[Flow cytometric analysis of cerebrospinal fluid in the diagnosis of central nervous system leukemia].

OBJECTIVE

To evaluate the value of flow cytometric immunophenotyping of cerebrospinal fluid (CSF) cells in the diagnosis of central nervous system leukemia.

METHODS

Ninety two CSF samples were analyzed with 4-color flow cytometry. Antibody panles CD19/CD34/CD3/CD45, CD117/CD34/CD5/CD45, CD7/CD34/ CD19/CD45, CD7/CD3/HLA-DR/CD45, CD20/CD10/CD3/CD45, and anti-g/anti-lambda/CD19/CD45 were used in determining cell composition and detecting abnormal cells. The results of flow cytometry were compared with conventional cell count and morphology. Flow cytometry analysis was repeated for five samples 48 hours after the initial test.

RESULTS

Abnormal cells were found in 33 out of the 92 (35.9%) samples. Among the 59 samples taken from patients with lymphocyte neoplasm, CD19 + blast cells were found in the CSF in 13 patients with B-cell lymphoblastic leukemia; CD7+ blast cells were found in 4 T-ALL cases; and monoclonal CD19+ cells were found in 6 other types of lymphoma cases. In the 32 patients with clinically diagnosed myeloid leukemia, CD117+ myeloid cells were found in the CSF of 7 patients and B cell blast cells were found in 2 CML cases. The abnormal cells in the CSF detected by immunophenotyping decreased significantly 48 hours after the initial test. Abnormal cells were detected in 25 samples (27.2%) by morphology, less than those detected by immunophenotyping. The cell concentrations of the eight samples in which abnormal cells were only detected by flow cytometry were lower than 10 X 10(6)/L. The immunophenotyping results of two ALL patients were still positive when morphologic results had become negative after chemotherapy.

CONCLUSION

Flow cytometric analysis of CSF may be helpful in the diagnosis of meningeal leukemia. It has higher positive rate and better accuracy than cytomorphology and cell count.