With the introduction of therapies to treat geographic atrophy (GA), GA management in clinical practice is now possible. A living systematic review can provide access to timely and robust evidence synthesis. This review found that complement factor 3 and 5 (C3 and C5) inhibition compared to sham likely reduces change in square root GA area at 12 months and untransformed GA area at 24 months. There is likely little to no difference in the rate of systemic treatment-emergent adverse events compared to sham. C3 and C5 inhibition, however, likely does not improve best-corrected visual acuity (BCVA) at 12 months, and the evidence is uncertain regarding change in BCVA at 24 months. Higher rates of ocular treatment emergent adverse effects with complement inhibition occur at 12 months and likely at 24 months. Complement inhibition likely results in new onset neovascular age-related macular degeneration at 12 months. This living meta-analysis will continuously incorporate new evidence.

BACKGROUND The incidence of glomerular disease recurrence in kidney transplant patients varies according to type of glomerulopathy; therefore, it is important to know the primary chronic kidney disease etiology. C3 glomerulopathy (C3G) is characterized by deposits of C3 in immunofluorescence and its pathogeny is based on the dysregulation of the alternative complement pathway. C3G has a high recurrence rate and, given its low prevalence, only case series have been published. A higher rate of recurrence and a more aggressive course have been described in association with monoclonal gammopathy (MG). CASE REPORT We describe the case of a 78-year-old man with chronic kidney disease of unknown etiology (no significant proteinuria) and monoclonal IgGl gammopathy with low risk of progression, who received a kidney transplant, presenting accelerated deterioration of kidney function. Histopathology showed predominant C3 deposits in immunofluorescence, compatible with C3 glomerulonephritis (C3GN). He was treated with eculizumab during 4 weeks while the study was completed. The response to treatment was not favorable and the patient remained in the dialysis program. CONCLUSIONS Further studies are needed to explain the pathogenic mechanisms of complement alternative pathway dysregulation mediated by monoclonal component in patients with C3GN and MG. Patients older than 50 years who are on a waiting list for kidney transplantation should have an MG detection study. The information provided to patients with MG on a waiting list for kidney transplantation should include not only the possibility of hematologic progression but also the recurrence/de novo appearance of associated kidney pathology.

OBJECTIVE: With the global increase in chronic liver disease and cirrhosis, there is an increasing need to identify non-invasive biomarkers to measure the severity of disease progression while reducing reliance on pathological biopsies. This study aimed to comprehensively evaluate the diagnostic value of PRO-C3 as a biomarker for staging liver fibrosis in patients with viral hepatitis or fatty liver disease.
METHODS: Articles published until January 6, 2023, were searched in the PubMed, Embase, MEDLINE, Web of Science, and Cochrane Library databases. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate the quality of the included studies. Pooled sensitivity, specificity, diagnostic odds ratio, and likelihood ratios were integrated using a random-effects model, and a summary receiver operating characteristic curve was constructed. Publication bias was also detected. Subgroup and meta-regression analyses, as well as sensitivity analysis, were also performed.
RESULTS: Fourteen studies with 4315 patients were included. Summary area under the curve of PRO-C3 for the identification of significant fibrosis (≥ F2) and advanced fibrosis (≥ F3) was 0.80 (95% confidence interval: 0.76-0.83). Subgroup and meta-regression analyses suggested that disease type and sample size may be the primary factors of heterogeneity in PRO-C3 diagnosis of ≥ F2, while study design, study sample type, and enzyme-linked immunosorbent assay kit brand may be the primary sources of heterogeneity in PRO-C3 diagnosis of ≥ F3.
CONCLUSIONS: PRO-C3 demonstrated clinically meaningful diagnostic accuracy when used alone as a non-invasive biomarker for diagnosing the liver fibrosis stage in individuals with viral hepatitis or fatty liver disease.

Hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) is complement-mediated due to the lack of complement inhibitors in the hemopoietic cell membranes, making complement inhibition the best approach to manage PNH. Three complement inhibitors are approved by the European Medicines Agency as targeted therapy for PNH: eculizumab and ravulizumab, two humanized monoclonal antibodies targeting the same complement 5 (C5) epitope, approved in 2007 and 2019, respectively, and the more recently approved cyclic peptide, the complement 3 (C3) inhibitor pegcetacoplan. Although national and international PNH treatment guidelines exist, they do not take into consideration the latest clinical trial evidence. Given the lack of evidence-based data for some clinical situations encountered in real life, we identified specific populations of patients who may benefit from switching to proximal C3 from terminal C5 inhibition.
The expert recommendations presented here were created using a Delphi-like process by a group of expert PNH specialists across Central Europe. Based on an initial advisory board meeting discussion, recommendations were prepared and reviewed as part of a Delphi survey to test agreement.
Using a systematic approach, literature databases were searched for relevant studies, and 50 articles were reviewed by the experts and included as supporting evidence.
Implementation of these recommendations uniformly across healthcare institutions will promote the best use of complement inhibition in managing PNH, and has the potential to positively impact patient outcomes in Central Europe and worldwide.

Objective: To report the clinical features and genetic variations of monogenic lupus caused by DNASE1L3 deficiency and to introduce preliminary experience on diagnosis and treatment for this disease. Methods: Clinical data of 3 children from the same pedigree were collected who were diagnosed with DNASE1L3 defect-associated monogenic lupus in August 2020 by Department of Pediatrics, Peking Union Medical College Hospital referred from Department of Pediatrics, Boai Hospital of Zhongshan. DNA was extracted from the peripheral blood of the patients and their parients to perform genetic analysis and confirmation. Six interferon-stimulated genes were relatively quantified to examine the activation of the type I interferon signaling. \"DNASE1L3\" \"systemic lupus erythematosus\" and \"SLE\" were searched in PubMed, Wangfang Data, CNKI databases for related reports from database established date to June 2022. Spectrum of genetic variations and clinical phenotypes were analyzed in combination with this pedigree. Results: Case 1, a 14-year-old girl with edema, hematuria, and heavy proteinuria, presented with membranous nephropathy. Case 2, the 12-year-old younger brother of case 1 with hematologic, cardiac, pulmonary, renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody and low complement C3, manifested with systemic lupus erythematosus. Case 3, the 8-year-old younger sister of case 1 with hematologic, cardiac, pulmonary and renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody, and low complement C3 and C4, manifested with systemic lupus erythematosus. Genetic testing revealed that all 3 patients carried homozygous deletions in exons 3 and 4 on DNASE1L3 gene. Interferon scores were elevated in case 1, 2 and their parents but normal in case 3. All 3 patients were diagnosed with monogenic lupus caused by DNASE1L3 defects. Literature searching identified 10 relevant publications in English and 0 publication in Chinese, involving 42 patients from 18 pedigrees (including the 3 cases from this pedigree). Nine variants were found: c.289_290delAC (p.T97Ifs*2), c.643delT (p.W215Gfs*2), c.320+4delAGTA, c.321-1G>A, Ex5 del, c.433G>A, c.581G>A (p.C194Y), c.537G>A (p.W179X), and Ex3-4 del. The hotspot variants were c.643delT (43% (36/84)) and c.289_290delAC (36% (30/84)). Kidney was affected in 31 cases (74%) of the 42 cases. Among the 25 patients, joints were affected in 16 cases (64%), fever were reported in 13 cases (52%) hematologic system was involved 13 cases (52%), rash was present in 10 cases (40%), intestinal tract was involved in 8 cases (32%), lungs were involved in 6 cases (24%), eyes were involved in 4 cases (16%), and the heart was involved in 4 cases (16%). The 2 cardiopulmonary affected patients from literature showed poor prognosis, with 1 died, and 1 right heart failure. Conclusions: The clinical manifestations of monogenic lupus caused by DNASE1L3 defect are highly heterogenous, primarily with renal, blood, joint, intestinal, and cardiopulmonary involvement. There is no correlation between the genotype and the phenotype. DNASE1L3 defects were predominantly mediated by null varations including nonsense, splicing, frameshift and exon deletions. The hotspot variants are c.643delT and c.289_290delAC. DNASE1L3 defects should be cautioned in early-onset lupus-like patients with renal, joint and hematologic involvement. Cardiopulmonary involved patients require close monitoring for poor prognosis. Copy number variations should be carefully analyzed after negative whole exome sequencing.
目的： 探讨DNASE1L3基因缺陷导致的单基因狼疮的临床特征及基因变异特点，并提供初步的诊治经验。 方法： 收集经中山市博爱医院儿科转诊至北京协和医院儿科2020年8月确诊的DNASE1L3基因缺陷相关单基因狼疮一家系3例患儿的临床资料，提取患儿及父母的外周血DNA进行遗传学分析及验证，并检测干扰素刺激基因相对表达量检测其Ⅰ型干扰素通路激活情况。分别以“DNASE1L3”“系统性红斑狼疮”“SLE”为关键词查阅PubMed数据库、万方数据库、中国知网数据库自建库至2022年6月相关文献，并结合本家系进行基因变异谱及临床资料分析总结。 结果： 例1，女，14岁，水肿、血尿、大量蛋白尿，表现为膜性肾病。例2，男，12岁，例1之弟，血液、心脏、肺、肾脏受累，抗核抗体、抗双链DNA抗体阳性，低补体C3，表现为系统性红斑狼疮。例3，女，8岁，例1之妹，血液、心脏、肺、肾脏受累，抗核抗体、抗双链DNA抗体阳性，低补体C3、C4，表现为系统性红斑狼疮。基因检测发现3例患儿均为DNASE1L3基因外显子3及4纯合缺失导致；干扰素评分例1、2及父母均升高，例3正常。3例患儿均确诊为DNASE1L3基因缺陷导致单基因狼疮。检索符合条件的英文文献10篇，中文文献0篇，包括本家系3例共42例（18个家系）患者，共发现9个变异位点：c.289_290delAC（p.T97Ifs*2）、c.643delT（p.W215Gfs*2）、c.320+4delAGTA、c.321-1G>A，Ex5 del，c.433G>A、c.581G>A（p.C194Y）、c.537G>A（p. W179X）以及Ex3-4 del。变异热点为c.643delT［43%（36/84）］及c.289_290delAC［36%（30/84）］。42例患者中31例（74%）有肾脏受累；25例患者中关节［16例（64%）］、发热［13例（52%）］、血液系统［13例（52%）］、皮疹［10例（40%）］、肠道［8例（32%）］、肺［6例（24%）］、眼［4例（16%）］、心脏［4例（16%）］受累，另有肌痛、光过敏、胸膜炎、肝大、意识改变各1例（4%）。2例合并心肺受累患者1例死亡，1例右心衰、预后不良。 结论： DNASE1L3基因缺陷导致的单基因狼疮临床表现异质性大，主要累及肾脏、血液、关节、肠道、心、肺系统等，临床表型与基因型无关；合并心、肺受累的患者预后较差。DNASE1L3基因缺陷以无义、剪切、移码、外显子缺失等无功能变异为主。对于起病年龄早、肾脏、关节、血液受累的系统性红斑狼疮疑似患儿需警惕DNASE1L3基因缺陷的发生，合并心、肺系统受累的患儿需密切监测病情进展以避免不良预后。对于全外显子组检测阴性患儿，需注意拷贝数变异的分析。.

C3 glomerulonephritis (C3GN) is a recently described form of GN that mainly occurs in children and young adults. It results from dysregulation of the alternative complement pathway. Studies have shown that dense deposit disease has a high recurrence rate; however, since C3GN is a recently described disorder, its recurrence rate is still variable. A 28-year-old male with end-stage renal disease caused by C3GN underwent renal transplantation. After 19 months, the patient experienced recurrent C3GN (rC3GN) that involved a variant of unknown significance in the ADAMTS13 gene. Over a short span of time, the patient suffered from rapid deterioration of the graft function that required renal replacement therapy. This is the first case of rC3GN that possibly involved genetic alteration, a variant within the ADAMTS 13 gene.

Alpha-1 antitrypsin (AAT) is the canonical serine protease inhibitor of neutrophil-derived proteases and can modulate innate immune mechanisms through its anti-inflammatory activities mediated by a broad spectrum of protein, cytokine, and cell surface interactions. AAT contains a reactive methionine residue that is critical for its protease-specific binding capacity, whereby AAT entraps the protease on cleavage of its reactive centre loop, neutralises its activity by key changes in its tertiary structure, and permits removal of the AAT-protease complex from the circulation. Recently, however, the immunomodulatory role of AAT has come increasingly to the fore with several prominent studies focused on lipid or protein-protein interactions that are predominantly mediated through electrostatic, glycan, or hydrophobic potential binding sites. The aim of this review was to investigate the spectrum of AAT molecular interactions, with newer studies supporting a potential therapeutic paradigm for AAT augmentation therapy in disorders in which a chronic immune response is strongly linked.

Atypical hemolytic uremic syndrome (aHUS) is a rare disease in pediatrics with 6-10% of cases associated with complement factor H autoantibodies. Ravulizumab is a new treatment option available for long-term management through blockage of the terminal complement cascade. We report a case of a previously healthy eight-year-old female who presented with hemolytic anemia, thrombocytopenia, and acute kidney injury. Low complement C3, normal ADAMTS13, and negative rheumatology and infectious disease panels suggested aHUS. A follow-up complement aHUS/TMA gene panel was negative for ADAMTS13, C3, CD46, CFB, CFD, CFH, CFHR1, CFHR3, CFHR5, CRI, DGKE, PLG, and THBD mutations and positive for MCP/CD46 haplotype and CFH-H3 haplotype. Further testing found decreased factor H (B1H) plasma level and increased factor H autoantibody, suggesting anti-factor H antibody-associated aHUS. She received hemodialysis (2 treatments) and eculizumab was initiated promptly. The patient had complete renal recovery after one month of therapy, and anemia, thrombocytopenia, and hemolysis resolved after two months of therapy. After five months of therapy, eculizumab was successfully switched to ravulizumab. After 12 months of initial diagnosis, complement C3 and factor H normalized, however, factor H autoantibody remained elevated. The case supports the notion that timely recognition of anti-FH-associated aHUS is important for disease management and that early specific therapy with immunosuppression results in favorable outcomes. It also illustrates that the blockade of the terminal complement cascade using eculizumab holds promise for pediatric cases. Finally, eculizumab can be safely switched to ravulizumab with an optimal longer duration between treatments in the context of aHUS.

The changes in the serum levels of aquaporin-4-IgG (AQP4-IgG), immunoglobulins, and inflammatory mediators in neuromyelitis optica spectrum disorder (NMOSD) cases treated with immunoadsorption have been rarely described in detail. Here we report a 29-year-old steroid-resistant NMOSD female with a severe disability (bilateral blindness and paraplegia) who received protein-A immunoadsorption as a rescue treatment. During the total 5 sessions, the circulating level of AQP4-IgG, immunoglobulins, and complement proteins (C3 and C4) showed a rapid and sawtooth-like decrease, and the serum AQP4-IgG titer declined from 1:320 to below the detectable limit at the end of the 3rd procedure. Of all the antibodies, IgG had the biggest removal rate (>96.1%), followed by IgM (>66.7%) and IgA (53%), while complement C3 and C4 also dropped by 73% and 65%, respectively. The reduced pro-inflammatory cytokines (interleukin-8 and tumor necrosis factor-α) and marked increased lymphocyte (T and B cell) counts were also observed. The improvement of symptoms initiated after the last session, with a low AQP4-IgG titer (1:32) persisting thereafter. Accordingly, protein-A immunoadsorption treatment could be one of the potential rescue therapies for steroid-resistant NMOSD patients with a severe disability.

BACKGROUND: Activation of the complement pathway by immune complexes is a key feature of systemic lupus erythematosus (SLE) and SLE glomerulonephritis, which translates into low levels of C3 and C4 during active disease. C3 glomerulonephritis (C3GN) is part of a broader group of rare renal diseases, the C3 glomerulopathies, characterized by prominent C3 accumulation in the glomeruli with minimal to no immunoglobulin (Ig) deposition secondary to dysregulation of the alternative pathway of the complement system. Distinguishing lupus nephritis from other complement-mediated kidney disorders, including C3GN, represents a diagnostic challenge with potential therapeutic implications.
METHODS: We report an unusual case of a 55-year-old woman with SLE and previous biopsy-proven class IV lupus nephritis, subsequently diagnosed with C3GN. Furthermore, we review the available literature published from January 2010-March 2021 on the clinical features and management of C3GN in the setting of SLE.
RESULTS: In addition to our case, very few reports exist in the literature regarding C3GN in association with SLE. The underlying pathogenic mechanism of C3GN consists of dysregulation of the alternative pathway of the complement system, either due to genetic variation in complement-related genes or to acquired autoantibodies targeting C3 or C5 convertases; the latter mechanism could explain the occurrence of C3GN in the setting of autoimmune diseases, although it was not definitively identified in our patient or others with SLE. Similar to some of the previous reports, after suboptimal renal response on mycophenolate mofetil and rituximab, our patient has been successfully treated with eculizumab, thus far with >50% improvement in proteinuria.
CONCLUSIONS: C3GN represents an additional mechanism of renal injury in SLE mediated by alternative complement pathway dysregulation. Although rare, patients with SLE and persistent proteinuria with very low C3 would benefit from expedited renal biopsy to evaluate for C3GN as well as genetic testing, since this entity could require a different therapeutic approach.