed a positive genetic correlation between IgAN and total serum IgA levels, allergy, tonsillectomy, and several infections, and a negative correlation with inflammatory bowel disease. All significant non-HLA loci shared with serum IgA levels had a concordant effect on the risk of IgAN. Moreover, IgAN loci were globally enriched in gene orthologs causing abnormal IgA levels when genetically manipulated in mice. The explained heritability was enriched in the regulatory elements of cells from the immune and hematopoietic systems and intestinal mucosa, providing support for the pathogenic role of extra-renal tissues. The polygenic risk of IgAN was associated with early disease onset, increased lifetime risk of kidney failure, as well as hematuria and several other traits in a phenome-wide association study of 590,515 individuals. In the comprehensive functional annotation analysis of candidate causal genes across genome-wide significant loci, we observed the convergence of biological candidates on a common set of inflammatory signaling pathways and cytokine ligand-receptor pairs, prioritizing potential new drug targets.

Dear Editor: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inherited kidney disorder and affects up to 12 million individuals worldwide. Radiologic imaging is critical for successful management. Until recently, the treatments were only symptomatic but EMA in 2017 and FDA in 2018 approved Tolvaptan for ADPKD therapy. Renal imaging provide important diagnostic and management guidance in the monitoring of disease progression. In the past, standard radiographic imaging has not provided the accuracy necessary to reliably measure renal [...]

Background Antibiotic resistance is a global problem today. The knowledge of bacterial resistances trend is crucial for antibiotic empiric therapy. Nephrology practice meets several sites of microbiological interest. We aimed to study the prevalence of bacterial pathogens and their emerging resistance patterns to antibiotics commonly used. Methods We reviewed 1249 microbiologic reports obtained between January 2009 and December 2013 from patients admitted to Nephrology Department. We analyzed the antibiotic susceptibility patterns for the firsts 4 identified bacterial pathogens. Results The bacterial pathogens most frequently isolated were: Escherichia coli , Staphylococcus aureus , Enterococcus faecalis , Pseudomonas aeruginosa , Candida , Staphylococcus epidermidis , Klebsiella pneumoniae . The percentage of extended spectrum beta-lactamase-producer Escherichia coli was 37% and methicillin-resistent Staphilococcus aureus was 15%. Conclusion Antibiotic resistance of bacterial pathogens to commonly used antibiotics is increasing. Our report on bacterial spectra of major antibiotic susceptibility patterns enables a more rational use.

Purpose: Calciphylaxis or Calcific Uraemic Arteriolopathy (CUA) is a rare systemic disorder associated with endstage renal disease and carrying a very poor prognosis and high mortality. It is characterized by skin necrosis and gangrene secondary to thrombosis and calcification of dermo-epidermal arterioles. Pathogenetic mechanisms inducing calciphylaxis are for the most part unknown. Methods: We report a case of calciphylaxis in a patient on long-term haemodialysis with severe secondary hyperparathyroidism. Despite therapies for hyperparathyroidism, the injury healed only after parathyroidectomy. Results: Calciphylaxis is an obliterative vasculopathy. The role of severe hyperparathyroidism in the pathogenesis of calciphylaxis is not well understood. A unique feature is the phenotypic differentiation of smooth muscle cells into osteoid-like cells. The vascular smooth muscle cells, exposed to high inorganic phosphate levels, could be transformed into osteoblast-like cells in patients undergoing haemodialysis with a poor control of phosphate intake. Conclusions: The uraemic condition contributes to vascular smooth muscle cell apoptosis and differentiation into bone forming osteoblast-like cells resulting in medial calcification. Nowadays no effective treatments are available for the successful management of calciphylaxis.

PurposeCalciphylaxis or Calcific Uraemic Arteriolopathy (CUA) is a rare systemic disorder associated with endstage renal disease and carrying a very poor prognosis and high mortality. It is characterized by skin necrosis and gangrene secondary to thrombosis and calcification of dermo-epidermal arterioles. Pathogenetic mechanisms inducing calciphylaxis are for the most part unknown.MethodsWe report a case of calciphylaxis in a patient on long-term haemodialysis with severe secondary hyperparathyroidism. Despite therapies for hyperparathyroidism, the injury healed only after parathyroidectomy.ResultsCalciphylaxis is an obliterative vasculopathy. The role of severe hyperparathyroidism in the pathogenesis of calciphylaxis is not well understood. A unique feature is the phenotypic differentiation of smooth muscle cells into osteoid-like cells. The vascular smooth muscle cells, exposed to high inorganic phosphate levels, could be transformed into osteoblast-like cells in patients undergoing haemodialysis with a...

Acute crescentic transformation is a rare but well described event in patients with membranous glomerulonephritis. We report our experience with a 66-year-old Caucasian man presented for rapid decline in renal function. For nearly 10 years, he was suffering from hypertension and mixed sensori-motor polyneuropathy. He performed therapy with prednisone and azathioprine, suspended 1 year before presentation. Moreover, six months before presentation, laboratory tests showed a serum creatinine concentration 220 mol/L and a 24-h protein excretion 0,75 g/d. The physical examination showed oedema and severe hypertension; the 24-h protein excretion was 1,1 gr/d and creatinine concentration was 550.8 mol/L; ANCA and other immunological tests were negative. There was no evidence of SLE, infection or malignancy. The kidney biopsy highlighted a membranous GN with crescentic overlap. The patient was treated with steroid and cyclophosphamide. Because there was no sign of improvement after 2 months, we stopped the cyclophosphamide therapy and the patient started chronic haemodialysis treatment. Unlike membranous nephropathy, patients with superimposed crescentic glomerulonephritis appear to have a more aggressive clinical course. The importance of recognizing this group of patients with membranous nephropathy and crescentic glomerulonephritis is that immunosuppressive therapy may ameliorate the progression of renal damage and in some cases early treatment was associated with useful recovery of renal function.

Leptospirosis is an emerging worldwide zoonotic disease. Renal involvement is common; it may vary from sub-clinical course with mild proteinuria and urinary sediment changes to severe renal failure. Leptospirosis-induced acute kidney injury is usually non oliguric and hypokalaemic. Renal impairment is mainly characterized by an association of interstitial and tubular damages. The most severe form of Leptospirosis, characterized by jaundice, acute kidney injury and haemorrhagic diathesis, is referred as Weil's disease. We describe a Weil's disease case with oliguric and hypokalaemic acute renal failure, hypotension, jaundice and lung haemorrhage. We performed haemodialysis treatment, steroid and antibiotic therapy with complete recovery of renal function.

To the Editor: Today in developed countries, infection-related glomerulonephritides are incommon and often associated with debilitating diseases. Legionnaires’ disease (LD) is one of the most common causes of severe community-acquired acute pneumonia in Europe and in up to 40% of cases of hospital-acquired pneumonia. The acute kidney injury (AKI) in LD is a well described complication but the renal morphology has only been reported in a few cases. The Tubulointerstitial Nephritis (TIN) is the most diagnosed histological change; instead, there [...]

The Erdheim-Chester disease is a rare form of Langherans cells. Since 1987 it is distinguished from other istiocytosis previously identified. The diagnosis of the disease relies on defined radiological (bone imaging) and pathological (histiocytic infiltration) criteria. Bone disease is crucial but systemic manifestations are reported more frequently at onset. Renal involvement is always asymptomatic at onset of disease or in the follow-up. In this review we analyze the reports of the literature; we highlight 3 pathological mechanisms of renal involvement: renal and retroperitoneal infiltration, urinary tract obstruction, renal arteries stenosis. No treatment to date has demonstrated an improvement in survival of patients with EC. Renal involvement is therefore symptomatic (ureteral stenting, percutaneous nephrostomy) or is adopted a wait-and-see attitude.

Strongyloidiasis is caused by a small intestinal nematode with a complex life cycle. In Italy the infection is endemic in rural areas of the Po Valley. The clinical syndrome of S. stercoralis encompasses a broad spectrum of symptoms and signs and, in the immunocompromised host, larvae can migrate to different organs and tissues. Also immune response seems to play a role in the pathogenesis of the disease. We report a case of strongyloidiasis complicated by Gram-negative sepsis and nephrotic syndrome in an immigrant from South America with a normal immune response. Whereas sepsis cleared up quickly, parasitic clearance was obtained only after treatment with ivermectin and nephrotic syndrome was still present three months after the end of treatment.

Wegener Granulomatosis is a systemic Anti-Neutrophil Cytoplasmic Autoantibody-associated Vasculitis, affecting small-to-medium vessels. Clinical presentation with simultaneous involvement of kidney and upper and lower respiratory tract is unusual. We report an instructive case of WG, analyzing clinical course, laboratory, and radiological features, kidney, lung, and larynx histological pictures. Besides renal biopsy, nephrology team performed larynx and lung biopsies because of unusual clinical presentation, computed tomography chest examination, and relevant malignancy risk regarding following immunosuppressant therapy.

Sir, We read with interest the recent case report ‘Minimal change disease with interferon-β therapy for relapsing remitting multiple sclerosis’ [1]. In this paper, the authors include renal thrombotic microangiopathy (TMA) among rare side effects of interferon (IFN) therapy, more frequently described with IFN-α [2]. We report here our experience about this topic. A 36-year-old white female with a 3-year history of multiple sclerosis and normal blood pressure and renal function was admitted for acute renal failure and pulmonary oedema. Three months previously, she started subcutaneous IFN-β-1a treatment of 22 μg thrice weekly. On admission, physical examination showed high blood pressure and severe pleuropericarditis without neurological or dermatological findings. Laboratory tests revealed microangiopathic haemolytic anaemia. Other immunological and microbiological laboratory tests were unremarkable. A renal biopsy disclosed signs of TMA; among 43 glomeruli, light microscopy revealed focal ischaemic signs and mild mesangial cell proliferation; vessel narrowing with thrombi and thickening of arteriolar walls and intimal onion skin-like swelling; light interstitial lymphomonocytic infiltration and focal tubular atrophy. Immunofluorescence showed mesangial IgM, C1q and fibrinogen staining. A diagnosis of haemolytic–uraemic syndrome was made. She was treated with transfusions, haemodialysis, plasma exchange and methylprednisolone i.v. followed by oral prednisone. Her cardiac function improved, and haematological signs progressively disappeared, but renal function did not recover. IFN-β treatment was discontinued. She is now receiving peritoneal dialysis treatment. IFN-α is known to cause a variety of renal lesions, including TMA [3,4], but to our knowledge, our observation is the first report of TMA induced by INF-β. Editorial note: This letter had been sent to Aravindan A. et al., but we did not receive a response. Conflict of interest statement. None declared.