Immune checkpoint inhibitors (ICIs) dramatically improve the prognosis of many malignancies but at the cost of numerous side effects, which may limit their benefits. Acute kidney injury associated with immune checkpoint inhibitors most frequently are acute tubulointerstitial nephritis (ATIN), but various cases of glomerulonephritis have also been reported. Herein, we report a case of severe IgA nephropathy (IgAN) associated with ICIs and carry out a literature review. IgAN was diagnosed in a median time of 5 months (range 1-12 months) after the initiation of ICIs, with heterogeneous severity, and usually treated by corticosteroid and discontinuation of ICIs. In contrast to our case, renal outcomes in literature were often favorable, with recovery of renal function and a reduction in proteinuria on treatment. Although IgAN related to ICIs is a much rarer complication than ATIN, it may still be underdiagnosed. Careful questioning and screening for asymptomatic hematuria should be performed before using ICIs.

Concurrent malignancy and IgA nephropathy are rare. Despite the lack of solid experimental evidence, there are theoretical hypotheses of pathophysiology for the development of glomerular damage in cancer patients, like aberrant immune activities. Here, we describe a nine-year-old child who was admitted due to nephrotic syndrome. Abdominal imaging examination accidentally revealed a retroperitoneal tumor, and surgical resection was performed with a pathological diagnosis of neuroblastoma. However, complete removal of the tumor had no impact on the clinical manifestation of nephrotic syndrome, like proteinuria. The use of corticosteroids alone only led to a partial resolution of proteinuria, and resistance developed after one month of treatment. A further kidney biopsy was performed, which suggested IgA nephropathy. Clinical remission of IgA nephropathy was achieved after standard combination treatment of corticosteroids and mycophenolate mofetil for 10 months. This study represented the first case report of neuroblastoma associated with IgA nephropathy. We postulated that IgA nephropathy pathogenesis might be associated with neuroblastoma, though a coincidence of these two conditions cannot be fully excluded. Standard treatment for IgA nephropathy is applicable for patients with concomitant cancer.

BACKGROUND: IgA nephropathy (IgAN) is a common cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Outcomes are highly variable and predicting risk of disease progression at an individual level is challenging. Accurate risk stratification is important to identify individuals most likely to benefit from treatment. The Kidney Failure Risk Equation (KFRE) has been extensively validated in CKD populations and predicts the risk of ESRD at 2 and 5 years using non-invasive tests; however, its predictive performance in IgAN is unknown. The Oxford classification (OC) describes pathological features demonstrated on renal biopsy that are associated with adverse clinical outcomes that may also inform prognosis. The objective of this systematic review is to compare the KFRE with the OC in determining prognosis in IgAN.
METHODS: A systematic review will be conducted and reported in line with PRISMA guidelines (PRISMA-P checklist attached as Additional file 1). Inclusion criteria will be cohort studies that apply the KFRE or OC to determine the risk of CKD progression or ESRD in individuals with IgAN. Multiple databases will be searched in duplicate to identify relevant studies, which will be screened first by title, then by abstract and then by full-text analysis. Results will be collated for comparison. Risk of bias and confidence assessments will be conducted independently by two reviewers, with a third reviewer available if required.
CONCLUSIONS: Identifying individuals at the highest risk of progression to ESRD is challenging in IgAN, due to the heterogeneity of clinical outcomes. Risk prediction tools have been developed to guide clinicians; however, it is imperative that these aids are accurate and reproducible. The OC is based on observations made by specialist renal pathologists and may be open to observer bias, therefore the utility of prediction models incorporating this classification may be diminished, particularly as in the future novel biomarkers may be incorporated into clinical practice.
BACKGROUND: PROSPERO CRD42022364569.

BACKGROUND: Medullary sponge kidney (MSK)is rare in association with glomerulonephritis. We report a patient with medullary sponge kidney, and the kidney biopsy revealed a diagnosis of IgA nephropathy.
METHODS: A 27-year-old female presented with hematuria and proteinuria, and imaging studies indicated the presence of medullary spongy kidney. With appropriate preparation, a kidney biopsy was performed. Considering the patient\'s clinical and pathological characteristics, the final diagnosis was determined to be medullary sponge kidney associated by IgA nephropathy. The combination of corticosteroids and angiotensin receptor blockers (ARBs) proved to be significantly effective in reducing proteinuria in the current case. To the best of our knowledge, this is the first reported case that demonstrates the coexistence of MSK and IgA nephropathy.
CONCLUSIONS: Administering precise therapy based on renal pathology can potentially enhance outcomes for patients with renal conditions, necessitating the need for clinicians to be vigilant about differential diagnosis in order to reduce the rates of missed diagnoses and misdiagnosis.

A 66-year-old non-smoker presented with a 2-week history of new-onset pedal oedema and gross haematuria. On evaluation, he was found to be hypertensive and oedematous with a haemoglobin of 19.1 g/dl, platelet count of 546,000/mm3, and creatinine of 2.6 mg/dl. Urine examination revealed abundant RBCs with 3+ albumin on three separate occasions. His 24-h urine protein level was 3830 mg/day, with a serum cholesterol level of 303 mg/dl. Secondary erythrocytosis and thrombocytosis tests were negative. Bone marrow examination revealed hypercellularity, erythroid hyperplasia, tight clusters of large megakaryocytes, and megakaryocytic hyperplasia suggestive of polycythemia vera. PCR analysis revealed a JAK2V617 F (exon 14) mutation. In view of nephrotic syndrome, azotemia, and microscopic haematuria, a renal biopsy was performed, which revealed features of IgA nephropathy with advanced interstitial fibrosis and tubular atrophy. He was started on angiotensin receptor blockers with hydroxy urea as a part of treatment. This case report highlights the association of glomerular disease with polycythaemia vera and the need of prompt renal biopsy for diagnosis and management.

BACKGROUND: Immunoglobulin type A (IgA) nephropathy is the most common primary glomerulonephritis (GN) worldwide with higher rates in East and Pacific Asia compared to North America and Europe. Despite high reported prevalence of IgAN in these countries, the overall disease prevalence across Asia is not available. Treatment patterns of IgAN patients across Asian countries have also not been summarized. The aim of this study was to review and summarize evidence on IgA nephropathy prevalence, treatment patterns, and humanistic and economic burden in mainland China, Taiwan, South Korea, Japan, and Australia.
METHODS: A targeted literature review was conducted in PubMed and local databases in China (including Taiwan), South Korea, Japan, and Australia between January 2010-December 2021. Website literature searches were conducted using Google Scholar and Baidu.
RESULTS: Sixty-nine publications and 3 clinical guidelines were included. Incidence ranged from 0 to 10.7 per 100 000 people per year in Australia, Japan, and Taiwan, and ranged from 6.3 to 24.70% among patients who underwent renal biopsy in mainland China. Prevalence and diagnosis rates ranged from 0 to 72.1% in mainland China, South Korea, Taiwan, Japan, and Australia. Mortality rates in mainland China, South Korea, and Japan varied widely. The top 3 commonly used therapies were angiotensin-converting enzyme inhibitor/angiotensin receptor blockers (0.9-99.6%), corticosteroids (3.5-100%), and immunosuppressants (1.6-85.5%) in Japan, mainland China, and South Korea. Patient quality of life was measured by different tools, and annual hospitalization costs ranged from $1 284.73 to $2 252.12 (2015-2018) in China.
CONCLUSIONS: The prevalence of IgA nephropathy among the general population in select countries/regions is not commonly available, despite evidence from studies and clinical guidelines. In addition, it is observed across geographic regions that heterogeneity exists in prevalence rates, and large variations exist in treatment patterns. There is need to fill in these gaps to understand the contributing factors behind the differences through population-based, multi-center, and real-world studies.

Erythrocytosis or polycythemia is defined as an increase in red blood cell concentration above the age- and sex-specific normal levels. Unlike anemia, which is very common in patients with chronic kidney disease (CKD), erythrocytosis is less frequent but requires specific understanding by health care professionals in order to provide the best care. Erythrocytosis, especially when undiagnosed and untreated, can lead to serious thrombotic events and higher mortality. Classic causes of erythrocytosis associated with CKD include cystic kidney diseases, kidney or other erythropoietin-secreting neoplasms, high-altitude renal syndrome, overdosage of erythropoietin-stimulating agents, androgen therapy, heavy smoking, chronic lung disease, obstructive sleep apnea, IgA nephropathy, post-kidney transplant erythrocytosis, renal artery stenosis, and congenital etiologies. After ruling out the common acquired causes of erythrocytosis and/or in the presence of suggestive parameters, primary erythrocytosis or polycythemia vera (PV) should be considered, and patients should be screened for JAK2V617F somatic mutation. The newest entity inducing erythrocytosis is linked to the use of sodium/glucose cotransporter 2 (SGLT2) inhibitors that hypothetically activate hypoxia-inducible factor 2α (HIF-2α) and in some cases unmask PV. This Review focuses on the pathogenesis, renal manifestations and management of PV, the pathophysiology of erythrocytosis induced by SGLT2 inhibitors and the relevance of timely JAK2 mutation screening in these patients.

UNASSIGNED: IgA nephropathy (IgAN), a condition posing a significant threat to public health, currently lacks a specific treatment protocol. Research has underscored the potential benefits of traditional Chinese medicine (TCM) for treating IgAN. Nevertheless, the effectiveness of various intervention strategies, such as combining TCM with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs), lacks a comprehensive systematic comparison. Therefore, this study aimed to conduct a network meta-analysis to assess the clinical efficacy of ACEIs, ARBs, TCM, and their combinations in treating IgAN to offer novel insights and approaches for the clinical management of IgAN.
UNASSIGNED: A systematic review conducted until November 2023 included relevant literature from databases such as PubMed, Embase, Cochrane, Web of Science, Scopus, CNKI, and Wanfang. Two independent researchers screened and assessed the data for quality. Network and traditional meta-analyses were performed using Stata 18.0 and RevMan 5.3 software, respectively. Outcome measures included 24-h urinary protein quantification (24 hpro), estimated glomerular filtration rate (eGFR), serum creatinine (Scr), blood urea nitrogen (BUN), and adverse event incidence rates (ADRs). Forest plots, cumulative ranking probability curves (SUCRA), and funnel plots generated using Stata 18.0 facilitated a comprehensive analysis of intervention strategies\' efficacy and safety.
UNASSIGNED: This study included 72 randomized controlled trials, seven interventions, and 7,030 patients. Comparative analysis revealed that ACEI + TCM, ARB + TCM combination therapy, and TCM monotherapy significantly reduced the levels of 24 hpro, eGFR, Scr, and BUN compared to other treatment modalities (p < 0.05). TCM monotherapy demonstrated the most favorable efficacy in reducing eGFR levels (SUCRAs: 78%), whereas the combination of ARB + TCM reduced Scr, 24 hpro, and BUN levels (SUCRAs: 85.7%, 95.2%, and 87.6%, respectively), suggesting that ARB + TCM may represent the optimal intervention strategy. No statistically significant differences were observed among the various treatment strategies in terms of ADR (p > 0.05).
UNASSIGNED: The combination of ACEI or ARB with TCM demonstrated superior efficacy compared to ACEI/ARB monotherapy in the treatment of IgAN without any significant ADRs. Therefore, combination therapies can be used to enhance therapeutic outcomes based on individual patient circumstances, highlighting the use of TCM as a widely applicable approach in clinical practice.
UNASSIGNED: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023476674.

OBJECTIVE: The effectiveness of immunosuppressive and corticosteroid treatments for Immunoglobulin A (IgA) nephropathy (IgAN) remains thoroughly evaluated. We undertook a meta-analysis to investigate the efficacy and safety of low-dose corticosteroids plus leflunomide for progressive IgA nephropathy.
METHODS: Eligible studies were obtained from PubMed, Embase, and Cochrane Library databases. We also searched the references of the included studies. Our protocol followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. Eligibility criteria were defined using a PICOS framework.
RESULTS: Our study included three articles presenting 342 patient cases. Findings revealed that low-dose corticosteroids combined with the leflunomide group were effective in relieving urine protein excretion (UPE) [mean difference (MD) = -0.35, 95% confidence interval (CI): -0.41 to -0.30, P < 0.00001] compared with the full-dose corticosteroids group. Regarding serum creatinine (SCr), estimated glomerular filtration rate (eGFR), complete remission rate, and overall response rate, there was no difference between the groups (p > 0.05). Regarding safety, low-dose corticosteroids combined with leflunomide significantly reduced the risk of serious adverse events [odds ratio (OR): 0.11, 95% CI: 0.01 to 0.91, P = 0.04]. Besides, no significant differences were observed between the two groups in the incidence of respiratory infection, abnormal liver function, diarrhea, herpes zoster, alopecia, pruritus, insomnia, pneumonia, diabetes, and urinary tract infection (P > 0.05).
CONCLUSIONS: Low-dose corticosteroids combined with leflunomide are a safe and effective treatment for progressive IgA nephropathy.
BACKGROUND: The PROSPERO registration number is CRD42022361883.

Anti-glomerular basement membrane (GBM) disease is a rare autoimmune condition characterized by the presence of positive anti-GBM autoantibodies, linear deposition of immunoglobulin G (IgG) along the GBM and severe kidney injury. In a limited number of cases, the association of anti-GBM disease with other glomerulonephritis has been reported. Herein, we present the case of a 66-year-old female patient with progressive worsen kidney function and decreased urine output. A renal biopsy revealed crescent glomerulonephritis with lineal IgG deposition along the GBM and mesangial IgA deposition, which supported the diagnosis of concurrent anti-GBM disease and IgA nephropathy (IgAN). In an extensive literature review, we identified a total of thirty-nine patients were reported anti-GBM disease combined with IgAN. The clinical characteristics of these patients demonstrate that the anti-GBM disease combined with IgAN tends to be milder with a more indolent course and a better prognosis than the classic anti-GBM disease, and its potential pathogenesis deserves to be further explored.