One- or two-day intervals in conditioning regimens for allo-HCT affect
chronic graft-versus-host disease, but not other clinical outcomes
Background. One- or two-day intervals are generally
inserted into scheduled conditioning regimens for allogeneic
hematopoietic cell transplantation (HCT), primarily due to various
social circumstances, such as unexpected natural adversities, abrupt
deterioration of patient health, and delays in graft source arrival. We
compared the clinical outcomes of patients with interrupted conditioning
to those with ordinarily scheduled conditioning.
Procedure. We retrospectively analyzed 83 patients
(children and adolescents) with oncologic disease who underwent
myeloablative conditioning with total body irradiation (TBI).
Interruption of conditioning was defined as a regimen in which one or
two vacant days (no chemotherapy drug administration or TBI) were added
to the initially scheduled regimen. Results. Overall and
event-free survival were similar between the scheduled conditioning
group and the interrupted conditioning groups (P = 0.955,
P = 0.908, respectively). Non-relapse mortality and relapse rates
were similar between the groups (P = 0.923, P = 0.946,
respectively). The engraftment rate was not affected by interruption
(P = 1.000). In contrast, the incidence of grade II–IV acute
graft-versus-host disease (GVHD) reached a marginally significant
difference between the groups (31% vs. 11%; P = 0.083).
Conditioning interruption was identified to be an independent risk
factor for chronic GVHD by multivariate analysis (odds ratio: 3.72; 95%
CI: 1.04–13.3; P = 0.043). Conclusion. Apart
from the incidence of chronic GVHD, clinical outcomes were not affected
by one- or two-day intervals during conditioning.