Immunoglobulin High Throughput Sequencing (Ig-HTS) Minimal Residual Disease (MRD) Analysis is an Effective Surveillance Tool in Patients With Mantle Cell Lymphoma.

INTRODUCTION: Mantle cell lymphoma (MCL) accounts for 4% to 6% of B-cell non-Hodgkin lymphoma with historically poor outcomes. With the advent of intensive first-line, targeted, and cellular therapies, outcomes have improved, and initial remission can be 8 to 10 years or longer. As patients experience longer remissions, this raises the question of the optimal surveillance modality. Peripheral blood minimal residual disease (MRD) analysis offers a potential alternative to surveillance imaging that is sensitive, less costly, and eliminates the risk of radiation exposure. MATERIALS AND METHODS: The clonoSEQ assay (Adaptive Biotechnologies) is an FDA-cleared commercially available Ig-HTS MRD assay with a sensitivity of 1 cell in 1,000,000. We performed a retrospective analysis of 34 patients from 2015 to 2021, who underwent MRD testing after achieving remission with first-line therapy. RESULTS: With a median follow-up of 6.5 years, 10-year progression free survival (PFS) was 60% and 10-year overall survival was 92% of the entire cohort. Among 12 patients who sustained a radiographic relapse, peripheral blood became MRD+ either at or prior to the time of relapse in 11 patients (92%). The first MRD+ test had a lead time of 0 to 24 months (median 34 days) prior to radiographic relapse. Only 1 patient had a MRD- result while being found to have progressive disease on imaging. Among 22 patients who sustained continuous clinical remission, 21 have remained MRD-. Several patients were able to enjoy 2 to 4-year intervals without surveillance imaging. CONCLUSIONS: Our data suggest that the clonoSEQ MRD assay is an effective surveillance tool for MCL patients following first-line therapy and is predictive of relapse prior to imaging.

Outcomes of limited stage primary bone diffuse large B-cell lymphoma in the rituximab era: a multicenter, retrospective study.

Primary bone diffuse large B cell lymphoma (DLBCL) is a rare variant of extranodal non-Hodgkin lymphoma (NHL) historically treated with induction chemotherapy followed by consolidative radiation therapy (RT). It remains unknown whether RT confers additional benefit following rituximab-based chemoimmunotherapy (CIT) induction in patients with limited-stage disease. We conducted a multicenter retrospective analysis of patients treated between 2005 and 2019 using rituximab-based CIT regimens with or without consolidative RT to discern whether consolidative RT adds benefit in patients with stage I-II disease that could be encompassed in one radiation field. A total of 112 patients were included: 78 received CIT and radiation (RT group), and 34 received CIT alone (no RT group). The OS at 10 years was 77.9% in the RT group and 89.0% in the no RT group (p = 0.42). The RFS at 10 years was 73.5% in the RT group and 80.3% in the no RT group (p = 0.88). Neither improved OS nor RFS was associated with the addition of consolidative RT. Subgroup analysis of patients only achieving a partial response after CIT suggests that these patients may benefit from consolidative RT.

Proposals for Clinical Trials in Chronic Myelomonocytic Leukemia.

OPINION STATEMENT: Chronic myelomonocytic leukemia (CMML) is a clonal hematologic malignancy of mostly older individuals that exhibits both myelodysplastic and myeloproliferative features. CMML presentation and outcome are variable, reflecting genetic and clinical heterogeneity. Hypomethylating agents are the mainstay of therapy but induce complete remissions in less than 20% of patients and do not prolong survival compared to hydroxyurea. Allogeneic stem cell transplant (ASCT) is potentially curative, but few patients qualify due to advanced age and/or comorbidities. Work of the past several years has identified key molecular pathways that drive disease proliferation and transformation to acute leukemia, including JAK/STAT and MAPK signaling and epigenetic dysregulation. There is increasingly compelling evidence that inflammation is a major driver of CMML progression. Thus far however, this mechanistic knowledge has not yet been translated into improved outcomes, suggesting that fundamentally new approaches are required. In this review, we discuss the disease course, new classifications, and current treatment landscape of CMML. We review ongoing clinical studies and discuss options for rationally based future clinical trials.

Using novel PF4-dependent P-selectin expression assay to diagnose heparin-induced thrombocytopaenia postliver transplantation.

Heparin-induced thrombocytopaenia (HIT) is a well-known adverse event associated with the use of heparin products. HIT may be difficult to diagnose in patients following liver transplantation as patients routinely require massive transfusion support and immunosuppression. As an alternative or adjunctive to the serotonin release assay, the PF4-dependent P-selectin expression assay (PEA) may be a useful diagnostic test in the determination of HIT in this patient population. In this case, we describe a 63-year-old man who had an orthotopic liver transplant that was complicated by HIT that was diagnosed using the PEA.

Management of Myeloproliferative Neoplasms in the Molecular Era: From Research to Practice.

The 1960 discovery of the Philadelphia chromosome in chronic myeloid leukemia (CML) marked the beginning of the modern genomic era of oncology. In the following years, the molecular underpinnings of CML were unraveled, culminating in the development of the first molecularly targeted therapy: imatinib. Imatinib revolutionized CML management, inducing deep molecular responses for most patients and aligning survival curves with those of age-matched control participants. Five additional tyrosine kinase inhibitors are now approved for CML: dasatinib, nilotinib, bosutinib, ponatinib, and asciminib (approved October 2021). The 2005 discovery of JAK2 mutations in myelofibrosis (MF) sparked enthusiasm that molecularly targeted therapies could have a similar impact in that disease. Three JAK inhibitors are now available for MF: ruxolitinib, fedratinib, and pacritinib (approved February 2022). JAK inhibitors are helpful for improving symptoms and splenomegaly but still only scratch the surface of MF pathophysiology. Clinical research testing novel agents, next-generation JAK inhibitors, and combinations of JAK inhibitors plus novel agents is moving at a tremendous pace in the hope that outcomes for patients with MF may mirror those with CML one day. This review provides an update on the status of clinical care and research for MF and addresses ongoing issues related to CML management.

Restoration of Corneal Transparency by Mesenchymal Stem Cells.

Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs) have gained prominence due to their inflammation-suppressing and tissue repair functions. Here, we investigate the potential of MSCs to restore corneal transparency following ocular injury. Using an in vivo mouse model of ocular injury, we report that MSCs have the capacity to restore corneal transparency by secreting high levels of hepatocyte growth factor (HGF). Interestingly, our data also show that HGF alone can restore corneal transparency, an observation that has translational implications for the development of HGF-based therapy.

Mesenchymal stem cells home to inflamed ocular surface and suppress allosensitization in corneal transplantation.

PURPOSE: To investigate whether systemically injected syngeneic mesenchymal stem cells (MSCs) can home to the transplanted cornea, suppress induction of alloimmunity, and promote allograft survival. METHODS: Mesenchymal stem cells were generated from bone marrow of wild-type BALB/c or GFP (green fluorescent protein)+ C57BL/6 mice, and 1×10(6) cells were intravenously injected to allografted recipients 3 hours after surgery. Mesenchymal stem cells homing to the cornea were examined at day 3 post transplantation by immunohistochemistry. MHC (major histocompatibility complex) II+CD11c+ cells were detected in the cornea and lymph nodes (LNs) 14 days post transplantation using flow cytometry. Cytokine expression of bone marrow-derived dendritic cells (BMDCs) was determined using real-time PCR. ELISPOT assay was used to assess indirect and direct host T cell allosensitization, and graft survival was evaluated by slit-lamp biomicroscopy weekly up to 8 weeks. RESULTS: Intravenously injected GFP+ MSCs were found in abundance in the transplanted cornea, conjunctiva, and LNs, but not in the ungrafted (contralateral) tissue. The frequencies of mature MHC II+CD11c+ antigen-presenting cells (APCs) were substantially decreased in the corneas and draining LNs of MSC-injected allograft recipients compared to control recipients. Maturation and function of in vitro cultured BMDCs were decreased when cocultured with MSCs. Draining LNs of MSC-injected allograft recipients showed lower frequencies of IFNγ-secreting Th1 cells compared to the control group. Allograft survival rate was significantly higher in MSC-injected recipients compared to non-MSC-injected recipients. CONCLUSIONS: Our data demonstrate that systemically administered MSCs specifically home to the inflamed ocular surface and promote allograft survival by inhibiting APC maturation and induction of alloreactive T cells.