ABSTRACT
ObjectiveThe glymphatic system regulates cerebral spinal fluid and interstitial fluid transport which might be one of the pathways of central nervous system （CNS） leukemia at the early stage. This study aimed to investigate the alteration of glymphatic system based on diffusion tensor image-analysis along the perivascular space （DTI-ALPS） in pediatric acute lymphoblastic leukemia （ALL） without clinically diagnosed CNS infiltration. MethodsTwenty-five ALL and typically developing （TD） children were prospectively recruited， and all subjects underwent DTI. Group differences in brain water diffusivities and ALPS-index were evaluated using the analysis of covariance. The Spearman correlation analysis was used to evaluate the relationship between biological characteristics and significant parameters in pediatric ALL. ResultsCompared with TDs， decreased Dxassoc value （PFDR-corrected = 0.048） and increased Dzassoc value （PFDR-corrected = 0.033） were found in pediatric ALL. Hence， lower ALPS-index was found in children with ALL （PFDR-corrected < 0.001）. ALPS-index was negatively associated with the risk classification （rs = -0.47， P = 0.018） as well as immunophenotype （rs = -0.40， P = 0.046） in pediatric ALL. ConclusionsOur results show dysfunction of the glymphatic system is presented in pediatric ALL without clinically diagnosed CNS infiltration， which suggests that the glymphatic system might be one of pathway in the early-stage of ALL CNS infiltration. The DTI-ALPS method can be used to evaluate the change of glymphatic system， providing a new method for exploring the underlying mechanisms and early detection of pediatric ALL CNS infiltration.
ABSTRACT
ObjectiveCentral nervous system （CNS） infiltration commonly occurs in children with acute lymphoblastic leukemia （ALL）. Early subclinical CNS infiltration in pediatric ALL is hard to detect with conventional methods. This study aimed to investigate the changes of brain structure volume parameters based on Synthetic MRI （SyMRI） in pediatric ALL without clinically diagnosed CNS infiltration. MethodsThirty-six ALL and twenty-nine typically developing （TD） children were prospectively collected and all underwent SyMRI. The Synthetic MR software was used to obtain brain volumetric parameters including total white matter volume （WMV）， gray matter volume （GMV）， cerebrospinal fluid （CSF） volume， etc. and their within-group differences were assessed by analysis of covariance. The Spearman correlation analysis was used to examine the correlation between biological characteristics and statistically significant brain volume parameters. ResultsALL children showed increased CSF volume （PFDR-corrected = 0.009） and decreased GMV （PFDR-corrected = 0.027） when compared to TD children. We also found a moderately negative association between GMV/intracranial volume and risk classification in pediatric ALL （rs = -0.380， P = 0.022）. ConclusionsPediatric ALL without clinically diagnosed CNS infiltration presented with accumulation of CSF and reduction of gray matter. The brain volumetric changes in subclinical CNS infiltration of pediatric ALL provides a new attempt for exploring the underlying mechanism and early detection of CNS infiltration in pediatric ALL.