The association of leukocyte immunoglobulin-like receptor subfamily B-4 expression in acute myeloid leukemia and central nervous system involvement.

Central nervous system (CNS) involvement in patients with acute myeloid leukemia (AML) varies, ranging from 0.6%-46%. Leukocyte immunoglobulin-like receptor B4 (LILRB4) has been shown to be critical in orchestration of infiltration of AML cells into the CNS in animal models, however it is unknown if an association exists between LILRB4 and CNS involvement (CNS+) in human patients with AML. LILRB4 was measured by flow cytometry in a heterogeneous population of fifty-six AML patients. Patients were then followed clinically for the development of CNS + . LILRB4 was positive in 91 % of patients with CNS + compared to 38 % without CNS involvement (p < 0.002). In logistic analysis: age, BMI, serum albumin and positive LILRB4 were predictive for CNS+ [OR, 95 % CI, p-value]: 0.95, 0.92-0.99, p < 0.01; 0.85, 0.73-0.998, p < 0.05; 0.23, 0.066-0.78, p < 0.02; 16.46, 1.93-140.2, p < 0.02, respectively. This finding of the association of LILRB4 with CNS + in combination with earlier findings suggests that LILRB4 has a mechanistic role in infiltration of the CNS and may provide insight into the pathogenesis of AML seeding the CNS. Moreover, this proof of concept and the findings in the present study may lead to the development of innovative and novel therapies to improve the lives of patients with AML.