Patterns and prognostic impact of CNS infiltration in adults with newly diagnosed acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is highly associated with central nervous system (CNS) infiltration and can be associated with higher risk of relapse. Conventional cytology (CC) is the traditional method for diagnosing CNS infiltration, although the use of immunophenotyping by flow cytometry (FC) has gained prominence in recent years due to its higher sensitivity. Also, some authors have proposed that CSF contamination by a traumatic lumbar puncture (TLP) could have a clinical impact. This retrospective study accessed the impact of CNS infiltration by CC or FC on overall survival, event-free survival, and relapse rate. In a cohort of 105 newly diagnosed ALL patients, CNS1, CNS2, and CNS3 status were found in 84%, 14%, and 2%, respectively. We found that extramedullary disease at the diagnosis, higher leukocyte counts, and higher blast percentage were associated with a positive CC. Sensitivity and specificity of CC were 53% and 98%, respectively. Three-year overall survival was 42.5%. Conversely, TLP was not associated with a positive CC nor had an impact on relapse rates. In multivariate analysis, a positive CC was associated with an increased relapse rate (HR 2.074, p = 0.037), while its detection by FC did not associate with this endpoint. Survival rates seem to be increasing over the last years by the adoption of a stratified CNS prophylaxis risk strategy. CSF contamination does not represent a major concern according to our report, as it did not increase CNS involvement or relapse rates.

Glymphatic system dysfunction in pediatric acute lymphoblastic leukemia without clinically diagnosed central nervous system infiltration: a novel DTI-ALPS method.

BACKGROUND AND OBJECTIVE: Central nervous system (CNS) infiltration commonly occurs in children with acute lymphoblastic leukemia (ALL). Nevertheless, CNS infiltration is rarely detected at the initial diagnosis. The glymphatic system, which regulates cerebrospinal fluid (CSF) and interstitial fluid transport, is considered one of the possible routes of CNS infiltration by leukemia cells. In this study, we used diffusion tensor image analysis along the perivascular space (DTI-ALPS) method to investigate glymphatic system function and obtained CSF volume using synthetic magnetic resonance imaging (SyMRI) in pediatric ALL without clinically diagnosed CNS infiltration. MATERIALS AND METHODS: Twenty-nine ALL and 29 typically developing (TD) children were prospectively recruited (age 4-16 years) in the present study. Group differences in brain volumetric parameters, brain water diffusivities, and the ALPS index were evaluated after controlling for age, gender, and handedness. Furthermore, significant group-different parameters were correlated with clinical information using partial correlations analysis. RESULTS: Lower Dxassoc and ALPS index, and increased CSF volume were found in pediatric ALL (all pFDR-corrected < 0.05). Moreover, the ALPS index was negatively associated with the risk classification (r = - 0.59, pFDR-corrected = 0.04) in pediatric ALL. CONCLUSIONS: Dysfunction of the glymphatic system and accumulation of CSF were presented in pediatric ALL without clinically diagnosed CNS infiltration. These novel findings suggested that the glymphatic system might be essential in the early-stage process of ALL CNS infiltration, which provides a new direction for exploring underlying mechanisms and early detection of pediatric ALL CNS infiltration. KEY POINTS: • Lower Dxassoc and ALPS index, and increased CSF volume were found in pediatric ALL (all pFDR-corrected < 0.05). • The ALPS index was negatively associated with the risk classification (r = -0.59, pFDR-corrected = 0.04) in pediatric ALL. • Dysfunction of the glymphatic system and accumulation of CSF were presented in pediatric ALL without clinically diagnosed CNS infiltration, which suggested that the ALPS index and CSF volume might be promising imaging markers for early detection of pediatric ALL CNS infiltration.

The expense of sending cerebrospinal fluid for analysis on all lumbar punctures in pediatric acute lymphoblastic leukemia patients.

BACKGROUND: Central nervous system (CNS) relapse in pediatric acute lymphoblastic leukemia (ALL) patients is uncommon. The cerebrospinal fluid (CSF) of patients with ALL is routinely sampled at each intrathecal chemotherapy treatment to screen for CNS relapse. The analysis of CSF is both time consuming and resource intensive and must be completed approximately 20 times per patient throughout treatment. Our objective was to examine the expense of routine screening on all CSF samples for CNS relapse in ALL patients, and to identify if CNS relapse can be detected clinically. METHODS: We identified all patients diagnosed with ALL at the Children's Hospital of Eastern Ontario (CHEO) between January 2001 and June 2021. We collected the total number of CSF samples in these patients and the number of CSF samples positive for CNS relapse. An in-depth chart review on the patients who relapsed in the CNS was completed to identify symptoms at relapse. RESULTS: Over the study period, 351 patients were diagnosed with ALL and underwent a total of 6515 lumbar punctures (LPs), each of which examined the CSF. The cost of CSF sample analysis is $14.32 (Canadian dollars [CDN]); thus, the total cost for the study sample was $93,294.80 (CDN). There were 14 CNS relapses and although symptoms including headache, vomiting, and fatigue were common, two patients were asymptomatic at relapse. CONCLUSIONS: Given the marginal cost of routine CSF screening and the lack of specific and sensitive symptoms for CNS relapse, we conclude that the routine practice of sending all CSF samples for analysis of CNS relapse in ALL patients is relatively inexpensive and beneficial.

Central nervous system (CNS) involvement has an adverse impact on survival in newly diagnosed adult acute lymphoblastic leukemia (ALL) assessed by flow cytometry.

The role of CNS involvement detected by flow cytometry (FCM) in patients with acute lymphoblastic leukemia has been discussed previously; however, its impact on survival has not been described enough. We analyzed a retrospective cohort of newly diagnosed ALL adult patients who had a cerebrospinal fluid (CSF) analysis by FCM and conventional cytology. We evaluated 81 patients; 19 (23.4%) were only positive by FCM, five (6.3%) were double-positive (DP) and 57 (70.4%) were double-negative (DN). The detection of CNS involvement was increased from 6% to 24%, employing FCM; In our final analysis, patients with FCM + had a lower survival of 7.01 months [95% CI (5.90-8.24)], compared with 11.71 months [IC95% (9.49-13.94)] in the DN group (p = 0.03).

Flow cytometric analysis of cerebrospinal fluid improves detection of leukaemic blasts in infants with acute lymphoblastic leukaemia.

Infants with acute lymphoblastic leukaemia (ALL) have a high frequency of central nervous system (CNS) involvement. Flow cytometric analysis of cerebrospinal fluid (CSF) was recently demonstrated to be a sensitive method for detecting CNS involvement in childhood ALL. In the present study, CSF from 14 infants was collected at routine lumbar punctures and analysed by multicolour flow cytometry. At initial diagnosis, leukaemic blasts were detected in CSF by flow cytometry in 11 patients (78·6%) compared to seven patients (50%) by cytospin. Larger studies are needed to determine if CSF flow cytometry has prognostic value in infant ALL.

Interleukin-6-Mediated Inflammation May Cause Methotrexate-Induced Leukoencephalopathy.

Children with leukemia treated with methotrexate (MTX) may develop MTX-induced leukoencephalopathy, which can present as seizures or focal neurological deficits. However, the precise pathophysiology has not been fully elucidated. Differences in cytokine/chemokine profiles in cerebrospinal fluid (CSF) between children with MTX-induced leukoencephalopathy and those with posterior reversible encephalopathy syndrome (PRES), an acute neurological condition associated with hypertension, were investigated. Interleukin (IL)-1ß, 2, 4, 5, 6, 7, 8, 10, 12, 13, and 17, tumor necrosis factor-alpha, interferon-gamma, granulocyte monocyte colony-stimulating factor, granulocyte colony-stimulating factor, macrophage inflammatory protein-1ß, and monocyte chemoattractant protein-1 concentrations were measured in CSF supernatants from 3 children with acute leukemia with MTX-induced leukoencephalopathy, 3 children with acute leukemia with PRES, 6 children with acute leukemia without neurological complications, and 8 children with acute encephalopathy. CSF IL-6 concentrations were higher in children with MTX-induced leukoencephalopathy than in children with acute leukemia with PRES, with acute leukemia without neurological complications, and with acute encephalopathy. We concluded that IL-6 may be involved in the pathogenesis of MTX-induced leukoencephalopathy.

The meninges enhance leukaemia survival in cerebral spinal fluid.

Central nervous system (CNS) relapse is a common cause of treatment failure in patients with acute lymphoblastic leukaemia (ALL) despite current CNS-directed therapies that are also associated with significant short- and long-term toxicities. Herein, we showed that leukaemia cells exhibit decreased proliferation, elevated reactive oxygen species (ROS) and increased cell death in cerebral spinal fluid (CSF) both in vitro and in vivo. However, interactions between leukaemia and meningeal cells mitigated these adverse effects. This work expands our understanding of the pathophysiology of CNS leukaemia and suggests novel therapeutic approaches for more effectively targeting leukaemia cells in the CNS.

Flow cytometric detection of leukemic blasts in cerebrospinal fluid predicts risk of relapse in childhood acute lymphoblastic leukemia: a Nordic Society of Pediatric Hematology and Oncology study.

Central nervous system (CNS) involvement by cytospin is associated with increased risk of relapse in childhood acute lymphoblastic leukemia. We investigated if flow cytometric analysis of cerebrospinal fluid (CSF) at diagnosis improves the prediction of relapse. This prospective cohort study included patients (1.0-17.9 years) treated according to the Nordic Society of Pediatric Hematology and Oncology ALL2008 protocol. CSF flow cytometry samples were obtained at 17 centers, preserved with Transfix®, and analyzed at a central laboratory. One-hundred and seventy-one (25.4%) of 673 patients were positive by flow cytometry (CNSflow+). The 4-year cumulative incidence of relapse was higher for patients with cytospin positivity (CNScyto+) (17.1% vs. 7.5%), CNSflow+ (16.5% vs. 5.6%), and cytospin and/or flow positivity (CNScomb+) (16.7% vs. 5.1%). In Cox regression analysis stratified by immunophenotype and minimal residual disease day 29 and adjusted by sex, predictors of relapse were age (hazard ratio [HR] 1.1, 95% CI 1.1-1.2, P < 0.001), white blood cell count at diagnosis (HR 1.4, 95% CI 1.1-1.6, P < 0.001), and CNScomb+ (HR 2.2, 95% CI 1.0-4.7, P = 0.042). Flow cytometric analysis of CSF improves detection of CNS leukemia, distinguishes patients with high and low risk of relapse, and may improve future risk stratification and CNS-directed therapy.

Asparagine levels in the cerebrospinal fluid of children with acute lymphoblastic leukemia treated with pegylated-asparaginase in the induction phase of the AIEOP-BFM ALL 2009 study.

Asparagine levels in cerebrospinal fluid and serum asparaginase activity were monitored in children with acute lymphoblastic leukemia treated with pegylated-asparaginase. The drug was given intravenously at a dose of 2,500 IU/m2 on days 12 and 26. Serum and cerebrospinal fluid samples obtained on days 33 and 45 were analyzed centrally. Since physiological levels of asparagine in the cerebrospinal fluid of children and adolescents are 4-10 µmol/L, in this study asparagine depletion was considered complete when the concentration of asparagine was ≤0.2 µmol/L, i.e. below the lower limit of quantification of the assay used. Over 24 months 736 patients (AIEOP n=245, BFM n=491) and 903 cerebrospinal fluid samples (n=686 on day 33 and n=217 on day 45) were available for analysis. Data were analyzed separately for the AIEOP and BFM cohorts and yielded superimposable results. Independently of serum asparaginase activity levels, cerebrospinal fluid asparagine levels were significantly reduced during the investigated study phase but only 28% of analyzed samples showed complete asparagine depletion while relevant levels, ≥1 µmol/L, were still detectable in around 23% of them. Complete cerebrospinal fluid asparagine depletion was found in around 5-6% and 33-37% of samples at serum asparaginase activity levels <100 and ≥ 1,500 IU/L, respectively. In this study cerebrospinal fluid asparagine levels were reduced during pegylated-asparaginase treatment, but complete depletion was only observed in a minority of patients. No clear threshold of serum pegylated-asparaginase activity level resulting in complete cerebrospinal fluid asparagine depletion was identified. The consistency of the results found in the two independent data sets strengthen the observations of this study. Details of the treatment are available in the European Clinical Trials Database at https://www.clin-icaltrialsregister.eu/ctr-search/trial/2007-004270-43/IT.

Plasma asparaginase activity and asparagine depletion in acute lymphoblastic leukemia patients treated with pegaspargase on Children's Oncology Group AALL07P4.

The efficacy of asparaginase in acute lymphoblastic leukemia (ALL) is dependent on depletion of asparagine, an essential amino acid for ALL cells. The target level of plasma asparaginase activity to achieve asparagine depletion has been between 0.05 and 0.4 IU/mL. COG AALL07P4 examined the asparaginase activity and plasma and CSF asparagine concentration of pegaspargase when given intravenously in the treatment of NCI high risk ALL. Matched plasma asparaginase/asparagine levels of the clearance of 54 doses of pegaspargase given in induction or consolidation demonstrated that all patients who had a plasma asparaginase level >0.02 IU/mL had undetectable plasma asparagine. No difference was observed in CSF asparagine levels associated with matched plasma asparaginase levels of 0.02-0.049 versus 0.05-0.22 IU/mL (p = .25). Our data suggest that a plasma asparaginase activity level of 0.02 IU/mL can effectively deplete plasma asparagine. The data also indicate that the 95% CI for plasma asparagine depletion after a pegaspargase dose is 22-29 days. Clinical trial registration: clinicaltrials.gov identifier NCT00671034.

Significance of CNS 2 cerebrospinal fluid status post-induction in pediatric and adolescent patients with acute lymphoblastic leukemia.

BACKGROUND: At diagnosis, there are prognostic implications of low-level leukemic blasts (CNS 2) in the cerebrospinal fluid (CSF) of patients with acute lymphoblastic leukemia (ALL). However, the significance of post-induction CNS 2 results and the impact of equipment on CNS 2 prevalence have not been well studied. PROCEDURE: A single-institution retrospective cohort study was conducted to analyze the outcome of patients with ≥1 post-induction CNS 2. A subanalysis compared the proportion of CNS 2 CSF results using 2 different cytocentrifuges; the Shandon Cytospin used from 2005 to 2008 and the Wescor Cytopro used from 2010 to 2014. RESULTS: Over 4500 post-induction CSF samples were analyzed, of which 59 were CNS 2. In covariate-adjusted analyses, post-induction CNS 2 did not significantly increase relapse risk. The proportion of CNS 2 results increased 4.3-fold in noninfants and 6.3-fold in infants using the Wescor Cytopro. Cytocentrifuge machine did not affect CNS 3 prevalence. CONCLUSIONS: These findings support our current practice of not changing management based on a post-induction CNS 2 CSF and highlight how equipment changes can significantly influence testing results. More data are needed to analyze relapse by subpopulations, such as those with repeated CNS 2 findings.

Application of Fluorescence In Situ Hybridization on Cerebrospinal Fluid Cytospins for the Detection of Residual Leukemic Cells in Patients With Childhood Acute Lymphoblastic Leukemia.

OBJECTIVES: Diagnosis of central nervous system involvement in acute lymphoblastic leukemia (ALL) requires morphologic expertise; therefore, we evaluated interphase fluorescence in situ hybridization (iFISH) of cerebrospinal fluid (CSF) cytospin preparations as a potential complementary test. METHODS: Twenty-three CSF cytospin specimens from 13 pediatric patients with ALL were included. iFISH probes detecting BCR-ABL1, ETV6-RUNX1, and KMT2A rearrangement and CDKN2A deletion, which were present at initial diagnosis, were used on follow-up CSF cytospin specimens and were compared with cytology. RESULTS: Seventeen (73.9%) follow-up specimens showed concordant results between iFISH and cytology. Two (8.7%) samples with discordant results were positive by iFISH but not by cytology; one (4.3%) was positive only by cytology. In the remaining three (13.0%) specimens, too few cells were available for cytology, whereas iFISH interpretation was possible. CONCLUSIONS: iFISH of CSF cytospin preparations improves malignant cell detection in pediatric ALL.

Subglottic acute lymphoblastic leukaemia.

Acute lymphoblastic leukaemia (ALL) is one of the the most common malignancies of childhood and can occasionally present as acute airway obstruction. We present the unusual case of a 1-year-old boy who was referred to our Paediatric Otolaryngology (ENT) clinic with a recurrent history of croup. This is the first reported case of localised ALL presenting as a subglottic mass in a paediatric patient. It highlights the need to have a broader differential diagnosis in children presenting with 'recurrent croup' including extramedullary presentation of leukaemia and to have a low threshold for performing endoscopy in such cases.

Central nervous disease in pediatric patients during acute lymphoblastic leukemia (ALL): a review.

Acute lymphoblastic leukemia (ALL) is one of the frequently reported malignancies of childhood age. Earlier it was thought to be a fatal pathological state with no cure, but with advancements in medicine and science, new therapeutic approaches have resulted in better management and cure. However, one of the major hurdles in achieving a complete cure is the relapse of ALL at extra-medullary sites like the central nervous system (CNS). The present review article is focused on recent diagnostic avenues available for the detection of CNS disease during acute lymphoblastic leukemia (ALL) in young patients.

Use of the Polymerase Chain Reaction as a Complementary Method for the Detection of Central Nervous System Involvement in Children and Adolescents with Acute Lymphoblastic Leukemia.

BACKGROUND: Cytological analysis of the cerebrospinal fluid (CSF) remains the most widely used method for diagnosing central nervous system (CNS) involvement in acute lymphoblastic leukemia (ALL). This study aimed at evaluating the use of polymerase chain reaction (PCR), in comparison to other methods, for the assessment of the presence of blast cells in the CSF at the time of diagnosis of ALL. METHODS: This was a prospective, single-centre, study enrolling all patients up to the age of 18 years who were admitted to a university hospital between November 2011 and November 2014 with a diagnosis of ALL and from whom it was possible to draw a sufficient amount of CSF for analysis by conventional cytology (CT), immunophenotyping (IMP), and PCR. RESULTS: A total of 46 CSF samples from 44 ALL pediatric patients were included. CT was performed in all samples, IMP in 44, and PCR in 34. Thirteen (28.2%) samples showed positive results: two by CT, four by IMP, four by PCR, and three by both IMP and PCR. CONCLUSIONS: The results of this study showed that PCR should be considered a complementary method for the evaluation of the CSF in ALL patients at diagnosis.

Treatment of two cases on the same day of intrathecal methotrexate overdose using cerebrospinal fluid exchange and intrathecal instillation of carboxypeptidase-G2.

BACKGROUND: Two 14-year old boys with acute lymphocytic leukemia were treated according to the NOPHO-ALL-08 protocol with intrathecal methotrexate (MTX) on the same day. Due to a preparation error in the hospital pharmacy, they were both given 240 mg of MTX instead of the prescribed 12 mg. Treatment (or methods): Both patients developed acute neurotoxicity with confusion, pain and seizures. Intravenous dexamethasone and folinic acid (leucovorin) was given. Exchange of cerebrospinal fluid was performed. Intrathecal glucarpidase (carboxypeptidase-G2) was administered after 11 h. RESULTS: One patient developed a toxic arachnoiditis. Three years after the incident, one patient has no neurological or neuropsychological sequelae after the overdose, while the other reports some loss of short-term memory. CONCLUSION: Fast recognition and treatment of intrathecal MTX overdose is critical to survival and outcome. Efforts to prevent such overdoses are of vital importance.

Flow cytometric analysis of cerebrospinal fluid in adult patients with acute lymphoblastic leukemia during follow-up.

OBJECTIVE: To explore the value of flow cytometric (FCM) analysis of cerebrospinal fluid (CSF) in the diagnosis of central nervous system involvement in adult patients with acute lymphoblastic leukemia (ALL) during follow-up. METHODS: A total of 2871 CSF samples from 357 adult patients with newly diagnosed ALL between the year of 2009 and 2015 were analyzed retrospectively. These patients were divided into 3 groups according to CSF results, FCM+/conventional cytology (CC)+ group, FCM+/CC- group, and FCM-/CC- group, respectively. The overall survival (OS) of the three groups was analyzed. RESULTS: Fifteen (4.2%) and 26 (7.3%) patients' CSF samples were FCM+/CC+ and FCM+/CC-, respectively. The remaining 316 (88.5%) patients' samples were FCM-/CC-. The 2-year OS for the FCM+/CC+, FCM+/CC-, and FCM-/CC- groups was 40.0%, 20.6%, and 64.2%, respectively (P < .001). There was no statistically significant difference in OS between FCM+/CC+ and FCM+/CC- patients (P = .195). In multivariate analysis, a high WBC count and LDH level were independent risk factors for central nervous system involvement in adult patients with ALL. CONCLUSIONS: FCM demonstrated a superior sensitivity over conventional cytology in the diagnosis of central nervous system involvement in adult patients with ALL. FCM+/CC- patients showed a similar survival with FCM+/CC+ patients, suggesting that an isolated FCM-positive status holds clinical significance.