Th157 - Study of CD4+ Th1, Th2, Th17 and Treg Cell Subpopulations in Myelotoxicity Related to Chemotherapy in Pediatric Patients with Acute Lymphoblastic Leukemia

Pablo Ortiz Lazareno – Researcher, Immunology, Mexican Institute of Social Security; Griselda Escobedo Melendez – Researcher, hemato-oncology, University of Guadalajara

Abstract Text: INTRODUCTION
Acute lymphoblastic leukemia represents 25% of pediatric cancer. Myelotoxicities are frequently produced in low-middle-income countries due to the high doses of antineoplastics in chemotherapy, which may increase the risk of mortality. CD4+ cells coordinate response against cancer cells; evidence suggests that Th1, Th2, Th17, Treg, and their cytokines are essential in progressing and responding to treatment. For this reason, monitoring these cell populations could allow the evaluation of the presence and severity of myelotoxicities and survival in ALL.
OBJECTIVES
To determine the changes related to myelotoxicity in CD4+ Th1, Th2, Th17 and Treg cells during the induction to remission phase in pediatric patients with ALL.
METHODS
We included ten pediatric patients with a recent diagnosis of ALL at Juan I. Menchaca Hospital, Civil of Guadalajara. Blood samples were collected at diagnostic consultation, during, and at the end of the RI. PBMC were separated, and staining was performed to identify the CD4+ subpopulations, which were determined by flow cytometry. Complete blood count and the Common Terminology Criteria documented the evaluation of myelotoxicities. The Research and Ethics Committees approved the study protocol.
RESULTS
Patients who completed the IR phase of chemotherapy with mild and/or moderate myelotoxicities present an increase in the frequency of Th1, Th2, and Th17 cells, with a decrease in Treg. In contrast, patients with severe myelotoxicities show an increase in the percentage of Treg and a reduction in Th1, Th2, and Th17 cells.
CONCLUSION
Treg cell population is related to severe myelotoxicities and could represent a therapeutic target.