[Clinical significance of cerebrospinal fluid beta 2-microglobulin determination in central nervous system leukemia]

Cerebrospinal fluid (CSF) beta 2-microglobulin (beta 2-MG) level was measured in 72 healthy subjects and the value (means +/- S means) was found to be 1.26 +/- 0.06 mg/L. The CSF beta 2-MG level in 33 patients who had simple acute leukemia without CNS involvement was 1.46 +/- 0.13 mg/L, which was not significantly different from that in the normal controls (P greater than 0.05). In 25 patients who had leukemia with involvement of CNS, the CSF beta 2-MG level (mean +/- S mean) was 3.94 +/- 0.30 mg/L, which was statistically different from that in the healthy controls (P less than 0.01). It is found that beta 2-MG level in CSF was one of the reliable criteria for diagnosis and indication of intrathecal chemotherapy in CNS leukemia.