Extracorporeal photopheresis induces NETosis in neutrophils derived from patients with chronic graft-vs-host disease

Idan Goldberg; Galit Granot; Alona Telerman; Shirly Partouche; Tzippy Shochat; Erez Halperin; Anat Gafter-Gvili; Liat Shargian; Moshe Yeshurun; Pia Raanani; Ofir Wolach; Vered Yahalom

doi:10.1002/jca.22073

Extracorporeal photopheresis induces NETosis in neutrophils derived from patients with chronic graft-vs-host disease

J Clin Apher. 2023 Oct;38(5):615-621. doi: 10.1002/jca.22073. Epub 2023 Jul 13.

Authors

Idan Goldberg^{1

2

3}, Galit Granot⁴, Alona Telerman⁴, Shirly Partouche⁴, Tzippy Shochat⁵, Erez Halperin¹, Anat Gafter-Gvili^{1

2

6}, Liat Shargian^{1

2}, Moshe Yeshurun^{1

2}, Pia Raanani^{1

2}, Ofir Wolach^{1

2}, Vered Yahalom^{2

7}

Affiliations

¹ Institute of Hematology, Davidoff Cancer Center, Beilinson Hospital, Rabin Medical Center, Petah Tikva, Israel.
² Sackler School Medicine, Tel Aviv University, Tel Aviv, Israel.
³ Department of Internal Medicine F - Recanati, Beilinson Hospital, Rabin Medical Center, Petah Tikva, Israel.
⁴ Felsenstein Medical Research Center, Beilinson Hospital, Rabin Medical Center, Petah Tikva, Israel.
⁵ Statistical Consulting Unit, Beilinson Hospital, Rabin Medical Centre, Petah Tikva, Israel.
⁶ Department of Internal Medicine A, Beilinson Hospital, Rabin Medical Center, Petah Tikva, Israel.
⁷ Blood Services & Apheresis Institute, Rabin Medical Center, Petah Tikva, Israel.

PMID: 37439388
DOI: 10.1002/jca.22073

Abstract

Introduction: Extracorporeal photopheresis (ECP) is considered an effective treatment for patients with chronic graft vs host disease (cGVHD) and demonstrates efficacy in ameliorating GVHD. The mechanism by which ECP acts against cGVHD is not fully understood. Preliminary observations have hinted at the potential involvement of neutrophil extracellular traps (NETs) formation in the pathogenesis of cGVHD. We aimed to assess the influence of ECP on the formation of NETs in patients with cGVHD as a potential mechanism in this setting.

Methods: Patients treated with ECP for cGVHD at the Rabin Medical Center were included in this study. Blood samples were obtained at three different time points: before starting an ECP cycle, at the end of the first day of treatment, and 24 h following the initiation of the ECP treatment cycle. Neutrophils were harvested from all blood samples. NET formation was assessed by measurement of NET-bound specific neutrophil elastase activity and by immunofluorescence staining.

Results: Six patients (two females and four males) with cGVHD were included in the study. We observed a significant increase in NET formation among all six patients following ECP. Net-bound specific neutrophil elastase activity was elevated from a median value of 2.23 mU/mL (interquartile range [IQR] 2.06-2.47 mU/mL) at baseline to a median value of 13.06 mU/mL (IQR 10.27-15.97 mU/mL) immediately after the treatment and to a peak median value of 14.73 mU/mL (IQR 9.6-22.38 mU/mL) 24 h following the initiation of the ECP cycle. A qualitative assessment of NET formation using immunofluorescence staining has demonstrated markedly increased expression of citrullinated histone H3, a marker of NET formation, following ECP treatment.

Conclusions: Our preliminary data indicate that ECP induces NET formation among patients with cGVHD. The contribution of increased NET formation to the therapeutic effect of cGVHD should be further investigated.

Keywords: extracorporeal photopheresis (ECP); graft vs host disease (GVHD); neutrophil extracellular traps (NETs).