Controversies in the management of central nervous system leukemia

Technological features of blast identification in the cerebrospinal fluid: A systematic review of flow cytometry and laboratory haematology methods

BACKGROUND

Involvement of the central nervous system (CNS) by acute leukemias (ALs) has important implications for risk stratification and disease outcome. The clinical laboratory plays an essential role in assessment of cerebrospinal fluid (CSF) specimens from patients with ALs at initial diagnosis, at the end of treatment, and when CNS involvement is clinically suspected. The two challenges for the laboratory are 1) to accurately provide a cell count of the CSF and 2) to successfully distinguish blasts from other cell types. These tasks are classically performed using manual techniques, which suffer from suboptimal turnaround time, imprecision, and inconsistent inter-operator performance. Technological innovations in flow cytometry and hematology analyzer technology have provided useful complements and/or alternatives to conventional manual techniques.

AIMS

We performed a PRISMA-compliant systematic review to address the medical literature regarding the development and current state of the art of CSF blast identification using flow cytometry and laboratory hematology technologies.

MATERIALS AND METHODS

We searched the peer reviewed medical literature using MEDLINE (PubMed interface), Web of Science, and Embase using the keywords "CSF or cerebrospinal" AND "blasts(s)".

RESULTS

108 articles were suitable for inclusion in our systematic review. These articles covered 1) clinical rationale for CSF blast identification; 2) morphology-based CSF blast identification; 3) the role of flow cytometry; 4) use of hematology analyzers for CSF blast identification; and 5) quality issues. 9 /L, which is much lower than the original machine count and platelet transfusion was warranted.

DISCUSSION

1) Clinical laboratory testing plays a central role in risk stratification and clinical management of patients with acute leukemias, most clearly in pediatric ALs; 2) studies focused on other patient populations, including adults and patients with AML are less prevalent in the literature; 3) improvements in instrumentation may provide better performance for the classification of CSF specimens.

CONCLUSION

Current challenges include: 1) more precisely characterizing the natural history of AL involvement of the CNS, 2) improvements in automated cell count technology of low cellularity specimens, 3) defining the role of flow MRD testing of CSF specimens and 4) improved recognition of specimen quality by clinicians and laboratory personnel.

How I treat relapsed acute lymphoblastic leukemia in the pediatric population

Relapsed acute lymphoblastic leukemia (ALL) has remained challenging to treat in children, with survival rates lagging well behind those observed at initial diagnosis. Although there have been some improvements in outcomes over the past few decades, only ∼50% of children with first relapse of ALL survive long term, and outcomes are much worse with second or later relapses. Recurrences that occur within 3 years of diagnosis and any T-ALL relapses are particularly difficult to salvage. Until recently, treatment options were limited to intensive cytotoxic chemotherapy with or without site-directed radiotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). In the past decade, several promising immunotherapeutics have been developed, changing the treatment landscape for children with relapsed ALL. Current research in this field is focusing on how to best incorporate immunotherapeutics into salvage regimens and investigate long-term survival and side effects, and when these might replace HSCT. As more knowledge is gained about the biology of relapse through comprehensive genomic profiling, incorporation of molecularly targeted therapies is another area of active investigation. These advances in treatment offer real promise for less toxic and more effective therapy for children with relapsed ALL, and we present several cases highlighting contemporary treatment decision-making.

Comparison of central nervous system relapse outcomes following haploidentical vs identical-sibling transplant for acute lymphoblastic leukemia

To explore the incidence, risk factors, and outcomes of central nervous system (CNS) relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute lymphoblastic leukemia (ALL) and to compare the differences in CNS relapse between haploidentical donor HSCT (HID-HSCT) and HLA-identical sibling donor HSCT (ISD-HSCT). We performed a retrospective nested case-control study on patients with CNS relapse after allo-HSCT. The cumulative incidence of CNS relapse was 4.06% after allo-HSCT in ALL, with a significantly poor prognosis. The incidence was 3.91% and 5.36% in HID-HSCT and ISD-HSCT, respectively (p = .227). Among the patients with CNS relapse, the overall survival (OS) at 3 years was 56.2 ± 6.8% in the HID-HSCT subgroup and 76.9 ± 10.2% in the ISD-HSCT subgroup (p = .176). The 3-year cumulative incidence of systemic relapse was also comparable between the two subgroups (HID-HSCT, 40.6 ± 7.4%; ISD-HSCT, 13.3 ± 8.7%, respectively, p = .085). Younger age (p = .045), T-ALL (p = .035), hyperleukocytosis at diagnosis (p < .001), advanced disease stage at transplant (p < .001), pre-HSCT CNS involvement (p < .001), and absence of chronic graft vs host disease (cGVHD) (p < .001) were independent risk factors for CNS relapse after allo-HSCT. In conclusion, CNS relapse was a significant complication after allo-HSCT in ALL and was associated with poor prognosis. The incidences and outcomes were comparable between HID-HSCT and ISD-HSCT.

Investigation of the optimal duration of bed rest in the supine position to reduce complications after lumbar puncture combined with intrathecal chemotherapy: a multicenter prospective randomized controlled trial

Purpose

This randomized, open-label trial was conducted to investigate the optimal duration of bed rest after intrathecal chemotherapy to reduce the incidence of complications without increasing patients’ tolerance to long-term bed rest.

Methods

A total of 390 patients receiving intrathecal chemotherapy were randomly assigned 1:1:1 to undergo bed rest for 6, 8, or 10 h after intrathecal chemotherapy. The primary outcome was the rate of complications after intrathecal chemotherapy. The analysis was per protocol.

Results

A total of 359 patients among the 390 patients in our study completed follow-up with 120 patients in the 6-h group, 120 in the 8-h group, and 119 in the 10-h group. The complications among the three groups differed significantly (P = 0.005). The 6-h group had significantly more complications than the 8- (50, 41.7% vs 29, 24.2%, P = 0.004) and 10-h groups (50, 41.7% vs 31, 26.1%, P = 0.011), whereas the difference between the 8- and 10-h groups was not significant (29, 24.2% vs 31, 26.1%, P = 0.737).

Conclusions

The overall results support that the optimal time interval for bed rest in the supine position after intrathecal chemotherapy is 8 h. This trial is registered with the Chinese Clinical Trial Registry (number ChiCTR-IOR-17011671).

Lesions of the central nervous system in leukemia: Pathological and magnetic resonance imaging features at presentation in 14 patients

The present study aimed to characterize the specific pathology and magnetic resonance imaging (MRI) findings observed in patients with leukemia with central nervous system (CNS) lesions, and to determine their value in the management of such patients. Lesions of the CNS were observed during and following treatment of leukemia. The data from stereotactic biopsy-proven pathology (12 patients) and MRI examinations (14 patients) were retrospectively evaluated. Proton-magnetic resonance-spectroscopy was performed in three patients. Factors that predisposed to lesions of the CNS were reviewed from the patient medical records. Among the 14 patients, eight had CNS leukemia, four had a CNS infection and two had a neurodegenerative disorder (one leukoencephalopathy and one glial cell hyperplasia). The clinical diagnosis based on clinical symptoms, signs and MRI features was not consistent with the pathological diagnosis in two patients. In one patient, the clinical diagnosis was a CNS infection; however, the patient's pathological diagnosis was CNS leukemia. In the other patient, the clinical diagnosis was CNS leukemia, but the pathological diagnosis was glial cell hyperplasia. CNS lesions in leukemia have a wide range of causes. Apart from the relapse of leukemia in the CNS, there are treatment-associated neurotoxicities and infections that are caused by immunocompromised states. As numerous leukemia-associated CNS lesions are treatable, early diagnosis is essential.

Therapies on the horizon for childhood acute lymphoblastic leukemia

PURPOSE OF REVIEW

The prognosis for children with the most common childhood malignancy, acute lymphoblastic leukemia (ALL), has improved dramatically. However, the burden of therapy can be substantial, with long-term side-effects, and certain subgroups continue to have a poor outcome.

RECENT FINDINGS

The recent discovery of new genetic alterations in high-risk subsets provides targets for precision medicine-based interventions using existing Food and Drug Administration approved agents. Novel immunotherapeutic approaches are being deployed in relapsed ALL, one of the leading causes of cancer cell death in children. Moreover, genomic analysis has charted the evolution of tumor subclones, and relapse-specific alterations now provide a mechanistic explanation for drug resistance, setting the stage for targeted therapy. There is greater recognition that host factors - genetic polymorphisms - influence cancer risk, response to therapy, and toxicity. In the future, it is anticipated that they will be integrated into clinical decision making to maximize cure and minimize side-effects. Recent efforts to limit prophylactic central nervous system irradiation have been successful, thereby sparing many children late neurocognitive impairments.

SUMMARY

Integration of advances in precision medicine approaches and novel agents will continue to increase the cure rate and decrease the burden of therapy for childhood ALL.

Myosin-IIA regulates leukemia engraftment and brain infiltration in a mouse model of acute lymphoblastic leukemia

Leukemia dissemination (the spread of leukemia cells from the bone marrow) and relapse are associated with poor prognosis. Often, relapse occurs in peripheral organs, such as the CNS, which acts as a sanctuary site for leukemia cells to escape anti-cancer treatments. Similar to normal leukocyte migration, leukemia dissemination entails migration of cells from the blood circulation into tissues by extravasation. To extravasate, leukemia cells cross through vascular endothelial walls via a process called transendothelial migration, which requires cytoskeletal remodeling. However, the specific molecular players in leukemia extravasation are not fully known. We examined the role of myosin-IIA a cytoskeletal class II myosin motor protein, in leukemia progression and dissemination into the CNS by use of a mouse model of Bcr-Abl-driven B cell acute lymphoblastic leukemia. Small hairpin RNA-mediated depletion of myosin-IIA did not affect apoptosis or the growth rate of B cell acute lymphoblastic leukemia cells. However, in an in vivo leukemia transfer model, myosin-IIA depletion slowed leukemia progression and prolonged survival, in part, by reducing the ability of B cell acute lymphoblastic leukemia cells to engraft efficiently. Finally, myosin-IIA inhibition, either by small hairpin RNA depletion or chemical inhibition by blebbistatin, drastically reduced CNS infiltration of leukemia cells. The effects on leukemia cell entry into tissues were mostly a result of the requirement for myosin-IIA to enable leukemia cells to complete the transendothelial migration process during extravasation. Overall, our data implicate myosin-IIA as a key mediator of leukemia cell migration, making it a promising target to inhibit leukemia dissemination in vivo and potentially reduce leukemia relapses.

Isolated central nervous system relapse of acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common form of childhood cancer and may exhibit central nervous system (CNS) involvement. Advances in chemotherapy and effective CNS prophylaxis have significantly decreased the incidence of CNS relapse of ALL to 5-10%. Here, we report the case of a patient with isolated CNS relapse of standard risk group pre-B-cell type ALL in an 11-year-old girl, relapsed 3 years after successful completion of chemotherapy. An 11-year-old girl visited our hospital complaining of headache, dizziness, vomiting, and visual field defects. Neurological examination revealed left-side homonymous hemianopsia. Brain magnetic resonance imaging showed a large irregular dural-based sulcal hematoma in the right parietal and occipital lobes. Surgery to remove the hematoma revealed the existence of hematopoietic malignancy after pathologic evaluation. Bone marrow biopsy was subsequently performed but showed no evidence of malignancy.

MIP-1α enhances Jurkat cell transendothelial migration by up-regulating endothelial adhesion molecules VCAM-1 and ICAM-1

The aim of this study is to evaluate the expression of macrophage inflammatory protein-1α (MIP-1α) in Jurkat cells and its effect on transendothelial migration. In the present study, human acute lymphoblastic leukemia Jurkat cells (Jurkat cells) were used as a model of T cells in human T-cell acute lymphoblastic leukemia (T-ALL), which demonstrated significantly higher MIP-1α expression compared with that in normal T-cell controls. The ability of Jurkat cells to cross a human brain microvascular endothelial cell (HBMEC) monolayer was almost completely abrogated by MIP-1α siRNA. In addition, the overexpression of MIP-1α resulted in the up-regulated expression of endothelial adhesion molecules, which enhanced the migration of Jurkat cells through a monolayer of HBMEC. MIP-1α levels in Jurkat cells appeared to be an important factor for its transendothelial migration, which may provide the theoretical basis to understand the mechanisms of brain metastases of T-ALL at cellular and molecular levels.

Focused ultrasound-induced blood-brain barrier disruption enhances the delivery of cytarabine to the rat brain

To investigate the feasibility of using focused ultrasound (FUS) with microbubbles for targeted delivery of cytarabine to the brain. Sprague-Dawly rats (weighing 200-250 g) received focused ultrasound with intravenous injection microbubbles. At 0, 2, 4, 8, and 24 hours (n=5 for each time point) after sonication, animals received intravenous administration of cytarabine at a normal dose of 4 mg/kg body weight. Additional five rats were given with a high dose (50 mg/kg body weight) of cytarabine alone. Blood-brain barrier (BBB) permeability and cerebral cytarabine were determined. FUS in conjunction with microbubbles caused a transient BBB opening. Sonication exposure promoted cytarabine accumulation at the sonicated site. Animals injected with a normal dose of cytarabine 2 hours after sonication had similar concentrations of cerebral cytarabine compared to those with higher cytarabine without sonication. FUS can temporarily open the BBB and thus facilitate the penetration of systemic cytarabine into the brain.