BTG1 inactivation drives lymphomagenesis and promotes lymphoma dissemination through activation of BCAR1.

Understanding the functional role of mutated genes in cancer is required to translate the findings of cancer genomics into therapeutic improvement. BTG1 is recurrently mutated in the MCD/C5 subtype of diffuse large B-cell lymphoma (DLBCL), which is associated with extranodal dissemination. Here, we provide evidence that Btg1 knock out accelerates the development of a lethal lymphoproliferative disease driven by Bcl2 overexpression. Furthermore, we show that the scaffolding protein BCAR1 is a BTG1 partner. Moreover, after BTG1 deletion or expression of BTG1 mutations observed in patients with DLBCL, the overactivation of the BCAR1-RAC1 pathway confers increased migration ability in vitro and in vivo. These modifications are targetable with the SRC inhibitor dasatinib, which opens novel therapeutic opportunities in BTG1 mutated DLBCL.

Timing of high-dose methotrexate CNS prophylaxis in DLBCL: a multicenter international analysis of 1384 patients.

Prophylactic high-dose methotrexate (HD-MTX) is often used for diffuse large B-cell lymphoma (DLBCL) patients at high risk of central nervous system (CNS) relapse, despite limited evidence demonstrating efficacy or the optimal delivery method. We conducted a retrospective, international analysis of 1384 patients receiving HD-MTX CNS prophylaxis either intercalated (i-HD-MTX) (n = 749) or at the end (n = 635) of R-CHOP/R-CHOP-like therapy (EOT). There were 78 CNS relapses (3-year rate 5.7%), with no difference between i-HD-MTX and EOT: 5.7% vs 5.8%, P = .98; 3-year difference: 0.04% (-2.0% to 3.1%). Conclusions were unchanged on adjusting for baseline prognostic factors or on 6-month landmark analysis (n = 1253). In patients with a high CNS international prognostic index (n = 600), the 3-year CNS relapse rate was 9.1%, with no difference between i-HD-MTX and EOT. On multivariable analysis, increasing age and renal/adrenal involvement were the only independent risk factors for CNS relapse. Concurrent intrathecal prophylaxis was not associated with a reduction in CNS relapse. R-CHOP delays of ≥7 days were significantly increased with i-HD-MTX vs EOT, with 308 of 1573 (19.6%) i-HD-MTX treatments resulting in a delay to subsequent R-CHOP (median 8 days). Increased risk of delay occurred in older patients when delivery was later than day 10 in the R-CHOP cycle. In summary, we found no evidence that EOT delivery increases CNS relapse risk vs i-HD-MTX. Findings in high-risk subgroups were unchanged. Rates of CNS relapse in this HD-MTX-treated cohort were similar to comparable cohorts receiving infrequent CNS prophylaxis. If HD-MTX is still considered for certain high-risk patients, delivery could be deferred until R-CHOP completion.

Primary central nervous system lymphomas in immunocompromised patients require specific response criteria.

PURPOSE: Immunosuppression is a well-established risk factor for primary central nervous system lymphomas (PCNSLs), which present in this context distinct radiological characteristics. Our aim was to describe the radiological evolution of treated PCNSL in immunocompromised patients and suggest adapted MRI response criteria. METHODS: We conducted a multicenter retrospective study of patients from the French LOC, K-Virogref and CANCERVIH network databases and enrolled adult immunocompromised patients with newly diagnosed PCNSL. RESULTS: We evaluated the baseline, intermediate, end-of-treatment and follow-up MRI data of 31 patients (9 living with HIV, 16 with solid organ transplantation and 6 with an autoimmune disease under chronic immunosuppressive therapy). At baseline, 23/30 (77%) patients had necrotic lesions with ring enhancement and 28% of the lesions were hemorrhagic. At the end of the first-line treatment, 12/28 (43%) patients could not be classified according to the IPCG criteria. Thirteen of 28 (46%) patients still harbored contrast enhancement, and 11/28 (39%) patients had persistent large necrotic lesions with a median diameter of 15 mm. These aspects were not associated with a pejorative outcome and progressively diminished during follow-up. Six patients relapsed; however, we failed to identify any neuroimaging risk factors on the end-of-treatment MRI. CONCLUSION: In immunocompromised patients, PCNSLs often harbor alarming features on end-of-treatment MRI, with persistent contrast-enhanced lesions frequently observed. However, these aspects seemed to be related to the necrotic and hemorrhagic nature of the lesions and were not predictive of a pejorative outcome. Specific response criteria for this population are thereby proposed.

CAR T-cell therapy induces a high rate of prolonged remission in relapsed primary CNS lymphoma: Real-life results of the LOC network.

The prognosis of relapsed primary central nervous system lymphoma (PCNSL) remains dismal. CAR T-cells are a major contributor to systemic lymphomas, but their use in PCNSL is limited. From the LOC network database, we retrospectively selected PCNSL who had leukapheresis for CAR-T cells from the third line of treatment, and, as controls, PCNSL treated with any treatment, at least in the third line and considered not eligible for ASCT. Twenty-seven patients (median age: 68, median of three previous lines, including ASCT in 14/27) had leukapheresis, of whom 25 received CAR T-cells (tisa-cel: N = 16, axi-cel: N = 9) between 2020 and 2023. All but one received a bridging therapy. The median follow-up after leukapheresis was 20.8 months. The best response after CAR-T cells was complete response in 16 patients (64%). One-year progression-free survival from leukapheresis was 43% with a plateau afterward. One-year relapse-free survival was 79% for patients in complete or partial response at CAR T-cell infusion. The median overall survival was 21.2 months. Twenty-three patients experienced a cytokine release syndrome and 17/25 patients (68%) a neurotoxicity (five grade ≥3). The efficacy endpoints were significantly better in the CAR T-cell group than in the control group (N = 247) (median PFS: 3 months; median OS: 4.7 months; p < 0.001). This series represents the largest cohort of PCNSL treated with CAR T-cells reported worldwide. CAR T-cells are effective in relapsed PCNSL, with a high rate of long-term remission and a reassuring tolerance profile. The results seem clearly superior to those usually observed in this setting.

Combining MYD88 L265P mutation detection and clonality determination on CSF cellular and cell-free DNA improves diagnosis of primary CNS lymphoma.

Diagnosis of primary central nervous system lymphoma (PCNSL) is challenging, and although brain biopsy remains the gold standard, cerebrospinal fluid (CSF) constitutes a less invasive source of lymphomatous biomarkers. In a retrospective cohort of 54 PCNSL cases tested at diagnosis or relapse, we evaluated the contribution of immunoglobulin heavy chain (IGH) gene clonality and MYD88 L265P detection on both CSF cell pellets and supernatants, in comparison with cytology, flow cytometry, interleukin (IL)-10 and IL-6 quantification. Clonality assessment included a new assay to detect partial IGH-DJ rearrangements. Clonal IGH rearrangements and/or MYD88 L265P mutation were detected in 27 (50%) cell pellets and 24 (44%) supernatant cell-free (cf) DNA. Combining analyses on both compartments, 36 (66%) cases had at least one detectable molecular marker, present only in cfDNA for 9 (16%) of them. While cytology and flow cytometry were positive in only 7 (13.0%) and 9 (17.3%) cases respectively, high IL-10 levels were observed in 36 (66.7%) cases. Overall, taking into account molecular and cytokine results, 46/54 (85%) cases had at least one lymphomatous biomarker detectable in the CSF. These results show that this combination of biomarkers evaluated on both cell pellet and supernatant CSF fractions improves significantly the biological diagnosis of PCNSL.

First line treatments in primary central nervous system lymphomas in young patients.

PURPOSE OF REVIEW: The aim of this review is to provide an update on current first-line treatments as well as on-going studies in immunocompetent patients with primary central nervous system lymphomas. RECENT FINDINGS: High-dose methotrexate (HD-MTX)-based polychemotherapy is widely used in induction treatment (IT). Among HD-MTX-based regimens, the best association is not yet defined. IT should be followed by a consolidation or a maintenance according to patient's age and performance status. Thiotepa-based intensive chemotherapy (IC) followed by autologous stem cell transplantation (ASCT) has improved survival in eligible patients compared to a nonmyeloablative consolidation. Because of the high risk of neurotoxicity, conventional whole brain radiotherapy (WBRT; 36-40 Gy) has been abandoned. Reduced-WBRT (23.4 Gy) is an alternative option in patients under 60 years-old in complete response after IT. Its safety remains to be demonstrated in elderly patients. The benefit of maintenance strategies to reduce the risk of relapse is being assessed in several studies in patients beyond 70 years-old. SUMMARY: HD-MTX-based polychemotherapy remains the corner stone of the IT, but the best regimen is not yet defined. Clinical trials assessing new IT regimens are ongoing. Intensive consolidation with IC + ASCT benefits patients up to 70 years-old. Predictive factors are under investigation to better define therapeutic response and guide treatment adjustment.

Primary vitreoretinal lymphoma: a diagnostic and management challenge.

Primary vitreoretinal lymphoma (PVRL) is a rare form of primary central nervous system (CNS) lymphoma (PCNSL) arising in the intraocular compartment without brain involvement. Despite its apparent indolent clinical course, PVRL can cause permanent vision loss and CNS relapse, the major cause of death in patients with PVRL. The pathophysiology of PVRL is unknown. As in PCNSL, the transformation of the tumor cells likely originates outside the CNS, before the cells migrate to the eye and proliferate within an immune-permissive microenvironment. PVRL exhibits a biased immunoglobulin repertoire, suggesting underlying antigen selection. The diagnosis remains challenging, requiring close coordination between ophthalmologists and cytologists. Because of their rarity and fragility in the vitreous, lymphoma cells cannot always be identified. Interleukin levels, molecular biology, and imaging are used in combination with clinical ophthalmological examination to support the diagnosis of PVRL. Multi-institutional prospective studies are urgently needed to validate the equivocal conclusions regarding treatments drawn from heterogeneous retrospective or small cohort studies. Intravitreal injection of methotrexate or rituximab or local radiotherapy is effective at clearing tumor cells within the eyes but does not prevent CNS relapse. Systemic treatment based on high-dose methotrexate chemotherapy, with or without local treatment, might reduce this risk. At relapse, intensive consolidation chemotherapy followed by stem cell transplantation can be considered. Single-agent ibrutinib, lenalidomide, and temozolomide treatments are effective in patients with relapsed PVRL and should be tested as first-line treatments. Therapeutic response assessment based on clinical examination is improved by measuring cytokine levels but still needs to be refined.

[18F]FDG PET-MRI provides survival biomarkers in primary central nervous system lymphoma in the elderly: an ancillary study from the BLOCAGE trial of the LOC network.

PURPOSE: Primary central nervous system lymphoma (PCNSL) incidence is rising among elderly patients, presenting challenges due to poor prognosis and treatment-related toxicity risks. This study explores the potential of combining [18F]fluorodeoxyglucose ([18F]FDG) PET scans and multimodal MRI for improving management in elderly patients with de novo PCNSL. METHODS: Immunocompetent patients over 60 years with de novo PCNSL were prospectively enrolled in a multicentric study between January 2016 and April 2021. Patients underwent brain [18F]FDG PET-MRI before receiving high-dose methotrexate-based chemotherapy. Relationships between extracted PET (metabolic tumor volume (MTV), sum of MTV for up to five lesions (sumMTV), metabolic imaging lymphoma aggressiveness score (MILAS)) and MRI parameters (tumor contrast-enhancement size, cerebral blood volume (CBV), cerebral blood flow (CBF), apparent diffusion coefficient (ADC)) and treatment response and outcomes were analyzed. RESULTS: Of 54 newly diagnosed diffuse large B-cell PCNSL patients, 52 had positive PET and MRI with highly [18F]FDG-avid and contrast-enhanced disease (SUVmax: 27.7 [22.8-36]). High [18F]FDG uptake and metabolic volume were significantly associated with low ADCmean values and high CBF at baseline. Among patients, 69% achieved an objective response at the end of induction therapy, while 17 were progressive. Higher cerebellar SUVmean and lower sumMTV at diagnosis were significant predictors of complete response: 6.4 [5.7-7.7] vs 5.4 [4.5-6.6] (p = 0.04) and 5.5 [2.1-13.3] vs 15.9 [4.2-19.5] (p = 0.01), respectively. Two-year overall survival (OS) was 71%, with a median progression-free survival (PFS) of 29.6 months and a median follow-up of 37 months. Larger tumor volumes on PET or enhanced T1-weighted MRI were significant predictors of poorer OS, while a high MILAS score at diagnosis was associated with early death (< 1 year). CONCLUSION: Baseline cerebellar metabolism and sumMTV may predict response to end of chemotherapy in PCNSL. Tumor volume and MILAS at baseline are strong prognostic factors.

Central nervous system lymphomas-Assessment and treatment and prevention of central nervous system relapse.

In this review focused on lymphoma and the central nervous system (CNS), we summarize recent developments in the management of primary (PCNSL) and secondary CNS lymphoma (SCNSL), treatment of CNS lymphoma in the older population, the neuroradiological assessment of CNS lymphoma and finally highlight the ongoing debate on optimal CNS prophylaxis. The section on PCNSL focuses on the different approaches available for frontline treatment in Europe and the United States and discusses consolidation strategies. We then highlight available strategies to treat PCNSL in the elderly population, an area of unmet need. New therapies aiming at minimizing toxicity and prioritizing quality of life are emerging for these patients. Secondary CNS lymphoma, especially in the relapsed/refractory setting is another area of unmet need, and the efficacy of CAR-T cell therapy is being explored. We provide an overview of the imaging challenges in the neuroradiological assessment of CNS lymphoma. Finally, the section on CNS prophylaxis summarizes recent findings from large retrospective studies challenging the efficacy of present approaches to prophylaxis in higher-risk patients with lymphoma.

Brain radiotherapy in patients treated for a newly diagnosed primary central nervous system lymphoma: professional practice evaluation in 19 French centers.

INTRODUCTION: The objective of this study was a multicentric evaluation of professional practices, analyzing the irradiation technique itself and its impact on survival and recurrence sites, in primary central nervous system lymphomas (PCNSLs). METHODS: We retrospectively analyzed the technical and clinical records of 79 PCNSL patients included in the database of the national expert network for oculocerebral lymphoma ('LOC') who were treated with brain radiotherapy as first-line treatment for newly diagnosed primary central nervous system lymphoma between 2011 and 2018. RESULTS: The number of patients treated with brain radiotherapy gradually decreased over time. The heterogeneity of radiotherapy prescriptions was significant, and 55% of them did not comply with published recommendations in terms of irradiation dose and/or volume. The proportion of complete responders to induction chemotherapy treated with reduced-dose radiotherapy increased over time. Partial brain radiotherapy was associated with significantly lower overall survival in univariate analysis. In partial responders to induction chemotherapy, increasing the total dose to the brain >30 Gy and adding a boost to the WBRT induced a trend toward improved progression-free and overall survival. Five recurrences (13%) occurred exclusively in the eyes, all in patients whose eyes had been excluded from the irradiation target volume and including 2 patients without ocular involvement at diagnosis. CONCLUSION: The visibility of recommendations for prescribing brain radiotherapy for the treatment of newly diagnosed primary central nervous system lymphoma needs to be improved to harmonize practices and improve their quality. We propose an update of the recommendations.

Radiotherapy for newly diagnosed primary central nervous system lymphoma: role and perspective.

Whole brain radiotherapy (WBRT) has long been a key treatment of newly diagnosed primary central nervous system lymphoma (PCNSL). In the 1990s, the addition of high dose Methotrexate-based induction chemotherapy (HD MTX-based CT) has enabled a drastic improvement in PCNSL patients outcome. However, combined treatment has led to radiation-induced delayed neurotoxicity, especially in older patients. Alternative treatment strategies have been assessed to improve the efficacy and neurotoxicity ratio. Nowadays, in the elderly patients WBRT is widely omitted or deferred, and in younger patients WBRT is challenged by high dose chemotherapy with autologous stem cell transplant (HCT-ASCT) for consolidation treatment after HD MTX-based CT. In this setting, this review is addressed to clinicians with the aim to summarize the role of WBRT in the treatment of newly diagnosed PCNSL and its perspectives.

Impact of severe acute respiratory syndrome coronavirus-2 infection on the outcome of primary central nervous system lymphoma treatment: A study of the International PCNSL Collaborative Group.

To optimise management of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection identifying high-risk patients and maintaining treatment dose intensity is an important issue in patients with aggressive lymphomas. In the present study, we report on the presentation, management, and outcome of an international series of 91 patients with primary central nervous system lymphoma and SARS-CoV-2 infection. SARS-CoV-2 was diagnosed before/during first-line treatment in 64 patients, during follow-up in 21, and during salvage therapy in six. Among the 64 patients infected before/during first-line chemotherapy, 38 (59%) developed pneumonia and 26 (41%) did not clear the virus. Prolonged exposure to steroids before viral infection and/or treatment with high-dose cytarabine favoured pneumonia development and virus persistence and were associated with poorer survival; 81% of patients who did not clear virus died early from coronavirus disease 2019 (COVID-19). Vaccination was associated with lower pneumonia incidence and in-hospital mortality. Chemotherapy was initiated/resumed in 43 (67%) patients, more commonly among patients who did not develop pneumonia, cleared the virus, or did not receive steroids during infection. Chemotherapy resumption in patients with viral persistence should be indicated cautiously as it was associated with a poorer survival (6-month, 70% and 87%, p = 0.07). None of the 21 patients infected during follow-up died from COVID-19, requiring similar measures as infected subjects in the general population.

Isolated intraocular relapses of primary cerebral lymphomas: An LOC network study.

Most relapses of primary central nervous system lymphoma (PCNSL) occur in the brain and are associated with a poor prognosis. Isolated intraocular relapses (IIORs) are rare and poorly described. We retrospectively selected from the French Lymphome Oculo-Cérébral database PCNSL patients who initially presented with cerebral localization and who experienced IIOR during the course of the disease. Of the 1472 patients included in the database, 55 patients presented an IIOR. Their median age was 68 years, and median Karnofsky Performance Status 80. IL-10 levels in the aqueous humor and/or in the vitreous were increased in 42/46 patients. 45/55 patients received systemic chemotherapy, and 11/55 received high-dose chemotherapy with autologous stem cell transplantation (HCT-ASCT) as consolidation treatment. After a median follow-up of 69 months, 42/55 patients had relapsed, including 90% of the patients who did not receive HCT-ASCT at IIOR and 40% of the patients who received HCT-ASCT at IIOR (p < 0.001). The first relapse after the initial IIOR was exclusively in the eye in 23/42 patients, and 29/42 patients had a subsequent brain relapse during the course of the disease. The median progression-free survival, brain-free survival and overall survival from IIOR were 12.2, 48.6 and 57.1 months, respectively. Isolated intraocular relapse is not exceptional in the course of PCNSL and deserves systematic ophthalmological follow-up. Its prognosis is much better than the prognosis of brain relapse, with an evolution close to that of primary vitreoretinal lymphoma. With the exception of patients who received HCT-ASCT at IIOR, almost all patients subsequently relapsed, often with other IIORs.

Primary vitreoretinal lymphoma: short review of the literature, results of a European survey and French guidelines of the LOC network for diagnosis, treatment and follow-up.

PURPOSE OF REVIEW: The aim of this study was to highlight the diagnostic and management challenges of primary vitreoretinal lymphoma (PVRL) through a review of the literature and a European survey on real-life practices for PVRL. RECENT FINDINGS: The care of PVRL patients is heterogeneous between specialists and countries. Upfront systemic treatment based on high-dose methotrexate chemotherapy, with or without local treatment, might reduce or delay the risk of brain relapse.Ibrutinib, lenalidomide with or without rituximab, and temozolomide are effective for patients with relapsed/refractory PVRL and should be tested as first-line treatments. SUMMARY: The prognosis of PVRL remains dismal. No firm conclusion regarding optimal treatment can yet be drawn. The risk of brain relapse remains high. Diagnostic procedures and assessment of therapeutic responses need to be homogenized. Collaboration between specialists involved in PVRL and multicentric prospective therapeutic studies are strongly needed. The recommendations of the French group for primary oculocerebral lymphoma (LOC network) are provided, as a basis for further European collaborative work.

Prolonged in-hospital stay and higher mortality after Covid-19 among patients with non-Hodgkin lymphoma treated with B-cell depleting immunotherapy.

Prolonged Covid-19 is an emerging issue for patients with lymphoma or immune deficiency. We aimed to examine prolonged length of in-hospital stay (LOS) due to Covid-19 among patients with lymphoma and assess its determinants and outcomes. Adult patients with lymphoma admitted for Covid-19 to 16 French hospitals in March and April, 2020 were included. Length of in-hospital stay was analyzed as a competitor vs death. The study included 111 patients. The median age was 65 years (range, 19-92). Ninety-four patients (85%) had B-cell non-Hodgkin lymphoma. Within the 12 months prior to hospitalization for Covid-19, 79 patients (71%) were treated for their lymphoma. Among them, 63 (57%) received an anti-CD20 therapy. Fourteen patients (12%) had relapsed/refractory disease. The median LOS was 14 days (range, 1-235). After a median follow-up of 191 days (3-260), the 6-month overall survival was 69%. In multivariable analyses, recent administration of anti-CD20 therapy was associated with prolonged LOS (subdistribution hazard ratio 2.26, 95% confidence interval 1.42-3.6, p < 0.001) and higher risk of death (hazard ratio 2.17, 95% confidence interval 1.04-4.52, p = 0.039). An age ≥ 70 years and relapsed/refractory lymphoma were also associated with prolonged LOS and decreased overall survival. In conclusion, an age ≥ 70 years, a relapsed/refractory lymphoma and recent administration of anti-CD20 therapy are risk factors for prolonged LOS and death for lymphoma patients hospitalized for Covid-19. These findings may contribute to guide the management of lymphoma during the pandemic, support evaluating specific therapeutic approaches, and raise questions on the efficacy and timing of vaccination of this particular population.

Intravenous high-dose methotrexate based systemic therapy in the treatment of isolated primary vitreoretinal lymphoma: An LOC network study.

The treatment of primary vitreoretinal lymphoma (PVRL) remains controversial regarding the use of local, systemic, or combined treatments. The aim of this study was to analyze the efficacy and toxicity of intravenous high-dose methotrexate (IV HD-MTX) based systemic therapy in a uniformly treated population of PVRL patients. From a nationwide French database, we retrospectively selected 59 patients (median age: 70 years, median Karnofsky Performance Status: 90%) with isolated PVRL at diagnosis who received first-line treatment with HD-MTX between 2011 and 2018. 8/59 patients also received a local treatment. No deaths or premature discontinuations of MTX due to toxicity were reported. A complete response was obtained in 40/57 patients after chemotherapy. Before treatment, IL-10 was elevated in the aqueous humor (AH) or in the vitreous in 89% of patients. After treatment, AH IL-10 was undetectable in 87% of patients with a CR/uCR/PR and detectable in 92% of patients with PD/SD. After a median follow-up of 61 months, 42/59 (71%) patients had relapsed, including 29 isolated ocular relapses as the first relapse and a total of 22 brain relapses. The median overall survival, progression-free survival, ocular-free survival and brain-free survival were 75, 18, 29 and 73 months, respectively. IV HD-MTX based systemic therapy as a first-line treatment for isolated PVRL is feasible, with acceptable toxicity, even in an elderly population. This strategy seems efficient to prevent brain relapse with prolonged overall survival. However, the ocular relapse rate remains high. New approaches are needed to improve local control of this disease, and ocular assessment could be completed by monitoring AH IL-10.

Ibrutinib induces multiple functional defects in the neutrophil response against Aspergillus fumigatus.

The Bruton tyrosine kinase inhibitor ibrutinib has become a leading therapy against chronic lymphoid leukemia. Recently, ibrutinib has been associated with the occurrence of invasive fungal infections, in particular invasive aspergillosis. The mechanisms underlying the increased susceptibility to fungal infections associated with exposure to ibrutinib are currently unknown. Innate immunity, in particular polymer-phonuclear neutrophils, represents the cornerstone of anti-Aspergillus immunity; however, the potential impact of ibrutinib on neutrophils has been little studied. Our study investigated the response to Aspergillus fumigatus and neutrophil function in patients with chronic lymphoid leukemia or lymphoma, who were undergoing ibrutinib therapy. We studied the consequences of ibrutinib exposure on the functions and anti-Aspergillus responses of neutrophils obtained from healthy donors and 63 blood samples collected at different time points from 32 patients receiving ibrutinib for lymphoid malignancies. We used both flow cytometry and video-microscopy approaches to analyze neutrophils' cell surface molecule expression, cytokine production, oxidative burst, chemotaxis and killing activity against Aspergillus Ibrutinib is associated, both in vitro and in patients under treatment, with multiple functional defects in neutrophils, including decreased production of reactive oxygen species, impairment of their capacity to engulf Aspergillus and inability to efficiently kill germinating conidia. Our results demonstrate that ibrutinib-exposed neutrophils develop significant functional defects that impair their response against Aspergillus fumigatus, providing a plausible explanation for the emergence of invasive aspergillosis in ibrutinib-treated patients.

Use of FDG-PET/CT for systemic assessment of suspected primary central nervous system lymphoma: a LOC study.

INTRODUCTION: Primary Central Nervous System Lymphoma (PCNSL) is a rare disease with different therapeutic implications than systemic lymphoma. In this study, we evaluated whole-body 18FDG-PET/CT for pre-chemotherapy imaging of suspected PCNSL. METHODS: One hundred and thirty consecutive immunocompetent patients were retrospectively included. The results of initial 18FDG-PET/CT, contrast-enhanced CT (CeCT) and bone marrow biopsy (BMB) when available were compared to a gold standard based on pathological diagnosis or follow-up. RESULTS: CNS lesion pathology showed large B-cell lymphoma in 95% of patients, including 11 patients with primary vitro-retinal lymphoma. Ten patients (8%) where ultimately diagnosed with systemic lymphoma involvement, including five pathologically confirmed cases, all of which were detected by 18FDG-PET/CT. 18FDG-PET/CT showed incidental systemic findings unrelated to lymphoma in 14% of patients. An SUVmax threshold of nine enabled good discrimination between systemic lymphoma and other lesions (sensitivity 92% and specificity 89%). CeCT and BMB performed in 108 and 77 patients respectively revealed systemic lesions in only three patients. CONCLUSION: 18FDG-PET/CT detected concomitant occult systemic involvement in a non-negligible proportion of suspected PCNSL cases (8%). In this setting its sensitivity is higher than that of CeCT. All of our patients ultimately diagnosed with concomitant systemic involvement had positive 18FDG-PET/CT. We believe it constitutes a safe one-stop shop evaluation for the systemic pre-treatment imaging of suspected PCNSL.

Primary CNS lymphoma patient-derived orthotopic xenograft model capture the biological and molecular characteristics of the disease.

Primary CNS lymphomas (PCNSL) are rare and poor prognosis diffuse large B-cell lymphomas. Because of the brain tumor environment and the restricted distribution of drugs in the CNS, specific PCNSL patient-derived orthotopic xenograft (PDOX) models are needed for preclinical research to improve the prognosis of PCNSL patients. PCNSL patient specimens (n = 6) were grafted in the caudate nucleus of immunodeficient nude mice with a 83% rate of success, while subcutaneous implantation in nude mice of human PCNSL sample did not generate lymphoma, supporting the role of the brain microenvironment in the PCNSL physiopathology. PDOXs showed diffuse infiltration of B-cell lymphoma cells in the brain parenchyma. Each model had a unique mutational signature for genes in the BCR and NF-κB pathways and retained the mutational profile of the primary tumor. The models can be stored as cryopreserved biobank. Human IL-10 levels measured in the plasma of PCNSL-PDOX mice showed to be a reliable tool to monitor the tumor burden. Treatment response could be measured after a short treatment with the targeted therapy ibrutinib. In summary, we established a panel of human PCNSL-PDOX models that capture the histological and molecular characteristics of the disease and that proved suitable for preclinical experiments. Our methods of generation and characterization will enable the generation of additional PDOX-PCNSL models, essential tools for cognitive and preclinical drug discovery.