The utility of flow cytometry for the detection of tumor cells in cerebrospinal fluid of patients with acute leukemia

Central nervous system infiltration by acute leukemia is a poor prognosis variable, and conventional cytology is the gold standard for its diagnosis; the technique is highly specific but not sensitive. To improve the diagnosis, flow cytometry has been used in different studies, showing greater sensitivity in the detection of leukemic cells. This study aimed to evaluate the presence of tumor cells by flow cytometry and conventional cytology, in cerebrospinal fluid from patients with acute leukemia as well as its relationship with clinical and biological parameters. In total, 156 CSF samples from 55 children with acute leukemia were studied. We found the following results: FCM-/CC- 131/156; FCM+/CC- 19/156; FCM-/CC+ 0; FCM+/CC+ 1/156; FC-/CC suspicious 1/156; and FCM+/CC suspicious 4/156. Patients with B-cell acute lymphoblastic leukemia and FCM+ showed a lower response to steroid-treatment, abnormal karyotype, neurological symptoms, and worse relapsefree survival. Patients with T-cell acute lymphoblastic leukemia and FCM+ demonstrated association with thrombocytopenia. In conclusion, flow cytometry has greater sensitivity for the detection of tumor infiltration in cerebrospinal fluid, a finding that correlates with prognostic parameters in patients with acute leukemia.