Transplantation outcomes
The median administered CD34+ cell dose was the same
between the scheduled and interrupted groups
(2.2×106/kg and 2.0×106/kg for the
scheduled and interrupted groups, respectively; P = 0.845).
Engraftment was achieved in most enrolled patients (92% and 95% of the
scheduled and interrupted groups, respectively; P = 1.000). The
median days until engraftment was also not significantly different
between the two groups (18 days vs. 19 days; P = 0.976). The
5-year OS and EFS in the interrupted group were the same as the
scheduled group (53% vs. 52%; P = 0.955; and 47% vs. 45%;P = 0.908, respectively). These results are shown in Figure 2.
Additionally, the 5-year NRM and RR were similar between the scheduled
and interrupted groups (16% vs. 16%; P = 0.923; and 42% vs.
44%; P = 0.946, respectively). The incidence of
transplantation-associated complications was not different between the
two groups (VOD/SOS; 6.3% vs. 5.3%, P = 1.000, TMA; 4.7% vs.
0.0%, P = 1.000, interstitial pneumonia; 9.4% vs. 5.3%,P = 1.000).
The incidences of acute and chronic GVHD in the two cohorts are
summarized in Table 2. Overall, aGVHD was more often identified in the
scheduled group than in the interrupted group, although the differences
were not statistically significant. The incidence of aGVHD in grades
I–IV in the scheduled and interrupted groups was 42% and 26%,
respectively (P = 0.286). Moreover, there was a trend toward a
higher incidence of grades II–IV aGVHD in the scheduled group compared
to the interrupted group (31% vs. 11%; P = 0.083). The
incidence of aGVHD in grades III–IV was also higher in the scheduled
group than in the interrupted group (19% vs. 5%; P = 0.280).
Furthermore, the group with interrupted conditioning showed a marginally
significant tendency toward a higher incidence of cGVHD than the
scheduled conditioning group (42% vs. 19%; P = 0.063). The
categorical variables entered into the multivariate model were age of ≥
10 years, female, interruption of conditioning, use of cyclosporin, and
tacrolimus. Consequently, interrupted conditioning for allo-HCT was
confirmed by the multivariate analysis to be an independent risk factor
for cGVHD (odds ratio: 3.72; 95% CI: 1.04–13.3; P = 0.043).
Additionally, age of ≥ 10 years and female gender were also identified
as significant risk factors for cGVHD. These results and the results of
univariate analysis for cGVHD are shown in Tables 3 and 4.