New insights into Poor Hematopoietic Reconstitution after allo-HSCT

Yuan KongPeking University People’s Hospital

Peking University Institute of HematologyBeijing Key Lab of HSCT

Peking University

1

I have no personal or financial interests to declare:

I have no financial support from an industry source at the current presentation.

대한혈액학회 Korean Society of Hematology

COI disclosureName of author ：Yuan Kong

2

Rapid and stable hematopoiesis and immune recovery are the basis for successful allo-HSCT

Good function

Dysfunction

1. Poor Graft Function(PGF)2. Prolonged isolated

thrombocytopenia(PT)3. GVHD4. Relapse5. Infection…

DonorHSCs

RecipientBM microenvironment

60-70%

Complications：30-40%

Hematopoiesis recoveryhomingImmune recovery

3

PGF:ANC ≤0.5×10E+9/L,PLT≤20×10E+9/L or hemoglobin ≤ 70 g/Lbeyond day +28 post-transplant with a transfusion requirement

PT: PLT≤20×10E+9/L

0%

20%

40%

Larocca A, et al. Haematologica. 2006Federmann B, et al. Haematologica.2012

P=0.000

No Primary Graft Failure

Graft Rejection

P=0.000

Rejection

PGF+PT

GGF

Definitions

Incidence Poor prognosis

YQ Sun,…, XJ Huang *. Ann Hematol. 2015YJ Chang,…,XJ Huang*. JHO. 2015

5-26%

4The pathogenesis of Poor Hematopoietic Reconstitution

remains poorly understood

Poor Hematopoietic Reconstitution is a life-threatening complication after allo-HSCT

BM microenvironment plays a crucial role in regulating hematopoiesis

Endosteal niche

Vascular niche

Perivascular niche

Immune niche

Donor HSCs

Calvi LM, et al. Nature. 2003Scadden DT. Nature. 2006Ding L, et al. Nature. 2012

Mercier FE, et al. Nat Rev Immunol 2012C Riether et al.Cell Death and Differentiation.2015

Endosteal niche

Vascular niche

Perivasular niche

Immune niche

…

BM microenvironment

5

01

02

03

Is the impaired BM microenvironmentcause or consequence of PGF and PT ?

Could BM microenvironment-directed interventions promote hematopoietic reconstitution?

Is there Impaired BM microenvironmentin patients with PGF and PT ?

Questions about PGF and PT

6

YK,…,XJH*. Biol Blood Marrow Transplant. 2013 HD

Periv

ascu

lar

Endo

stea

lVa

scul

ar

GGF PGF

BM endosteal, vascular and perivasularmicroenvironments are impaired in PGF patients

prospective case-control studies

YK,…,XJH*. Bone Marrow Transplant. 2016

Perivascular cells ECs

7

Dysfunctional BM endothelial cells in PGF and PT patients

MMS#, YK#,... XJH*. Blood. 2016YK#, MMS#, ... XJH*. AJH. 2018

Increased ROS and apoptosis

Reduced tube formation, migration,proliferation, double-positive staining

ROS

Tube formation

Double-positive staining

8

Dysfunctional BM MSCs in PGF and PT patients

YK,YS,…,XJH*. British Journal of Haematology. 2018YS,…,XJH, YK*. Biol Blood Marrow Transplant. 2018

Increased ROS and senescence

Reduced proliferation and HSCs-supporting capacities

ROS Proliferation

Senescence

9

Dysregulated BM T cell subsetsin PGF and PT patients

YTW#,YK#,…,XJH*. Biol Blood Marrow Transplant. 2016YK,…,XJH*. Journal of Translational Medicine. 2017YS…,XJH, YK*. Biol Blood Marrow Transplant. 2017

Increased Th1, Tc1, Th17 and Tc17

Reduced Th2 and Tc2 Increased ratios of

Th1/Th2, Tc1/Tc2 and Th17/Treg

Tc1/Tc2

Th1 Th2 Tc2Tc1 Th1/Th2

Th17/Treg

Tc1/Tc2

10

Unbalanced monocyte macrophage polarizationin BM of PGF patients

HYZ,…,XJH, YK*. British Journal of Haematology. 2018

Increased M1 Reduced M2 Increased M1/M2

ratio

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BM endosteal, vascular, perivascular and immune microenvironments are impaired in

PGF and PT patients

Increased ROS are found in BM ECs and MSCs of PGF and PT patients

In summary

Patients with PGF and PThad impaired BM microenvironment

A multifaceted problem

12

01

02

03

Is the impaired BM microenvironmentcause or consequence of PGF and PT ?

Could BM microenvironment-directed interventions promote hematopoietic reconstitution?

Impaired BM microenvironmentin patients with PGF and PT

Questions about PGF and PT

13

YK…,XJH*. Oncotarget. 2016

Donor HSCs in frozen

Donor HSCs for PGF/GGF patients

Donor HSCs for PGF and GGF patientshad similar capabilities to reconstitute in NSG mice

Similar human Engraftment in BM

Similar human Engraftment in

Spleen

NSG mice

14

YK,…,XJH*. Biol Blood Marrow Transplant. 2013 YK,…,XJH*. Bone Marrow Transplant. 2016

prospective case-control studies

Infused CD34+ CD34+ in PGF

PGF GGF PGF GGF HD

The frequency of infused donor HSCs was normal pre-HSCT, but HSCs were markedly reduced in PGF patients

15

Dysfunctional HSCs in PGF patients

prospective case-control studies

G0ROS CFU

YK…,XJH*. Oncotarget. 201616

PGF and PT patients showed defectiveBM ECs pre-HSCT

Increased ROS levelsin BM ECs

Reduced BM ECs

17YK…,XJH*. Blood advances. 2019

The occurrence of PGF+PT

HSCs

In summary

Impaired BM microenvironment play a crucial role in the pathogenesis of PGF and PT post allo-HSCT

Increased ROS

BM endosteal, vascular, perivascular and immune microenvironments are impaired in PGF and PT patients

Dysfunctional HSCs

18

01

02

03

Impaired BM microenvironment is causeof PGF and PT

Could BM microenvironment-directed interventions promote hematopoietic reconstitution?

Impaired BM microenvironment in patients with PGF and PT

Questions about PGF and PT

19

N-acetyl-L-cysteine (NAC)– Reactive oxygen species (ROS) scavenger

A clinical mucolytic drug without

significant side effects

NAC could enhance HSCs engraftment

in mice

Cai H, et al. Circulation. 2000Hu L, et al. Blood. 2014

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NAC could improve HSCs ability by repairing the impaired BM ECs in PGF patients

MMS#, YK#,... XJH*. Blood. 2016

1.Repair EC in PGF patients

Increase percentage, proliferation, tube formation of ECs

Decrease ROS and apoptosis of ECs

Increase CFU ability

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NAC improved the impaired BM ECs in PT patients

2.Repair EC in PT patients

YK#, MMS#, ... XJH*. American Journal of Hematology. 2018

Increase percentage, migration, tube formation of ECs

Decrease ROS and apoptosis of ECs

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NAC could improve thrombopoiesis in PT Patients

2.Repair EC in PT patients

Increase MK polyploidy, platelets

Increase CFU-MK

23YK#, MMS#, ... XJH*. American Journal of Hematology. 2018

Complete response: 10% (2/20)Response: 50% (10/20)Overall response: 60% (12/20)

Complete response: >100×109/LResponse: 50-100 × 109/L and atleast doubling of the baselinecountOverall response: CR+R

NAC: 400mg tid

Our clinical cohort study showed that NAC was safe and effective in PT patients

2.Repair EC in PT patients

BM ECs were improved after NAC

24YK#, MMS#, ... XJH*. American Journal of Hematology. 2018

ROC curves showed that BM EC<0.1% pre-HSCT could identify high-risk patients with PGF and PT

3.Repair EC before HSCT

25YK…,XJH*. Blood advances. 2019

Could prophylactic NAC reduce PGF+PT through repairing BM ECs?

3.Repair EC before HSCT

Analyze BM ECs

26YK…,XJH*. Blood advances. 2019

NCT03236220

Prophylactic NAC enhanced the quantity of BM ECs post-HSCT

Decrease ROS levelsin BM ECs

Increase the percentage of BM ECs

3.Repair EC before HSCT

27YK…,XJH*. Blood advances. 2019

Prophylactic NAC improved the function of BM ECs post-HSCT

28YK…,XJH*. Blood advances. 2019

Prophylactic NAC prevented the occurrence of PGF and PT

29YK…,XJH*. Blood advances. 2019

30YK…,XJH*. Blood advances. 2019

In summary

BM microenvironment-directed strategiespromise to improve PGF and PT

Facilitate hematopoietic recovery in PGF or PT

Normal Hematopoiesis

Improve the impaired BM microenvironment

Effective treatment

In summary

NAC

NAC

31YK*. Seminars in Hematology. 2019

Acknowledgement

Department of Bone Marrow Transplant Xiao-Jun Huang Xiao-Hui Zhang Kai-Yan Liu Lan-Ping XuYu Wang Huan Chen Yu-Qian Sun Chen-Hua YanYu-Hong Chen Yuan-Yuan Zhang

Department of ChemotherapyBin Jiang Qian JiangHao Jiang Jin Lu

Key Laboratory of HSCTYuan Kong Ying-Jun ChangXiang-Yu Zhao Xiao-Su Zhao Jiang-Ying Liu Min-Min Shi Yang Song Hong-Yan ZhaoXie-Na Cao Zhong-Shi Lyv Qi Wen

Supported by Key Program of National Natural Science Foundation of China

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Thanks for your attention!