Investigation of Treg in Pediatric Acute Lymphocytic Leukemia Patients during Chemotherapy Stages and Relapse

Abstract

A cross-sectional case-control study has been carried out on Treg cells in pediatric acute
lymphoblastic leukemia (ALL) patients admitted to Al-Basrah Children Teaching Specialty
Hospital from November 2022 to May 2023. A total number of 70 patients (25 newly
diagnosed, 12 relapse, 21 during induction, and 12 during consolidation chemotherapy)
were enrolled, aged 2 to 14 years, along with 54 healthy controls who were the same
age and gender as the study. Blood samples were collected from all participants for flow
cytometer applied to study Treg cell markers. The results of the current study showed
that the highest percentage of ALL patients was in the age group of 2 to 5 years 54.3%
followed by age group 6 to 12 years 41.4%, whereas the lowest percentage was in patients
older than 12 year 4.3% (p-value 0.802). The p-value was considered significant if it is ?
0.05 and highly significant if ? 0.001. Regarding the flow cytometry analysis results for
CD3, CD4 and CD25, ALL patients had a significantly higher mean of these markers than
the control group (p-value ? 0.005). A slightly higher level CD4 was noted in new cases
compared to relapse cases, and induction and consolidation (p = 0.080). The results of
Treg levels cells in relapse, induction, consolidation and new diagnosis cases. On the other
hand, demonstrate higher levels in the relapse group, with highly significant differences
for the two parameters: CD3–CD25 (p ? 0.005). The level of CD25 displayed a highly
significant difference when comparing induction with consolidation (p ? 0.005). From
this study, we conclude that the immunological marker (CD 25) specifically provided the
most highly significant value as immunosuppression parameters in all patients, whereas
chemotherapy represents the key risk factor for immunosuppression in all patients varies
significantly among chemotherapy stages, with consolidation having the most impact.
This effect may be due to the high dose of MTX.
Background: T regulatory cells (Tregs) are immunosuppressive cells that can be divided
into numerous subsets. Tregs comprise a small but heterogeneous population, which the
phenotype may identify as CD3+CD4+CD25+. They play a crucial role in the preservation of immunological homeostasis and self-tolerance. They also play important roles In the control of cancer immunity. Tregs may
also be important in acute leukemia.
Patients and Methods: A7 0 blood samples of both sexes with the age range 2 to 14 years old were collected from patients with
ALL. Additionally, this investigation included 54 healthy controls included in CD3, CD4 and CD25 expression on leukemic
blast cells were assessed using flow cytometry.
Results: Increased values of CD3+CD25+ T cells were observed in children with all in comparison to healthy controls with
significant differences in the markers for Tregs (mean ± SD, 14.971 ± 11.06 vs. 5.680 ± 2.96 pg/mL) (p <0.05).
Following these findings, significant differences in the levels of CD25 was higher in consolidation than in the induction
chemotherapy stage (mean ± SD, 17.657 ± 13.890 vs. 5.100 ± 5.1438) pg/mL (p <0.05), children with all were also found to
have significantly higher levels of CD4 in the current study when compared to healthy controls (mean ± SD, 29.261 ± 13.828
vs. 28.3465 ± 11.17146) pg/mL (p <0.05), Table 2.
According to the chemotherapy stage there were significant significant differences in the levels of CD25 in the relapse state,
which was higher than the chemotherapy stage for new diagnosis (mean ± SD, 22.185 ± 15.148 vs. 13.649 ± 5. 83) pg/mL (p
<0.05). A further finding was that the frequency of lymphoblast that expresses CD25 was considerably higher in the high-risk
group compared to the standard risk group (mean ± SD, 15.75 ± 4.74 vs. 7.92 ± 1.012) pg/mL (p <0.05) Table 3.
Conclusion: Chemotherapy represents the interested immunosuppression risk factor in ALL patients. There is a significant
variation among chemotherapy stages in ALL patient immunosuppression. Consolidation represent the high influence on ALL
patient in immune suppression may be related to the high dose of MTX.