Tyrosine Hydroxylase Expression is Associated with Bone Marrow Infiltration in Neuroblastoma Patients

Background: Neuroblastoma is a complex heterogeneous disease. Bone marrow is the most commonly affected metastatic site. The aim of the work: The current study aimed to assess the role of tyrosine hydroxylase in diagnosing bone marrow infiltration in neuroblastoma. Methods: Tyrosine hydroxylase was assessed in the bone marrow aspirate of 104 pediatric neuroblastoma patients, compared to 25 matched normal controls by real time polymerase chain reaction. The data were correlated to the clinic-pathological features of the patients, response to treatment, bone marrow infiltration, disease free survival and overall survival. Results: Tyrosine hydroxylase was expressed in 78/104 [75%] of the patients. Bone marrow infiltration was significantly higher in patients with high tyrosine hydroxylase expression compared to those with tyrosine hydroxylase low expression [median [range]: 193 [0-277750] versus 4 [0- 7849]; p=0.003]. Use of tyrosine hydroxylase for diagnosis of bone marrow involvement in neuroblastoma had a sensitivity of 55.2%, a specificity of 65.2%, and positive predictive value of 66.7% and negative predictive value of 53.6%. Conclusions: Tyrosine hydroxylase may serve as a useful tool for diagnosis of bone marrow infiltration in neuroblastoma. Bone marrow infiltration is associated with poor disease free survival and overall survival.