IgA肾病(immunoglobulin A nephropathy, IgAN)是一种以肾小球系膜区IgA或IgA为主的免疫球蛋白沉积为特点的肾小球肾炎。1968年法国肾脏病学家Jacques Berger博士首次发现并报道了IgAN，因此该病也被称为Berger病^[1]。IgAN确诊依赖肾活检，是全球最常见的原发性肾小球疾病，但全球不同地区发病率存在差异，其中亚洲地区IgAN发病率最高，我国IgAN约占全部肾活检病例54.3%^[2]。该病临床表现多样，可表现为发作性肉眼血尿、无症状镜下血尿伴或不伴蛋白尿、高血压、急性肾损伤乃至慢性肾衰竭，IgAN也是我国慢性肾脏病和终末期肾病的主要原因之一^[3]，高达40%的IgAN患者在诊断后20年内达到终末期肾病^[4]。目前认为，IgAN的发病机制可概括为"四重打击"^[5]：(1)遗传易感性导致IgA1产生和糖基化调控缺陷，半乳糖缺乏的IgA1(galactose-deficient IgA1, Gd-IgA1)增多，导致末端N-乙酰半乳糖胺的暴露；(2)由浆细胞产生以末端N-乙酰半乳糖胺为靶点的聚糖特异性IgG或IgA1自身抗体抗聚糖抗体；(3)由抗Gd-IgA1自身抗体与Gd-IgA1以及可溶性sCD89结合，形成Gd-IgA1循环免疫复合物；(4)免疫复合物在系膜沉积激活炎症途径、补体途径导致肾小球损伤。肾活检是确诊IgAN的唯一方法，对于符合慢性肾炎综合征、复发性或持续性血尿与蛋白尿，疑似IgAN的患者，可考虑行肾穿刺活检。本共识针对原发性IgAN，不适用于继发性IgAN(紫癜性肾炎或IgA型血管炎、系统性红斑狼疮等)，以及肝硬化、炎性肠病等疾病所致IgA在肾组织沉积者，旨在为肾内科专科医师，尤其针对地市和县级医疗单位具有一定肾科专业基础的临床医师提供临床诊疗指导。

In June 2019, the American Society for Apheresis (ASFA) released the eighth edition of guidelines on the use of therapeutic apheresis in clinical practice. Based on the published literature, this guideline determined the quality of evidence and the strength of recommendations for therapeutic apheresis in the treatment of diseases, and discussed the clinical application of therapeutic apheresis in 84 diseases (157 indications). The guideline divided the therapeutic apheresis into two categories: blood cell purification technology, and plasma components purification technology. The plasma purification technology mainly referred to plasma exchange and immunoadsorption. This article focused on the interpretation of clinical multidisciplinary applications of plasma exchange and immunoadsorption.

This article summarized the important progress of clinical research in nephrology in 2020, mainly including primary glomerular diseases (IgA nephropathy, membranous nephropathy) and secondary glomerular diseases (diabetic nephropathy, lupus nephritis, kidney damage due to anti-neutrophil cytoplasmic antibody-associated vasculitis, blood system disease-related kidney damage), acute kidney injury, and chronic kidney disease-mineral and bone disorders. These advances will greatly help the clinical work in terms of disease diagnosis, prognosis judgment, and treatment guidance.

In recent years, the research on the relationship between ferroptosis and acute kidney injury (AKI) has been deepening, but the molecular biological mechanism of ferroptosis in AKI caused by nuclear radiation has not been clarified. This article reviewed the progress of research on the role of ferroptosis in the biological process of AKI induced by nuclear radiation so as to look for the potential detection methods and therapeutic targets for treating AKI induced by nuclear radiation.

Hypertension is one of the most common chronic diseases, and is the second most recognized risk factor for chronic kidney disease (CKD). Early diagnosis and effective treatment of hypertension can help prevent or delay the occurrence and development of CKD, and also help reduce the risk of cardiovascular events and all-cause death. From 2017 to 2020, the United States, Europe, China, Japan, and the International Society of Hypertension have successively published the latest guidelines for hypertension management. This article mainly reviewed and interpreted the guidelines on the management of hypertension in patients with CKD.

Podocytes are the basic structural unit for maintaining glomerular function, and are of crucial significance for maintaining glomerular filtration. Cellular autophagy helps maintain podocyte integrity. Mitochondria, as the main organelle for cell energy supply, play an important role in regulating cell survival and death. As a kind of specific autophagy, mitochondrial autophagy can timely remove damaged and aging mitochondria in cells, thereby ensuring the number and function of normal mitochondria in cells, and playing an important role in cell growth and metabolism. Studies have shown that podocyte damage occurs in a variety of kidney diseases, accompanied by mitochondrial dysfunction or abnormal cell autophagy. Podocyte mitochondrial autophagy activity can regulate the homeostasis of podocytes through signal pathways of PINK1/Parkin and Nrf2/Keap1, etc. This article summarized the physiopathological manifestations of mitochondria and podocytes, and reviewed the possible mechanisms of the role of mitochondrial autophagy homeostasis in podocyte disease, which might be helpful in exploring new therapeutic pathways for podocyte disease.

This article is an excerpt and a brief review of the clinical research progress in the field of blood purification in 2020. The main progress included blood purification treatment for COVID-19 pneumonia complicated with severe acute kidney injury, the initiation time and the optimal net ultrafiltration rate of continuous kidney replacement therapy, the effect of citrate anticoagulation on the prognosis, plasmapheresis therapy for ANCA-associated vasculitis, drug-coated balloon treatment of arteriovenous fistula stenosis, and regional anesthesia in the establishment of arteriovenous fistula. Advances in these areas will make it possible to improve the clinical practice of blood purification.

To further enhance the clinical diagnosis and treatment level of diabetic kidney disease（DKD）， standardize the clinical application of Western and traditional Chinese medicines for DKD， and promote the development of precise diagnosis and treatment of DKD by integrated traditional Chinese and Western medicine， the Chinese Association of Integrative Medicine， the China Association of Chinese Medicine， the Chinese Medical Association， and the Chinese PLA General Hospital have taken the lead in initiating the formulation of guidelines for diagnosis and treatment of DKD with integrated traditional Chinese and Western medicine. This article elaborated on the formation process of the guideline development committee， the definition of clinical questions， data collection and selection strategies， the retrieval and screening process for evidence， the establishment of recommendations， external review of the guidelines，publication strategies， and promotion and implementation measures. The aim of this article was to provide a clear framework and technical support for the development of the guidelines， enhance the transparency of the guidelines development process， and offer references and insights for the formulation of other diagnostic and treatment guidelines in the field of integrated traditional Chinese and Western medicine.

Objective

To establish and compare three animal models of acute kidney disease（AKD） to provide basic research evidence for investigating the pathophysiological mechanisms of AKD.

Methods

Ninety healthy male C57BL/6J mice aged 6-8 weeks were selected， and divided into model groups and control groups （15 mice/group） to establish three AKD models： folic acid model group （given intraperitoneal injection of 0.5% folic acid at 250 mg/kg）， folic acid control group （given intraperitoneal injection of the same amount of 0.3 M sodium bicarbonate）， unilateral ureteral obstruction （UUO） model group （given unilateral ureteral obstruction）， UUO control group （given sham operation）， unilateral ischemia-reperfusion （UIR） model group （given clamping of unilateral renal pedicle for 30 minutes）， and UIR control group （given sham operation）.On day 2， day 8， and day 14 after the modeling， samples were collected to measure serum creatinine， blood urea nitrogen， and proteinuria levels.Renal tissue pathology was observed， and renal injury and collagen deposition were assessed.Western blotting was used to detect the expressions of fibrosis-related proteins such as vimentin and α-smooth muscle actin.RT-qPCR was used to detect renal mRNA expressions of kidney injury molecule-1 （KIM-1） and inflammatory factors including TNF-α， IL-1β， IL-8， and IFN-γ）.

Results

In the folic acid model group， serum creatinine and blood urea nitrogen significantly increased at day 8 after the modeling （both P＜0.05）， while the KIM-1 expression was higher than those in the other two model groups at day 2 after the modelings.At day 8 after the modelings， the expression of KIM-1 in the UUO model group was higher than those in the other two model groups （all P＜0.05）.The tubular injury scores and collagen deposition in the three model groups showed a time-dependent increase， and were all higher than those in their respective control groups.At day 14 after modeling， the UUO model group showed higher tubular injury scores and collagen deposition， as well as higher expressions of vimentin and α-smooth muscle actin than the other two model groups （all P＜0.05）.At day 8 after the modelings， the mRNA expressions of IL-8， IL-1β， TNF-α， and IFN-γ in the three model groups were all higher than those in their respective control groups （all P＜0.05）， while the expressions of these inflammatory factors in the UUO model group were higher than those in the other two model groups （all P＜0.05）.

Conclusion

The folic acid model， UUO model， and UIR model of mice AKD were all established at day8after the modeling operations， among which the renal fibrosis during the disease progression was more severe in the UUO model.

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is the most common complication of chronic kidney disease. It is due to the decline in glomerular filtration rate, which leads to the retention of multiple substances and toxins. Its clinical manifestations includes disorders of blood calcium, phosphorus and related regulatory hormones such as parathyroid hormone, vitamin D, and fibroblast growth factor 23, which in turn cause metabolic bone disease or fractures, and cardiovascular diseases, and increase the hospitalization rate and mortality of patients. The "China guidelines for the diagnosis and treatment of CKD-MBD" launched in 2018 has played a very good role in standardizing the diagnosis and treatment of CKD-MBD. This article interpreted the CKD-MBD guidelines combing with the clinical experience of the authors.

For decades, standard regimens based on corticosteroids and classic immunosuppressive agents have become the main therapy for patients with immune-mediated glomerular diseases, but some patients had poor efficacy or intolerance to these classic drugs. The emergence of new biological agents has brought dawn to the targeted treatment of such diseases, and is of great significance in improving patients′ clinical symptoms and quality of life. However, the treatment options, the effectiveness, and safety of the treatment have yet to be further refined by large randomized controlled trials. This article reviewed the application progress of the widely used new biological agents like rituximab, belimumab, eculizumab, and bortezomib in the treatment of kidney diseases.