TY - JOUR
T1 - Lentiviral gene therapy corrects platelet phenotype and function in patients with Wiskott-Aldrich syndrome
AU - Sereni, Lucia
AU - Castiello, Maria Carmina
AU - Di Silvestre, Dario
AU - Della Valle, Patrizia
AU - Brombin, Chiara
AU - Ferrua, Francesca
AU - Cicalese, Maria Pia
AU - Pozzi, Loris
AU - Migliavacca, Maddalena
AU - Bernardo, Maria Ester
AU - Pignata, Claudio
AU - Farah, Roula
AU - Notarangelo, Lucia Dora
AU - Marcus, Nufar
AU - Cattaneo, Lorella
AU - Spinelli, Marco
AU - Giannelli, Stefania
AU - Bosticardo, Marita
AU - van Rossem, Koen
AU - D'Angelo, Armando
AU - Aiuti, Alessandro
AU - Mauri, Pierluigi
AU - Villa, Anna
N1 - Publisher Copyright:
© 2019 The Authors
PY - 2019/9
Y1 - 2019/9
N2 - Background: Thrombocytopenia is a serious issue for all patients with classical Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) because it causes severe and life-threatening bleeding. Lentiviral gene therapy (GT) for WAS has shown promising results in terms of immune reconstitution. However, despite the reduced severity and frequency of bleeding events, platelet counts remain low in GT-treated patients. Objective: We carefully investigated platelet defects in terms of phenotype and function in untreated patients with WAS and assessed the effect of GT treatment on platelet dysfunction. Methods: We analyzed a cohort of 20 patients with WAS/XLT, 15 of them receiving GT. Platelet phenotype and function were analyzed by using electron microscopy, flow cytometry, and an aggregation assay. Platelet protein composition was assessed before and after GT by means of proteomic profile analysis. Results: We show that platelets from untreated patients with WAS have reduced size, abnormal ultrastructure, and a hyperactivated phenotype at steady state, whereas activation and aggregation responses to agonists are decreased. GT restores platelet size and function early after treatment and reduces the hyperactivated phenotype proportionally to WAS protein expression and length of follow-up. Conclusions: Our study highlights the coexistence of morphologic and multiple functional defects in platelets lacking WAS protein and demonstrates that GT normalizes the platelet proteomic profile with consequent restoration of platelet ultrastructure and phenotype, which might explain the observed reduction of bleeding episodes after GT. These results are instrumental also from the perspective of a future clinical trial in patients with XLT only presenting with microthrombocytopenia.
AB - Background: Thrombocytopenia is a serious issue for all patients with classical Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) because it causes severe and life-threatening bleeding. Lentiviral gene therapy (GT) for WAS has shown promising results in terms of immune reconstitution. However, despite the reduced severity and frequency of bleeding events, platelet counts remain low in GT-treated patients. Objective: We carefully investigated platelet defects in terms of phenotype and function in untreated patients with WAS and assessed the effect of GT treatment on platelet dysfunction. Methods: We analyzed a cohort of 20 patients with WAS/XLT, 15 of them receiving GT. Platelet phenotype and function were analyzed by using electron microscopy, flow cytometry, and an aggregation assay. Platelet protein composition was assessed before and after GT by means of proteomic profile analysis. Results: We show that platelets from untreated patients with WAS have reduced size, abnormal ultrastructure, and a hyperactivated phenotype at steady state, whereas activation and aggregation responses to agonists are decreased. GT restores platelet size and function early after treatment and reduces the hyperactivated phenotype proportionally to WAS protein expression and length of follow-up. Conclusions: Our study highlights the coexistence of morphologic and multiple functional defects in platelets lacking WAS protein and demonstrates that GT normalizes the platelet proteomic profile with consequent restoration of platelet ultrastructure and phenotype, which might explain the observed reduction of bleeding episodes after GT. These results are instrumental also from the perspective of a future clinical trial in patients with XLT only presenting with microthrombocytopenia.
KW - Wiskott-Aldrich syndrome
KW - X-linked thrombocytopenia
KW - gene therapy
KW - platelets
UR - http://www.scopus.com/inward/record.url?scp=85067124154&partnerID=8YFLogxK
U2 - 10.1016/j.jaci.2019.03.012
DO - 10.1016/j.jaci.2019.03.012
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C2 - 30926529
AN - SCOPUS:85067124154
SN - 0091-6749
VL - 144
SP - 825
EP - 838
JO - Journal of Allergy and Clinical Immunology
JF - Journal of Allergy and Clinical Immunology
IS - 3
ER -