Urinary complement profile in IgA nephropathy and its correlation with the clinical and pathological characteristics.

Background and objectives: The activated complement profile in IgA nephropathy (IgAN) is still unclear. Our study investigated the profile of urinary complements in IgAN patients and its correlations with clinical and pathological characteristics. Methods: Urinary protein abundance was detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 50 IgAN, 50 membranous nephropathy (MN), and 68 healthy controls (HC). Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to identify differentially expressed proteins in IgAN patients. The differentially expressed complement proteins were screened in IgAN patients, and their correlations with laboratory or pathological parameters were analyzed. Thereafter, 7 complement components were validated by enzyme-linked immunosorbent assay (ELISA) in the urine samples of 45 IgAN patients. Results: There were 786 differentially expressed proteins between IgAN and HC. KEGG analysis showed that differentially expressed urinary proteins in IgAN were enriched with complement. Of these, 67% of urinary complement protein abundance was associated with the estimated glomerular filtration rate. The urinary complement-related protein collectin12 (colec12), complement H factor (CFH), complement H factor-related protein 2 (CFHR2), and complement B factor (CFB) were positively correlated with serum creatinine; colec12, CFHR2, CFB, and C8g were positively correlated with glomerulosclerosis; CFH, CFHR2, C8g, and C9 were positively correlated with tubular atrophy/interstitial fibrosis. Conclusion: Abnormally increased components of complement pathways significantly correlate with reduced renal function, proteinuria, and renal histological damage in IgAN. It could provide a potential biomarker panel for monitoring IgAN and provide clues for therapeutic choice targeting complement system of IgAN patients.

Predictive value of the complement factors B and H for women with gestational diabetes mellitus who are at risk of preeclampsia.

OBJECTIVES: We aimed to define the relationships between the serum concentrations of complement factors B and H in mid-pregnancy and the risk of preeclampsia (PE) in patients with gestational diabetes mellitus (GDM). STUDY DESIGN: We performed a prospective nested case-control study of 503 patients with GDM who attended Peking University Third Hospital between March 2018 and December 2018. 456 patients were followed until delivery and blood samples were collected between gestational weeks 24 and 28. Thirty patients developed PE, 12 developed gestational hypertension (GH), and 42 matched cases were selected as a control group. RESULTS: The incidence of PE was 5.96 %. The serum concentrations of triacylglycerol (TG), FB, and FH of women with GDM who developed PE (GDM-PE group) in mid-pregnancy were significantly higher than those of the GDM group [TG: 3.60 (2.94-4.63) vs 2.54 (2.14-3.01) mmol/L, p < 0.001; FB: 346 (314-378) vs 284 (263-323) mg/L, p < 0.001; FH: 417 ± 45 vs 379 ± 47 mg/L, p = 0.003]. Multivariate regression analysis showed that high serum concentrations of TG and FB in mid-pregnancy were related to the risk of patients with GDM developing PE [TG: odds ratio (OR) 2.035 (95 % confidence interval (CI) 1.032-4.013); FB: OR 1.018 (95 % CI 1.001-1.035)]. The area under the curve (AUC) of FB for the prediction of PE was 0.821 (95 % CI 0.722-0.921) and that for a combination of TG, FB, and FH was 0.857 (95 % CI 0.770-0.944). CONCLUSIONS: High serum FB concentration during mid-pregnancy is a potential predictor of the risk of PE in patients with GDM, and the combination of FB, FH, and TG increased this predictive value.

Analysis focusing on plasma von Willebrand factor in pachychoroid neovasculopathy and age-related macular degeneration.

Pachychoroid neovasculopathy (PNV) is a new concept of macular disorder. Some cases diagnosed as age-related macular degeneration (AMD) have been re-diagnosed as PNV. However, the biological features of PNV are still uncertain. The purpose of this study was to compare PNV and AMD by analyses focusing on von Willebrand factor (VWF) and complement factor H (CFH). Ninety-seven patients who were previously diagnosed with treatment naïve AMD were enrolled in this study. They were re-classified as either PNV or AMD based on the clinical criteria and 33 patients were classified as PNV and 64 patients as AMD. We examined the clinical data, analyzed VWF multimer and two genetic polymorphisms (I62V and Y402H) in the CFH. PNV group was significantly younger than AMD group (P = 0.001). In both I62V and Y402H, there were no significant differences between PNV and AMD while the recessive homozygous (AA) was found only in PNV group in I62V. The presence of unusually large VWF multimers (UL-VWFMs) and subretinal hemorrhages were significantly higher in PNV than in AMD (P = 0.045, P = 0.020, respectively). Thus, the residual UL-VWFMs may result in platelet thrombosis and hemorrhages in the choriocapillaris of PNV. In conclusion, our results suggest the biological differences between PNV and AMD.

The role of complement factor H in gestational diabetes mellitus and pregnancy.

BACKGROUND: Complement factor H (CFH) has been found to be associated with insulin resistance. This study assessed the correlation between CFH and other clinical parameters, and determined whether CFH played a role in gestational diabetes mellitus (GDM) and adverse pregnancy outcomes. METHODS: A total of 397 pregnant women were included for analysis in this nested case-control study. Clinical parameters and serum were collected within the 11-17th gestational age at the first prenatal visit. At 24-28 weeks of gestation, a 75 g oral glucose tolerance test was performed and subjects were divided into a GDM (n = 80) and a non-GDM control group (n = 317). The delivery data were also followed. The serum CFH level was assayed by ELISA. RESULTS: CFH was higher in GDM than in non-GDM controls (280.02 [58.60] vs. 264.20 [68.77]; P = 0.014). CFH level was moderately associated with pre-pregnancy body mass index (BMI), BMI and total triglycerides (TG), and slightly associated with gestational age, low density lipoprotein cholesterol (LDL-C), total cholesterol (TC) in GDM and non-GDM (all P <  0.05). Moreover, CFH level was moderately correlated with alkaline phosphatase (ALP) and slightly correlated with age, uric acid (UA) and total bilirubin (TB) in non-GDM (all P <  0.05). After adjustment for clinical confounding factors, BMI, TG, gestational age, ALP, TB, age and UA were independent risk factors for log10 CFH levels (all P <  0.05) in all subjects. In addition, overweight or obese pregnant women, women with hypertriglyceridemia and women in the second trimester had significantly higher CFH levels than normal weight and underweight group (P <  0.001), the non-hypertriglyceridemia group (P <  0.001) and women in the first trimester group (P < 0.05) in all pregnant women respectively. Following binary logistic regression, CFH was not independently associated with GDM and related pregnant outcomes. CONCLUSIONS: The CFH in 11-17th weeks of gestation might be affected by many factors, including BMI, TG, gestational age, ALP, TB, age and UA. CFH was not an independent risk factor for GDM and avderse pregnancy outcomes.

Inflammatory cytokines, complement factor H and anhedonia in drug-naïve major depressive disorder.

OBJECTIVE: Anhedonia is a core symptom of major depressive disorder (MDD) and often associated with poor prognosis. The main objective of the present study was to explore the relationship between complement factor H (CFH), inflammatory cytokines and anhedonia in drug-naïve MDD patients. METHODS: A total of 215 participants (61 MDD patients with anhedonia, 78 MDD patients without anhedonia, and 76 control subjects) were included. Severity of depression and levels of anhedonia were evaluated by Hamilton Rating Scale for Depression-17 (HAMD-17) and SHAPS (Snaith-Hamilton Pleasure Scale). Plasma levels of CFH, interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α) were measured. RESULTS: The plasma levels of CFH, IL-10 and TNF-α were higher in drug-naïve MDD patients than control subjects. Compared to MDD patients without anhedonia, patients with anhedonia showed higher levels of CFH and IL-6. The stepwise regression analysis revealed that IL-10, TNF-α, as well as IL-10 × TNF-α were associated with depressive symptoms measured by HAMD-17 in drug-naïve MDD patients, while only CFH levels were identified as a mediator factor for the severity of anhedonia in the patients. CONCLUSION: MDD patients with anhedonia showed different inflammatory characteristics compared to patients without anhedonia. Our results provide novel evidence suggesting that increased plasma CFH levels may be a potential biomarker of anhedonia of subtyping MDD.

A Family Affair: Addressing the Challenges of Factor H and the Related Proteins.

Inflammation is a common denominator of diseases. The complement system, an intrinsic part of the innate immune system, is a key driver of inflammation in numerous disorders. Recently, a family of proteins has been suggested to be of vital importance in conditions characterized by complement dysregulation: the human Factor H (FH) family. This group of proteins consists of FH, Factor H-like protein 1 and five Factor H-related proteins. The FH family has been linked to infectious, vascular, eye, kidney and autoimmune diseases. In contrast to FH, the functions of the other highly homologous proteins are largely unknown and, hence, their role in the different disease-specific pathogenic mechanisms remains elusive. In this perspective review, we address the major challenges ahead in this emerging area, including 1) the controversies about the functional roles of the FH protein family, 2) the discrepancies in quantification of the FH protein family, 3) the unmet needs for validated tools and 4) limitations of animal models. Next, we also discuss the opportunities that exist for the immunology community. A strong multidisciplinary approach is required to solve these obstacles and is only possible through interdisciplinary collaboration between biologists, chemists, geneticists and physicians. We position this review in light of our own perspective, as principal investigators of the SciFiMed Consortium, a consortium aiming to create a comprehensive analytical system for the quantitative and functional assessment of the entire FH protein family.

Hemolytic Tests Exploring Factor H Functional Activities.

Impairment of the complement regulatory protein Factor H (FH) is implicated in the physiopathological mechanisms of different diseases like atypical hemolytic and uremic syndrome and C3 glomerulopathies. It may be due to genetic abnormalities or acquired with the development of autoantibodies. FH has several ligands; therefore, the exploration of its functions requires to perform different tests. Among them, two hemolytic tests are very useful because they give specific and complementary information about FH functions. The first one is dedicated to explore the FH capacity to dissociate the alternative pathway C3 convertase, whereas the second one is designed to explore the capacity of FH to bind cell surfaces and to protect them from complement attack. This chapter describes the procedures to perform these two hemolytic tests, exploring in a complementary way the FH functionality.

Atypical hemolytic uremic syndrome with C3 mutation: A case report and literature review.

INTRODUCTION: Atypical hemolytic uremic syndrome (aHUS) is characterized by hemolytic anemia, thrombocytopenia, and acute kidney injury. Uncontrolled activation of the complement system induced by single or combined complement gene mutations is one of the mechanisms leading to the pathogenesis of aHUS. CASE PRESENTATION: We report a case of a 26-year-old female with a C3 heterozygous gene mutation (p.Asn153Asn). The patient was found to have low complement H factor (CFH) but normal levels of anti-CFH autoantibody. She was treated primarily with plasma exchange and plasma infusion. The patient did not relapse during a 1-year follow-up. CONCLUSION: This is the first case of a novel C3 mutation (p.Asn153Asn) in a patient with aHUS. Further studies are needed to confirm the association between this mutation and the CFH level.

A Systematic Investigation on Complement Pathway Activation in Diabetic Retinopathy.

The complement system plays a crucial role in retinal homeostasis. While the proteomic analysis of ocular tissues in diabetic retinopathy (DR) has shown the deposition of complement proteins, their exact role in the pathogenesis of DR is yet unclear. We performed a detailed investigation of the role of the complement system by evaluating the levels of major complement proteins including C3, C1q, C4b, Complement Factor B (CFB), and Complement Factor H (CFH) and their activated fragments from both the classical and alternative pathways in vitreous humor and serum samples from proliferative DR (PDR) patients and controls. Further, the expressions of complements and several other key pro- and anti-angiogenic genes in the serum and vitreous humor were analyzed in the blood samples of PDR and non-PDR (NPDR) patients along with controls without diabetes. We also assessed the pro-inflammatory cytokines and matrix metalloproteinases in the vitreous humor samples. There was a significant increase in C3 and its activated fragment C3bα' (110 kDa) along with a corresponding upregulation of CFH in the vitreous of PDR patients, which confirmed the increased activation of the alternative complement pathway in PDR. Likewise, a significant upregulation of angiogenic genes and downregulation of anti-angiogenic genes was seen in PDR and NPDR cases. Increased MMP9 activity and upregulation of inflammatory markers IL8 and sPECAM with a downregulation of anti-inflammatory marker IL-10 in PDR vitreous indicated the possible involvement of microglia in DR pathogenesis. Further, a significantly high C3 deposition in the capillary wall along with thickening of basement membranes and co-localization of CFH expression with CD11b+ve activated microglial cells in diabetic retina suggested microglia as a source of CFH in diabetic retina. The increased CFH levels could be a feedback mechanism for arresting excessive complement activation in DR eyes. A gradual increase of CFH and CD11b expression in retina with early to late changes in epiretinal membranes of DR patients indicated a major role for the alternative complement pathway in disease progression.

Complement factor H levels are decreased and correlated with serum C-reactive protein in late-onset Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia. Despite numerous studies on the subject, the pathologies for AD are still unclear and there is still no ideal biomarker for diagnosis. The present study aimed to investigate clinical significance of human complement factor H (CFH) in patients with late-onset AD. METHODS: The present prospective study included 187 late-onset AD patients who went to our hospital from January 2015 to December 2017. One hundred patients with mild cognitive impairment (MCI) and 80 healthy individuals who were age and gender matched to AD patients were enrolled as controls. Demographic data such as age, gender, and education duration were recorded. Blood samples were collected and serum levels of C-reactive protein (CRP), CFH, and brain-derived neurotrophic factor (BDNF) were determined by Enzyme-linked immunosorbent assay (ELISA). The mini-mental state examination (MMSE) score was measured for all patients. RESULTS: No significant difference was found in age, gender, and education duration for all participants. The MMSE scores showed AD patients had lower MMES scores than the other two groups. All factors of CFH, CRP, and BDNF were dramatically decreased in AD patients compared with the MCI and the ealthy control. Levels of CFH were found to be positively correlated with levels of CRP; however, no significant correlation was found between CFH and BDNF, nor CFH and MMSE. CONCLUSION: CFH was decreased in late-onset AD patients, and serum levels of CFH was correlated with serum levels of CRP, but not MMSE and BDNF. These results may provide more clinical evidences for the role of CFH in AD patients.

Complement factor H levels are decreased and correlated with serum C-reactive protein in late-onset Alzheimer's disease / Os níveis de fator H do complemento estão diminuídos e correlacionados com a proteína C-reativa sérica na doença de Alzheimer de início tardio

Abstract Alzheimer's disease (AD) is the most common cause of dementia. Despite numerous studies on the subject, the pathologies for AD are still unclear and there is still no ideal biomarker for diagnosis. The present study aimed to investigate clinical significance of human complement factor H (CFH) in patients with late-onset AD. Methods: The present prospective study included 187 late-onset AD patients who went to our hospital from January 2015 to December 2017. One hundred patients with mild cognitive impairment (MCI) and 80 healthy individuals who were age and gender matched to AD patients were enrolled as controls. Demographic data such as age, gender, and education duration were recorded. Blood samples were collected and serum levels of C-reactive protein (CRP), CFH, and brain-derived neurotrophic factor (BDNF) were determined by Enzyme-linked immunosorbent assay (ELISA). The mini-mental state examination (MMSE) score was measured for all patients. Results: No significant difference was found in age, gender, and education duration for all participants. The MMSE scores showed AD patients had lower MMES scores than the other two groups. All factors of CFH, CRP, and BDNF were dramatically decreased in AD patients compared with the MCI and the ealthy control. Levels of CFH were found to be positively correlated with levels of CRP; however, no significant correlation was found between CFH and BDNF, nor CFH and MMSE. Conclusion: CFH was decreased in late-onset AD patients, and serum levels of CFH was correlated with serum levels of CRP, but not MMSE and BDNF. These results may provide more clinical evidences for the role of CFH in AD patients.

Resumo A doença de Alzheimer (DA) é a causa mais comum de demência. Apesar de inúmeros estudos sobre DA, suas patologias ainda não são claras e ainda não existe um biomarcador ideal para o diagnóstico da condição. O presente estudo teve como objetivo investigar a significância clínica do fator H do complemento humano (CFH) em pacientes com DA de início tardio. Métodos: O presente estudo prospectivo incluiu um total de 187 pacientes com DA de início tardio que foram ao nosso hospital entre janeiro de 2015 e dezembro de 2017. Cem pacientes com comprometimento cognitivo leve (CCL) e 80 indivíduos saudáveis com idade e sexo pareados com pacientes com DA foram incluídos como controle. Dados demográficos como idade, sexo e duração da educação foram registrados. As amostras de sangue foram coletadas e os níveis séricos de proteína C-reativa (PCR), CFH e fator neurotrófico derivado do cérebro (BDNF) foram determinados pelo ensaio imunoabsorvente ligado à enzima (ELISA). O escore do miniexame do estado mental (MEEM) foi medido para todos os pacientes. Resultados: Não foram encontradas diferenças significativas em idade, sexo e duração da educação para todos os participantes. Pacientes com DA tinham os menores escores de MEEM em relação aos outros dois grupos. Todos os fatores de CFH, PCR e BDNF diminuíram drasticamente em pacientes com DA em comparação com o CCL e o controle saudável. Os níveis de CFH mostraram correlação positiva com os níveis de PCR; no entanto, não foi encontrada correlação significativa entre CFH e BDNF, nem CFH e MEEM. Conclusão: A CFH diminuiu nos pacientes com DA de início tardio e os níveis séricos de CFH foram correlacionados com os níveis séricos de PCR, mas não o MEEM e o BDNF. Esses resultados podem fornecer mais evidências clínicas do papel da CFH em pacientes com DA.

Serum Clusterin and Complement Factor H May Be Biomarkers Differentiate Primary Sjögren's Syndrome With and Without Neuromyelitis Optica Spectrum Disorder.

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a neurological complication of primary Sjögren's syndrome (pSS). Objective: We aimed to explore potential serological differences between pSS patients with and without NMOSD. Methods: There were 4 pSS patients with NMOSD and 8 pSS patients without NMOSD enrolled as the screening group for two-dimensional difference gel electrophoresis (DIGE) analysis. Then differential expressed protein spots between groups were identified by MALDI-TOF/TOF MS. The levels of the identified potential biomarkers were verified by ELISA in a second independent cohort including 22 pSS patients with NMOSD, 26 pSS without NMOSD and 30 NMOSD patients. Results: Nine proteins were identified significantly differently expressed (more than 1.5-fold, p < 0.05) between these two groups. Serum levels of clusterin and complement factor H (CFH) were further verified by ELISA. Results showed that the serum clusterin was significantly higher in NMOSD with pSS than without (298.33 ± 184.52 vs. 173.49 ± 63.03 ng/ml, p < 0.01), while the levels of CFH were lower in pSS patients with NMOSD than without (24.19 ± 1.79 vs. 25.87 ± 3.98 ng/ml, p < 0.01). Conclusion: This is the first study of serological comparative proteomics between pSS patients with and without NMOSD. Serum clusterin and CFH might be potential biomarkers for pSS patients with NMOSD and play important role in the pathogenesis of the disease but needs further verification.

Identification of Salivary Biomarkers for Oral Cancer Detection with Untargeted and Targeted Quantitative Proteomics Approaches.

Oral cavity squamous cell carcinoma (OSCC) is one of the most common cancers worldwide. In Taiwan, OSCC is the fifth leading cause of cancer-related mortality and leads to 2800 deaths per year. The poor outcome of OSCC patients is principally ascribed to the fact that this disease is often advanced at the time of diagnosis, suggesting that early detection of OSCC is urgently needed. Analysis of cancer-related body fluids is one promising approach to identify biomarker candidates of cancers. To identify OSCC biomarkers, salivary proteomes of OSCC patients, individuals with oral potentially malignant disorders (OPMDs), and healthy volunteers were comparatively profiled with isobaric tags for relative and absolute quantitation (iTRAQ)-based mass spectrometry (MS). The salivary levels of 67 and 18 proteins in the OSCC group are elevated and decreased compared with that in the noncancerous group (OPMD and healthy groups), respectively. The candidate biomarkers were further selected using the multiple reaction monitoring (MRM)-MS and validated with the immunoassays. More importantly, the higher salivary level of three proteins, complement factor H (CFH), fibrinogen alpha chain (FGA), and alpha-1-antitrypsin (SERPINA1) was correlated with advanced stages of OSCC. Our results indicate that analysis of salivary proteome is a feasible strategy for biomarker discovery, and the three proteins are potential salivary markers for OSCC diagnosis.

Fluorescent silver nanoclusters as antibody label in a competitive immunoassay for the complement factor H.

Silver nanoclusters (AgNCs) were investigated as labels for the development of a fluoroimmunoassay for the complement factor H (CFH). The reductive one-pot synthesis of AgNCs using lipoic acid as a ligand was optimized by varying the concentration of NaBH4, the temperature and the reaction time. The average diameter and crystal structure of the AgNCs (which display red fluorescence) were determined by HR-TEM. The silver concentration was quantified by ICP-MS. Labelling of the antibody against CFH with AgNCs was optimized. The antibody was labeled with the AgNCs without compromising the recognition capabilities of the antibody. A competitive fluoroimmunoassay was then developed. Fluorescence is measured at excitation/emission maxima of 430/660 nm. The assay has a 0.4 ng mL-1 detection limit and a linear range that extends from 1.2 to 23 ng mL-1. The results compare favorably with those obtained by a commercial ELISA kit. The method was applied to the determination of CFH in spiked human serum. Graphical abstract Schematic presentation of the method for the determination of complement factor H (CFH) protein in human blood by using a CFH-antibody labelled with fluorescent silver nanoclusters.

Possible role of complement factor H in podocytes in clearing glomerular subendothelial immune complex deposits.

Podocytes are known to express various complement factors including complement factor H (CFH) and to promote the removal of both subendothelial and subepithelial immune complex (IC) deposits. Using podocyte-selective injury model NEP25 mice and an IgG3-producing hybridoma clone 2B11.3 established by MRL/lpr mice, the present study investigated the role of podocyte complement regulation in only subendothelial IC deposition. In immunotoxin (LMB2) induced fatal podocyte injury (NEP25/LMB2) at day 12, glomerular CFH and C3a receptor (C3aR) expression was decreased as compared with NEP25/vehicle mice. In contrast, in sublytic podocyte injury 5 days after LMB2, glomerular CFH and C3aR expression was increased as compared with NEP25/vehicle mice. Intra-abdominal injection of 2B11.3 hybridoma to NEP25 mice (NEP25/hybridoma) caused IC deposition limited to the subendothelial area associated with unaltered CFH expression. NEP25/hybridoma mice with sublytic podocyte injury (NEP25/hybridoma/LMB2) resulted in increased glomerular CFH expression (1.7-fold) accompanied by decreased subendothelial IC deposition, as compared with NEP25/hybridoma. Immunostaining revealed that CFH was dominantly expressed in podocytes of NEP25/hybridoma/LMB2. In addition, puromycin-induced sublytic podocyte injury promoted CFH expression in immortalized mouse podocytes in vitro. These results suggest that in response to sublytic levels of injury, podocyte induced CFH expression locally and clearance of subendothelial IC deposits.

Serum immunoinflammation-related protein complexes discriminate between inflammatory bowel disease and colorectal cancer.

PURPOSE: Inflammatory bowel disease (IBD) is an important risk factor for colon cancer. Novel serum immunoinflammation-related protein complexes (IIRPCs) have shown associations with early cancer detection. Herein, we investigated the potential of serum IIRPCs for discriminating between IBD and colorectal cancer (CRC) patients. METHODS: Serum protein complexes of 65 healthy controls, 57 CRC, 69 (ulcerative colitis) UC, and 67 (Crohn's disease) CD patients were isolated by native-PAGE. The gray values of serum IIRPCs bands in the gel were quantified using Quantity One software. The receiver-operating characteristic (ROC) curves were constructed to assess the discriminating ability by calculating the area under the ROC curve. RESULTS: The serum IIRPCs levels in IBD and CRC patients were significantly elevated compared to healthy controls. ROC analysis indicated certain diagnostic ability of serum IIRPCs in differentiating IBD from CRC. Specifically, "a3" complex discriminated UC from CRC, with an AUC value of 0.722, sensitivity of 69.4% and specificity of 63.8%. Similarly, "b4" complex discriminated UC from CRC, with an AUC value of 0.709, sensitivity of 70.4%, and specificity of 60.0%. In addition, the "a3" complex also discriminated CD from CRC, with an AUC value of 0.785, sensitivity of 73.1%, and specificity of 74.1%, while the "b4" complex showed a tendency to discriminate CD from CRC, with an AUC value of 0.663, sensitivity of 67.9% and specificity of 50.0%. Thus, an equation based on multiple IIRPCs was built to further improve the discriminating power. CONCLUSIONS: Serum IIRPCs can be used to discriminate IBD from CRC and may also be associated with early screening of colitis-associated cancer.

An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome.

RATIONALE & OBJECTIVE: Although primary atypical hemolytic uremic syndrome (aHUS) is associated with abnormalities in complement genes and antibodies to complement factor H, the role of complement in secondary aHUS remains debatable. We evaluated the usefulness of an ex vivo test to: (1) detect complement activation within the endothelium in primary and secondary aHUS, (2) differentiate active disease from remission, (3) monitor the effectiveness of eculizumab therapy, and (4) identify relapses during eculizumab dosage tapering and after discontinuation of treatment. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 121 patients with primary aHUS and 28 with secondary aHUS. Serum samples were collected during acute episodes, following remission, and during eculizumab treatment and were assessed using a serum-induced ex vivo C5b-9 endothelial deposition test. RESULTS: Serum-induced C5b-9 deposition on cultured microvascular endothelium was quantified by calculating the endothelial area covered by C5b-9 staining; values were expressed as percentage of C5b-9 deposits induced by a serum pool from healthy controls. Testing with adenosine diphosphate-activated endothelium demonstrated elevated C5b-9 deposits for all untreated patients with aHUS independent of disease activity, while testing with unstimulated endothelium demonstrated deposits only in active disease. Similar findings were observed in secondary aHUS. Serum-induced C5b-9 deposits on activated and unstimulated endothelium normalized during eculizumab treatment. 96% (22/23) of patients receiving eculizumab at extended 3- or 4-week dosing intervals demonstrated normal C5b-9 deposits on activated endothelium, despite most patients having CH50Eq (serum complement activity) > 20 UEq/mL, indicating that adequate complement control was achieved even with incomplete blockade of circulating C5. During eculizumab dosage tapering or after treatment discontinuation, all patients experiencing relapses versus only 6% (1/17) of those in stable remission had elevated C5b-9 deposits on unstimulated endothelium. LIMITATIONS: The C5b-9 endothelial deposition test can be performed in only specialized laboratories. Findings on eculizumab dosage tapering need to be confirmed with longitudinal monitoring of C5b-9 deposition. CONCLUSIONS: The C5b-9 endothelial deposition assay may represent an advance in our ability to monitor aHUS activity and individualize therapy.

Increased risk of central serous chorioretinopathy following end-stage renal disease: A nationwide population-based study.

This retrospective, nationwide, matched cohort study investigated the risk of central serous chorioretinopathy (CSCR) following end-stage renal disease (ESRD). The study cohort included 84722 ESRD patients who were registered between January 2000 and December 2009 at the Taiwan National Health Insurance Research Database. An age- and sex-matched control group comprised 84722 patients selected from the Taiwan Longitudinal Health Insurance Database 2000. We collected information for each patient from the index date until December 2011. During the follow-up period, we found a significantly elevated risk of CSCR in the ESRD patients compared with controls (incidence rate ratio = 1.51, 95% confidence interval = 1.24-1.84). After adjustment for potential confounders, including age, sex, coronary artery disease, peptic ulcer, and obstructive sleep apnea, ESRD patients were 1.41 times more likely to develop CSCR (adjusted hazard ratio = 1.41, 95% confidence interval = 1.14-1.73). In conclusion, we found that ESRD patients showed a significantly higher risk of developing CSCR and recommend regular retina examinations and education regarding CSCR for patients with ESRD.

Potentiation of complement regulator factor H protects human endothelial cells from complement attack in aHUS sera.

Mutations in the gene encoding for complement regulator factor H (FH) severely disrupt its normal function to protect human cells from unwanted complement activation, resulting in diseases such as atypical hemolytic uremic syndrome (aHUS). aHUS presents with severe hemolytic anemia, thrombocytopenia, and renal disease, leading to end-stage renal failure. Treatment of severe complement-mediated disease, such as aHUS, by inhibiting the terminal complement pathway, has proven to be successful but at the same time fails to preserve the protective role of complement against pathogens. To improve complement regulation on human cells without interfering with antimicrobial activity, we identified an anti-FH monoclonal antibody (mAb) that induced increased FH-mediated protection of primary human endothelial cells from complement, while preserving the complement-mediated killing of bacteria. Moreover, this FH-activating mAb restored complement regulation in sera from aHUS patients carrying various heterozygous mutations in FH known to impair FH function and dysregulate complement activation. Our data suggest that FH normally circulates in a less active conformation and can become more active, allowing enhanced complement regulation on human cells. Antibody-mediated potentiation of FH may serve as a highly effective approach to inhibit unwanted complement activation on human cells in a wide range of hematological diseases while preserving the protective role of complement against pathogens.