P1601COMPLEMENT MEMBRANE ATTACK COMPLEX DURING THE FIRST WEEK AFTER KIDNEY TRANSPLANTATION AS SEVERITY BIOMARKER TO DELAYED GRAFT FUNCTION

Abstract Background and Aims Ischemia-reperfusion (I/R) damage is a relevant cause of delayed graft function (DGF). Complement activation is involved in experimental I/R injury, but few data are available about the expression of the complement cascade final component -membrane attack complex (MAC)- and I/R injury in KT patients. We studied the dynamics of membrane attack complex (MAC) as plasma fraction (pMAC) and the histological deposit pattern of C3b, complement factor H (FH) and MAC in DGF patients. Method We evaluated pMAC levels in 59 recipients, 38 with immediate graft function and 21 without serum creatinine decreased at day 7 (DGF). pMAC was measured at admission for KT (day 0) and 7 days after KT (day 7). Sandwich ELISAs were used to measure MAC. Additionally, we performed imunohistoquimical stained for MAC, C3b and kidney biopsies (KB) with DGF (n=12) and a control group of one-year protocol biopsies without damage (n=4) Results Patients in the DGF group were older, more frequently diabetics and received kidneys from older donors and more frequently controlled cardio-circulatory death type. Day0 and day7 post-KT pMAC levels were similar in non-DGF patients 5902±3049 mAu/L vs 6178±2882 mAu/L; p=0.686). However, patients with DGF showed a significant increase of pMAC levels between day0 and day7 (6621±2202 mAu/L vs 9625±4142 mAu/L; p=0.006. Figure 1 Percentage pMAC levels increase (Δ0-7 pMAC%) discriminative assessment analyzed by ROC curve showed a good discriminative value for DGF with an AUC of 0.78; p<0.001 (sensitivity 81%, specificity 66% by cut-off point of 5%). In patients with DGF longer than ten days, we found more frequently patients with a Δ0-7 pMAC >5% (83% vs 17% Δ0-7 pMAC <5% ; p=0.003).Patients with DGF showed renal function at 3 and 6 months, but worse renal function 1 year after KT (serum creatinine 1.78±0.61 vs 1.35±0.30 mg/dl in non-DGF patients). DGF patients with Δ0-7 pMAC >5% displayed worse renal function 1 and 2 year after KT compared to DGF patients with Δ0-7 pMAC <5%. MAC, C3b and FH stains were observed in tubular epithelial cells basal membrane. DGF-kidney biopsies showed more frequently high-intensity stain for MAC and FH than controls, without differences to C3b stain. DGF-kidney biopsies also showed a higher number of tubules with positive stain and larger perimeter of tubules with positive stains for MAC, C3b and FH than the controls. Figure 2. Among the 12 patients with DGF-biopsies, three (25%) never recovered renal function, all of them presented Δ0-7 pMAC >5% and intense, diffuse and positive staining in more than 50% of tubular perimeter for MAC, FH and C3b Conclusion Complement activation during peritrasplant period could be related with the severity of graft injury and the presence of DGF. Therefore, the determination of MAC levels could be useful to identify patients with possible complement dependent graft injury that might benefit from complement inhibitor therapies

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Activation of final complement components after kidney transplantation as a marker of delayed graft function severity

Clinical Kidney Journal ◽

10.1093/ckj/sfaa147 ◽

2020 ◽

Author(s):

Carlos E Arias-Cabrales ◽

Marta Riera ◽

María José Pérez-Sáez ◽

Javier Gimeno ◽

David Benito ◽

...

Keyword(s):

Epithelial Cells ◽

Graft Function ◽

Basal Membrane ◽

Factor H ◽

Delayed Graft Function ◽

Control Group ◽

Complement Factor ◽

Tubular Epithelial Cells ◽

Complement Components ◽

Protocol Biopsies

Abstract Background Ischaemia–reperfusion (I/R) damage is a relevant cause of delayed graft function (DGF). Complement activation is involved in experimental I/R injury, but few data are available from kidney transplant (KT) patients. We studied the dynamics of membrane attack complex (C5b-9) as a soluble fraction (SC5b-9) and the histological deposit pattern of C3b, complement Factor H (FH) and C5b-9 in DGF patients. Methods We evaluated SC5b-9 levels in 59 recipients: 38 with immediate graft function and 21 with DGF. The SC5b-9 was measured at admission for KT and 7 days after KT. DGF-kidney biopsies (n = 12) and a control group of 1-year protocol biopsies without tissue damage (n = 4) were stained for C5b-9, C3b and FH. Results SC5b-9 increased significantly in DGF patients (Day 0: 6621 ± 2202 mAU/L versus Day 7: 9626 ± 4142 mAU/L; P = 0.006), while it remained stable in non-DGF patients. Days 0–7 increase >5% was the better cut-off associated with DGF versus non-DGF patient discrimination (sensitivity = 81%). In addition, SC5b-9 increase was related to DGF duration and worse graft function, and independently associated with DGF occurrence. SC5b-9, C3b and FH stains were observed in tubular epithelial cells basal membrane. DGF-kidney biopsies showed a more frequently high-intensity stain, a higher number of tubules with positive stain and larger perimeter of tubules with positive stains for SC5b-9, C3b and FH than control patients. Conclusions Both SC5b-9 levels and SC5b-9, C3b and FH deposits in tubular epithelial cells basal membrane are highly expressed in patients experiencing DGF. SC5b-9 levels increase could be useful as a marker of DGF severity.

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Three Cases of Patients with Complement Regulatory Factor Genetic Mutations and Acquired Thrombotic Thrombocytopenic Purpura (TTP)

Blood ◽

10.1182/blood.v128.22.1362.1362 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1362-1362

Author(s):

Shebli Atrash ◽

David Kent McKelvey ◽

Appalanaidu Sasapu ◽

Muthu Veeraputhiran ◽

Soumya Pandey ◽

...

Keyword(s):

Renal Function ◽

Plasma Exchange ◽

Genetic Predisposition ◽

Normal Renal Function ◽

Complement Activation ◽

Factor H ◽

Complement Factor H ◽

Complement Factor ◽

Laboratory Parameters ◽

Gene Testing

Abstract Acquired TTP is a thrombotic microangiopathy (TMA) associated with deficiency of the vonWillebrandfactor cleaving protein ADAMTS13. Atypical hemolytic uremic syndrome (aHUS) is a TMA with a genetic predisposition todysregulationin the alternative complement pathway. Causes ofaHUSinclude mutations in CD46, complement factor I (CFI), complement factor B, complement component 3 (C3), complement factor H-related 5 (CFHR5), andthrombomodulin(THBD) or secondary to Complement factor H (CFH) autoantibodies. Treatment of these two TMAs differs. Whereas therapeutic plasma exchange (TPE), steroids, rituximab, cyclophosphamide and/or vincristine are used in TTP,aHUSrequires controlling unrestrained complement activation with eculizumab, an antibody preventing cleavage of C5. Testing for genetic predisposition to complementdysregulationis not commonly considered in TTP. To our knowledge, only one case report has described such a genetic association (Ref: PMID# 22409250). Here we describe 3 new cases with concurrent TTP,aHUSand genetic changes in complement genes. Case 1: 24y.o. African American (AA) man with XXY syndrome presented with bloody diarrhea, diffuse abdominal pain and renal dysfunction and a presumptive diagnosis ofaHUS. He was treated with eculizumab prior to transfer to our institution. On arrival to us, ADAMTS13 was low and inhibitor elevated. He initially responded to TPE but renal failure progressed andaHUS gene testing was ordered revealing a CFHR1-CFHR3 homologous deletion. Eculizumab was restarted but increased ADAMTS13 inhibitor required continued TPE, rituximab and vincristine; eculizumab was held until ADAMTS13 inhibitor was no longer detectable. At 8 months he continues on eculizumab with undetectable ADAMTS13 inhibitor and normal renal function, platelets and LDH (Figure). Case 2: 35y.o. AA woman presented with complaints of slurred speech, left-sided numbness, and thrombocytopenia, but normal renal function. Testing revealed ADAMTS13 <5%, presence of inhibitor (2.2 BU; normal <0.4 BU) and normal complement levels. TPE and steroids were initiated, with rituximab and vincristine added due to inhibitor boosting after initial response. Despite continued treatment, clinical/laboratory parameters did not improve, C3 and C4 levels declined, andaHUS genetic mutation analysis was ordered. This revealed heterozygous missense variants in exon 11 (c.1246A>C, plle416Leu) and exon 7 (c.1135G>C,p.Val379Leu). Once platelets recovered, we treated her with one dose of eculizumab; however, subsequently her plateletsdropped as she had not yet cleared the inhibitor. We then resumed plasma exchange and added eculizumab to her treatment at a later point (figure). Her laboratory parameters have normalized and she is on eculizumab maintenance. Case 3: 67y.o. AA woman presented with thrombocytopenia, microangiopathic hemolytic anemia, and left arm weakness. Renal function was mildly affected, with GFR ~ 30 mL/min/1.73m2. ADAMTS13 was <5% and inhibitor titer was 1.1 BU. TPE and steroids were initiated on admission, followed by rituximab, but due to lack of response after 14 days, she was given eculizumab. She had an immediate rise in platelet count after one dose and a sustained rise after the second dose. Her CBC and hemolysis parameters normalized after 4 doses. She continued treatment with eculizumab for a total of 6 months after which she opted to stop the drug. Within a month of discontinuing treatment, she developed a deep venous thrombosis and received anticoagulation for 6 months. She is now 2 years out of stopping eculizumab and has a normal CBC and LDH. Subsequent gene testing revealed the same CFHR1-CFHR3 homologous deletion identified in case 1. (Figure) Conclusion: We found treatment of TTP first allowed control of complementdysregulation, while treatment ofaHUSfirst did not allow control of TTP. This suggests that low ADAMTS13 levels may be the initiating factor in uncontrolled complement activation inaHUS. These cases suggest the need to test forgermlinemutations leading to abnormal complement activation in patients with refractory TTP, as they may have a dual diagnosis of both TTP andaHUSas our patients did. We therefore suggest treating the underlying TTP first, monitoring the ADAMTS13 activity and inhibitor levels to assess the clearance of the inhibitor, and initiating treatment with eculizumab once the inhibitor has cleared. Figure Figure. Disclosures No relevant conflicts of interest to declare.

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Complement Activation in Liver Transplantation: Role of Donor Macrosteatosis and Implications in Delayed Graft Function

International Journal of Molecular Sciences ◽

10.3390/ijms19061750 ◽

2018 ◽

Vol 19 (6) ◽

pp. 1750 ◽

Cited By ~ 7

Author(s):

Kelley Núñez ◽

Paul Thevenot ◽

Abeer Alfadhli ◽

Ari Cohen

Keyword(s):

Liver Transplantation ◽

Complement Activation ◽

Graft Function ◽

Delayed Graft Function

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P1644SAPS AND EPTS SCORES AS PREDICTORS OF RENAL FUNCTION IN RECENT RENAL TRANSPLANTATION

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p1644 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Jimmy Reinaldo Sanchez Gil ◽

Armando Coca ◽

Guadalupe Rodriguez Portela ◽

Carmen Aller Aparicio ◽

Alicia Mendiluce

Keyword(s):

Renal Function ◽

Renal Transplantation ◽

Serum Creatinine ◽

Roc Curve ◽

Graft Function ◽

Risk Scores ◽

Critical Care Units ◽

Saps Ii ◽

Combined Use ◽

The Us

Abstract Background and Aims The risk scores used in Critical Care Units estimate the severity and mortality of patients. The SAPS (Simplified Acute Physiologic Score) and its SAPS II and SAPS III variants calculate the severity by collecting the values recorded in the first 24 hours. The EPTS (Estimated Post-Transplant-Survival) is used as a reference for the allocation of organs in the US by the OPTN. The objective is to determine its use in recent renal transplant units as estimator of subsequent renal function, in services where patients move from the operating room to a nephrological intermediate care unit. Method The SAPS (II and III) and OPTN scores were applied in 87 (N = 87) consecutive renal transplanted patients. The point value of each of the scales was evaluated with the creatinine values at hospital discharge, and one month after the transplant. The scores obtained on the SAPS scales were divided as follows (SAPSIIA <20 points, SAPSIIB ≥20 points) (SAPSIII A <30 points, SAPSIIIB ≥30 points). In the EPTS scale, two cut-off points were used to divide the groups (20% Score; EPTS-IA ≤20%, EPTS-IB> 20%), (Score 40%; EPTS-IIA ≤40%, EPTS -IIB> 40). The sérum creatinine means of each of the groups were compared. Data were analyzed with SPSS 20.0.0 Results Significant differences were found in serum creatinine levels in renal function at the first month of transplantation in the SAPS II groups (SAPS IIA 1.38 mg / dl, SAPS IIB 1.79 mg / dl; P = 0.017 95% CI). With an area under the ROC curve of 0.65 (P = 0.017 95% CI). In the SAPS III groups no significant differences were found. In the EPTS scales, there were also significant differences in creatinine one month after the transplant in the group with a score of 40% (EPTS-IIA ≤40% 1.42 mg / dl, EPTS-IIB> 40 1.81 mg / dl; P = 0.024 95% CI) With an Area under the ROC curve of 0.64 (P = 0.037 95% CI). Conclusion The SAPSII and EPTS scores can be a useful tool in estimating renal function one month after renal transplantation, giving a prognosis of renal graft function. The combined use of these scales together with other functional graft tests could have an important relevance in the management and follow-up of recent renal transplantation. Other studies with larger sample sizes are necessary to establish the appropriate cut-off points for the scales.

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Upregulation of MicroRNA-146a by Hepatitis B Virus X Protein Contributes to Hepatitis Development by Downregulating Complement Factor H

mBio ◽

10.1128/mbio.02459-14 ◽

2015 ◽

Vol 6 (2) ◽

Cited By ~ 36

Author(s):

Jun-Feng Li ◽

Xiao-Peng Dai ◽

Wei Zhang ◽

Shi-Hui Sun ◽

Yang Zeng ◽

...

Keyword(s):

Innate Immunity ◽

Hepatitis B Virus ◽

Hepatitis B ◽

Complement Activation ◽

Factor H ◽

Hbv Infection ◽

Complement Factor ◽

Liver Inflammation ◽

X Protein ◽

B Virus

ABSTRACT Hepatic injuries in hepatitis B virus (HBV) patients are caused by immune responses of the host. In our previous study, microRNA-146a (miR-146a), an innate immunity-related miRNA, and complement factor H (CFH), an important negative regulator of the alternative pathway of complement activation, were differentially expressed in HBV-expressing and HBV-free hepatocytes. Here, the roles of these factors in HBV-related liver inflammation were analyzed in detail. The expression levels of miR-146a and CFH in HBV-expressing hepatocytes were assessed via analyses of hepatocyte cell lines, transgenic mice, adenovirus-infected mice, and HBV-positive human liver samples. The expression level of miR-146a was upregulated in HBV-expressing Huh-7 hepatocytes, HBV-expressing mice, and patients with HBV infection. Further results demonstrated that the HBV X protein (HBx) was responsible for its effects on miR-146a expression through NF-κB-mediated enhancement of miR-146a promoter activity. HBV/HBx also downregulated the expression of CFH mRNA in hepatocyte cell lines and the livers of humans and transgenic mice. Furthermore, overexpression and inhibition of miR-146a in Huh-7 cells downregulated and upregulated CFH mRNA levels, respectively. Luciferase reporter assays demonstrated that miR-146a downregulated CFH mRNA expression in hepatocytes via 3′-untranslated-region (UTR) pairing. The overall effect of this process in vivo is to promote liver inflammation. These results demonstrate that the HBx–miR-146a–CFH–complement activation regulation pathway might play an important role in the immunopathogenesis of chronic HBV infection. These findings have important implications for understanding the immunopathogenesis of chronic hepatitis B and developing effective therapeutic interventions. IMPORTANCE Hepatitis B virus (HBV) remains an important pathogen and can cause severe liver diseases, including hepatitis, liver cirrhosis, and hepatocellular carcinoma. Although HBV was found in 1966, the molecular mechanisms of pathogenesis are still poorly understood. In the present study, we found that the HBV X protein (HBx) promoted the expression of miR-146a, an innate immunity-related miRNA, through the NF-κB signal pathway and that increasingly expressed miR-146a downregulated its target complement factor H (CFH), an important negative regulator of the complement alternative pathway, leading to the promotion of liver inflammation. We demonstrated that the HBx–miR-146a–CFH–complement activation regulation pathway is potentially an important mechanism of immunopathogenesis caused by chronic HBV infection. Our data provide a novel molecular mechanism of HBV pathogenesis and thus help to understand the correlations between the complement system, an important part of innate immunity, and HBV-associated disease. These findings will also be important to identify potential therapeutic targets for HBV infection.

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