[Correlation Analysis between Cerebrospinal Fluid Status and Prognosis in Childhood with Acute Lymphoblastic Leukemia by Flow Cytometry].

Objective: To study the cerebrospinal fluid (CSF) status and prognosis value in patients with newly diagnosed acute lymphoblastic leukemia (ALL) by flow cytometry (FCM).

Methods: The clinical features of the 75 newly diagnosed ALL patients from September 2020 to December 2021 in our centre were retrospective analyzed, as well as the bone marrow (BM) and CSF minimal residual disease (MRD) data, and the CSF conventional cytology data. Central nervous system infiltration(CNSI) positive was as CSF MRD positive by FCM or leukemia cells detected by conventional cytology. The status of CSF were compared and analyzed by FCM and conventional cytology, the clinical features and the prognosis value of different CNSI status in these patients were analyzed.

Results: Among 75 newly diagnosed ALL, 16 cases (21%) with CNSI positive (CNSI) were detected by FCM, while only 2 positive cases (3%) were detected by conventional cytology. The CNSI rate detected by FCM was significantly higher than conventional cytology(<0.05). Compared with CNSI ALL patients, the median age of CNSI ALL patients was significantly younger, and the median platelet count was significantly lower, the difference was statistically significant (<0.05). Up to follow-up time (August 31, 2022), four ALL patients were died, including 3 patients were CNSI and 1 patient was CNSI. Furthermore, three cases were primary disease relapse, including 1 case was CNSI. There was no significant difference in overall survival (OS) rate and relapse-free survival (RFS) rate of the patients with different CNSI status.

Conclusion: Compared with conventional cytology, FCM is a more sensitive assay to evaluate the central nervous system status in ALL patients. After active treatment, there was no significant difference in OS and RFS between patients with different CNSI status at diagnosis.