B-cell Clones Research Articles

Recurrent primary cutaneous marginal zone lymphoma: acomparative study of initial tumours, recurrences, andoutcomes in 61 patients.

Primary cutaneous marginal zone lymphoma (PCMZL) is considered a lymphoproliferative disorder (International Consensus Classification, ICC) or an overt lymphoma (WHO-HAEM5). Seeking evidence for a reactive process or true lymphoma, we retrieved recurrent PCMZLs from the French Study Group of Cutaneous Lymphoma (GFELC) database. Histology, phenotype (light-chain restriction, immunoglobulin, and immune-receptor translocation-associated protein-1 [IRTA1] expression) and B-cell clonality at diagnosis and recurrence were compared according to recurrence site (local, locoregional, or distant) and outcomes. Initial lesions of the 61 patients (mean age 52) were mostly isolated on the trunk (48%) and classified T1 (70%). Times to first recurrence for local, locoregional, and distant recurrences, were 20, 29, and 37 months, respectively. Light-chain restriction type did not differ significantly between local/locoregional recurrences and distal recurrences (P = 0.06; n = 60). The same B-cell clones were identified for 23/42 local/locoregional recurrences, while 5/19 distant recurrences showed different clonal profiles (P = 0.0003). No tumour expressed IRTA1. Fifty-eight tumours were heavy-chain (IgG/IgG4) class-switched PCMZLs and 3 IgM+/IgD- PCMZLs. All IgM+ tumours underwent either transformation (skin or brain) into diffuse large B-cell lymphomas (DLBCLs) and extracutaneous spreading. As suggested by WHO-HAEM5, immunoglobulin phenotype assessment (IgM alongside IgD) appears to be a possible valuable tool in the initial diagnosis of PCMZL to differentiate between the indolent class-switched PCMZL (IgM-negative) and IgM+ (IgD-) PCMZL, which has an uncertain prognosis. The variation in B-cell rearrangements and light chain restriction observed in distant recurrences of PCMZL may suggest different antigen-driven stimulation processes.

Cell therapy for a rare disease- hairy cell leukemia variant

ABSTRACT Hairy cell leukemia variant (HCL-v) is a rare malignancy of clonal mature B-cells that follows a chronic disease course. HCL-v patients are often resistant to purine nucleoside analogs, which are the first-line therapy. To address the shortcomings of current therapy for HCL-v, we investigated the activity of a BAFF ligand-based CAR-T cell which binds to all three BAFF receptors, BAFF-receptor, TACI, and BCMA. Here, we demonstrate that HCLv patient-derived cells highly express all three BAFF receptors and that BAFF CAR-T cells induce significant cytotoxicity in vitro against both cell lines and HCL-v patient cells. This cytotoxicity corresponds with significant CAR-T cell activation, degranulation, and release of pro-inflammatory cytokines after co-incubation with HCLv cells. Furthermore, we successfully generated BAFF CAR-T cells directly from an HCLv patient and observed direct autologous killing against patient tumor cells in vitro. These HCLv patient-derived CAR-T cells were also effective in killing the Hair-M cell line and tumor cells derived from a different HCLv patient. Lastly, we also developed two mouse xenograft models for HCL, a subcutaneous Bonna-12 model and intravenous Hair-M xenograft model. We observed decreases in tumor burden and prolonged overall survival without significant toxicity. In conclusion, here we show that BAFF CAR-T cells exert anti-tumor effects in vitro and in vivo against multiple cell lines and patient-derived HCL-v samples and may be a successful therapeutic strategy for HCLv patients.

MGCS: where do we stand today?

Monoclonal gammopathies of clinical significance (MGCS) are a heterogeneous group of disorders characterized by the presence of an indolent B-cell or plasma-cell clone producing a toxic monoclonal immunoglobulin resulting in end-organ dysfunction. MGCS is a clinicopathologic diagnosis that requires the demonstration of a monoclonal immunoglobulin in the correct clinical setting. The most common MGCS syndromes are renal, neurologic, and cutaneous, although hematologic and multi-organ MGCS syndromes are also increasingly recognized. Therapy most commonly targets the underlying clonal population; immunoglobulin-targeting therapies as well as complement and cytokine antagonists have emerged for selected MGCS syndromes and may be temporizing in a subset of patients. Other chapters review renal and neurologic MGCS; this chapter focuses on hematologic and multi-organ MGCS syndromes.

Renal manifestations of MGUS.

Kidney disease is a common complication of monoclonal immunoglobulin (MIg)-secreting B-cell disorders and predominantly occurs in patients who do not meet the criteria for an overt hematological disease. To distinguish this situation from monoclonal gammopathy of undetermined significance, which lacks organ damage, the term monoclonal gammopathy of renal significance (MGRS) was introduced to depict the association of a small, otherwise indolent B-cell clone, with renal disease induced by the secreted MIg. The spectrum of renal disorders in MGRS is wide, encompassing both tubular and glomerular disorders, classified according to the composition of deposits and their ultrastructural pattern of organization. Renal lesions, independent of the tumor burden, are mostly governed by the molecular characteristics of the MIg variable domain and involve either direct (deposition or precipitation) or indirect (autoantibody activity, complement activation) mechanisms. The diagnosis, often suggested by careful analysis of renal and extrarenal symptoms, almost always requires histological confirmation by a kidney biopsy with light, immunofluorescence, and electron microscopy studies. Most patients do not have a known monoclonal gammopathy at presentation. Hematologic investigations should include serum and urine protein electrophoresis and immunofixation, serum-free light chain measurements, and bone marrow studies with flow cytometry and cytogenetics to determine the nature of the pathogenic clone (most commonly plasmocytic). Early diagnosis before the development of severe chronic kidney disease and rapid achievement of deep hematological response through clone-targeted chemotherapy (currently based on proteasome inhibitor and monoclonal anti-CD38 antibody-based combinations for plasma cell clones) are the main factors influencing long-term renal and patient outcomes.

Genomic Profiling of Two Successive Post-Transplant Lymphoproliferative Disorders with Different Morphology in a Pediatric Lung Transplant Recipient

Introduction Post-transplant lymphoproliferative disorders (PTLD) encompass a broad spectrum of lymphoid proliferations, a consequence of externally induced immunosuppression following solid organ or hematopoietic stem cell transplantation. These disorders range from indolent proliferations to polyclonal polymorphic diseases, but they can also present as aggressive malignant lymphomas that highly resemble those observed in the immunocompetent population. Due to the shared pathogenetic mechanisms, studying PTLDs can provide valuable insights into the pathogenesis of lymphomas in general. One of the most intriguing real-life models of lymphomagenesis represent patients who develop multiple PTLDs with different morphologies, even though such cases are extremely rare. Aims In this study, we focused on a case of a lung transplant patient who gradually developed two PTLDs with different morphologies. Our aim was to evaluate the relationship between these two diseases and to elucidate the morphological progression. Methods A female EBV seronegative patient with cystic fibrosis underwent a lung transplantation from EBV seropositive donor at 16 years of age. She first developed polymorphic PTLD in the colon 11 months post-transplantation (CD20+CD30-EBV+). She was treated with reduction of immunosuppression and 6 doses of rituximab according to Ped-PTLD-2005-Pilot protocol. The clinical status of the patient improved significantly and a PET-CT scan performed after the 4th dose of rituximab showed marked regression of all the lesions. However, 15 months post-transplantation, she presented with diffuse large B-cell lymphoma (DLBCL) in the duodenum (CD20+CD30+EBER+). The patient was treated with R2 arm of NHL-BFM 2004 protocol and has achieved long-lasting remission of the disease. DNA was isolated from formalin-fixed, paraffin-embedded (FFPE) samples of polymorphic PTLD and DLBCL using QIAamp DNA FFPE Tissue kit (Qiagen). Immunoglobulin (IG) rearrangements were analyzed by Biomed-2 IGH FR3 Multiplex PCR. Allele-specific oligonucleotide quantitative PCR was designed based on monoclonal IGH sequence from DLBCL to backtrack the clone in PTLD and in peripheral blood (PB) samples with sensitivity of 1E^-04. Whole exome sequencing (WES) was performed on DNA from FFPE PTLD biopsy samples and pre-transplant PB using the SureSelect XT HS2 Human All Exon V8+UTRs library preparation kit (Agilent Technologies) and NextSeq 500 instrument (Illumina). Bioinformatic analysis was performed using Varsome Clinical. Variants not present in germline with sufficient coverage and sequencing quality predicted as pathogenic or of uncertain significance were filtered out. Results An identical monoclonal IGHV4-39-IGHJ4 rearrangement was detected in biopsy samples of both PTLDs. This rearrangement was also detected in PB two weeks prior to the DLBCL diagnosis. PB samples (n=10) taken at previous time points before and after transplantation were all negative. WES identified 103 somatic variants in total: 32 were present only in polymorphic PTLD, 60 only in DLBCL, and 11 were shared between the two diseases. Of the 26 variants with the highest predicted pathogenicity, only 5 were present in polymorphic PTLD and 25 in DLBCL. Notably, variants in the FAS, KMT2C, and LRP1B genes were detected in DLBCL but not in polymorphic PTLD. Variants in these genes have been previously described in pediatric PTLD-DLBCL (Salmerón-Villalobos et al., Blood, 2024) and in adult refractory DLBCL and transformed follicular lymphoma (Morin et al., Clinical Cancer Research, 2016), often occurring concurrently, suggesting synergistic effect. Conclusions The polymorphic PTLD and DLBCL developed from the same B-cell clone with an identical IGH rearrangement. The progression to DLBCL was most likely driven by the selection of a clone with newly acquired somatic variants in the FAS, KMT2C, and LRP1B genes. To our knowledge, only a few cases of multiple PTLDs with different morphologies in a single patient have been described in the literature, and none have been evaluated to this extent at the genomic level. This case highlights that PTLDs can provide valuable insights into the pathogenesis of NHLs in general. Supported by the European Union - Next Generation EU - program No. LX22NPO5102, Charles University Research Centre program No. UNCE/24/MED/003 and MH CZ - DRO, Motol University Hospital, Prague, Czech Republic 00064203

Clonal Bronchopulmonary B-Cell Proliferations of Indeterminate Malignant Potential in Patients with Common Variable Immune Deficiency (CVID) associated Granulomatous Lymphocytic Interstitial Lung Disease (GLILD)

Abstract Introduction/Objective Pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is often challenging to distinguish from reactive nodular lymphoid hyperplasia, and assessing B-cell clonality in such cases is crucial in making the distinction. However, patients with common variable immune deficiency (CVID) can harbor clonal or oligoclonal lymphoid populations in their tissues, particularly in association with granulomatous lymphocytic interstitial lung disease (GLILD), making the distinction from MALT lymphoma extremely challenging. We report six cases of GLILD with clonal or oligoclonal B cell infiltrates in lung wedge resection specimens and describe their clinicopathologic characteristics, management, and outcomes. Methods/Case Report A retrospective review was performed to collect lung wedge resection specimens from patients with CVID showing atypical B-cell infiltrates associated with GLILD between 01/2015 and 08/2023. The clinicopathologic findings, management, and response to treatment were studied. Results (if a Case Study enter NA) A total of six GLILD cases were identified with variable degrees of architectural and cytologic lymphoid atypia. Clonality of the lymphoid infiltrate was assessed by kappa/lambda in situ hybridization staining in all six, flow cytometry in 3/6, and IGH gene rearrangement in 4/6 cases. The infiltrate showed frank lambda restriction in 1/6, lambda predominance in 1/6, polytypic expression in 1/6, and no significant plasmacytic component in 3/6 cases. Flow cytometry detected atypical light chain skewed B-cell populations in 3/3 of cases. IGH was positive for clonality in 3/4 and oligoclonal in 1/4 cases. Four patients received therapeutic intervention for GLILD, including one with Rituximab monotherapy, two with Rituximab+Azathioprine, and one with Rituximab+Mycophenolate leading to marked symptomatic and radiologic improvement in all four patients. The remaining two patients were observed to have stable disease. Conclusion Patients with CVID can harbor clonal B-cell populations due to their underlying immune dysfunction. Studies have shown that these can be transient and may not always progress to overt lymphoma. In the setting of GLILD, detecting these populations makes the distinction from MALT lymphoma very challenging. Given that the first- line therapy for both GLILD and MALT is anti-CD20 therapy, the malignant potential of these clones remains uncertain and can only be determined with long-term clinical follow-up.

Monoclonal Membranous Glomerulopathy in a Patient with Positive Serology for Lupus Nephritis

Abstract Introduction/Objective Monoclonal membranous glomerulopathy (M-MGN) is a rare entity; only two reports are available in the literature. Monoclonal membranous glomerulopathy has been called either monoclonal immunoglobulin deposition disease associated with membranous features in a 3-patient small series report or membranous glomerulopathy with light chain restriction in another larger series with 28 cases. We report M-MGN in a patient with positive serology lupus. Methods/Case Report The patient was a 74-year-old man with hypertension and nephrotic range proteinuria (protein/creatinine ratio at 8.5). His serum creatinine remained normal at 0.6 mg/dL. The patient was positive for double-stranded DNA and ANA at low titer, but had reduced complement C3 and C4. Immunofixation was negative for monoclonal protein. The light microscopy of the renal biopsy revealed thickened loops of glomeruli with mild interstitial nephritis. Immunofluorescent studies showed a positive linear/granular pattern of IgG and lambda but negative kappa staining along the glomerular loops. Electron microscopy revealed smooth contoured stage 2 subepithelial deposits. An outside consultation confirmed our diagnosis and found IgG2 restriction in glomeruli. Electrophoresis revealed no monoclonal protein in the serum. Results (if a Case Study enter NA) NA Conclusion Our patient demonstrated M-MGN with mild interstitial nephritis; the latter may be related to his lupus status. As 30% of patients with M-MGN have either monoclonal serology or B-cell lymphoproliferative disorders, with most having a restricted IgG subtyping, a close follow-up and even chemotherapy for a B-cell clone should be considered.

Immune repertoire profiling in myasthenia gravis.

Myasthenia gravis (MG) is the most frequent immune-mediated neurological disorder, characterized by fluctuating muscle weakness. Specific recognition of self-antigens by T-cell receptors (TCRs) and B-cell receptors (BCRs), coupled with T-B cell interactions, activates B cells to produce autoantibodies, which are critical for the initiation and perpetuation of MG. The immune repertoire comprises all functionally diverse T and B cells at a specific time point in an individual, reflecting the essence of immune selectivity. By sequencing the nucleotide sequences of TCRs and BCRs, it is possible to track individual T- and B-cell clones. This review delves into the generation of autoreactive TCRs and BCRs in MG and comprehensively examines the applications of immune repertoire sequencing in understanding disease pathogenesis, developing diagnostic and prognostic markers and informing targeted therapies. We also discuss the current limitations and future potential of this approach.

APRIL/BAFF upregulation is associated with clonal B-cell expansion in Hunner-type interstitial cystitis.

Hunner-type interstitial cystitis (HIC) is a chronic inflammatory disease of the urinary bladder with an unknown etiology. We conducted comprehensive immunogenomic profiling of bladder specimens obtained by biopsy and cystectomy from 37 patients with HIC. Next-generation RNA sequencing demonstrated abundant plasma cell infiltration with frequent light chain restriction in HIC-affected bladder tissue. Subsequent analysis of the B-cell receptor repertoire revealed spatial and temporal expansion of B-cell clones. The extent of B-cell clonal expansion was significantly correlated with the gene expression levels of TNFSF13 and TNFSF13B, which encode APRIL and BAFF, respectively. These findings indicate that APRIL and BAFF are the key regulators of clonal B-cell expansion in HIC and might serve as therapeutic targets in this debilitating disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Overlapping Gene Expression and Molecular Features in High-Grade B-Cell Lymphoma

Aggressive B-cell lymphoma encompasses Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and, as per the 2016 WHO classification, high-grade B-cell lymphoma (HGBL) not otherwise specified (NOS) and HGBL double/triple hit (DH/TH). However, the diagnostic distinction of HGBL from BL and DLBCL is difficult by means of histology/immunostaining in a substantial number of patients. This study aimed to improve subtyping by the identification of molecular features of aggressive B-cell lymphomas, with a specific focus on HGBL. To this end, we performed a comprehensive gene expression and mutational pattern analysis as well as the detection of B-cell clonality of 34 cases diagnosed with BL (n = 4), DLBCL (n = 16), HGBL DH (n = 8), and HGBL NOS (n = 6). Three distinct molecular subgroups were identified based on gene expression, primarily influenced by MYC expression/translocation and cell proliferation. In HGBL, compared to BL, there was an upregulation of PRKAR2B and TERT. HGBL DH exhibited elevated expression of GAMT and SMIM14, while HGBL NOS showed increased expression of MIR155HG and LZTS1. Our gene mutation analysis revealed MYC, ARID1A, BCL2, KMT2D, and PIM1 as the most affected genes in B-cell lymphoma, with BCL2 and CREBBP predominant in HGBL DH, and MYC and PIM1 in HGBL NOS. Clonality analysis of immunoglobulin heavy and light chain rearrangements did not show distinguishable V- or J-usage between the diagnostic subgroups.

Splenic marginal zone lymphoma with prolymphocytic transformation and cyclin D1 expression in the absence of CCND1 rearrangement.

Splenic marginal zone lymphoma (SMZL) is one of the most common B-cell lymphomas that affect the spleen. We report a case with splenomegaly and lymphocytosis that showed a clonal B-cell population lacking CD5 and CD10 expression. Notably, the atypical lymphoid cells showed prolymphocytoid morphology and expressed cyclin D1. Fluorescence in-situ hybridization was negative for CCND1/IgH rearrangement. The prolymphocytoid morphology and cyclin D1 expression present a diagnostic pitfall. The clinical presentation, morphology, immunophenotype, and molecular genetic findings are most consistent with a diagnosis of SMZL with prolymphocytic transformation and cyclin D1 expression. Here, we present this case along with a review of the literature, and summarize the clinicopathological characteristics of SMZL with prolymphocytic transformation.

Histologic, Phenotypic, and Molecular Characterization of Feline Hodgkin-Like Lymphoma With Classical Reed-Sternberg Cells.

Hodgkin-like lymphoma (HLL) is a rare neoplasm in cats that shares characteristics with the human disease. The hallmark of HLL is the presence of Reed-Sternberg (RS) cells expressing CD30 and CD20. This study aimed to elucidate the clinicopathologic features, immunophenotype and clonality patterns of feline HLL. A comprehensive retrospective review of clinicopathologic and molecular data of nodal lymphomas over a 6-year period was conducted in MyLav laboratory. Twenty-four cases were identified. All cats presented with submandibular or retropharyngeal lymphadenopathy. Histopathologic examination revealed a multifocal to diffuse proliferation of medium-to-large lymphoid cells with low mitotic activity, interspersed RS cells, and a heterogeneous inflammatory infiltrate comprising T-cells, plasma cells and neutrophils. In addition, extensive necrosis was a consistent finding. Immunohistochemistry showed a variable membranous CD20 and nuclear PAX5 expression in neoplastic cells, while RS cells displayed only mild to moderate CD20 positivity and were negative to PAX5. In 21/24 cases (87.5%), RS cells were diffusely CD30-positive. PARR analysis demonstrated clonal B-cell expansion in 60% of cases, with the remaining 40% exhibiting polyclonality. For the 10 cats with available follow-up, the prognosis was generally favourable, with only two cats succumbing to progressive disease. In conclusion, diagnosing feline HLL is challenging. The expression of CD30 and CD20 by RS cells should be considered a hallmark of the disease, but only after excluding differential diagnoses such as anaplastic B-cell lymphoma and granulomatous lymphadenopathy.

Nonequilibrium Antigen Recognition during Infections and Vaccinations

The initial immune response to an acute primary infection is a coupled process of antigen proliferation, molecular recognition by naive B cells, and their subsequent clonal expansion. This process contains a fundamental problem: the recognition of an exponentially time-dependent antigen signal. Here, we show that an efficient immune response must be stringently constrained to B-cell lineages with high antigen binding affinity. We propose a tuned proofreading mechanism for primary recognition of new antigens, where the molecular recognition machinery is adapted to the complexity of the immune repertoire. We show that this process produces potent, specific, and fast recognition of antigens, maintaining a spectrum of genetically distinct B-cell lineages as input for affinity maturation. Our analysis maps the proliferation-recognition dynamics of a primary infection to a generalized Luria-Delbrück process, akin to the dynamics of the classic fluctuation experiment. This map establishes a link between signal recognition dynamics and evolution. We derive the resulting statistics of the activated immune repertoire: Antigen binding affinity, expected size, and frequency of active B-cell clones are related by power laws, which define the class of generalized Luria-Delbrück processes. Their exponents depend on the antigen and B-cell proliferation rate, the number of proofreading steps, and the lineage density of the naive repertoire. We extend the model to include spatiotemporal processes, including the diffusion-recognition dynamics of a vaccination. Empirical data of activated mouse immune repertoires are found to be consistent with activation involving about three proofreading steps. The model predicts key clinical characteristics of acute infections and vaccinations, including the emergence of elite neutralizers and the effects of immune aging. More broadly, our results establish infections and vaccinations as a new probe into the global architecture and functional principles of immune repertoires. Published by the American Physical Society 2024

Bilateral development of biclonal ocular adnexal marginal zone lymphoma at a 2-year interval.

Ocular adnexal marginal zone B-cell lymphoma (OAMZL) of the mucosa-associated lymphoid tissue is a distinct subtype of B-cell lymphoma. OAMZL occasionally occurs on both sides with a varied sequence in the time course. However, few case reports have described clonal analysis of bilateral OAMZ. Here we present a case of biclonal OAMZL, that developed bilaterally at a 2-year interval. A 38-year-old woman was diagnosed with OAMZL in the right lower eyelid conjunctiva and received local radiation therapy, resulting in the disappearance of the tumor. Two years later, she developed another tumor in the left lower eyelid and was diagnosed with relapse of OAMZL. She was re-treated successfully with radiation therapy. Analysis of immunoglobulin (Ig) gene rearrangement in the bilateral tumor samples showed different clonotypic VDJ recombination within the Ig heavy chain gene and different patterns of rearrangement of the Ig light chain genes. The results indicated that independent B-cell clones causing the specific subtype of lymphoma had generated in both eyes. The biclonal nature of the lymphoma that developed sequentially in the same anatomic site in this case suggests that underlying inherent or environmental factors may lead to ongoing emergence of new tumor clones.

Immunophenotypic features of early haematopoietic and leukaemia stem cells.

Many tumours are organised in a hierarchical structure with at its apex a cell that can maintain, establish, and repopulate the tumour-the cancer stem cell. The haematopoietic stem cell (HSC) is the founder cell for all functional blood cells. Like HSCs, the leukaemia stem cells (LSC) are hypothesised to be the leukaemia-initiating cells, which have features of stemness such as self-renewal, quiescence, and resistance to cytotoxic drugs. Immunophenotypically, CD34+CD38- defines HSCs by adding lineage negativity and CD90+CD45RA-. At which stage of maturation the further differentiation is blocked, determines the type of leukaemia, and determines the immunophenotype of the LSC specific to the leukaemia type. No apparent LSC phenotype has been described in lymphoid leukaemia, and it is debated if a specific acute lymphocytic leukaemia-initiating cell is present, as all cells are capable of engraftment in a secondary mouse model. In chronic lymphocytic leukaemia, a B-cell clone is responsible for uncontrolled proliferation, not a specific LSC. In chronic and acute myeloid leukaemia, LSC is described as CD34+CD38- with the expression of a marker that is aberrantly expressed (LSC marker), such as CD45RA, CD123 or in the case of chronic myeloid leukaemia CD26. In acute myeloid leukaemia, the LSC load had prognostic relevance and might be a biomarker that can be used for monitoring and as an addition to measurable residual disease. However, challenges such as the CD34-negative immunophenotype need to be explored.

Primary diffuse large B-cell lymphoma of the central nervous system identified with CSF biomarkers

BackgroundDiagnosis of primary diffuse large B-cell lymphoma of the central nervous system (PCNSL) is challenging and often delayed. MRI imaging, CSF cytology and flow cytometry have a low sensitivity and even brain biopsies can be misleading. We report three cases of PCNSL with various clinical presentation and radiological findings where the diagnosis was suggested by novel CSF biomarkers and subsequently confirmed by brain biopsy or autopsy.Case presentations.The first case is a 79-year-old man with severe neurocognitive dysfunction and static ataxia evolving over 5 months. Brain MRI revealed a nodular ventriculitis. An open brain biopsy was inconclusive. The second case is a 60-year-old woman with progressive sensory symptoms in all four limbs, evolving over 1 year. Brain and spinal MRI revealed asymmetric T2 hyperintensities of the corpus callosum, corona radiata and corticospinal tracts. The third case is a 72-year-old man recently diagnosed with primary vitreoretinal lymphoma of the right eye. A follow-up brain MRI performed 4 months after symptom onset revealed a T2 hyperintense fronto-sagittal lesion, with gadolinium uptake and perilesional edema. In all three cases, CSF flow cytometry and cytology were negative. Mutation analysis on the CSF (either by digital PCR or by next generation sequencing) identified the MYD88 L265P hotspot mutation in all three cases. A B-cell clonality study, performed in case 1 and 2, identified a monoclonal rearrangement of the immunoglobulin light chain lambda (IGL) and kappa (IGK) gene. CSF CXCL-13 and IL-10 levels were high in all three cases, and IL-10/IL-6 ratio was high in two. Diagnosis of PCNSL was later confirmed by autopsy in case 1, and by brain biopsy in case 2 and 3.ConclusionsTaken together, 5 CSF biomarkers (IL-10, IL-10/IL-6 ratio, CXCL13, MYD88 mutation and monoclonal IG gene rearrangements) were strongly indicative of a PCNSL. Using innovative CSF biomarkers can be sensitive and complementary to traditional CSF analysis and brain biopsy in the diagnosis of PCNSL, potentially allowing for earlier diagnosis and treatment.

Efficacy of autologous stem cell transplantation for crystalline kappa light chain proximal tubulopathy early recurrence after kidney transplantation

Monoclonal gammopathy of renal significance is defined as kidney injury due to underlying immunoglobulin-secreting plasma-cell or B-cell clone. Here, we report the case of a patient with incomplete Fanconi Syndrome diagnosed two months after Kidney Transplantation (KT)

The immune response behind peptide vaccination in diffuse midline glioma.

A first-in-human trial demonstrated that a vaccine targeting the histone mutation H3K27M can induce an immune response, in a mutation-specific manner, in patients with diffuse midline glioma. In a recent study by Boschert etal., the same group now dissects the functional immune response triggered after effective vaccination of one of the patients, who has been in remission for over 3 years. The H3K27M peptide vaccine, named H3-vac, induces a CD4+ T-cell-specific immune response in this patient and expands the repertoire of polyclonal H3K27M-specific T-cell receptors. A clonal H3K27M-reactive B-cell population was also detected in the patient's cerebrospinal fluid. Importantly, the immune response is induced across various human leukocyte antigen alleleotypes, indicating the potential efficacy of the vaccine in diverse populations. By exploring in detail the immune response linked to this patient's long-term survival, the authors prove peptide vaccinations as a viable therapeutic approach. This paves the way for personalised therapies harnessing immunogenic T- and B-cell responses against different tumour types.

Cold-antibody Autoimmune Hemolytic Anemia: its Association with Neoplastic Disease and Impact on Therapy.

Cold-antibody mediated autoimmune hemolytic anemia (cAIHA) is subclassified as cold agglutinin disease (CAD), secondary cold agglutinin syndrome (CAS), and paroxysmal cold hemoglobinuria (PCH). This review aims to address the occurrence of neoplastic disorders with these three entities and analyze the impact of such neoplasias on treatment for cAIHA. "Primary" CAD is a distinct clonal B-cell lymphoproliferative disorder in probably all cases, although not classified as a malignant lymphoma. CAS is secondary to malignant lymphoma in a minority of cases. Recent findings allow a further clarification of these differential diagnoses and the therapeutic consequences of specific neoplastic entities. Appropriate diagnostic workup is critical for therapy in cAIHA. Patients with CAD should be treated if they have symptomatic anemia, significant fatigue, or bothersome circulatory symptoms. The distinction between CAD and CAS and the presence of any underlying malignancy in CAS have essential therapeutic implications.

Integrated spatial and multimodal single-cell transcriptomics reveal patient-dependent cell heterogeneity in splenic marginal zone lymphoma.

Biological hallmarks of splenic marginal zone lymphoma (SMZL) remain poorly described. Herein, we performed in-depth SMZL characterization through multimodal single-cell analyses of paired blood/spleen samples. The 3'-single-cell RNA-sequencing, Cellular Indexing of Transcriptomes and Epitopes by sequencing, and 5'-V(D)J single-cell RNA-sequencing datasets were integrated to characterize SMZL transcriptome profiles, including B-cell receptor and T-cell receptor repertoires. Hyperexpanded B-cell clones in the spleen were at a memory-like stage, whereas recirculating tumor B-cells in blood encompassed multiple differentiation stages, indicating an unexpected desynchronization of the B-cell maturation program in SMZL cells. Spatial transcriptomics showed the enrichment of T-effector and T-follicular helper (TFH) signatures in the nodular subtype of SMZL. This latter also exhibited gene-based cell-cell interactions suggestive of dynamic crosstalk between TFH and cancer cells in transcriptomics, further substantiated by using imaging mass cytometry. Our findings provide a comprehensive high-resolution description of SMZL biological hallmarks and characterize, for the first time in situ, inter- and intra-patient heterogeneity at both transcriptomic and protein levels. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.