Venous and arterial thrombosis in patients with VEXAS syndrome.

ABSTRACT: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, caused by somatic mutations in UBA1, is an autoinflammatory disorder with diverse systemic manifestations. Thrombosis is a prominent clinical feature of VEXAS syndrome. The risk factors and frequency of thrombosis in VEXAS syndrome are not well described, due to the disease's recent discovery and the paucity of large databases. We evaluated 119 patients with VEXAS syndrome for venous and arterial thrombosis and correlated their presence with clinical outcomes and survival. Thrombosis occurred in 49% of patients, mostly venous thromboembolism (VTE; 41%). Almost two-thirds of VTEs were unprovoked, 41% were recurrent, and 20% occurred despite anticoagulation. The cumulative incidence of VTE was 17% at 1 year from symptom onset and 40% by 5 years. Cardiac and pulmonary inflammatory manifestations were associated with time to VTE. M41L was positively associated specifically with pulmonary embolism by univariate (odds ratio [OR]: 4.58, confidence interval [CI] 1.28-16.21, P = .02) and multivariate (OR: 16.94, CI 1.99-144.3, P = .01) logistic regression. The cumulative incidence of arterial thrombosis was 6% at 1 year and 11% at 5 years. The overall survival of the entire patient cohort at median follow-up time of 4.8 years was 88%, and there was no difference in survival between patients with or without thrombosis (P = .8). Patients with VEXAS syndrome are at high risk of VTE; thromboprophylaxis should administered be in high-risk settings unless strongly contraindicated.

Natural history study of patients with familial platelet disorder with associated myeloid malignancy.

ABSTRACT: Deleterious germ line RUNX1 variants cause the autosomal dominant familial platelet disorder with associated myeloid malignancy (FPDMM), characterized by thrombocytopenia, platelet dysfunction, and a predisposition to hematologic malignancies (HMs). We launched a FPDMM natural history study and, from January 2019 to December 2021, enrolled 214 participants, including 111 patients with 39 different RUNX1 variants from 45 unrelated families. Seventy of 77 patients had thrombocytopenia, 18 of 18 had abnormal platelet aggregometry, 16 of 35 had decreased platelet dense granules, and 28 of 55 had abnormal bleeding scores. Nonmalignant bone marrows showed increased numbers of megakaryocytes in 12 of 55 patients, dysmegakaryopoiesis in 42 of 55, and reduced cellularity for age in 30 of 55 adult and 17 of 21 pediatric cases. Of 111 patients, 19 were diagnosed with HMs, including myelodysplastic syndrome, acute myeloid leukemia, chronic myelomonocytic leukemia, acute lymphoblastic leukemia, and smoldering myeloma. Of those 19, 18 were relapsed or refractory to upfront therapy and referred for stem cell transplantation. In addition, 28 of 45 families had at least 1 member with HM. Moreover, 42 of 45 patients had allergic symptoms, and 24 of 30 had gastrointestinal (GI) symptoms. Our results highlight the importance of a multidisciplinary approach, early malignancy detection, and wider awareness of inherited disorders. This actively accruing, longitudinal study will genotype and phenotype more patients with FPDMM, which may lead to a better understanding of the disease pathogenesis and clinical course, which may then inform preventive and therapeutic interventions. This trial was registered at www.clinicaltrials.gov as #NCT03854318.

The Effectiveness of Dual-Staining Immunohistochemistry in the Detection of Mantle Cell Lymphoma in the Bone Marrow.

OBJECTIVES: Immunohistochemistry (IHC) is a useful method for mantle cell lymphoma (MCL) detection in the bone marrow (BM). However, recognition of the neoplastic B cells can be challenging, especially when there is low-level disease. METHODS: We examined BM from 105 patients with MCL. IHC was performed using cyclin D1/CD79a and PAX5/CD5 dual stains, which were compared with single stains that included CD20, CD79a, cyclin D1, and CD5 and with multiparameter flow cytometry (FC). RESULTS: Based on the FC data, the overall sensitivity of the dual IHC stains was 95.6%. Both dual IHC stains showed better efficacy for detecting MCL cells compared with the aggregated single stains (P = .012). While three cases were positive by FC analysis but negative for dual staining, four cases showed cells positive for cyclin D1/CD79a and PAX5/CD5 dual staining that were not detected by FC. Two of these latter cases were in patients with minimal or focal disease involvement. CONCLUSIONS: Cyclin D1/CD79a and PAX5/CD5 dual IHC staining is an efficient procedure for the detection of MCL in the marrow and is particularly helpful in low-level or focal involvement by MCL. This approach can be particularly useful when marrow aspirates are inadequate or unavailable.

Long term follow-up of a phase II study of cladribine with concurrent rituximab with hairy cell leukemia variant.

Hairy cell leukemia variant (HCLv) responds poorly to purine analogue monotherapy. Rituximab concurrent with cladribine (CDAR) improves response rates, but long-term outcomes are unknown. We report final results of a phase 2 study of CDAR for patients with HCLv. Twenty patients with 0 to 1 prior courses of cladribine and/or rituximab, including 8 who were previously untreated, received cladribine 0.15 mg/kg on days 1 to 5 with 8 weekly rituximab doses of 375 mg/m2 beginning day 1. Patients received a second rituximab course ≥6 months after cladribine, if and when minimal residual disease (MRD) was detected in blood. The complete remission (CR) rate from CDAR was 95% (95% confidence interval, 75-100). Sixteen (80%) of 20 patients (95% confidence interval, 56-94) became MRD negative according to bone marrow at 6 months. The median duration of MRD-negative CR was 70.1 months, and 7 of 16 are still MRD negative up to 120 months. With a median follow-up of 69.7 months, 11 patients received delayed rituximab, and the 5-year progression-free survival (PFS) and overall survival (OS) were 63.3% and 73.9%, respectively. Five patients with TP53 mutations had shorter PFS (median, 36.4 months vs unreached; P = .0024) and OS (median, 52.4 months vs unreached; P = .032). MRD-negative CR at 6 months was significantly associated with longer PFS (unreached vs 17.4 months; P < .0001) and OS (unreached vs 38.2 months; P < .0001). Lack of MRD in blood at 6 months was also predictive of longer PFS and OS (P < .0001). After progression following CDAR, median OS was 29.7 months. CDAR is effective in HCLv, with better outcomes in patients who achieve MRD-negative CR. This trial is registered at www.clinicaltrials.gov as #NCT00923013.

Carfilzomib, Lenalidomide, and Dexamethasone Followed by Lenalidomide Maintenance for Prevention of Symptomatic Multiple Myeloma in Patients With High-risk Smoldering Myeloma: A Phase 2 Nonrandomized Controlled Trial.

IMPORTANCE: High-risk smoldering myeloma has a 5-year risk of progression to symptomatic multiple myeloma of approximately 75%. Treatment with lenalidomide decreases the risk of progression; however, novel triplet regimens are superior, and earlier disease may be more treatment sensitive. OBJECTIVE: To evaluate the use of carfilzomib, lenalidomide, and dexamethasone (KRd) with lenalidomide maintenance therapy as early intervention in high-risk smoldering myeloma and to determine the rates of minimal residual disease (MRD)-negative complete response (CR). DESIGN, SETTING, AND PARTICIPANTS: In this single-arm, single-center, phase 2 nonrandomized controlled trial, responses were evaluated at every cycle during KRd treatment and every 3 cycles subsequently. Bone marrow biopsies and imaging were performed by cycle 8 and then annually. The study enrolled patients from May 29, 2012, to July 23, 2020, at the National Institutes of Health Clinical Center, a highly specialized tertiary cancer center. Patient key eligibility criteria included a diagnosis of high-risk smoldering myeloma based on the Mayo Clinic, Spanish, and/or Rajkumar, Mateos, and Landgren criteria. INTERVENTIONS: Patients received eight 4-week cycles of intravenous carfilzomib 36 mg/m2 (first 2 doses, 20 mg/m2), dexamethasone (20 mg, cycles 1-4; 10 mg, cycles 5-8 twice weekly), and lenalidomide 25 mg (days 1-21) followed by twenty-four 28-day cycles of maintenance lenalidomide 10 mg (days 1-21). Stem cell harvest and storage were optional. MAIN OUTCOMES AND MEASURES: The primary outcome was the MRD-negative CR rate. Key secondary outcomes included duration of MRD-negative CR and progression to multiple myeloma. RESULTS: A total of 54 patients (median age, 59 years [range, 40-79 years]; 30 men [55.6%]; and 2 Asian [3.7%], 15 Black [27.8%], 1 Hispanic [1.9%], and 36 White [66.7%] patients) were enrolled, with a median potential follow-up time of 31.9 months (range, 6.7-102.9 months). The MRD-negative CR rate was 70.4% (95% CI, 56.4%-82.0%), with a median sustained duration of 5.5 years (95% CI, 3.7 years to not estimable). The 8-year probability of being free from progression to multiple myeloma was 91.2% (95% CI, 67.4%-97.9%), and no deaths occurred. Nonhematologic grade 3 adverse events occurred in 21 patients (38.9%) and included thromboembolism, rash, and lung infection, with no grade 4 events. CONCLUSIONS AND RELEVANCE: Results of this phase 2 nonrandomized controlled trial suggest that treatment of high-risk smoldering myeloma with novel triplet regimens, such as KRd and lenalidomide maintenance therapy, may alter the natural history of smoldering myeloma by significantly delaying development of end-organ disease. Randomized clinical trials are needed to confirm this favorable benefit-to-risk profile. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01572480.

Avelumab, a PD-L1 Inhibitor, in Combination with Hypofractionated Radiotherapy and the Abscopal Effect in Relapsed Refractory Multiple Myeloma.

LESSONS LEARNED: Despite the initial optimism for using immune checkpoint inhibition in the treatment of multiple myeloma, subsequent clinical studies have been disappointing. Preclinical studies have suggested that priming the immune system with various modalities in addition to checkpoint inhibition may overcome the relative T-cell exhaustion or senescence; however, in this small data set, radiotherapy with checkpoint inhibition did not appear to activate the antitumor immune response. BACKGROUND: Extramedullary disease (EMD) is recognized as an aggressive subentity of multiple myeloma (MM) with a need for novel therapeutic approaches. We therefore designed a proof-of-principle pilot study to evaluate the synergy between the combination of the anti-PD-L1, avelumab, and concomitant hypofractionated radiotherapy. METHODS: This was a single-arm phase II Simon two-stage single center study that was prematurely terminated because of the COVID-19 pandemic after enrolling four patients. Key eligibility included patients with relapsed/refractory multiple myeloma (RRMM) who had exhausted or were not candidates for standard therapy and had at least one lesion amenable to radiotherapy. Patients received avelumab until progression or intolerable toxicity and hypofractionated radiotherapy to a focal lesion in cycle 2. Radiotherapy was delayed until cycle 2 to allow the avelumab to reach a study state, given the important observation from previous studies that concomitant therapy is needed for the abscopal effect. RESULTS: At a median potential follow-up of 10.5 months, there were no objective responses, one minimal response, and two stable disease as best response. The median progression-free survival (PFS) was 5.3 months (95% confidence interval [CI]: 2.5-7.1 months), and no deaths occurred. There were no grade ≥3 and five grade 1-2 treatment-related adverse events. CONCLUSION: Avelumab in combination with radiotherapy for patients with RRMM and EMD was associated with very modest systemic clinical benefit; however, patients did benefit as usual from local radiotherapy. Furthermore, the combination was very well tolerated compared with historical RRMM treatment regimens.

Daratumumab for delayed RBC engraftment following major ABO mismatched haploidentical bone marrow transplantation.

BACKGROUND: Recent case reports have described the efficacy of daratumumab to treat refractory pure red cell aplasia (PRCA) following major ABO mismatched allogeneic hematopoietic stem cell transplantation (HSCT). In this report, we describe the use of daratumumab as a first-line agent for treatment of delayed red blood cell (RBC) engraftment following a major ABO mismatched pediatric HSCT and provide a review of the literature. STUDY DESIGN AND MATERIALS: We report on a 14-year-old with DOCK8 deficiency who underwent a myeloablative, haploidentical bone marrow transplant from her major ABO mismatched sister (recipient O+, donor A+) for treatment of her primary immunodeficiency. Despite achieving full donor chimerism, she had delayed RBC engraftment requiring ongoing transfusions. Due to iron deposition, symptomatic anemia, and persistence of anti-A iso-hemagglutinins despite discontinuation of immunosuppression, treatment for delayed RBC engraftment with the CD38-targeted monoclonal antibody daratumumab was selected as a less immunosuppressive agent that could more selectively target iso-hemagglutinin producing plasma cells without causing broad B-cell aplasia. RESULTS: Clinical effect with daratumumab was demonstrated by reduced iso-hemagglutinin titer, increased reticulocytosis, normalization of her hemoglobin, and transfusion independence. In the 11-month follow-up period to date, no additional transfusions or immunosuppression have been necessary, despite persistence of low-level anti-A iso-hemagglutinin. CONCLUSION: Our experience suggests that daratumumab was an effective first-line therapy for delayed RBC engraftment and that earlier consideration for daratumumab in treatment of delayed RBC engraftment may be warranted.

Randomized Phase II Study of First-Line Cladribine With Concurrent or Delayed Rituximab in Patients With Hairy Cell Leukemia.

PURPOSE: Single-agent purine analog, usually cladribine, has been the standard first-line therapy of hairy cell leukemia (HCL) for 30 years. High complete remission (CR) rates often include minimal residual disease (MRD), leading to relapse and repeated treatments. Rituximab can clear MRD, but long-term results are unknown and optimal timing of rituximab undefined. PATIENTS AND METHODS: Patients were randomly assigned to first-line cladribine 0.15 mg/kg intravenously days 1-5 with 8 weekly doses of rituximab 375 mg/m2 begun either day 1 (concurrent, CDAR) or ≥ 6 months later (delayed) after detection of MRD in blood. MRD tests included blood and bone marrow (BM) flow cytometry, and BM immunohistochemistry. RESULTS: Sixty-eight patients with purine analog-naïve classic HCL were randomly assigned 1:1 to concurrent versus delayed arms. At 6 months after CDAR versus cladribine monotherapy, CR rates were 100% versus 88% (P = .11), MRD-free CR rates 97% versus 24% (P < .0001, primary end point), and blood MRD-free rates 100% versus 50% (P < .0001), respectively. At 96 months median follow-up, 94% versus 12% remained MRD free. Compared with CDAR, delayed rituximab after cladribine achieved lower rate (67% of 21 evaluable patients; P = .0034) and durability (P = .0081, hazard radio favoring CDAR, 0.094) of MRD-free CR. Nevertheless, 12 patients in the delayed arm remained MRD free when restaged 6-104 (median, 78) months after last delayed rituximab treatment. Compared with cladribine monotherapy, CDAR led to brief grade 3/4 thrombocytopenia (59% v 9%; P < .0001) and platelet transfusions without bleeding (35% v 0%; P = .0002), but higher neutrophil (P = .017) and platelet (P = .0015) counts at 4 weeks. CONCLUSION: Achieving MRD-free CR of HCL after first-line cladribine is greatly enhanced by concurrent rituximab and less so by delayed rituximab. Longer follow-up will determine if MRD-free survival leads to less need for additional therapy or cure of HCL.

Immunophenotyping of Acute Myeloid Leukemia.

Immunophenotyping by multiparameter flow cytometry is a rapid and efficient technique to simultaneously assess and correlate multiple individual cell properties like size and internal complexity along with antigen expression in a population of cells. This method is utilized for rapid characterization of the blasts and classification of acute myeloid leukemia (AML), in both the peripheral blood (PB) and bone marrow (BM). This technique is not only useful in the initial diagnosis but also in monitoring and determining prognosis of the disease through minimal residual disease (MRD) testing. This chapter provides an overview of procedures for specimen processing, staining, and immunophenotyping of AML and describes the principles of data analysis for AML classification and MRD testing.

The challenging task of enumerating blasts in the bone marrow.

Enumeration of blasts in the bone marrow is critical for diagnostic, prognostic, and therapeutic response evaluation in myelodysplastic syndromes, myeloproliferative neoplasms and acute leukemias. However, few studies have examined the accuracy and precision of marrow blast counting using standard microscopic procedures. In our study, 4 experienced hematopathologists evaluated blast percentages in marrow using either differential counts on aspirate smears or visual estimates on CD34-stained trephine biopsies. Results of an independent observer's manual counts of individual labeled and unlabeled cells performed on high resolution digital images of CD34-stained trephine biopsies were designated as the "Digital Reference." Hematopathologists' blast counts showed excellent interobserver reproducibility, but the counts in smears and trephine biopsies correlated poorly with each other. Compared to the Digital Reference, both smear and trephine evaluations showed positive bias and high variability. The biopsy showed less variability but higher positive bias relative to the smears, indicating that counts were overestimated more in the hematopathologists' biopsy evaluation. Flow cytometric counts correlated well with the Digital Reference, and cases with high blast count generally showed worse cytogenetic findings. Our results demonstrate the need for better counting methods if significant decisions are made based on microscopic enumeration of blasts. Further efforts should be made to develop markers to better define blast cells and perhaps incorporate automated digital imaging technologies to enumerate them. Also, consideration should be given to quantifying blasts per marrow area in biopsies instead of per nucleated cells.

Detection of paroxysmal nocturnal hemoglobinuria (PNH) in bone marrow aspirates☆.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired condition in which, due to a mutation of the phosphatidylinositol glycan class A gene, hematopoietic cells lack proteins that are normally anchored to the cell surface by glycosylphosphatidylinositol (GPI). Thus, PNH cells show poor expression of surface proteins, such as CD55 and CD59, and dim or absent binding of fluorescently labeled modified aerolysin (FLAER). In clinical diagnostic laboratories, the detection and quantitation of PNH is currently performed by flow cytometry (FC) analysis of peripheral blood (PB) samples. Although PB remains the preferred source of cells for PNH detection, we and other authors have shown that a careful FC analysis of bone marrow (BM) aspirates can provide results for PNH detection and quantitation equivalent to those obtained with PB. Here, we review studies delineating the expression of GPI-anchored proteins and FLAER binding in normal BM cells, and summarize published findings demonstrating the feasibility of identifying and quantitating PNH cells in BM using FLAER as well as antibodies against GPI-anchored proteins. Detection of PNH cells in BM should be useful in patients with unsuspected PNH or with severe cytopenia in whom PB FC analysis may be challenging.

Bone Marrow as a Source of Cells for Paroxysmal Nocturnal Hemoglobinuria Detection.

OBJECTIVES: To determine fluorescently labeled aerolysin (FLAER) binding and glycophosphatidylinositol-anchored protein expression in bone marrow (BM) cells of healthy volunteers and patients with paroxysmal nocturnal hemoglobinuria (PNH) detected in peripheral blood (PB); compare PNH clone size in BM and PB; and detect PNH in BM by commonly used antibodies. METHODS: Flow cytometry analysis of FLAER binding to leukocytes and expression of CD55/CD59 in erythrocytes. Analysis of CD16 in neutrophils and CD14 in monocytes in BM. RESULTS: FLAER binds to all normal BM leukocytes, and binding increases with cell maturation. In PNH, lymphocytic clones are consistently smaller than clones of other BM cells. PNH clones are detectable in mature BM leukocytes with high specificity and sensitivity using common antibodies. CONCLUSIONS: PNH clone sizes measured in mature BM leukocytes and in PB are comparable, making BM suitable for PNH assessment. We further demonstrate that commonly used reagents (not FLAER or CD55/CD59) can reliably identify abnormalities of BM neutrophils and monocytes consistent with PNH cells.

Expression of the IL-6 receptor alpha-chain (CD126) in normal and abnormal plasma cells in monoclonal gammopathy of undetermined significance and smoldering myeloma.

IL-6 activity in normal plasma cells (nPCs) and abnormal plasma cells (aPCs) is CD126 (subunit of IL-6 receptor) dependent. We quantified CD126 expression on nPCs and aPCs in monoclonal gammopathy of undetermined significance (MGUS), smoldering myeloma (SMM), and multiple myeloma (MM). CD126 was detected on all nPCs and aPCs indicating that CD126 does not have diagnostic utility. CD126 expression was higher in aPCs than in nPCs in 85% SMM but only 41% MGUS and there was evidence that CD126 was higher in aPCs than nPCs in the SMM (p = .048) but not MGUS (p = .96) patients. There is also a greater association between nPC and aPC CD126 expression in low risk MGUS than observed in high risk MGUS and SMM, suggesting normal regulation of CD126 decreases with disease progression. Future studies need to elucidate the role of bone marrow milieu versus escape from normal CD126 regulation in malignant transformation of clonal plasma cells.

Disruption of in vivo Chronic Lymphocytic Leukemia Tumor-Microenvironment Interactions by Ibrutinib--Findings from an Investigator-Initiated Phase II Study.

PURPOSE: Chronic lymphocytic leukemia (CLL) cells depend on microenvironmental interactions for proliferation and survival that are at least partially mediated through B-cell receptor (BCR) signaling. Ibrutinib, a Bruton tyrosine kinase inhibitor, disrupts BCR signaling and leads to the egress of tumor cells from the microenvironment. Although the on-target effects on CLL cells are well defined, the impact on the microenvironment is less well studied. We therefore sought to characterize the in vivo effects of ibrutinib on the tumor microenvironment. EXPERIMENTAL DESIGN: Patients received single-agent ibrutinib on an investigator-initiated phase II trial. Serial blood and tissue samples were collected pretreatment and during treatment. Changes in cytokine levels, cellular subsets, and microenvironmental interactions were assessed. RESULTS: Serum levels of key chemokines and inflammatory cytokines decreased significantly in patients on ibrutinib. Furthermore, ibrutinib treatment decreased circulating tumor cells and overall T-cell numbers. Most notably, a reduced frequency of the Th17 subset of CD4(+)T cells was observed concurrent with reduced expression of activation markers and PD-1 on T cells. Consistent with direct inhibition of T cells, ibrutinib inhibited Th17 differentiation of murine CD4(+)T cells in vitro Finally, in the bone marrow microenvironment, we found that ibrutinib disaggregated the interactions of macrophages and CLL cells, inhibited secretion of CXCL13, and decreased the chemoattraction of CLL cells. CONCLUSIONS: In conjunction with inhibition of BCR signaling, these changes in the tumor microenvironment likely contribute to the antitumor activity of ibrutinib and may impact the efficacy of immunotherapeutic strategies in patients with CLL. See related commentary by Bachireddy and Wu, p. 1547.

Treatment With Carfilzomib-Lenalidomide-Dexamethasone With Lenalidomide Extension in Patients With Smoldering or Newly Diagnosed Multiple Myeloma.

IMPORTANCE: Carfilzomib-lenalidomide-dexamethasone therapy yields deep responses in patients with newly diagnosed multiple myeloma (NDMM). It is important to gain an understanding of this combination's tolerability and impact on minimal residual disease (MRD) negativity because this end point has been associated with improved survival. OBJECTIVE: To assess the safety and efficacy of carfilzomib-lenalidomide-dexamethasone therapy in NDMM and high-risk smoldering multiple myeloma (SMM). DESIGN, SETTING, AND PARTICIPANTS: Clinical and correlative pilot study at the National Institutes of Health Clinical Center. Patients with NDMM or high-risk SMM were enrolled between July 11, 2011, and October 9, 2013. Median follow-up was 17.3 (NDMM) and 15.9 months (SMM). INTERVENTIONS: Eight 28-day cycles were composed of carfilzomib 20/36 mg/m2 on days 1, 2, 8, 9, 15, and 16; lenalidomide 25 mg on days 1 through 21; and dexamethasone 20/10 mg (cycles 1-4/5-8) on days 1, 2, 8, 9, 15, 16, 22, and 23. Patients who achieved at least stable disease subsequently received 24 cycles of lenalidomide extended dosing. MAIN OUTCOMES AND MEASURES: Primary end points were neuropathy of grade 3 or greater (NDMM) and at least very good partial response rates (SMM). Minimal residual disease was also assessed. RESULTS: Of 45 patients with NDMM, none had neuropathy of grade 3 or greater. Of 12 patients with high-risk SMM, the most common of any-grade adverse events were lymphopenia (12 [100%]) and gastrointestinal disorders (11 [92%]). All patients with SMM achieved at least a very good partial response during the study period. Among the 28 patients with NDMM and the 12 with SMM achieving at least a near-complete response, MRD negativity was found in 28 of 28 (100% [95% CI, 88%-100%]), 11 of 12 (92% [95% CI, 62%-100%]) (multiparametric flow cytometry), 14 of 21 (67% [95% CI, 43%-85%]), and 9 of 12 (75% [95% CI, 43%-94%]) (next-generation sequencing), respectively. In patients with NDMM, 12-month progression-free survival for MRD-negative vs MRD-positive status by flow cytometry and next-generation sequencing was 100% vs 79% (95% CI, 47%-94%; P < .001) and 100% vs 95% (95% CI, 75%-99%; P = .02), respectively. CONCLUSIONS AND RELEVANCE: Carfilzomib-lenalidomide-dexamethasone therapy is tolerable and demonstrates high rates of MRD negativity in NDMM, translating into longer progression-free survival in patients achieving MRD negativity. Carfilzomib-lenalidomide-dexamethasone therapy also demonstrates efficacy in high-risk SMM.

Bone marrow plasma cells are a primary source of serum HIV-1-specific antibodies in chronically infected individuals.

Several potent and broadly neutralizing Abs to HIV-1 have been isolated recently from peripheral blood B cells of infected individuals, based on prescreening of Ab activity in the serum. However, little is known regarding the cells that make the Abs that circulate in the blood. Accordingly, we investigated the most likely source, the bone marrow, of chronically HIV-1-infected individuals who were not receiving antiretroviral therapy. Increased frequencies of plasma cells, as well as B cell precursors, namely preB-I and preB-II, and decreased frequencies of mature B cells were observed in bone marrow aspirates of these individuals compared with HIV-negative counterparts. Increased frequencies of bone marrow plasma cells are consistent with known hallmarks of HIV-1 infection, namely hypergammaglobulinemia and increased frequencies of peripheral blood plasmablasts. Levels of HIV-1 envelope (Env)-binding and HIV-1-neutralizing Abs were measured in serum, and corresponding frequencies of Ab-secreting or Env-binding cells were measured in the blood (plasmablasts and memory B cells) and in the bone marrow (plasma cells). A strong correlation was observed between serum HIV-1-specific Abs and Env-specific bone marrow-derived plasma cells, but not circulating plasmablasts or memory B cells. These findings demonstrate that, despite HIV-1-induced phenotypic and functional B cell dysregulation in the peripheral blood and secondary lymphoid tissues, bone marrow plasma cells remain a primary source for circulating HIV-1-specific Abs in HIV-1-infected individuals.

JMML and RALD (Ras-associated autoimmune leukoproliferative disorder): common genetic etiology yet clinically distinct entities.

Ras-associated autoimmune leukoproliferative disorder (RALD) is a chronic, nonmalignant condition that presents with persistent monocytosis and is often associated with leukocytosis, lymphoproliferation, and autoimmune phenomena. RALD has clinical and laboratory features that overlap with those of juvenile myelomonocytic leukemia (JMML) and chronic myelomonocytic leukemia (CMML), including identical somatic mutations in KRAS or NRAS genes noted in peripheral blood mononuclear cells. Long-term follow-up of these patients suggests that RALD has an indolent clinical course whereas JMML is fatal if left untreated. Immunophenotyping peripheral blood from RALD patients shows characteristic circulating activated monocytes and polyclonal CD10(+) B cells. Distinguishing RALD from JMML and CMML has implications for clinical care and prognosis.