Rituximab or Cyclophosphamide in the Treatment of Membranous Nephropathy: The RI-CYCLO Randomized Trial

BACKGROUND

A cyclic corticosteroid-cyclophosphamide regimen is the first-line therapy for membranous nephropathy. Compared with this regimen, rituximab therapy might have a more favorable safety profile, but a head-to-head comparison is lacking.

METHODS

We randomly assigned 74 adults with membranous nephropathy and proteinuria >3.5 g/d to rituximab (1 g) on days 1 and 15, or a 6-month cyclic regimen with corticosteroids alternated with cyclophosphamide every other month. The primary outcome was complete remission of proteinuria at 12 months. Other outcomes included determination of complete or partial remission at 24 months and occurrence of adverse events.

RESULTS

At 12 months, six of 37 patients (16%) randomized to rituximab and 12 of 37 patients (32%) randomized to the cyclic regimen experienced complete remission (odds ratio [OR], 0.4; 95% CI, 0.13 to 1.23); 23 of 37 (62%) receiving rituximab and 27 of 37 (73%) receiving the cyclic regimen had complete or partial remission (OR, 0.61; 95% CI, 0.23 to 1.63). At 24 months, the probabilities of complete and of complete or partial remission with rituximab were 0.42 (95% CI, 0.26 to 0.62) and 0.83 (95% CI, 0.65 to 0.95), respectively, and 0.43 (95% CI, 0.28 to 0.61) and 0.82 (95% CI, 0.68 to 0.93), respectively, with the cyclic regimen. Serious adverse events occurred in 19% of patients receiving rituximab and in 14% receiving the cyclic regimen.

CONCLUSIONS

This pilot trial found no signal of more benefit or less harm associated with rituximab versus a cyclic corticosteroid-cyclophosphamide regimen in the treatment of membranous nephropathy. A head-to-head, pragmatic comparison of the cyclic regimen versus rituximab may require a global noninferiority trial.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Rituximab versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO), NCT03018535.

P0057ADPKD: COMPLEX GENOTYPES MAY EXPLAIN SEVERE PHENOTYPE AND INTRAFAMILIAL PHENOTYPIC VARIABILITY

Background and Aims

Discordant affected relative-pairs are seen in ∼10% of families with Autosomal Dominant Polycystic Kidney Disease (ADPKD); <1% of patients exhibit very early onset (VEO) disease. Complex genotypes may result in renal disease variability beyond that predicted by the sole effect of a single PKD mutant allele, leading to the discovery of biallelic or digenic disease. Here we illustrate such complexity in 6 ADPKD pedigrees.

Method

Among our single-center ADPKD cohort (186 index patients), we selected pedigrees (P) in which marked familial phenotypic variability or severe and early onset disease was investigated by NGS and MLPA analysis of PKD1 and PKD2 genes and NGS analysis of other cystogenes. Segregation analysis by Sanger sequencing of PKD variants was performed in available affected and unaffected family members.

Results

In P1 and P2, the index cases (IC), presented with very early onset (VEO) disease characterized by prenatal/neonatal enlarged and hyperechogenic kidneys mimicking autosomal recessive polycystic kidney disease (ARPKD). In P1, with neonatal onset, the ADPKD affected father transmitted a PKD1 PT variant p.Gln4231*, whereas the mother, without renal cystic phenotype, transmitted a PKD1 hypomorphic variant p.Asp1332Asn.

In P2, the ADPKD-PKD2 mother’s pregnancy was complicated by Potter sequence. Parent’s PKHD1 gene analysis was negative. Two missense NT variants in PKD1/PKD2 genes were detected in the healthy father, respectively p.Gly1944Arg and p.Thr203Ile. Therefore, a complex PKD inheritance was supposed in the fetus. Fetus DNA was not available.

In P3 early onset (EO) ADPKD in two monozygous twins was underpinned by a PKD1 NT variant (p.Arg1951Gln) inherited by the ADPKD mild affected father and worsened by a de novo PKD1 truncating variant p.Arg2402*.

In P4 and P5 a digenic ADPKD (PKD1 +PKD2 and PKD1 +PKHD1) was diagnosed in severe ADPKD IC. In P4 the two most severely affected siblings carried a PKD2 T variant (p.Ala365fs) and a PKD1 NT variant p-Cys259Tyr.

In P5 the IC presented with EO ADPKD, a de novo splicing variant c.2097 + 5_+6insT in PKD1 gene was discovered but the phenotype was probably worsened by the presence of biallelic variant in a second cystogene PKHD1: one paternally inherited: p.Gly1712Arg and one maternally inherited: p.Asp3088Asn .

Elderly parents in P6 had mild ADPKD with bilateral few kidney cysts and preserved eGFR, whereas IC showed moderate/severe CKD due to ADPKD biallelic variants. The IC carried a homozygous PKD1 NT variant (p.Arg4154Cys): each mutant allele inherited from the mild ADPKD affected parents.

Conclusion

Our study illustrates the genetic complexity in an otherwise “simple” Mendelian disorder, providing insights into the genetic basis of severity of ADPKD cases and into ADPKD intrafamilial disease variability. In our pedigree all cases with more severe clinical picture in the family presented at least two PKD variants. In P5 we found for the first time an EO ADPKD due to both PKD1 and PKHD1 variants.

PKD1 and PKD2 sequence analysis together with cystic kidney disease gene panel analysis is recommended in those patients with discordant phenotype compared to family members. Molecular study of PKD patients is expected to be a good prognostic tool together with clinical and renal imaging data to better manage disease therapy, follow-up and reproductive issues.

P0074EXPANDING THE VARIABILITY OF THE ADPKD-GANAB CLINICAL PHENOTYPE: A NEW FAMILY OF ITALIAN ANCESTRY

Background and Aims

Causative GANAB mutations have been described in only 123 families, 98 diagnosed with late-onset mild ADPKD and 35 with ADPLD. We describe a new family with mild, late-onset ADPKD due to p. R839W GANAB mutation, previously reported in an ADPLD patient requiring liver transplantation.

Method

Mutation analysis of PKD1, PKD2, GANAB genes was performed by targeted NGS analysis. To analyze GANAB gene we developed a custom panel of 11 kidney cystogenes (GANAB, PKDH1, TSC1, TSC2, UMOD, HNF1B, REN, OFD1, PARN, DNAJB11, SEC61A1) designed using Ion Ampliseq Designer. Sanger sequencing was performed in order to validate all the variants classified as pathogenic, likely pathogenic and VUS. Raw sequence data analysis, including base calling, demultiplexing, alignment to the hg19 human reference genome, was performed using the Torrent Suite Software version 5.5; the average depth of total coverage was set at 500X and for variant calls at minimum of 30X. Deletion and duplication analysis of PKD1 and PKD2 was performed using MLPA P351-C1 and P352-D1 probemixes, MRC-Holland.

Results

Diagnosis of ADPKD was made in a 45-year old man during pre-surgical screening for umbilical and inguinal hernia repair. The patient's clinical course was characterized by several complications pertaining to the ADPKD spectrum: nephrolithiasis (20 yo); umbilical/bilateral inguinal hernia repair, hypertension and mild aortic root dilation (45 yo) and AKI due to ureteral obstruction (50 yo). Abdomen CT scan showed bilateral renal cysts (TKV 565 cc), nephrolithiasis, normal-sized liver with multiple cysts, and sigmoid colon diverticulosis. Renal function was normal (SCr 0.69 mg/dL, CKD-EPI 115 ml/min). In the index case, NGS and MLPA analysis of PKD1 and PKD2 genes did not detect variants. We then use the abovementioned multigene NGS panel and identified a missense heterozygous c.2515C>T (p.R839W) variant in the GANAB gene. Screening was then extended to family members. No family members displayed renal function impairment. Both the 80 yo mother and the 84 yo father were found to have multiple bilateral kidney cysts (HtTKV of 239 ml and 435 ml, respectively), no liver cysts were found in either of them. Parents segregation analysis identified the GANAB variant p.R839W in the mother and in the maternal aunt. The father tested negative for all the abovementioned cystogenes.

Conclusion

we confirm that the renal phenotype caused by mutations in GANAB is very different from those due to mutations in PKD1 and PKD2, giving rise to a mild form of renal cystic disease, usually not progressing to ESRD. Despite the mild renal cystic burden, the index case showed a plethora of renal and extrarenal manifestations of ADPKD. The finding that patients with GANAB mutation can present with renal and liver cystic phenotype is intriguing, indicating a commonality between pathogenic background of two different inherited disorders, ADPKD and ADPLD. The missense GANAB mutation identified in our ADPKD family was first described in a pedigree reported by Porath et al. and diagnosed as ADPLD. This suggests that, beyond the effect of the shared mutation on GII subunit α, other modifier loci and environmental factors may influence the course of liver disease development and progression. Our study illustrates the important diagnostic role of a broader genetic testing, able to screen not only for PKD1 and PKD2 variants, but also for pathogenic variants in other cystogenes.

Rituximab versus steroids and cyclophosphamide for the treatment of primary membranous nephropathy: protocol of a pilot randomised controlled trial

INTRODUCTION

Primary membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. The disease may have different long-term outcomes. After 10 years of follow-up, 35%-50% of the untreated patients with persistent nephrotic syndrome may die or progress to end stage renal disease. The 2012 KDIGO (Kidney Disease Improving Global Outcomes) guidelines recommend that initial therapy should consist of alternating steroids and an alkylating agent for 6 months. Recent observational studies showed that the anti-CD20 antibody rituximab may be effective in inducing remission. We designed a pilot multicentre randomised trial to inform the design of a larger trial testing the efficacy and safety of treatment with steroids and cyclophosphamide versus rituximab in patients with primary MN and heavy proteinuria (>3.5 g/24 hours).

METHODS AND ANALYSIS

This pilot, open-label, two-parallel-arm, randomised clinical trial will enrol 70 patients with primary MN and heavy proteinuria. Patients will be randomised in a 1:1 ratio to either the intervention arm (rituximab) or the active comparator arm (corticosteroid/alkylating-agent therapy). The study will provide estimates of the probability of complete remission of proteinuria and risk of serious side effects at 12 months to inform the design of a larger trial. We will also assess the recruitment potential of each participating centre to address study feasibility.

ETHICS AND DISSEMINATION

The trial received ethics approval from the local ethics boards. We will publish pilot data to inform the design of a larger clinical trial.

TRIAL REGISTRATION NUMBERS

NCT03018535; 2011-006115-59.

[Practical approach to patient therapy affected by Autosomal Dominant Autosomic Polycystic Kidney Disease]

The Autosomal Dominant Polycystic Kidney Disease(ADPKD) is the most frequent renal genetic condition and involves 7 to 10% of subjects undergoing renal replacement therapy. It is estimated that between 24,000 and 34,000 subjects in Italy are affected by this condition. For an illness that has long been neglected due to a lack of treatment options, an attractive treatment possibility is now available: tolvaptan has shown clinical efficacy regarding disease progression in two clinical trials (ADPKD patients with mild renal failure and ADPKD patients with advanced renal failure). The possible liver toxicity expressed in about 4% of the subjects exposed to the drug and an important aquaretic effect suggest prudence and attention in the use of this new molecule. Based on these critical points, some clinicians with direct experience in the use of the drug have briefly collected in the pages to follow the main clinical recommendations for the treatment of ADPKD patints. The recommendations concern the general approach to the patient affected by ADPKD but with particular attention to the aspects related to the new treatment. The delicate task of introducing the opportunities and limitations of the offered therapy to the patient will be deepened. Finally, the document wants to suggest how best to organize a clinic dedicated to this condition.

[Hyperuricemia and Gout]

Already known to ancient Egyptians, gout is one of the first diseases which have been described as a clinical entity. To date, gout is the most common form of inflammatory arthritis. Gout is defined by the deposition of monosodium urate crystals within tissues, causing episodes of acute arthritis and the development of tophi, nephrolithiasis, and urate nephropathy. Hyperuricemia, i.e. levels of serum uric acid above 6.8 mg / dL(404mol/L), is a condition necessary, yet not sufficient for gout to develop. The increasing incidence of risk factors such as hypertension, obesity, and renal failure together with an ever-growing life expectancy has led in recent decades to a significant increase in gout prevalence, which has more than doubled when compared to the 1960s. This article addresses the issue of gout by highlighting the role played by the kidneys in uric acid homeostasis; the clinical effect of crystal deposition in tissues, including the kidney; the more recent guidelines on diagnosis and management strategies, with special regard to the use of old and new drugs in renal patients.

[ADPKD and Heart]

Autosomal Polycystic Kidney Disease ( ADPKD) is the most common inherited renal disease. ADPKD is caused by mutations in PKD1 and PKD2, encoding polycystin 1 and 2, respectively. ADPKD is a systemic disease, with renal and extrarenal involvement. Renal disease is characterized by formation and growth of cysts, with progressive destruction of renal parenchyma and development of End Stage Renal Disease (ESRD) in about 50% of affected individuals at the age of 60 years. Extrarenal disease usually involves the liver, heart and vasculature. Cardiovascular manifestations occur in a high percentage of patients with ADPKD, including hypertension, left ventricular hypertrophy, cardiac valvular abnormalities, and intracranial aneurysms. An early treatment of hypertension may decreased the risk of cardiovascular complications, the leading cause of morbidity and mortality. The antihypertensive agents of choice should be ACE inhibitors and angiotensin II receptor antagonists. In this review, we will focuses on the cardiovascular problems of patients with ADPKD.

[ADPKD: predictors of Renal Disease progression]

Factors predicting rapid progression of kidney disease in ADPKD can be divided into genetic (non-modifiable) and clinical (modifiable) risk factors. Patients harbouring PKD1 mutations, in particular if truncating, have a more severe form of ADPKD. Clinical risk factors include decrease in glomerular filtration rate and renal blood flow at a young age; high total kidney volume; hypertension and urological complications <35 years; albuminuria/proteinuria. The renal disease is also more severe in males and in subjects with family history of ESRD <55 years. In recent years, two models for predicting progression in ADPKD have been published: the Mayo model, based on height-adjusted TKV, age and eGFR, and the Brest model, based on PKD gene mutation type, gender, and early onset of hypertension and urological complications. With the emergence of new disease-modifying therapies, prediction tools are essential. However, the high variability in ADPKD makes the predicting models difficult to apply on an individual patient basis. Thus, the above-mentioned predicting models should be viewed as complimentary to clinical evaluation and follow-up. In the future, an individual risk score linking genetic, imaging and clinical data might prove the most accurate way of predicting long-term outcome.

[Genetics and genetic counseling]

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most frequent genetic disease, characterized by progressive development of bilateral renal cysts. Two causative genes have been identified: PKD1 and PKD2. ADPKD phenotype is highly variable. Typically, ADPKD is an adult onset disease. However, occasionally, ADPKD manifests as very early onset disease. The phenotypic variability of ADPKD can be explained at three genetic levels: genic, allelic and gene modifier effects. Recent advances in molecular screening for PKD gene mutations and the introduction of the new next generation sequencing (NGS)- based genotyping approach have generated considerable improvement regarding the knowledge of genetic basis of ADPKD. The purpose of this article is to provide a comprehensive review of the genetics of ADPKD, focusing on new insights in genotype-phenotype correlation and exploring novel clinical approach to genetic testing. Evaluation of these new genetic information requires a multidisciplinary approach involving a nephrologist and a clinical geneticist.

Tubulointerstitial nephritis is a dominant feature of hereditary apolipoprotein A-I amyloidosis

Apolipoprotein A-I is the main protein of high-density lipoprotein particles, and is encoded by the APOA1 gene. Several APOA1 mutations have been found, either affecting the lecithin:cholesterol acyltransferase activity, determining familial HDL deficiency, or resulting in amyloid formation with prevalent deposits in the kidney and liver. Evaluation of familial tubulointerstitial nephritis in patients with the Leu75Pro APOA-I amyloidosis mutation resulted in the identification of 253 carriers belonging to 50 families from Brescia, Italy. A total of 219 mutation carriers underwent clinical, laboratory, and instrumental tests. Of these, 62% had renal, hepatic, and testicular disease; 38% were asymptomatic. The disease showed an age-dependent penetrance. Tubulointerstitial nephritis was diagnosed in 49% of the carriers, 13% of whom progressed to kidney failure requiring dialysis. Hepatic involvement with elevation of cholestasis indices was diagnosed in 30% of the carriers, 38% of whom developed portal hypertension. Impaired spermatogenesis and hypogonadism was found in 68% of male carriers. The cholesterol levels were lower than normal in 80% of the mutation carriers. Thus, tubulointerstitial nephritis was highly prevalent in this large series of patients with Leu75Pro apoA-I amyloidosis. Persistent elevation of alkaline phosphatase, reduced HDL cholesterol plasma levels, and hypogonadism in men are key diagnostic features of this form of amyloidosis.

[Genetics of mesangial IgA nephropathy]

IgA nephropathy is the most common form of primary glomerulonephritis, with a variable prevalence depending on the geographic area of examination. Marked differences in disease prevalence has suggested that genetics could play a role in the pathogenesis of the disease, indicating the existence of susceptibility genes detected with different frequencies in geographically separated populations. Moreover, familial forms of IgAN have been reported worldwide, in sibling pairs, families and extended pedigrees belonging to geographically isolated populations. In this article we describe recent discoveries in genetic studies on IgAN. If candidate-gene association studies require first survey on the pathogenesis of the disease, since the candidate loci are selected on the basis of information gathered from traditional biology, the linkage analysis consist in an alternative approach. Several susceptibility loci have been identified in pedigrees segregating for IgAN, but not the causative mutations of the disease. Further progress in the field of knowledge about the genetics of IgAN has recently been obtained by the application of genome-wide association studies (GWAS) in large cohorts of cases and controls of IgAN. GWAS have identified multiple susceptibility loci coding for genes involved in critical mechanisms for the development of IgAN and, accordingly, have shed new light on the biology of the disease, revealing unknown pathogenic pathways. The close connection between IgAN and many autoimmune diseases has been demonstrated. Moreover, these studies have made the correlation of genetic risk score of developing IgAN with the geo-epidemiological aspect of the disease possible. The goal of the integrated genomic approach will be to discover new potential therapeutic targets.

Short-term effects of rituximab in children with steroid- and calcineurin-dependent nephrotic syndrome: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Prednisone and calcineurin inhibitors are the mainstay therapy of idiopathic nephrotic syndrome (INS) in children. However, drug dependence and toxicity associated with protracted use are common. Case series suggest that the anti-CD20 monoclonal antibody rituximab (RTX) may maintain disease remission.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This open-label randomized controlled trial was powered to show that a strategy based on RTX and lower doses of prednisone and calcineurin inhibitors was noninferior to standard doses of these agents in maintaining 3-month proteinuria as low as baseline or up to 1 g/d greater (noninferiority margin). Participants were stratified by the presence of toxicity to prednisone/calcineurin inhibitors and centrally assigned to add RTX (Mabthera, 375 mg/m(2) intravenously) to lower doses of standard agents or to continue with current therapy alone. The risk of relapse was a secondary outcome.

RESULTS

Fifty-four children (mean age 11 ± 4 years) with INS dependent on prednisone and calcineurin inhibitors for >12 months were randomized. Three-month proteinuria was 70% lower in the RTX arm (95% confidence interval 35% to 86%) as compared with standard therapy arm (intention-to-treat); relapse rates were 18.5% (intervention) and 48.1% (standard arm) (P = 0.029). Probabilities of being drug-free at 3 months were 62.9% and 3.7%, respectively (P < 0.001); 50% of RTX cases were in stable remission without drugs after 9 months.

CONCLUSIONS

Rituximab and lower doses of prednisone and calcineurin inhibitors are noninferior to standard therapy in maintaining short-term remission in children with INS dependent on both drugs and allow their temporary withdrawal.

[Genetics and nosological classification of renal cystic diseases]

Renal cystic diseases are the major group of inherited renal disorders in humans and a leading cause of end-stage renal disease. Dominant and recessive polycystic kidney disease (ADPKD and ARPKD, respectively) account for most of the clinical conditions. However, nephronophthisis (NPHP), medullary cystic kidney disease (MCKD), and dominant glomerulocystic kidney disease (GCKD) still have a relevant clinical impact, particularly in children. The discovery that the proteins that are defective in ADPKD and ARPKD localize to the primary cilium and the recognition of the role of this organelle in cystogenesis have led to the term ''ciliopathies''. In the last decade, the list of ciliopathies has continued to grow. Analysis of the protein products of the nine NPHP genes (NPHP 1-9) evinced a strong relation between ciliary function and pathogenesis of NPHP. The oral-facial-digital syndrome (OFD) type I, characterized by congenital malformations and cystic kidney disease, was found to result from mutations in the OFD1 gene, which encodes a protein located to the primary cilium. Parallel to these advances, mutations in UMOD, the gene encoding uromodulin, were identified in pedigrees with MCKD2, familial juvenile hyperuricemic nephropathy, and autosomal dominant GCKD. In all these disorders, uromodulin was found to be accumulating in intracellular aggregates, suggesting a common pathogenesis. Taken together, these findings suggest the need for the separation of renal cystic diseases due to UMOD mutations (uromodulin-associated diseases) from renal cystic diseases related to mutation of genes encoding for proteins expressed in the primary cilium (ciliopathies).

Lack of association between dialysis modality and outcomes in atheroembolic renal disease

BACKGROUND AND OBJECTIVES

Atheroembolic renal disease (AERD) can require dialytic support. Because anticoagulation may trigger atheroembolization, peritoneal dialysis may be preferred to hemodialysis. However, the effect of dialysis modality on renal and patient outcomes in AERD is unknown.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

A subcohort of 111 subjects who developed acute/subacute renal failure requiring dialysis was identified from a larger longitudinal study of AERD. The main exposure of interest was dialysis modality (peritoneal versus extracorporeal therapies). Logistic regression was used to study the probability of renal function recovery. Times from dialysis initiation to death were studied using Cox's regression.

RESULTS

Eighty-six patients received hemodialysis and 25 received peritoneal dialysis. The probability of renal function recovery was similar by dialysis modality (25% among hemodialysis patients and 24% among peritoneal dialysis patients; P = 0.873). During follow-up, 58 patients died, 14 among peritoneal patients and 44 among hemodialysis patients (P = 0.705). In multivariable analysis, gastrointestinal tract involvement and use of statins maintained an independent effect on the risk of patient death.

CONCLUSIONS

This study does not support the notion that one dialysis modality is superior to the other. However, the observational nature of the data precludes any firm conclusions.

[Controversial issues in the Giornale Italiano di Nefrologia: how to treat patients with focal segmental glomerular sclerosis]

Primary focal segmental glomerular sclerosis (FSGS) commonly presents with nephrotic syndrome. Spontaneous remission is rare and persistent nephrotic syndrome is a marker of poor prognosis. For this reason, obtaining remission using drugs with minimal side effects is desirable. The treatment of FSGS, however, represents a challenge. Not only is there a lack of prospective controlled trials, but FSGS is a syndrome of unknown pathophysiology, generally treated with drugs having a mechanism of action that is poorly understood in this setting, the use of which has often drawn criticism because it is based on empirical assumptions rather than pathogenetic evidence. At present, corticosteroids are the standard first-line approach in patients with idiopathic FSGS. Cytotoxic agents and cyclosporin A constitute a good therapeutic option for steroid-dependent patients or frequent relapsers. Mycophenolate mofetil, rituximab and plasmapheresis should be used as rescue treatment because further studies are required to determine their safety and efficacy. Clearly, real progress in FSGS treatment can only be obtained by research focused on the pathophysiology of this disease, so that a therapeutic approach can be defined that is based on reason rather than chance.

[Atheroembolic renal disease]

Atheroembolic renal disease can be defined as renal failure due to occlusion of the renal arterioles by cholesterol crystal emboli usually dislodged from ulcerated atherosclerotic plaques of the aorta. Atheroembolic renal disease is part of multisystem disease, since the embolization usually involves other organ systems such as the gastrointestinal system, central nervous system, and lower extremities. The kidney is frequently involved because of the proximity of the renal arteries to the abdominal aorta, where erosion of atheromatous plaques is most likely to occur. Embolization may occur spontaneously or after angiographic procedures, vascular surgery, and anticoagulation. In the last decade, atheroembolic renal disease has become a recognizable cause of renal disease. An ante-mortem diagnosis of the disease is possible in a significant proportion of cases as long as the level of diagnostic suspicion is high. The disease can severely affect kidney and patient survival. Although no specific treatment has been proven efficacious, use of statins may be justifiable and such therapy would be a reasonable choice for future treatment trials.

[Choosing the right treatment approach in focal and segmental glomerular sclerosis with chronic renal failure]

Focal and segmental glomerular sclerosis (FSGS) is a heterogeneous disease from a clinical, etiological and clinical point of view. FSGS may be idiopathic, usually associated with nephrotic syndrome, which requires an ''etiological'' treatment approach. In addition, hereditary and secondary forms of FSGS have been described. The response to therapy, including steroids, cytotoxic drugs and calcineurin inhibitors, is considered the best clinical indicator of outcome. Many uncertainties exist regarding the best therapeutic approach to FSGS in patients presenting with chronic renal failure. In this setting, before planning any treatment, the physician should always assess the presence of superimposed functional renal insufficiency and evaluate the severity of the renal impairment, the histological picture, previous immunosuppressive treatments, and the individual patient's risk for side effects. Keeping in mind these considerations and in the absence of appropriate studies, we can formulate the following suggestions: 1. there is no absolute contraindication to the use of full-dose prednisone as initial therapy, although the likelihood of a good response is low; 2. the use of cytotoxic drugs is not recommended unless the patient presents with a steroid-responsive form of the disease; 3. in patients with a glomerular filtration rate of less than 40 mL/min, the use of calcineurin inhibitors should be avoided.

[Atheroembolic renal disease: a diagnostic challenge]

Atheroembolic renal disease is a part of a multisystem disease and can be defined as renal failure secondary to the occlusion of renal arterioles and glomerular capillaries with cholesterol crystal emboli deriving from the aorta and other major arteries. The kidney is usually involved because of the proximity of the renal arteries to abdominal aorta (where the erosion of atheromatous plaque is most likely to occur), and the high renal blood flow. Cholesterol crystal embolism can also occur in other visceral organs, as well as in the upper and lower extremities. Embolization may occur spontaneously or after angiographic and surgical procedures, and anticoagulation. Atheroembolic renal disease is an important yet underdiagnosed component of the spectrum of kidney diseases associated with atherosclerosis and remains an unexplored field of nephrology research.

Cholesterol crystal embolism (atheroembolism)

Cholesterol crystal embolism, known as atheroembolic disease, is caused by showers of cholesterol crystals from an atherosclerotic plaque that occludes small arteries. Embolization can occur spontaneously or as an iatrogenic complication from an invasive vascular procedure (angiography or vascular surgery) and after anticoagulant therapy. The atheroembolism can give rise to different degrees of renal impairment. Some patients show a moderate loss of renal function, others severe renal failure requiring dialysis. Renal outcome can be variable: some patients deteriorate or remain on dialysis, some improve and some remain with chronic renal impairment. Clinically, three types of atheroembolic renal disease have been described: acute, subacute or chronic. More frequently a progressive loss of renal function occurs over weeks. Atheroembolization can involve the skin, gastrointestinal system and central nervous system. The diagnosis is difficult and controversial for the protean extrarenal manifestations. In the past, the diagnosis was often made post-mortem. In the last 10 yrs, awareness of atheroembolic renal disease has improved. The correct diagnosis requires the clinician to be alert. The typical patient is a white male aged >60 yrs with a history of hypertension, smoking and arterial disease. The presence of a classic triad (precipitating event, renal failure and peripheral cholesterol crystal embolization) suggests the diagnosis. This can be confirmed by a biopsy of the target organs. A specific treatment is lacking; however, it is an important diagnosis to make because an aggressive therapeutic approach can be associated with a more favorable clinical outcome.