What Is Hidden in Patients with Unknown Nephropathy? Genetic Screening Could Be the Missing Link in Kidney Transplantation Diagnosis and Management.

Between 15-20% of patients with end stage renal disease (ESRD) do not know the cause of the primary kidney disease and can develop complications after kidney transplantation. We performed a genetic screening in 300 patients with kidney transplantation, or undiagnosed primary renal disease, in order to identify the primary disease cause and discriminate between overlapping phenotypes. We used a custom-made panel for next-generation sequencing (Agilent technology, Santa Clara, CA, USA), including genes associated with Fabry disease, podocytopaties, complement-mediated nephropathies and Alport syndrome-related diseases. We detected candidate diagnostic variants in genes associated with nephrotic syndrome and Focal Segmental Glomerulosclerosis (FSGS) in 29 out of 300 patients, solving about 10% of the probands. We also identified the same genetic cause of the disease (PAX2: c.1266dupC) in three family members with different clinical diagnoses. Interestingly we also found one female patient carrying a novel missense variant, c.1259C>A (p.Thr420Lys), in the GLA gene not previously associated with Fabry disease, which is in silico defined as a likely pathogenic and destabilizing, and associated with a mild alteration in GLA enzymatic activity. The identification of the specific genetic background may provide an opportunity to evaluate the risk of recurrence of the primary disease, especially among patient candidates living with a donor kidney transplant.

Refractory IgA Nephropathy: A Challenge for Future Nephrologists.

IgA nephropathy (IgAN) represents the most prevalent form of primary glomerulonephritis, and, on a global scale, it ranks among the leading culprits behind end-stage kidney disease (ESKD). Presently, the primary strategy for managing IgAN revolves around optimizing blood pressure and mitigating proteinuria. This is achieved through the utilization of renin-angiotensin system (RAS) inhibitors, namely, angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs). As outlined by the KDIGO guidelines, individuals who continue to show a persistent high risk of progressive ESKD, even with comprehensive supportive care, are candidates for glucocorticoid therapy. Despite these therapies, some patients have a disease refractory to treatment, defined as individuals that present a 24 h urinary protein persistently >1 g after at least two rounds of regular steroids (methylprednisolone or prednisone) and/or immunosuppressant therapy (e.g., mycophenolate mofetil), or who do not tolerate regular steroids and/or immunosuppressant therapy. The aim of this Systematic Review is to revise the current literature, using the biomedical database PubMed, to investigate possible therapeutic strategies, including SGLT2 inhibitors, endothelin receptor blockers, targeted-release budesonide, B cell proliferation and differentiation inhibitors, fecal microbiota transplantation, as well as blockade of complement components.

Hidden genetics behind glomerular scars: an opportunity to understand the heterogeneity of focal segmental glomerulosclerosis?

Focal segmental glomerulosclerosis (FSGS) is a complex disease which describes different kinds of kidney defects, not exclusively linked with podocyte defects. Since nephrin mutation was first described in association with early-onset nephrotic syndrome (NS), many advancements have been made in understanding genetic patterns associated with FSGS. New genetic causes of FSGS have been discovered, displaying unexpected genotypes, and recognizing possible site of damage. Many recent large-scale sequencing analyses on patients affected by idiopathic chronic kidney disease (CKD), kidney failure (KF) of unknown origin, or classified as FSGS, have revealed collagen alpha IV genes, as one of the most frequent sites of pathogenic mutations. Also, recent interest in complex and systemic lysosomal storage diseases, such as Fabry disease, has highlighted GLA mutations as possible causes of FSGS. Tubulointerstitial disease, recently classified by KDIGO based on genetic subtypes, when associated with UMOD variants, may phenotypically gain FSGS features, as well as ciliopathy genes or others, otherwise leading to completely different phenotypes, but found carrying pathogenic variants with associated FSGS phenotype. Thus, glomerulosclerosis may conceal different heterogeneous conditions. When a kidney biopsy is performed, the principal objective is to provide an accurate diagnosis. The broad spectrum of phenotypic expression and genetic complexity is demonstrating that a combined path of management needs to be applied. Genetic investigation should not be reserved only to selected cases, but rather part of medical management, integrating with clinical and renal pathology records. FSGS heterogeneity should be interpreted as an interesting opportunity to discover new pathways of CKD, requiring prompt genotype-phenotype correlation. In this review, we aim to highlight how FSGS represents a peculiar kidney condition, demanding multidisciplinary management, and in which genetic analysis may solve some otherwise unrevealed idiopathic cases. Unfortunately there is not a uniform correlation between specific mutations and FSGS morphological classes, as the same variants may be identified in familial cases or sporadic FSGS/NS or manifest a variable spectrum of the same disease. These non-specific features make diagnosis challenging. The complexity of FSGS genotypes requires new directions. Old morphological classification does not provide much information about the responsible cause of disease and misdiagnoses may expose patients to immunosuppressive therapy side effects, mistaken genetic counseling, and misguided kidney transplant programs.

The impact of puberty on the onset, frequency, location, and severity of attacks in hereditary angioedema due to C1-inhibitor deficiency: A survey from the Italian Network for Hereditary and Acquired Angioedema (ITACA).

Introduction: Hereditary angioedema due to C1-inhibitor deficiency is influenced by hormonal factors, with a more severe course of disease in women. Our study aims to deepen the impact of puberty on onset, frequency, location and severity of attacks. Methods: Retrospective data were collected through a semi-structured questionnaire and shared by 10 Italian reference centers of the Italian Network for Hereditary and Acquired Angioedema (ITACA). Results: The proportion of symptomatic patients increased significantly after puberty (98.2% vs 83.9%, p=0.002 in males; 96.3% vs 68,4%, p<0.001 in females); the monthly mean of acute attacks was significantly higher after puberty, and this occurred both in females (median (IQR) = 0.41(2) in the three years before puberty vs 2(2.17) in the three years after, p<0.001) and in males (1(1.92) vs 1.25(1.56) respectively, p<0.001). The increase was greater in females. No significant differences were detected in attack location before and after puberty. Discussion: Overall, our study confirms previous reports on a more severe phenotype in the female gender. Puberty predisposes to increased numbers of angioedema attacks, in particular in female patients.

Management of patients with a failed kidney transplant: what should we do?

The number of kidney transplant recipients returning to dialysis after graft failure is steadily increasing over time. Patients with a failed kidney transplant have been shown to have a significant increase in mortality compared with patients with a functioning graft or patients initiating dialysis for the first time. Moreover, the risk for infectious complications, cardiovascular disease and malignancy is greater than in the dialysis population due to the frequent maintenance of low-dose immunosuppression, which is required to reduce the risk of allosensitization, particularly in patients with the prospect of retransplantation from a living donor. The management of these patients present several controversial opinions and clinical guidelines are lacking. This article aims to review the leading evidence on the main issues in the management of patients with failed transplant, including the ideal timing and modality of dialysis reinitiation, the indications for an allograft nephrectomy or the correct management of immunosuppression during graft failure. In summary, retransplantation is a feasible option that should be considered in patients with graft failure and may help to minimize the morbidity and mortality risk associated with dialysis reinitiation.

Podocytes: The Role of Lysosomes in the Development of Nephrotic Syndrome.

This commentary highlights the article by Li et al that links ceramide accumulation in podocytes to cellular damage and nephrotic syndrome.

Citation classics: ranking of the top 100 most cited articles in nephrology.

BACKGROUND: The number of citations of a scientific article is considered a weight of that work in the field of interest. Bibliometric analysis of the most cited articles conducted in some medical disciplines has identified the most relevant scientific contributions that pushed forward knowledge and clinical practice of that discipline. METHODS: We conducted a bibliometric analysis of the most cited articles in nephrology, by extracting relevant words that identify issues of nephrological interest and querying the Google Scholar database. A rank with the 100 most cited articles was obtained, based on the absolute number of citations. Articles were clustered in different areas of interest. RESULTS: Word(s) extracted from the Google Scholar database that restituted at least 100 000 hits were 50. The extracted 100 most cited articles collected cumulatively >285 000 citations. Nine subcategories were identified and the most populated one was 'Renal function assessment' (16 articles and 68 000 citations, 24% of total). The other relevant group of articles (16, with 46 652 citations) belonged to the category 'Randomized trials and pharmacology'. Almost 70% of the articles in the top 100 were published by eight major international journals. The top 100 list included 62 articles generated from USA scientists and the author with higher number of articles was A.S. Levey (10). CONCLUSIONS: The top 100 list of articles in nephrology helps delineate the major interests of this medical discipline. Assessment of renal functions, probably for its multidisciplinary relevance, is the heaviest topic, based on number of citations.