Early-Onset Cytokine Release Syndrome Following Allogeneic Haploidentical Peripheral Blood Stem Cell Transplantation Might Decrease Overall Survival

Alberto Hernández-Sánchez1,  Almudena  Cabero  Martínez1,  Borja  Puertas Martínez1, Sandra Patricia Gómez Úbeda1, Daniela Caballero Álvarez2, Paula Lázaro del Campo3, Luz Gema Román Molano1, Raúl Azibeiro Melchor1, Marta Fonseca Santos1,Alejandro Avendaño Pita1, Mónica Baile González1,  Ana  África  Martín  López1,  Estefanía  Pérez  López1,  Mónica  Cabrero1,  Miriam  López  Parra1, Fermín  Sánchez-Guijo1,  M  Manuela  Salinero  Peral1,  Ángela  Rodríguez  Rodríguez1,  M  Dolores  Caballero Barrigón1,Lucía López Corral1

1 Hematología, Hospital  Universitario  de  Salamanca
2 Hematología,  Hospital  Universitario  de  Basurto
3 Hematología, Hospital Universitario La Paz

ABSTRACT
Haploidentical HLA stem cell transplantation (haplo-HSCT) is increasingly being used as part of the treatment of hematological malignancies lacking a suitable HLA-matched donor. Cytokine release syndrome (CRS) has been described in haplo-HSCT, but its clinical impact on these patients is controversial.In order to identify novel CRS features that might have a prognostic impact on haplo-HSCT, retrospective data from 51 patients receiving peripheral blood haplo-HSCT in 2019 and 2020 in our centre was analyzed.The median age was 51 years (range 17-72), 59% were male. Median follow-up was 359 days for alive patients. 84% of the patients presented with CRS after haplo-HSCT (71% of them occurred in the first 48 hours after infusion). CRS was mild in most patients: grade 1 in 29 (71%) and grade 2 in 12 (29%); no grade 3 CRS or further occurred. Graft cryopreservation accounted for 13 (25%) patients.Early-onset CRS (<48h since stem cell infusion) was associated with lower overall survival (p=0,01), as well as lower event free survival (relapse or death, p=0,03) when compared with the remaining patients in a univariate analysis.Although this is a retrospective single-centre analysis, it might provide new insights about the relevance of CRS in haplo-HSCT.
INTRODUCTION
Haploidentical HLA stem cell transplantation (haplo-HSCT) is increasingly being used as part of the treatment of hematological malignancies lacking a suitable HLA-matched donor.Cytokine release syndrome (CRS) is a systemic inflammatory response with aberrant immune activation and hyperstimulation which has been described in a number of clinical settings, including haplo-HSCT. However, clinical impact of CRS on these patients is controversial.During COVID-19 pandemic, graft cryopreservation in haplo-HSCT has increased in our centre. As a result, we clinically noticed a change in CRS onset in these patients.
METHOD
A cohort of 154 patients undergoing allogeneic stem cell transplantation in 2019 and 2020 in our centre, from which 51 patients receiving peripheral blood haplo-HSCT from 1st February 2019 to 31st December 2020 were selected. Two of them were excluded for the CRS analysis due  to  relevant  microbiological isolation close  to  the  infusion  date  and  impossibility  to distinguish between infectious  and  CRS  fever. CRS  was  graded  according  to  the  ASBMT consensus[1].
RESULT
The median age was 51 years (range 17-72), 59% were male.Median follow-up was 359daysfor alive patients.Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) was low risk in 45%, intermediate risk in 22% and high risk in 33%. Most patients (71%) had an intermediate Disease  Risk  Index  (DRI).  Conditioning  regimen  was  myeloablative  in  12  (24%).  84%  of  the patients presented with CRS after haplo-HSCT(71% of them occurred in the first 48 hours after infusion). CRS was mild in most patients (grade 1 in 29 (71%) and grade 2 in 12 (29%); no grade 3 CRS or further occurred. Graft cryopreservation accounted for 13 (25%)patients.Baseline patient characteristics from our cohort are summarizedin Table 1.Early-onset   CRS (<48h   since   stem   cell   infusion) was   associated   with   loweroverall survival(Figure  1,p=0,01),as  well  as  lowerevent  free  survival(relapse  or  death,p=0,03)when compared with the remaining patients in a univariate analysis.Non-myeloablative  conditioning  was  associated  with  a  higher  proportion  of  early-onset  CRS, which  could  be  related  to  different  immunossuppresion  platform,  as  we  also  found  higher proportion of early-onset CRS with modified Baltimore platform (starting both tacrolimus and mycophenolate on day +5 and administering cyclophosphamide on  days +3 and +4[2]) when compared to Raiola platform(starting calcineurin inhibitor on day 0, mycophenolateon +1 and administering cyclophosphamide on  days +3 and +5[3]), regardless of conditioning regimen.Age  >60  years  was  also  associated with  a  higher  proportion  of  early-onset  CRS  (80%  vs  45% p=0,014)and itshould be noted that age>60 yearsdid not impact on overall survival in the first year following haplo-HSCTin our patients (p=0,485).We alsofound an interesting trend between graft cryopreservation and early-onset CRS(only 38%  of  patients  with  graft  cryopreservation  presented  early-onset  CRS,  whereas  67%  of patients with fresh graft did so,p=0,075).Cryopreservation was  related to  less  proportion of  CRS  grade≥2(0% vs 33%,p=0,014)  and it did  not  impact on engraftment,  overall  survival  nor  graft  versus  receptor  disease  rate  or severityin  our  patients.  Patients  with  refractory  disease  prior  to  transplantation  presented higher rates of CRS grade ≥2 (75% vs 20%,p=0,041).  Moreover,  a  trend  was  observed  for mononucleated  cell  count  >8  x  108(37%  vs  14%,p=0,067). However, CRS grade ≥2 did not impactonoverall survival in our patients (p=0,251).Variables associated with developing early-onset CRS following haplo-HSCT in our patients are summarized in Table 2.

Figure 1

Figure 2

Figure 3

CONCLUSION
Early-onset CRS is associatedwith less overall survival and less event-free survival following the first  year  after  haplo-HSCT.  Cryopreservation is  associated  with  less  CRS grade≥2 probability and might also reduce the chance of developing early-onset CRS. Although this is a retrospective single-centre analysis, it might provide new insights about the relevance of CRS in haplo-HSCT.
REFERENCES
1 Lee DW et al. ASTCT Consensus Grading for Cytokine Release Syndrome and Neurologic Toxicity Associated with Immune Effector Cells. Biol Blood Marrow Transplant 2019; 25(4): 625-38.
2 Luznik L et al. HLA-haploidentical bone marrow transplantation for hematologic malignancies using nonmyeloablative conditioning and high-dose, posttransplantation cyclophosphamide. Biol Blood Marrow Transplant. 2008;14(6):641–50.
3 Raiola AM et al. Unmanipulated haploidentical bone marrow transplantation and posttransplantation cyclophosphamide for hematologic malignancies after myeloablative conditioning. Biol Blood Marrow Transplant. 2013;19(1):117–22.
The data in this poster was presented at EHA 2021. Published with permission from the Copyright owner.