Cerebrospinal Fluid Flow Cytometry in Acute Lymphoblastic Leukemia/Lymphoma: Is It Beneficial?.

Abstract

2576 Cerebrospinal fluid (CSF) involvement by leukemic blasts occurs in fewer than 10 % of adult patients with newly diagnosed acute lymphoblastic leukemia/lymphoma (ALL). Leukemic meningitis is diagnosed by microscopic detection of blasts in the CSF. Flow cytometry is a highly sensitive tool for detection of aberrant cells. We sought to analyze the additional benefit flow cytometry might provide for the diagnosis of leukemic meningitis. Between 11/2007 and 8/2011, 80 patients were diagnosed with ALL and treated at Emory University. 800 CSF samples were available for analysis 80 of which were collected from a diagnostic lumbar puncture (LP), 689 from follow-up LPs and 31 from LPs obtained at the time of relapse. As shown in the table, flow cytometry confirmed the presence of leukemic blasts in one, four and five samples diagnosed with leukemic meningitis by cytology at diagnosis, different stages of treatment and relapse, respectively. One and three samples were positive for leukemic blasts by cytology but negative by flow cytometry during different treatment stages and relapse respectively. We conclude that flow cytometry provided no additional benefit to cytology in the diagnosis of leukemic meningitis. Table: CSF Cytology and Flow Cytometry in 80 Adult ALL patients: CSF samples New Diagnosis N=80 Induction/Consolidation/Intensification/Maintenance/Remission/Post-transplant N = 689 Systemic relapse N = 31 N Cytology N = 80 Flow cytometry N = 66 Cytology N = 689 Flow cytometry N = 188 Cytology N = 31 Flow cytometry N = 13 Negative 79/80 65/66 684/689 184/188 23/31 8/13 Positive 1/80 1/66∼ 5/689 4/188∼* 8/31 5/13∼** ∼ CSF samples positive by flow cytometry were also positive by cytology * One CSF sample was positive by cytology but negative by flow cytometry ** CSF flow cytometry was not done in 3/8 positive CSF samples by cytology Disclosures: No relevant conflicts of interest to declare.

Central nervous system (CNS) involvement has an adverse impact on survival in newly diagnosed adult acute lymphoblastic leukemia (ALL) assessed by flow cytometry

“…Few studies have also aimed to describe its role in the detection of leukemic blasts in cerebrospinal fluid. Many studies have proposed its usefulness given the low sensitivity of cytology which is unable to detect infiltration with low cell counts since it relies solely on the observer's experience and training in distinguishing pathological cells from normal lymphocytes [6,[16][17][18][19][20].…”