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

Miriam Galbusera, Marina Noris, Sara Gastoldi, Elena Bresin, Caterina Mele, Matteo Breno, Paola Cuccarolo, Marta Alberti, Elisabetta Valoti, Rossella Piras, Roberta Donadelli, Marina Vivarelli, Luisa Murer, Carmine Pecoraro, Elisa Ferrari, Annalisa Perna, Ariela Benigni, Valentina Portalupi, Giuseppe Remuzzi

Research output: Contribution to journalArticle

Abstract

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.

Original languageEnglish
JournalAmerican Journal of Kidney Diseases
DOIs
Publication statusE-pub ahead of print - Mar 6 2019

Fingerprint

Complement Membrane Attack Complex
Hemolytic-Uremic Syndrome
Complement Activation
Endothelium
Serum
Therapeutics
eculizumab
Complement Factor H
Recurrence
Atypical Hemolytic Uremic Syndrome
Adenosine Diphosphate

Cite this

An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome. / Galbusera, Miriam; Noris, Marina; Gastoldi, Sara; Bresin, Elena; Mele, Caterina; Breno, Matteo; Cuccarolo, Paola; Alberti, Marta; Valoti, Elisabetta; Piras, Rossella; Donadelli, Roberta; Vivarelli, Marina; Murer, Luisa; Pecoraro, Carmine; Ferrari, Elisa; Perna, Annalisa; Benigni, Ariela; Portalupi, Valentina; Remuzzi, Giuseppe.

In: American Journal of Kidney Diseases, 06.03.2019.

Research output: Contribution to journalArticle

Galbusera, Miriam ; Noris, Marina ; Gastoldi, Sara ; Bresin, Elena ; Mele, Caterina ; Breno, Matteo ; Cuccarolo, Paola ; Alberti, Marta ; Valoti, Elisabetta ; Piras, Rossella ; Donadelli, Roberta ; Vivarelli, Marina ; Murer, Luisa ; Pecoraro, Carmine ; Ferrari, Elisa ; Perna, Annalisa ; Benigni, Ariela ; Portalupi, Valentina ; Remuzzi, Giuseppe. / An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome. In: American Journal of Kidney Diseases. 2019.
@article{7b83ea70d36440f5992a61f548529b92,
title = "An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome",
abstract = "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.",
author = "Miriam Galbusera and Marina Noris and Sara Gastoldi and Elena Bresin and Caterina Mele and Matteo Breno and Paola Cuccarolo and Marta Alberti and Elisabetta Valoti and Rossella Piras and Roberta Donadelli and Marina Vivarelli and Luisa Murer and Carmine Pecoraro and Elisa Ferrari and Annalisa Perna and Ariela Benigni and Valentina Portalupi and Giuseppe Remuzzi",
note = "Copyright {\circledC} 2019 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.",
year = "2019",
month = "3",
day = "6",
doi = "10.1053/j.ajkd.2018.11.012",
language = "English",
journal = "American Journal of Kidney Diseases",
issn = "0272-6386",
publisher = "W.B. Saunders Ltd",

}

TY - JOUR

T1 - An Ex Vivo Test of Complement Activation on Endothelium for Individualized Eculizumab Therapy in Hemolytic Uremic Syndrome

AU - Galbusera, Miriam

AU - Noris, Marina

AU - Gastoldi, Sara

AU - Bresin, Elena

AU - Mele, Caterina

AU - Breno, Matteo

AU - Cuccarolo, Paola

AU - Alberti, Marta

AU - Valoti, Elisabetta

AU - Piras, Rossella

AU - Donadelli, Roberta

AU - Vivarelli, Marina

AU - Murer, Luisa

AU - Pecoraro, Carmine

AU - Ferrari, Elisa

AU - Perna, Annalisa

AU - Benigni, Ariela

AU - Portalupi, Valentina

AU - Remuzzi, Giuseppe

N1 - Copyright © 2019 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

PY - 2019/3/6

Y1 - 2019/3/6

N2 - 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.

AB - 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.

U2 - 10.1053/j.ajkd.2018.11.012

DO - 10.1053/j.ajkd.2018.11.012

M3 - Article

C2 - 30851964

JO - American Journal of Kidney Diseases

JF - American Journal of Kidney Diseases

SN - 0272-6386

ER -