Managing CNS disease in adults with acute lymphoblastic leukemia

Neurological manifestations in dogs with acute leukemia

Canine acute leukemia is a rare hematopoietic neoplasm. Neurological abnormalities have been frequently reported in dogs with acute leukemia (AL). However, the description of the presentation and findings are limited. This study aimed to describe the clinical findings in dogs with acute leukemia presenting with neurological signs as their primary complaint. The database of a private referral hospital was searched for cases that presented to the neurological department with neurological deficits and were subsequently diagnosed with acute leukemia. Six cases were included; all had neurological clinical signs and an abnormal neurological examination. All cases had a focal neuroanatomical localisation on neurological examination (brain n = 4; spinal = 2). Out of the four dogs with a complete magnetic resonance imaging (MRI) study, there was an ill-defined infiltrative pattern with abnormal signal intensity in the central nervous system (CNS) in three dogs and the loss of grey and white matter differentiation in the brain (n = 2) and/or spinal cord (n = 2). Other MRI findings included abnormal meningeal enhancement (n = 3), changes affecting spinal nerves and epaxial muscles (n = 2), and lymphadenopathy in the field of view (n = 2). The bone marrow assessment on MRI showed evidence of signal change (n = 3), characterized by a loss of normal fat opacity and an abnormal degree of contrast enhancement. The cerebrospinal fluid (CSF) analysis of the four dogs showed an increased protein level with non-specific pleocytosis and without evidence of malignant cells. Treatment with cytotoxic medication was implemented in two dogs. The dogs diagnosed with acute leukemia had focal neuroanatomical localisation, an infiltrative CNS pattern, and bone marrow remodulation on MRI with an increase in CSF protein and negative cytology analysis.

Advances in CAR-T-cell therapy in T-cell malignancies

Significant advances have been made in chimeric antigen receptor T (CAR-T)-cell therapy for the treatment of recurrent or refractory B-cell hematologic malignancies. However, CAR-T-cell therapy has not yet achieved comparable success in the management of aggressive T-cell malignancies. This article reviews the challenges of CAR-T-cell therapy in treating T-cell malignancies and summarizes the progress of preclinical and clinical studies in this area. We present an analysis of clinical trials of CAR-T-cell therapies for the treatment of T-cell malignancies grouped by target antigen classification. Moreover, this review focuses on the major challenges encountered by CAR-T-cell therapies, including the nonspecific killing due to T-cell target antigen sharing and contamination with cell products during preparation. This review discusses strategies to overcome these challenges, presenting novel therapeutic approaches that could enhance the efficacy and applicability of CAR-T-cell therapy in the treatment of T-cell malignancies. These ideas and strategies provide important information for future studies to promote the further development and application of CAR-T-cell therapy in this field.

Management of ALL in adults: 2024 ELN recommendations from a European expert panel

ABSTRACT

Experts from the European Leukemia Net (ELN) working group for adult acute lymphoblastic leukemia have identified an unmet need for guidance regarding management of adult acute lymphoblastic leukemia (ALL) from diagnosis to aftercare. The group has previously summarized their recommendations regarding diagnostic approaches, prognostic factors, and assessment of ALL. The current recommendation summarizes clinical management. It covers treatment approaches, including the use of new immunotherapies, application of minimal residual disease for treatment decisions, management of specific subgroups, and challenging treatment situations as well as late effects and supportive care. The recommendation provides guidance for physicians caring for adult patients with ALL which has to be complemented by regional expertise preferably provided by national academic study groups.

Nuanced Management of a Skull Base Tumor in the Setting of Relapsed Acute Lymphoblastic Leukemia

Introduction  Relapsed acute lymphoblastic leukemia (ALL) involving the central nervous system (CNS) is a significant issue that contributes to both morbidity and mortality. Given the poor outcomes in patients with CNS relapse, understanding how ALL involving intracranial relapse presents and is treated is critical. Here, we present a complex case of relapsed recurrent ALL in a pediatric patient. Case Report  An 11-year-old patient presented with double relapse of ALL in the form of an extensive skull base lesion and again with leptomeningeal disease. For the skull base lesion, she was treated nonsurgically with chemotherapy and radiation, which led to a remarkable reduction in the size of the lesion. However, she was found to have early recurrence with leptomeningeal enhancement resulting in hydrocephalus 5 months after completing therapy. A shunt was placed successfully. Currently, she is being managed with monthly intrathecal chemotherapy with cerebrospinal fluid sampling and bone marrow biopsies every 2 months. Discussion  We report the significant effect of chemotherapy and radiotherapy in reducing the size of the extensive skull base lesion, saving the patient from the risks associated with surgery. This patient's initial relapse, with a large skull base lesion that had intracranial involvement, is an unusual presentation of relapsed ALL. The additional early recurrence of leptomeningeal disease further makes this case unique and the management even more nuanced. Here, we demonstrate a multidisciplinary approach for the successful treatment of our patient, which can help guide the management of similar patients in the future.

Management of adult acute lymphoblastic leukemia in the Gulf Cooperation Council (GCC) countries: A consensus report from the GCC Adult ALL Working Group

Leukemia burden is growing in the Gulf Council Cooperation (GCC) countries. Nonetheless, there is no unified protocol for managing adult acute lymphoblastic leukemia (ALL) patients in the GCC-countries. Therefore, the GCC Adult-ALL Treaters working group developed this consensus to address the adult-ALL treatment protocols in the GCC-countries and related toxicities' management. Besides, the consensus aimed to highlight the current unmet needs and treatment gaps and provide recommendations to optimize adult-ALL care and patient-centered communication. A three-step modified Delphi method to develop evidence-based recommendations through two-voting rounds and in-between virtual meetings are used in the manuscript development. A 12 experts' panel from five GCC-countries and two international experts were invited to participate in this consensus. This consensus consisted of 35-statements that highlighted the experts' recommendations to optimize ALL adults' care in the first line setting and manage pediatric or pediatric-inspired regimens-related toxicities. Besides, guidance was provided for future research direction and improve patient-centered communication. In conclusion, the adult-ALL management landscape is evolving, and the current evidence highlights better response and survival outcomes with pediatric or pediatric-inspired regiments. Therefore, protocols are needed to optimize the adult-ALL management in the GCC and tailored clinical-trials findings according to the GCC patients' characteristics and local-healthcare infrastructure.

Sequential autologous CAR-T and allogeneic CAR-T therapy successfully treats central nervous system involvement relapsed/refractory ALL: a case report and literature review

Background

The central nervous system (CNS) is the most common site of extramedullary invasion in acute lymphoblastic leukemia (ALL), and involvement of the CNS is often associated with relapse, refractory disease, and poor prognosis. Chimeric antigen receptor-T (CAR-T) cell therapy, a promising modality in cancer immunotherapy, has demonstrated significant advantages in the treatment of hematological malignancies. However, due to associated adverse reactions such as nervous system toxicity, the safety and efficacy of CAR-T cell therapy in treating CNSL remains controversial, with limited reports available.

Case report

Here, we present the case of a patient with confirmed B-ALL who experienced relapse in both bone marrow (BM) and cerebrospinal fluid (CSF) despite multiple cycles of chemotherapy and intrathecal injections. The infusion of autologous CD19 CAR-T cells resulted in complete remission (CR) in both BM and CSF for 40 days. However, the patient later experienced a relapse in the bone marrow. Subsequently, allogeneic CD19 CAR-T cells derived from her brother were infused, leading to another achievement of CR in BM. Significantly, only grade 1 cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) events were detected during the treatment period and showed improvement with symptomatic management. During subsequent follow-up, the patient achieved a disease-free survival of 5 months and was successfully bridged to hematopoietic stem cell transplantation.

Conclusion

Our study provides support for the argument that CNS involvement should not be deemed an absolute contraindication to CAR-T cell therapy. With the implementation of suitable management and treatment strategies, CAR-T therapy can proficiently target tumor cells within the CNS. This treatment option may be particularly beneficial for relapsed or refractory patients, as well as those with central nervous system involvement who have shown limited response to conventional therapies. Additionally, CAR-T cell therapy may serve as a valuable bridge to allogeneic hematopoietic stem cell transplantation (allo-HSCT) in these patients.

Diagnostic and therapeutic advances in adults with acute lymphoblastic leukemia in the era of gene analysis and targeted immunotherapy

Acute lymphoblastic leukemia (ALL) is one of the most rapidly changing hematological malignancies with advanced understanding of the genetic landscape, detection methods of minimal residual disease (MRD), and the development of immunotherapeutic agents with good clinical outcomes. The annual incidence of adult ALL in Korea is 300-350 patients per year. The WHO classification of ALL was revised in 2022 to reflect the molecular cytogenetic features and suggest new adverse- risk subgroups, such as Ph-like ALL and ETP-ALL. We continue to use traditional adverse-risk features and cytogenetics, with MRD-directed post-remission therapy including allogeneic hematopoietic cell transplantation. However, with the introduction of novel agents, such as ponatinib, blinatumomab, and inotuzumab ozogamicin incorporated into frontline therapy, good MRD responses have been achieved, and overall survival outcomes are improving. Accordingly, some clinical trials have suggested a possible era of chemotherapy-free or transplantation-free approaches in the near future. Nevertheless, relapse of refractory ALL still occurs, and some poor ALL subtypes, such as Ph-like ALL and ETP-ALL, are unsolved problems for which novel agents and treatment strategies are needed. In this review, we summarize the currently applied diagnostic and therapeutic practices in the era of advanced genetic analysis and targeted immunotherapies in United States and Europe and introduce real-world Korean data.

Philadelphia chromosome-positive acute lymphoblastic leukemia presenting with bilateral serous retinal detachment: A case report and review of the literature

We report a case who presented with bilateral serous retinal detachment (SRD) as the initial sign of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). A 49-year-old female presented with blurred vision. A colored fundus image of the patient revealed SRD around the posterior pole’s optic disc. Bone marrow aspiration showed infiltration with lymphoblasts. The patient was diagnosed with Ph+ ALL. SRD regressed in the color fundus image of the patient after induction chemotherapy and intrathecal methotrexate. The patient’s visual symptoms completely regressed. In conclusion, acute leukemia should be considered in the differential diagnosis of cases presenting with SRD.

Deep learning enhances acute lymphoblastic leukemia diagnosis and classification using bone marrow images

Acute lymphoblastic leukemia (ALL) poses a significant health challenge, particularly in pediatric cases, requiring precise and rapid diagnostic approaches. This comprehensive review explores the transformative capacity of deep learning (DL) in enhancing ALL diagnosis and classification, focusing on bone marrow image analysis. Examining ten studies conducted between 2013 and 2023 across various countries, including India, China, KSA, and Mexico, the synthesis underscores the adaptability and proficiency of DL methodologies in detecting leukemia. Innovative DL models, notably Convolutional Neural Networks (CNNs) with Cat-Boosting, XG-Boosting, and Transfer Learning techniques, demonstrate notable approaches. Some models achieve outstanding accuracy, with one CNN reaching 100% in cancer cell classification. The incorporation of novel algorithms like Cat-Swarm Optimization and specialized CNN architectures contributes to superior classification accuracy. Performance metrics highlight these achievements, with models consistently outperforming traditional diagnostic methods. For instance, a CNN with Cat-Boosting attains 100% accuracy, while others hover around 99%, showcasing DL models' robustness in ALL diagnosis. Despite acknowledged challenges, such as the need for larger and more diverse datasets, these findings underscore DL's transformative potential in reshaping leukemia diagnostics. The high numerical accuracies accentuate a promising trajectory toward more efficient and accurate ALL diagnosis in clinical settings, prompting ongoing research to address challenges and refine DL models for optimal clinical integration.

Intrathecal chemotherapy for the management of lymphoblastic lymphoma in a 4-year-old dog: a case report

Intrathecal chemotherapy is used in human medicine for the treatment or prophylaxis of CNS hematopoietic neoplasia. However, the clinical benefits in veterinary medicine have been scarcely documented. A 4-year-old male entire cross-breed dog presented with a 24-h history of severe lethargy, pelvic limb weakness, and urinary retention. Examination revealed generalized peripheral lymphadenomegaly, and the neurological findings were suggestive of a myelopathy in the region of T3-L3. Following the diagnosis of multicentric lymphoblastic B-cell lymphoma (stage Vb), a modified L-LOP with cytosine arabinoside was started, and complete clinical remission was achieved. After 4 weeks, there was acute neurological deterioration (spinal pain and proprioceptive deficits) without peripheral lymphadenomegaly. MRI findings and CSF analysis were consistent with meningeal and spinal cord lymphoma infiltration at the level of L3. Intrathecal chemotherapy (cytosine arabinoside and methotrexate) were administered in the cisterna magna with systemic dexamethasone and analgesia. Clinical signs were resolved within 24 h, and the patient remained asymptomatic for 3.5 weeks. After this period, CNS relapse (proprioceptive deficits and severe thoracolumbar pain) was suspected, and repeat intrathecal chemotherapy was declined. The patient was humanely euthanized 9 weeks after the initial diagnosis. This is the first report on the clinical benefit of intrathecal chemotherapy with a combination of methotrexate and cytarabine for the management of CNS lymphoma in dogs. Based on our case, intrathecal chemotherapy with methotrexate and cytarabine can induce a short-lasting CNS clinical remission (3 weeks).

Diagnosis and management of adult central nervous system leukemia

Central nervous system leukemia (CNSL) is a prominent infiltration reason for therapy failing in acute leukemia. Recurrence rates and the prognosis have alleviated with current prophylactic regimens. However, the accurate stratification of relapse risk and treatment regimens for relapsed or refractory patients remain clinical challenges yet to be solved. Recently, with hematopoietic stem cell transplantation (HSCT) and chimeric antigen receptor-T (CAR-T) cellular therapy showing encouraging effects in some CNSL patients, advances in treating CNSL have already been reported. The development of molecular targeted agents as well as antibody-based drugs will provide patients with more personalized treatment. This article summarized recent research developments about risk factors, diagnosis, prevention, and treatment in adults with CNSL.

Mesenchymal Stem Cells and Myeloid-Derived Suppressor Cells Interplay in Adjuvant-Induced Arthritis Rat Model

There has not been much researchs on the biological relationship between myeloid-derived suppressor cells (MDSCs) and mesenchymal stem cells (MSCs). The goal of the current work is to examine how these cells cooperate with one another in a rat model of adjuvant-induced arthritis (AIA). Three groups of equal numbers of rats were created; the first group served as the control. Complete Freund's adjuvant (CFA) was injected into the second group to induce AIA. The third group underwent MSCstreatment. Three weeks later, ANA, IL-1β, IL-4, IL-6, IL-10, TNF-α, IFN-γ, M-CSF, iNOS and Arg-1 were determined using ELISA. Flowcytometric studies for MDSCs using CD11bc + and His48 + antibodies were performed. Current results showed significantly higher levels of WBCs, ANA, IL-1, IL-4, IL-6, IL-10, TNF-α, M-CSF, iNOS and Arg-1 along with a significant rise in MDSCs % in the AIA group compared to the control group. As opposed to AIA animals, MSCs administration resulted in a considerable improvement in cytokine levels, supporting the immunomodulation function of MSCs. Histological examination of the joints in the AIA group revealed articular cartilage degradation as well as infiltration of inflammatory cells and fibroplasia. These several evidences suggested that MDSCs may perform various roles in autoimmunity. Understanding how MDSCs and MSCs contribute to arthritis may help their prospective application in immunotherapy. Therefore, the reciprocal collaboration of MSCs and MDSCs must therefore be the subject of new investigations, which can offer new platforms for the development of more effective and individualized therapies for the treatment of immunological illnesses.

Effects of isolated central nervous system involvement evaluated by multiparameter flow cytometry prior to allografting on outcomes of patients with acute lymphoblastic leukemia

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a major strategy to cure patients with acute lymphoblastic leukemia (ALL). The aim of this study was to evaluate whether isolated flow cytometry (FCM)-positive central nervous system (CNS) involvement before allo-HSCT is clinically significant.

Methods

The effects of isolated FCM-positive CNS involvement prior to transplantation on the outcomes of 1406 ALL patients with complete remission (CR) were retrospectively investigated.

Results

Patients were classified into isolated FCM-positive CNS involvement (n=31), cytology-positive CNS involvement (n = 43), and negative CNS involvement (n = 1332) groups. Among the three groups, the 5-year cumulative incidence of relapse (CIR) values were 42.3%, 48.8%, and 23.4%, respectively (P<0.001). The 5-year leukemia-free survival (LFS) values were 44.7%, 34.9%, and 60.8%, respectively (P<0.001). Compared with the negative CNS group (n=1332), the 5-year CIR of the pre-HSCT CNS involvement group (n=74) was higher (46.3% vs. 23.4%, P<0.001], and the 5-year LFS was inferior (39.1% vs. 60.8%, P<0.001). Multivariate analysis indicated that four variables, T-cell ALL, in second complete remission or beyond (CR2+) at HSCT, pre-HSCT measurable residual disease positivity, and pre-HSCT CNS involvement, were independently associated with a higher CIR and inferior LFS. A new scoring system was developed using the following four variables: low-risk, intermediate-risk, high-risk, and extremely high-risk groups. The 5-year CIR values were 16.9%, 27.8%, 50.9%, and 66.7%, respectively (P<0.001), while the 5-year LFS values were 67.6%, 56.9%, 31.0%, and 13.3%, respectively (P<0.001).

Conclusion

Our results suggest that ALL patients with isolated FCM-positive CNS involvement are at a higher risk of recurrence after transplantation. Patients with pre-HSCT CNS involvement had higher CIR and inferior survival outcomes.

How I prevent and treat central nervous system disease in adults with acute lymphoblastic leukemia

The central nervous system (CNS) is the most important site of extramedullary disease in adults with acute lymphoblastic leukemia (ALL). Although CNS disease is identified only in a minority of patients at the time of diagnosis, subsequent CNS relapses (either isolated or concurrent with other sites) occur in some patients even after the delivery of prophylactic therapy targeted to the CNS. Historically, prophylaxis against CNS disease has included intrathecal (IT) chemotherapy and radiotherapy (RT), although the latter is being used with decreasing frequency. Treatment of a CNS relapse usually involves intensive systemic therapy and cranial or craniospinal RT along with IT therapy and consideration of allogeneic hematopoietic cell transplant. However, short- and long-term toxicities can make these interventions prohibitively risky, particularly for older adults. As new antibody-based immunotherapy agents have been approved for relapsed/refractory B-cell ALL, their use specifically for patients with CNS disease is an area of keen interest not only because of the potential for efficacy but also concerns of unique toxicity to the CNS. In this review, we discuss data-driven approaches for these common and challenging clinical scenarios as well as highlight how recent findings potentially support the use of novel immunotherapeutic strategies for CNS disease.

The evolution of acute lymphoblastic leukemia research and therapy at MD Anderson over four decades

Progress in the research and therapy of adult acute lymphoblastic leukemia (ALL) is accelerating. This analysis summarizes the data derived from the clinical trials conducted at MD Anderson between 1985 and 2022 across ALL subtypes. In Philadelphia chromosome-positive ALL, the addition of BCR::ABL1 tyrosine kinase inhibitors (TKIs) to intensive chemotherapy since 2000, improved outcomes. More recently, a chemotherapy-free regimen with blinatumomab and ponatinib resulted in a complete molecular remission rate of 85% and an estimated 3-year survival rate of 90%, potentially reducing the role of, and need for allogeneic stem cell transplantation (SCT) in remission. In younger patients with pre-B Philadelphia chromosome-negative ALL, the integration of blinatumomab and inotuzumab into the frontline therapy has improved the estimated 3-year survival rate to 85% across all risk categories. Our future strategy is to evaluate the early integration of both immunotherapy agents, inotuzumab and blinatumomab, with low-dose chemotherapy (dose-dense mini-Hyper-CVD-inotuzumab-blinatumomab) into the frontline setting followed by CAR T cells consolidation in high-risk patients, without any further maintenance therapy. In older patients, using less intensive chemotherapy (mini-Hyper-CVD) in combination with inotuzumab and blinatumomab has improved the 5-year survival rate to 50%. Among patients ≥ 65-70 years, the mortality in complete remission (CR) is still high and is multifactorial (old age, death in CR with infections, development of myelodysplastic syndrome or acute myeloid leukemia). A chemotherapy-free regimen with inotuzumab and blinatumomab is being investigated. The assessment of measurable residual disease (MRD) by next-generation sequencing (NGS) is superior to conventional assays, with early MRD negativity by NGS being associated with the best survival. We anticipate that the future therapy in B-ALL will involve less intensive and shorter chemotherapy regimens in combination with agents targeting CD19 (blinatumomab), CD20, and CD22 (inotuzumab). The optimal timing and use of CAR T cells therapy may be in the setting of minimal disease, and future trials will assess the role of CAR T cells as a consolidation among high-risk patients to replace allogeneic SCT. In summary, the management of ALL has witnessed significant progress during the past four decades. Novel combination regimens including newer-generation BCR::ABL1 TKIs and novel antibodies are questioning the need and duration of intensive chemotherapy and allogeneic SCT.

Differential Expression of LLT1, SLAM Receptors CS1 and 2B4 and NCR Receptors NKp46 and NKp30 in Pediatric Acute Lymphoblastic Leukemia (ALL)

Acute lymphoblastic leukemia (ALL) represents the most common pediatric cancer. Most patients (85%) develop B-cell ALL; however, T-cell ALL tends to be more aggressive. We have previously identified 2B4 (SLAMF4), CS1 (SLAMF7) and LLT1 (CLEC2D) that can activate or inhibit NK cells upon the interaction with their ligands. In this study, the expression of 2B4, CS1, LLT1, NKp30 and NKp46 was determined. The expression profiles of these immune receptors were analyzed in the peripheral blood mononuclear cells of B-ALL and T-ALL subjects by single-cell RNA sequencing data obtained from the St. Jude PeCan data portal that showed increased expression of LLT1 in B-ALL and T-ALL subjects. Whole blood was collected from 42 pediatric ALL subjects at diagnosis and post-induction chemotherapy and 20 healthy subjects, and expression was determined at the mRNA and cell surface protein level. A significant increase in cell surface LLT1 expression in T cells, monocytes and NK cells was observed. Increased expression of CS1 and NKp46 was observed on monocytes of ALL subjects at diagnosis. A decrease of LLT1, 2B4, CS1 and NKp46 on T cells of ALL subjects was also observed post-induction chemotherapy. Furthermore, mRNA data showed altered expression of receptors in ALL subjects pre- and post-induction chemotherapy treatment. The results indicate that the differential expression of the receptors/ligand may play a role in the T-cell- and NK-cell-mediated immune surveillance of pediatric ALL.

Incidence, treatment and outcome of central nervous system relapse in adult acute lymphoblastic leukaemia patients treated front-line with paediatric-inspired regimens: A retrospective multicentre Campus ALL study

Within the Campus ALL network we analyzed the incidence, characteristics, treatment and outcome of a central nervous system (CNS) relapse in 1035 consecutive adult acute lymphoblastic leukemia (ALL) patients treated frontline with pediatric-inspired protocols between 2009 and 2020. Seventy-one patients (6.8%) experienced a CNS recurrence, more frequently in T- (28/278; 10%) than in B-ALL (43/757; 5.7%) (p = 0.017). An early CNS relapse-< 12 months from diagnosis-was observed in 41 patients. In multivariate analysis, risk factors for early CNS relapse included T-cell phenotype (p = <0.001), hyperleucocytosis >100 × 10⁹ /L (p<0.001) and male gender (p = 0.015). Treatment was heterogeneous, including chemotherapy, radiotherapy, intrathecal therapy and novel agents. A complete remission (CR) was obtained in 39 patients (55%) with no differences among strategies. After CR, 26 patients underwent an allogenic transplant, with a significant overall survival benefit compared to non-transplanted patients (p = 0.012). After a median observation of 8 months from CNS relapse, 23 patients (32%) were alive. In multivariate analysis, the time to CNS relapse was the strongest predictor of a lower 2-year post-relapse survival (p<0.001). In conclusion, in adult ALL the outcome after a CNS relapse remains very poor. Effective CNS prophylaxis remains the best approach and allogenic transplant should be pursued when possible.

Post-Hematopoietic Cell Transplantation Relapsed Acute Lymphoblastic Leukemia: Current Challenges and Future Directions

Allogeneic hematopoietic cell transplantation (allo-HCT) represents an important and potentially curative treatment option for adult patients with acute lymphoblastic leukemia. Relapse continues to remain the most important factor influencing overall survival post allo-HCT. We discuss early identification, clinical manifestations, and management of relapsed disease. Routine evaluation of measurable residual disease (MRD) and change in donor chimerism play a crucial role in early detection. Pivotal clinical trials have led to FDA approval of multiple novel agents like blinatumomab and inotuzumab. Combining targeted therapy with cellular immunotherapy serves as the backbone for prolonging overall survival in these patients. Donor lymphocyte infusions have traditionally been used in relapsed disease with suboptimal outcomes. This review provides insight into use of cellular therapy in MRD positivity and decreasing donor chimerism. It also discusses various modalities of combining cellular therapy with novel agents and discussing the impact of chimeric antigen receptor T-cell therapy in the setting of post allo-HCT relapse both as consolidative therapy and as a bridge to second transplant.

Case Report: Blinatumomab therapy for the treatment of B-cell acute lymphoblastic leukemia patients with central nervous system infiltration

The treatment of B-cell acute lymphoblastic leukemia (B-ALL) with central nervous system (CNS) involvement poses a significant clinical challenge because most chemotherapeutic agents exhibit weak permeability to the blood-brain barrier (BBB). In addition, current anti-CNS leukemia treatments often bring short or long-term complications. Immunotherapy including chimeric antigen T-cell therapy and bispecific antibody have shown profound treatment responses in relapsed/refractory B-ALL. However, there is a lack of data on the efficacy of bispecific antibody in treating B-ALL with CNS involvement. Here, we report two ALL patients with CNS leukemia who received blinatumomab. Case 1 was diagnosed with chronic myeloid leukemia in lymphoid blast phase. The patient developed CNS leukemia and bone marrow relapse during the treatment with dasatinib. Case 2 was diagnosed with B-ALL and suffered early hematologic relapse and cerebral parenchyma involvement. After treatment with one cycle of blinatumomab, both patients achieved complete remission in the bone marrow and CNS. Furthermore, this is the first report on the efficacy of blinatumomab in treating CNS leukemia with both of the cerebral spinal fluid and the cerebral parenchymal involvement. Our results suggest that blinatumomab might be a potential option for the treatment of CNS leukemia.

Optimizing Management of the Central Nervous System in Patients with Acute Lymphoblastic Leukemia Undergoing Allogeneic Stem Cell Transplantation

Purpose

To evaluate clinical outcomes and patterns of failure, specifically in regards to the central nervous system (CNS), in patients with acute lymphoblastic leukemia (ALL) undergoing allogeneic hematopoietic stem cell transplantation (HSCT) using total body irradiation (TBI)-based conditioning regimens.

Methods and Materials

All adult patients (aged ≥18 years) with ALL undergoing allogeneic HSCT using TBI-based conditioning regimens treated from 1995 to 2020 at Duke University Medical Center were evaluated. Various patient, disease, and treatment-related factors were collected, including CNS prophylaxis and treatment interventions. Clinical outcomes, including freedom from CNS relapse, were calculated using the Kaplan-Meier method for patients with and without CNS disease at presentation.

Results

One hundred and fifteen patients with ALL were included the analysis (myeloablative, 110; nonmyeloablative, 5). Of the 110 patients undergoing a myeloablative regimen, most (n = 100) did not have CNS disease before transplant. For this subgroup, peritransplant intrathecal chemotherapy was administered in 76% (median of 4 cycles) and 10 received a radiation boost to the CNS (cranial irradiation, 5; craniospinal, 5). Only 4 failed in the CNS after transplant, none of whom received a CNS boost, with freedom from CNS relapse at 5 years of 95% (95% confidence interval (CI), 84-98%). Freedom from CNS relapse was not improved with a radiation therapy boost to the CNS (100% vs 94%, P = .59). Overall survival, leukemia-free survival, and nonrelapse mortality at 5 years were 50%, 42%, and 36%, respectively. Among the 10 patients with CNS disease before transplant, 10 of 10 received intrathecal chemotherapy and 7 received a radiation boost to the CNS (cranial irradiation, 1; craniospinal, 6) and none subsequently failed in the CNS. A nonmyeloablative HSCT was pursued for 5 patients because of advanced age or comorbidities. None of these patients had prior CNS disease or received a CNS or testicular boost, and none failed in the CNS after transplant.

Conclusions

A CNS boost may not be necessary in patients with high-risk ALL without CNS disease undergoing a myeloablative HSCT using a TBI-based regimen. Favorable outcomes were observed with a low-dose craniospinal boost in patients with CNS disease.

Changing Landscape in the Treatment of Adult Acute Lymphoblastic Leukemia (ALL)

Acute lymphoblastic leukemia (ALL) is a rare hematological malignancy characterized by proliferation and accumulation of premature lymphoid blasts. Depending on risk factors, the survival of acute lymphoblastic leukemia has significantly improved over the last decades. During the last years, measurable residual disease (MRD) assessment has evolved into one of the most sensitive markers for prognosis and risk of relapse. For this reason, measurable residual disease detection and monitoring count as standard evaluation in patients with acute lymphoblastic leukemia. Allogeneic stem cell transplantation is still the recommended treatment option for patients with high and highest risk profiles as well as for relapsed or refractory settings. The increased understanding of the pathomechanism and heterogeneity of acute lymphoblastic leukemia has led to the development of several novel therapeutic opportunities such as tyrosine-kinase inhibitors, antibody-based therapies and CAR-T cells with the aim of improving clinical outcomes. Furthermore, the major advances in disease understanding of ALL have led to the identification of different subgroups and better disease stratification. Even though novel therapy targets are constantly developed, acute lymphoblastic leukemia remains a challenging and life-threatening disease. To improve the historically unsatisfying result in therapy of adult acute lymphoblastic leukemia many clinical trials have recently been initiated to determine the optimum combination regimens of novel and old agents for adult acute lymphoblastic leukemia.

Physiologically based pharmacokinetic modeling of ponatinib to describe drug-drug interactions in patients with cancer

PURPOSE

This study aimed to investigate the drug-drug interactions of ponatinib with strong, moderate, or weak CYP3A4 inhibitors/inducers by developing physiologically based pharmacokinetic (PBPK) models.

METHODS

Simcyp^® Ver 20.1 (Certara Inc., Sheffield, UK) was used to construct a PBPK model for ponatinib and to predict its interaction with strong, moderate, or weak CYP3A4 inhibitors/inducers. The constructed model was validated by comparing predicted values with actual observed values. Inhibitors or inducers that increased or decreased the area under the plasma concentration curve of ponatinib by more than two-fold when used in combination were considered significant.

RESULTS

The PBPK model of ponatinib accurately represented its oral pharmacokinetics. It also reasonably predicted its pharmacokinetics when combined with ketoconazole and rifampicin. No weak to strong CYP3A4 inhibitor combinations significantly increased the AUC of ponatinib. However, the strong CYP3A4 inducers rifampicin (oral, 600 mg QD) and phenytoin (oral, 100 mg TID) decreased AUC by 60-70% and 50%, respectively.

CONCLUSIONS

The PBPK model predicted a significant drug interaction when ponatinib was combined with a strong CYP3A4 inducer. Conversely, the combination with weak-to-strong CYP3A4 inhibitors did not suggest a drug interaction with ponatinib.

Clinical Characteristics and Outcomes of Acute Lymphoblastic Leukemia in Adolescents and Young Adults in Malawi

There are limited data on treatment and outcomes for acute lymphoblastic leukemia (ALL) among adolescents and young adults in sub-Saharan Africa. We describe a prospective observational cohort in Malawi.

Malignant invasion of the cerebrospinal fluid in adult and paediatric patients with haematological and solid malignancies: a monocentric retrospective study

OBJECTIVES

In this study, we describe the clinical presentation, the cerebrospinal fluid (CSF) characteristics and outcome of children and adults with leptomeningeal invasion due to haematological and solid malignancies.

METHODS

Routine CSF samples analyzed from 2008 to 2018 at our institution were retrospectively reviewed for the presence of malignant cells based on cytomorphological analysis.

RESULTS

Leptomeningeal invasion was identified in 212 patients: 45 children versus 167 adults, and 92 haematological versus 120 solid malignancies. Leukaemic invasion in childhood was mainly due to ALL, and lymphoma invasion was often due to a high-grade B-cell lymphoma in adults. Metastatic invasion by solid tumours was almost exclusively seen in adults. Patients suffered most frequently from cranial neuropathy and headache (both 32%), while asymptomatic presentations were seen mainly in children (33%) and haematological malignancies (17%). Laboratory CSF parameters often showed an elevated WBC count (87%), total protein (74%) and lactate (76%) and a decreased glucose (77%). These deviations were especially found in solid malignancies (>84%) and adults (>82%). Brain and/or spinal cord imaging was more often suggestive for the leptomeningeal invasion in solid than in haematological malignancies (86% vs. 46%). The 5-year overall survival (OS) rates for patients with haematological and solid malignancies were 21.5% and 5.9%, respectively. The 5-year OS rate for children (55.6%) was significantly better than for adults (3.5%).

CONCLUSION

Leptomeningeal invasion is more often asymptomatic, and CSF parameters and imaging are more often normal in children and haematological malignancies than in adults and solid malignancies, possibly leading to underdiagnosis.

Pharmacotherapeutic management of T-cell acute lymphoblastic leukemia in adults: an update of the literature

INTRODUCTION

T-cell acute lymphoblastic leukemia (T-ALL) is a rare but potentially life-threatening heterogeneous hematologic malignancy that requires prompt diagnosis and treatment by hematologists. So far, therapeutic advances have been achieved in the management of this disease mainly by adopting pediatric-like regimens, and cure rates are significantly worse than in childhood. In T-ALL, less than 70% of adults achieve long-term survival. The prognosis after relapse is still very poor. Hence, there is urgent need to improve therapy of T-ALL by testing new compounds and combinations for the treatment of this disease.

AREAS COVERED

This review provides a comprehensive update on the most recent treatment approaches in adults with de novo and relapsed/refractory adult T-ALL.

EXPERT OPINION

Intensifying chemotherapy may reduce the incidence of recurrent disease in adult patients, but it has not come without a cost. Novel agents with selective T-ALL activity (e.g. nelarabine) may improve survival in some patient subsets. Due to modern genomic and transcriptomic techniques, various novel potential targets might change the treatment landscape in the next few years and will, hopefully alongside with cellular therapies, augment the therapeutic armamentarium in the near future.

Efficiency of anti-VEGF therapy in central nervous system AML relapse: A case report and literature review

There have been few reports on the treatment of central nervous system (CNS) acute myeloid leukemia (AML) relapse. This case study demonstrates that bevacizumab may be a viable treatment option when combined with IT chemotherapy as maintenance therapy for those with CNS leukemia.

Intrathecal methotrexate-induced aseptic meningitis in a patient with acute lymphoblastic leukemia

The central nervous system is often a site of spread for patients with acute lymphoblastic leukemia (ALL). ALL is often treated with ongoing intrathecal chemotherapy with the most common regimens including methotrexate and/or cytarabine. Uncommonly, intrathecal methotrexate has been associated with stroke-like symptoms. To the author’s knowledge, we present the first reported case of a patient who developed symptoms more akin to bacterial meningitis than stroke-like symptoms as a consequence of intrathecal methotrexate chemotherapy.

Prognostic significance of CNSL at diagnosis of childhood B-cell acute lymphoblastic leukemia: A report from the South China Children's Leukemia Group

OBJECTIVES

The prognostic significance of acute lymphoblastic leukemia (ALL) patients with central nervous system leukemia (CNSL) at diagnosis is controversial. We aimed to determine the impact of CNSL at diagnosis on the clinical outcomes of childhood B-cell ALL in the South China Children's Leukemia Group (SCCLG).

METHODS

A total of 1,872 childhood patients were recruited for the study between October 2016 and July 2021. The diagnosis of CNSL depends on primary cytological examination of cerebrospinal fluid, clinical manifestations, and imaging manifestations. Patients with CNSL at diagnosis received two additional courses of intrathecal triple injections during induction.

RESULTS

The frequency of CNLS at the diagnosis of B-cell ALL was 3.6%. Patients with CNSL at diagnosis had a significantly higher mean presenting leukocyte count (P = 0.002) and poorer treatment response (P <0.05) compared with non-CNSL patients. Moreover, CNSL status was associated with worse 3-year event-free survival (P = 0.030) and a higher risk of 3-year cumulative incidence of relapse (P = 0.008), while no impact was observed on 3-year overall survival (P = 0.837). Multivariate analysis revealed that CNSL status at diagnosis was an independent predictor with a higher cumulative incidence of relapse (hazard ratio = 2.809, P = 0.016).

CONCLUSION

CNSL status remains an adverse prognostic factor in childhood B-cell ALL, indicating that additional augmentation of CNS-directed therapy is warranted for patients with CNSL at diagnosis.

Successful Treatment of Refractory and Relapsed CNS Acute Lymphoblastic Leukemia With CD-19 CAR-T Immunotherapy: A Case Report

In recent decades, survival was significantly improved in B cell acute lymphoblastic leukemia (B-ALL) patients. But refractory and relapsed B-ALL still has aggressive clinical behavior and poor prognosis. Especially, the patients with central nervous system infiltration is very difficult to achieve complete remissions with routine treatment. Chimeric antigen receptor-modified T-cell therapy targeting CD-19 has shown to be a beneficial treatment approach in refractory and relapsed B cell acute lymphoblastic leukemia (r/r ALL). However, there are very few studies reporting to treatment of refractory and relapsed B cell ALL with central nervous system infiltration. Here, we reported one single case of a patient diagnosed with relapsed B cell ALL with CNS infiltration who was successfully treated by second generation CAR containing a co-stimulator CD28 or 4-1BB therapy. Long-term proliferation of CAR-T cells in peripheral blood and bone marrow was observed more than 18 months. After CAR-T treatment, the patient got toxicity of grade 1 cytokine release syndrome and achieved significantly 36 months event free survival of follow-up. It is suggested that CD-19 CAR containing CD28 or 4-1BB costimulatory may be an effective therapy in refractory and relapsed B cell ALL with central nervous system infiltration. Its toxicity is mild, and its safety is high.

Clinical Trial Registration:ClinicalTrials.gov Identifier: NCT02349698.

Prognostic factors for clinical outcomes of patients with central nervous system leukemia

Prognostic factors associated with clinical outcomes of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) patients with central nervous system (CNS) involvement are unknown. We retrospectively studied the characteristics and outcomes of 66 (18 pediatric and 48 adult) patients with CNS leukemia with ALL (n = 41) or AML (n = 25). The median age of patients at diagnosis of CNS leukemia was 30 (range, 1-69) years. Nearly two-third patients had CNS involvement at the initial diagnosis of leukemia. Complete remission of CNS leukemia was attained in 58 (88%) patients, and probability of overall survival at 36 months after the diagnosis of CNS leukemia was 43% for the entire cohort. We identified that achieving remission of systemic leukemia and having CNS leukemia diagnosed and treated before allogeneic transplantation were the factors associated with CNS leukemia remission. Prognostic factors associated with better overall survival in patients with CNS leukemia included pediatric age, diagnosis of CNS leukemia before receiving allogenic transplantation, achieving clearance of systemic or CNS leukemia, receiving no cranial radiation in conjunction with intrathecal chemotherapy (IT), and receiving IT consolidation after achieving remission of CNS leukemia. Our findings show that patients with CNS leukemia are at considerable risk of mortality. Awareness of modifiable prognostic factors such as avoidance of cranial radiation whenever possible and use of IT consolidation can result in improved outcomes in subset of patients with CNS leukemia.

Multiple cranial nerve palsies revealing blast crisis in patient with chronic myeloid leukemia in the accelerated phase under nilotinib during severe infection with SARS-COV-19 virus: Case report and review of literature

Since the introduction of tyrosine kinase inhibitors as primary therapy for patients with chronic myeloid leukemia (CML), the prognosis of these patients has improved significantly, and the number of patients who progress to the blast phase has decreased considerably. We report the case of a 35 year-old CML patient in accelerated phase treated with nilotinib, who presents a severe COVID-19 infection requiring non-invasive ventilation, and who subsequently presents a multiple cranial nerve palsy revealing a blast crisis of his CML. Multiple cranial nerve palsy is a sign of neurological involvement of CML in its blast phase. The blast crisis represents a real challenge for the clinician, especially during COVID-19 infection. The treatment remains the association of a tyrosine kinase inhibitors with a chemotherapy protocol, as well as the administration of methotrexate and cytarabine by intrathecal and intravenous infusion in high doses. Despite the importance of the association of CML with COVID-19 infection, there is not yet enough data to know the true impact of this infection on the evolution of this hemopathy.

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).

Pan-PI3Ki targets multiple B-ALL microenvironment interactions that fuel systemic and CNS relapse

The majority of adult patients with acute lymphoblastic leukemia (ALL) suffer relapse, and in patients with central nervous system (CNS) metastasis, prognosis is particularly poor. We recently demonstrated a novel route of ALL CNS metastasis dependent on PI3Kδ regulation of the laminin receptor integrin α6. B-ALL cells did not, however, rely on PI3Kδ signaling for growth. Here we show that broad targeting of PI3K isoforms can induce growth arrest in B-ALL, reducing systemic disease burden in mice treated with a single agent pan-PI3Ki, copanlisib. Moreover, we show that cellular stress activates PI3K/Akt-dependent survival pathways in B-ALL, exposing their vulnerability to PI3Kδ and pan-PI3Ki. The addition of a brief course of copanlisib to chemotherapy delivered the combined benefits of increased survival, decreased systemic disease, and reduced CNS metastasis. These data suggest the promising, multifaceted potential of pan-PI3Ki for B-ALL CNS prophylaxis, systemic disease control, and chemosensitization.

Opportunities and Challenges for Gut Microbiota in Acute Leukemia

Acute leukemia (AL) is a highly heterogeneous hematologic malignancy, and although great progress has been made in the treatment of AL with allogeneic hematopoietic stem cell transplantation (Allo-HSCT) and new targeted drugs, problems such as infection and GVHD in AL treatment are still serious. How to reduce the incidence of AL, improve its prognosis and reduce the side effects of treatment is a crucial issue. The gut microbiota plays an important role in regulating disease progression, pathogen colonization, and immune responses. This article reviews recent advances in the gut microbiota and AL pathogenesis, infection, treatment and its role in allo-HSCT.

Clinical utility of brain biopsy for presumed CNS relapse of systemic lymphoma

OBJECTIVE

The objective of this study was to determine the frequency with which brain biopsy for presumed CNS relapse of systemic hematological malignancies yields new, actionable diagnostic information. Hematological malignancies represent a disparate group of genetic and histopathological disorders. Proclivity for brain involvement is dependent on the unique entity and may occur synchronously or metasynchronously with the systemic lesion. Diffuse large B-cell lymphomas (DLBCLs) have a high propensity for brain involvement. Patients in remission from systemic DLBCL may present with a lesion suspicious for brain relapse. These patients often undergo brain biopsy. The authors' a priori hypothesis was that brain biopsy in patients with a history of systemic DLBCL and a new brain MRI lesion would have lower diagnostic utility compared with patients with non-DLBCL systemic malignancies.

METHODS

The authors performed a retrospective review of patients who underwent brain biopsy between 2000 and 2019. Inclusion criteria were patients ≥ 18 years of age with a prior systemic hematological malignancy in remission presenting with a new brain MRI lesion concerning for CNS relapse. Patients with a history of any CNS neoplasms, demyelinating disorders, or active systemic disease were excluded. The main outcome was the proportion of patients with a distinct histopathological brain diagnosis compared with the systemic malignancy. The authors secondarily assessed overall survival, procedure-related morbidity, and 30-day mortality.

RESULTS

Sixty patients met inclusion criteria (40 males and 20 females); the median age at brain biopsy was 67 years (range 23-88 years). The median follow-up was 8.5 months (range 0.1-231 months). Thirty-nine (65.0%) patients had DLBCL and 21 (35%) had non-DLBCL malignancies. Thirty-five of 36 (97.2%) patients with prior systemic DLBCL and a diagnostic biopsy had histopathological confirmation of the original systemic disease versus 0 of 21 patients with non-DLBCL systemic malignancies (p < 0.001). Morbidity and 30-day mortality were 8.3% and 10.0%, respectively; 2 of 6 30-day mortalities were directly attributable to the biopsy. The median overall survival following brain biopsy was 10.8 months.

CONCLUSIONS

Patients with a history of systemic DLBCL and presumed CNS relapse gained minimal clinical benefit from brain biopsy but were at high risk of morbidity and mortality. In patients with a history of non-DLBCL systemic malignancies, brain biopsy remained critical given the high likelihood for discovery of distinct diagnostic entities. It was determined that patients with a prior systemic DLBCL and presumed brain relapse should likely receive empirical therapy obviating treatment delay and the risks of brain biopsy.

Serous retinal detachment as a sign of leukemic choroidopathy: A systematic review

Leukemia is a rare disease associated with a high mortality rate. The presence of unilateral or bilateral serous retinal detachment (SRD) as a sign of choroidal infiltration can be one of the manifestations of acute leukemia, both as a primary sign or in a relapse. We consolidated the literature on SRD as a sign of leukemic choroidopathy regarding its epidemiology, clinical manifestations, and main imaging diagnostic tools. Well-documented cases regarding acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), relapsed ALL and relapsed AML published until September, 2020, in peer reviewed journals were included. The literature shows an interesting range of choroidal infiltration cases assessed by modern imaging techniques, such as optical coherence tomography (OCT) with and without enhanced depth imaging (EDI) and fluorescein angiography (FA). These tools allow choroidal assessment and better understanding and characterization of this rare condition. Complete ophthalmological workup should be performed in these patients using both FA and EDI-OCT to assess the choroidal anatomy and integrity. An increase in choroidal thickness measured with EDI-OCT can reveal active disease and potentially diagnose a leukemic relapse promptly.

Case Report: B Lymphocyte Disorders Under COVID-19 Inflammatory Pressure

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infects humans through the angiotensin converting enzyme-2 (ACE-2) receptor expressed on many cells, including lymphocytes. In Covid-19 patients IL-6 is overexpressed, and hyperactivated plasmacytoid lymphocytes are detected in peripheral blood film. We hypothesize that, due to the unpredictable interaction between the new virus and the B cell lineage of infected patients, a cascade of out of control events can ensue, capable of determining unexpected pathologic disorders involving such lineage. Here we report two cases of autoimmune hemolytic anemia (AIHA) and two cases of B-cell hematological malignancies developed or reactivated during acute SARS-CoV-2 infection. The temporal relationship of the events may suggest a potential causal relationship between SARS-CoV-2 infection and the hematopoietic disorders. We suggest that special attention should be paid to COVID-19 patients with underlining B cell lineage disorders.

Treatment of Aggressive T Cell Lymphoblastic Lymphoma/leukemia Using Anti-CD5 CAR T Cells

While treatment for B-cell malignancies has been revolutionized through the advent of CAR immunotherapy, similar strategies for T-cell malignancies have been limited. Additionally, T-cell leukemias and lymphomas can commonly metastasize to the CNS, where outcomes are poor and treatment options are associated with severe side effects. Consequently, the development of safer and more effective alternatives for targeting malignant T cells that have invaded the CNS remains clinically important. CD5 CAR has previously been shown to effectively target various T-cell cancers in preclinical studies. As IL-15 strengthens the anti-tumor response, we have modified CD5 CAR to secrete an IL-15/IL-15sushi complex. In a Phase I clinical trial, these CD5-IL15/IL15sushi CAR T cells were tested for safety and efficacy in a patient with refractory T-LBL with CNS infiltration. CD5-IL15/IL15sushi CAR T cells were able to rapidly ablate the CNS lymphoblasts within a few weeks, resulting in the remission of the patient's lymphoma. Despite the presence of CD5 on normal T cells, the patient only experienced a brief, transient T-cell aplasia. These results suggest that CD5-IL15/IL15sushi CAR T cells may be a safe and useful treatment of T-cell malignancies and may be particularly beneficial for patients with CNS involvement.Graphical Abstract.

A narrative review of central nervous system involvement in acute leukemias

Acute leukemias (both myeloid and lymphoblastic) are a group of diseases for which each year more successful therapies are implemented. However, in a subset of cases the overall survival (OS) is still exceptionally low due to the infiltration of leukemic cells in the central nervous system (CNS) and the subsequent formation of brain tumors. The CNS involvement is more common in acute lymphocytic leukemia (ALL), than in adult acute myeloid leukemia (AML), although the rates for the second case might be underestimated. The main reasons for CNS invasion are related to the expression of specific adhesion molecules (VLA-4, ICAM-1, VCAM, L-selectin, PECAM-1, CD18, LFA-1, CD58, CD44, CXCL12) by a subpopulation of leukemic cells, called “sticky cells” which have the ability to interact and adhere to endothelial cells. Moreover, the microenvironment becomes hypoxic and together with secretion of VEGF-A by ALL or AML cells the permeability of vasculature in the bone marrow increases, coupled with the disruption of blood brain barrier. There is a single subpopulation of leukemia cells, called leukemia stem cells (LSCs) that is able to resist in the new microenvironment due to its high adaptability. The LCSs enter into the arachnoid, migrate, and intensively proliferate in cerebrospinal fluid (CSF) and consequently infiltrate perivascular spaces and brain parenchyma. Moreover, the CNS is an immune privileged site that also protects leukemic cells from chemotherapy. CD56/NCAM is the most important surface molecule often overexpressed by leukemic stem cells that offers them the ability to infiltrate in the CNS. Although asymptomatic or with unspecific symptoms, CNS leukemia should be assessed in both AML/ALL patients, through a combination of flow cytometry and cytological analysis of CSF. Intrathecal therapy (ITT) is a preventive measure for CNS involvement in AML and ALL, still much research is needed in finding the appropriate target that would dramatically lower CNS involvement in acute leukemia.

Clinical significance of occult central nervous system disease in adult acute lymphoblastic leukemia. A multicenter report from the Campus ALL Network

In acute lymphoblastic leukemia (ALL), flow cytometry (FCM) detects leukemic cells in patients’ cerebrospinal fluid (CSF) more accurately than conventional cytology (CC). However, the clinical significance of FCM positivity with a negative cytology (i.e., occult central nervous system [CNS] disease) is not clear. In the framework of the national Campus ALL program, we retrospectively evaluated the incidence of occult CNS disease and its impact on outcome in 240 adult patients with newly diagnosed ALL. All CSF samples were investigated by CC and FCM. The presence of ≥10 phenotypically abnormal events, forming a cluster, was considered to be FCM positivity. No CNS involvement was documented in 179 patients, while 18 were positive by modified conventional morphology with CC and 43 were occult CNS disease positive. The relapse rate was significantly lower in CNS disease negative patients and the disease-free and overall survival (OS) were significantly longer in CNS disease negative patients than in those with manifest or occult CNS disease positivity. In multivariate analysis, the status of manifest and occult CNS disease positivity was independently associated with a worse OS. In conclusion, we demonstrate that in adult ALL patients at diagnosis FCM can detect occult CNS disease at high sensitivity and that the status of occult CNS disease positivity is associated with an adverse outcome. (Registered at clinicaltrials.gov identifier: NCT03803670).

Evolving therapy of adult acute lymphoblastic leukemia: state-of-the-art treatment and future directions

Recent years have witnessed major advances that have improved outcome of adults with acute lymphoblastic leukemia (ALL). The emergence of the concept of measurable residual disease has fine-tuned our prognostic models and guided our treatment decisions. The treatment paradigms of ALL have been revolutionized with the advent of tyrosine kinase inhibitors targeting BCR-ABL1, monoclonal antibodies targeting CD20 (rituximab), antibody-drug conjugates targeting CD22 (inotuzumab ozogamicin), bispecific antibodies (blinatumomab), and CD19 chimeric antigen receptor T cell therapy (tisagenlecleucel). These highly effective new agents are allowing for novel approaches that reduce reliance on intensive cytotoxic chemotherapy and hematopoietic stem cell transplantation in first remission. This comprehensive review will focus on the recent advances and future directions in novel therapeutic strategies in adult ALL.

Bilateral macular detachment: Choroid as a sanctuary of acute lymphoblastic leukemia

Purpose

To describe a bilateral macular detachment as the only sign of acute lymphoblastic leukemia relapse and prompt reversal with total body irradiation without ocular protection.

Observations

We present the case of a 20-year-old patient, diagnosed with a high-risk phy-negative, pre-B acute lymphoblastic leukemia (ALL), with a positive MLL gene rearrangement. After a Berlin-Frankfurt-Munster-like regimen chemotherapy protocol and a first complete remission, ALL relapse was diagnosed, so he was commenced on a FlaG-Ida protocol (fludarabine, idarubicin, granulocyte-colony stimulating factor, and high-dose cytarabine). He achieved a second complete remission with positive minimal residual disease and was scheduled for urgent allogeneic bone marrow transplant.

Five days before the conditioning regimen was initiated, the patient complained of visual loss in the left eye and then in the right eye. Ophthalmological evaluation showed a best corrected visual acuity of the right eye (OD) of 20/100 and of the left eye (OS) of 20/400. Optical coherence tomography (OCT) showed a bilateral serous sub-foveal detachment. The sub-foveal choroidal thickness was measured by enhanced depth imaging (EDI-OCT) and showed a significant increase (OD 836 μm and OS 1036 μm) compared with normal (average 310 μm). This choroidal thickness increase, associated with the serous macular detachment, was interpreted as a choroidal leukemic infiltration.

A lumbar puncture with cytologic studies and flow cytometry was performed, showing no evidence of central nervous system (CNS) involvement of leukemia. CNS and orbital magnetic nuclear resonance imaging showed no pathology. No extramedullary involvement could be confirmed.

Retinal fluorescein angiography showed multiple and diffuse leakage points (pinpoint pattern) within the macular area. This pattern reinforced our presumptive diagnosis, even though the lumbar puncture and flow cytometry were negative.

The hematologist decided to proceed with the bone marrow transplant. A myeloablative conditioning regimen was delivered, based on total body irradiation (TBI) with a total dose of 12 Gy plus fludarabine 30 mg/m² for five days. No ocular protection was used during TBI.

Only 2 h after TBI commenced, the patient reported a significant improvement in his visual acuity. We confirmed 20/20 in both eyes. The OCT showed a dramatic decrease in the choroidal thickness measurement (OD 387 μm and OS 408 μm compared with 836 μm and 1036 μm measured before radiotherapy).

Conclusions and importance

Complete ophthalmological evaluation and EDI-OCT choroidal thickness measurement could be fundamental tools necessary to determine CNS involvement of ALL, even in cases with negative cerebrospinal fluid and brain imaging.

Approach to the Adult Acute Lymphoblastic Leukemia Patient

During recent decades, understanding of the molecular mechanisms of acute lymphoblastic leukemia (ALL) has improved considerably, resulting in better risk stratification of patients and increased survival rates. Age, white blood cell count (WBC), and specific genetic abnormalities are the most important factors that define risk groups for ALL. State-of-the-art diagnosis of ALL requires cytological and cytogenetical analyses, as well as flow cytometry and high-throughput sequencing assays. An important aspect in the diagnostic characterization of patients with ALL is the identification of the Philadelphia (Ph) chromosome, which warrants the addition of tyrosine kinase inhibitors (TKI) to the chemotherapy backbone. Data that support the benefit of hematopoietic stem cell transplantation (HSCT) in high risk patient subsets or in late relapse patients are still questioned and have yet to be determined conclusive. This article presents the newly published data in ALL workup and treatment, putting it into perspective for the attending physician in hematology and oncology.

A lot of nerve

A 71-year-old woman with a history of acute lymphoblastic leukemia presented with unilateral optic disc edema. Laboratory evaluations for infectious, inflammatory, and neoplastic etiologies were negative. Magnetic resonance imaging of the orbits with and without contrast demonstrated enhancement and thickening of the right optic nerve with mild stranding of the intraconal fat. She underwent three large-volume lumbar punctures, all of which were negative for malignancy. An optic nerve biopsy was ultimately performed, demonstrating malignant cells on immunohistochemical staining. This case illustrates a rare case of biopsy-proven leukemic infiltration of the optic nerve head as the presenting sign of leukemic relapse despite a negative systemic workup. Leukemic infiltration should be considered in the differential diagnosis for cases of acquired disc edema, especially in patients with a past medical history of leukemia.