LGR5 expressing skin fibroblasts define a major cellular hub perturbed in scleroderma.

Systemic sclerosis (scleroderma, SSc) is an incurable autoimmune disease with high morbidity and mortality rates. Here, we conducted a population-scale single-cell genomic analysis of skin and blood samples of 56 healthy controls and 97 SSc patients at different stages of the disease. We found immune compartment dysfunction only in a specific subtype of diffuse SSc patients but global dysregulation of the stromal compartment, particularly in a previously undefined subset of LGR5+-scleroderma-associated fibroblasts (ScAFs). ScAFs are perturbed morphologically and molecularly in SSc patients. Single-cell multiome profiling of stromal cells revealed ScAF-specific markers, pathways, regulatory elements, and transcription factors underlining disease development. Systematic analysis of these molecular features with clinical metadata associates specific ScAF targets with disease pathogenesis and SSc clinical traits. Our high-resolution atlas of the sclerodermatous skin spectrum will enable a paradigm shift in the understanding of SSc disease and facilitate the development of biomarkers and therapeutic strategies.

Delineating the heterogeneity of matrix-directed differentiation toward soft and stiff tissue lineages via single-cell profiling.

Mesenchymal stromal/stem cells (MSCs) form a heterogeneous population of multipotent progenitors that contribute to tissue regeneration and homeostasis. MSCs assess extracellular elasticity by probing resistance to applied forces via adhesion, cytoskeletal, and nuclear mechanotransducers that direct differentiation toward soft or stiff tissue lineages. Even under controlled culture conditions, MSC differentiation exhibits substantial cell-to-cell variation that remains poorly characterized. By single-cell transcriptional profiling of nonconditioned, matrix-conditioned, and early differentiating cells, we identified distinct MSC subpopulations with distinct mechanosensitivities, differentiation capacities, and cell cycling. We show that soft matrices support adipogenesis of multipotent cells and early endochondral ossification of nonadipogenic cells, whereas intramembranous ossification and preosteoblast proliferation are directed by stiff matrices. Using diffusion pseudotime mapping, we outline hierarchical matrix-directed differentiation and perform whole-genome screening of mechanoresponsive genes. Specifically, top-ranked tropomyosin-1 is highly sensitive to stiffness cues both at RNA and protein levels, and changes in TPM1 expression determine the differentiation toward soft versus stiff tissue lineage. Consistent with actin stress fiber stabilization, tropomyosin-1 overexpression maintains YAP1 nuclear localization, activates YAP1 target genes, and directs osteogenic differentiation. Knockdown of tropomyosin-1 reversed YAP1 nuclear localization consistent with relaxation of cellular contractility, suppressed osteogenesis, activated early endochondral ossification genes after 3 d of culture in induction medium, and facilitated adipogenic differentiation after 1 wk. Our results delineate cell-to-cell variation of matrix-directed MSC differentiation and highlight tropomyosin-mediated matrix sensing.

Development and manufacture of novel locally produced anti-BCMA CAR T cells for the treatment of relapsed/refractory multiple myeloma: results from a phase I clinical trial.

Anti-B-cell maturation antigen (BCMA) chimeric antigen receptor T-cell (CAR T) therapy shows remarkable efficacy in patients with relapsed and/or refractory (R/R) multiple myeloma (MM). HBI0101, a novel second generation optimized anti- BCMA CAR T-cell therapy, was developed in an academic setting. We conducted a phase I dose-escalation study of HBI0101 (cohort 1: 150x106 CAR T cells, n=6; cohort 2: 450x106 CAR T cells, n=7; cohort 3: 800x106 CAR T cells, n=7) in 20 heavily pre-treated R/R MM patients. Grade 1-2 cytokine release syndrome (CRS) was reported in 18 patients (90%). Neither grade 3-4 CRS nor neurotoxicity of any grade were observed. No dose-limiting toxicities were observed in any cohort. The overall response rate (ORR), (stringent) complete response (CR/sCR), and very good partial response rates were 75%, 50%, and 25%, respectively. Response rates were dose-dependent with 85% ORR, 71% CR, and 57% minimal residual disease negativity in the high-dose cohort 3. Across all cohorts, the median overall survival (OS) was 308 days (range 25-466+), with an estimated OS of 55% as of June 27th (data cut-off). The median progression-free survival was 160 days, with 6 subjects remaining progression free at the time of data cut-off. Our findings demonstrate the manageable safety profile and efficacy of HBI0101. These encouraging data support the decentralization of CAR T production in an academic setting, ensuring sufficient CAR T supply to satisfy the increasing local demand. Clinicaltrials.gov NCT04720313.

Risk factors and outcomes of COVID-19 in adult patients with hematological malignancies: A single-center study showing lower than expected rates of hospitalization and mortality.

BACKGROUND: Studies addressing coronavirus disease 2019 (COVID-19) in patients with hematological malignancies have reported mortality rates of up to 40%; however, included predominantly hospitalized patients. METHODS: During the first year of the pandemic, we followed adult patients with hematological malignancies treated at a tertiary center in Jerusalem, Israel, who contracted COVID-19, with the aim of studying risk factors for adverse COVID-19-related outcomes. We used remote communication to track patients managed at home-isolation, and patient questioning to assess the source of COVID-19 infection, community versus nosocomial. RESULTS: Our series included 183 patients, median age was 62.5 years, 72% had at least one comorbidity and 39% were receiving active antineoplastic treatment. Hospitalization, critical COVID-19, and mortality rates were 32%, 12.6%, and 9.8%, respectively, remarkably lower than previously reported. Age, multiple comorbidities, and active antineoplastic treatment were significantly associated with hospitalization due to COVID-19. Treatment with monoclonal antibodies was strongly associated with both hospitalization and critical COVID-19. In older (≥60) patients not receiving active antineoplastic treatment, mortality, and severe COVID-19 rates were comparable to those of the general Israeli population. We did not detect patients that contracted COVID-19 within the Hematology Division. CONCLUSION: These findings are relevant for the future management of patients with hematological malignancies in COVID-19-affected regions.

Response rates of extra-nodal diffuse large B cell lymphoma to anti-CD19-CAR T cells: A real word retrospective multicenter study.

Chimeric antigen receptor T-cells (CAR-T) are widely used for the treatment of relapsed/refractory diffuse large B cell lymphoma (DLBCL). The data for CAR-T cell therapy in patients with extra-nodal (EN) lymphoma is restricted. We included 126 consecutive patients with DLBCL treated with commercially available CAR-T cells (tisagenlecleucel, n = 100, 79.4% and axicabtagene ciloleucel, n = 26, 20.6%). At lymphodepletion, 72 of 126 (57%) patients had EN disease, 42 of 126 (33%) patients had nodal disease (ND)-only and 12 of 126 (10%) showed no disease assessed by PET-CT. There were no significant differences in CAR-T related toxicities and in the median Progression free survival (PFS) between EN patients and ND (10.76 [95% CI: 7.8-13.6] vs. 14.1 [95% CI: 10-18.1] months, p = .126). Similarly, median overall survival (OS) was not significantly different (15.36 [95% CI 12.5-18.2] vs. 18.4 [95% CI 14.8-22.1] months, p = .100). Subgroup analysis according to the number of EN involved sites showed that median PFS and OS were significantly higher in patients with <3 EN sites (12.3 months [95% CI 9-15.5] vs. 4.28 months [95% CI 0.6-7.9], p = .010) compared to patients with >2 EN sites, respectively (16.5 months [95% CI 13.4-19.6] vs. 8.7 months [95% CI 4.6-12.8], p = .05). In multivariate cox regression analysis, increased number sites of EN disease and high lactate dehydrogenase (LDH) at lymphodepletion negatively impacted PFS (p = .021 and <.001, respectively), while sex, type of product administered, age and performance status did not predict PFS and OS. Of note, all the patients with involvement of gastrointestinal tract (n = 9), urinary tract (n = 9), or pharynx (n = 3) at lymphodepletion, progressed or had an early relapse. In conclusions, patients with >2 EN sites at lymphodepletion have significantly worse clinical outcomes compared to patients with <3 EN sites. Patients with specific sites of EN disease may demonstrate grim prognosis.

Two decades of stem cell transplantation in patients with Fanconi anemia: Analysis of factors affecting transplant outcomes.

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for the hematological complications of patients with Fanconi anemia (FA). Over the last two decades, HSCT outcomes have improved dramatically following the development of regimens tailored for FA patients. In this study, we analyzed genetic, clinical, and transplant data of 41 patients with FA who underwent HSCT at Hadassah Medical Center between November 1996 and September 2020. Overall survival (OS) was 82.9% with a median follow-up time of 2.11-years (95% CI, .48-16.56). Thirteen patients (31.7%) developed acute graft-versus-host disease (GVHD), three of them with grades 3-4. Nine patients developed chronic GVHD, five had extensive disease. Twelve patients (29.3%) developed stable mixed-chimerism with complete resolution of bone marrow failure (BMF); none of them had acute nor chronic GVHD. Significantly higher GVHD rates were observed in transplants from peripheral blood stem cell grafts as compared to other stem cell sources (p = .002 for acute and p = .004 for chronic GVHD). Outcome parameters were comparable between HSCT from matched-sibling (n = 20) to other donors (n = 21), including survival rates (p = .1), time to engraftment (p = .69 and p = .14 for neutrophil and platelet engraftment time, respectively), chimerism status (p = .36 and p = .83 for full-donor and mixed chimerism, respectively), and GVHD prevalence (p = 1). Our results demonstrate the vast improvements in HSCT outcomes of patients with FA, narrowing the gap between matched-sibling versus alternative donor transplantations. Our data identifies factors that may significantly affect transplant outcomes such as graft source and chimerism status.

High rate of adenovirus detection in gastrointestinal biopsies of symptomatic stem cell transplant recipients.

OBJECTIVES: The gastrointestinal (GI) tract is a major human adenovirus (HAdV) replication site in patients undergoing hematopoietic stem cell transplantation (HSCT), yet the prevalence and correlates of HAdV GI infection in this setting have remained poorly recognized, especially among adult HSCT recipients. DESIGN OR METHODS: We retrospectively studied the prevalence and risk factors of HAdV GI-tissue infection in HSCT recipients (73 adults and 15 children) with GI symptoms who underwent GI-tissue biopsy between January-2012 and December-2017. The presence of HAdV in the GI tissues was determined by real-time PCR. RESULTS: HAdV GI-tissue infection was detected in 21 (23.9%) patients, with similar infection rates identified in adults and children. GI-tissue detection was more common at late (>100 days) compared to early times post-transplantation (50% vs. 12.9%, p < .001). The presence of bloody diarrhea, Arab ethnicity (p = .014) and concurrent cytomegalovirus GI-tissue detection (p = .025) were significantly correlated with HAdV GI-tissue infection, while chronic graft versus host disease was of borderline association (p = .055). CONCLUSIONS: Our findings reveal a high rate and new clinical-demographic correlates of HAdV GI-tissue infection in adult and pediatric HSCT recipients with GI symptoms. The findings highlight the need for future prospective studies to assess the relatedness of HAdV infection to the GI symptoms, and the prevalence, impact, and treatment of HAdV GI infection in HSCT recipients.

Altered Serum Alpha1-Antitrypsin Protease Inhibition before and after Clinical Hematopoietic Stem Cell Transplantation: Association with Risk for Non-Relapse Mortality.

α1-Antitrypsin (AAT), an acute-phase reactant not unsimilar to C-reactive protein (CRP), is a serine protease inhibitor that harbors tissue-protective and immunomodulatory attributes. Its concentrations appropriately increase during conditions of extensive tissue injury, and it induces immune tolerance, in part, by inhibiting the enzymatic activity of the inflammatory serine protease, proteinase 3 (PR3). Typically administered to patients with genetic AAT deficiency, AAT treatment was recently shown to improve outcomes in patients with steroid-refractory graft-versus-host disease (GVHD). GVHD represents a grave outcome of allogeneic hematopoietic stem cell transplantation (HSCT), a potentially curative intervention for hematological diseases. The procedure requires radio/chemotherapy conditioning of the prospective marrow recipient, a cytotoxic process that causes vast tissue injury and, in some formats, interferes with liver production of AAT. To date, changes in the functional profile of AAT during allogeneic HSCT, and during the cytotoxic intervention that precedes HSCT, are unknown. The present study followed 53 patients scheduled for allogeneic HSCT (trial registration NCT03188601). Serum samples were tested before and after HSCT for AAT and CRP levels and for intrinsic anti-proteolytic activity. The ex vivo response to clinical-grade AAT was tested on circulating patient leukocytes and on a human epithelial cell line treated with patient sera in a gap closure assay. According to the ex vivo experiments, circulating leukocytes responded to AAT with a favorable immune-regulated profile, and epithelial gap closure was enhanced by AAT in sera from GVHD-free patients but not in sera from patients who developed GVHD. According to serum collected prior to HSCT, non-relapse mortality was reliably predicted by combining three components: AAT and CRP levels and serum anti-proteolytic activity. Taken together, HSCT outcomes are significantly affected by the anti-proteolytic function of circulating AAT, supporting early AAT augmentation therapy for allogeneic HSCT patients.

Mesenchymal Stromal Cell-Derived Small Extracellular Vesicles Modulate Apoptosis, TNF Alpha and Interferon Gamma Response Gene mRNA Expression in T Lymphocytes.

Recent studies have highlighted the therapeutic potential of small extracellular bodies derived from mesenchymal stem cells (MSC-sEVs) for various diseases, notably through their ability to alter T-cell differentiation and function. The current study aimed to explore immunomodulatory pathway alterations within T cells through mRNA sequencing of activated T cells cocultured with bone marrow-derived MSC-sEVs. mRNA profiling of activated human T cells cocultured with MSC-sEVs or vehicle control was performed using the QIAGEN Illumina sequencing platform. Pathway networks and biological functions of the differentially expressed genes were analyzed using Ingenuity pathway analysis (IPA)® software, KEGG pathway, GSEA and STRING database. A total of 364 differentially expressed genes were identified in sEV-treated T cells. Canonical pathway analysis highlighted the RhoA signaling pathway. Cellular development, movement, growth and proliferation, cell-to-cell interaction and inflammatory response-related gene expression were altered. KEGG enrichment pathway analysis underscored the apoptosis pathway. GSEA identified enrichment in downregulated genes associated with TNF alpha and interferon gamma response, and upregulated genes related to apoptosis and migration of lymphocytes and T-cell differentiation gene sets. Our findings provide valuable insights into the mechanisms by which MSC-sEVs implement immunomodulatory effects on activated T cells. These findings may contribute to the development of MSC-sEV-based therapies.

[STEM CELL TRANSPLANTATIONS FOR PATIENTS WITH FANCONI ANEMIA: AN ISRAELI TERTIARY CENTER EXPERIENCE].

INTRODUCTION: Fanconi anemia (FA) is a rare genetic syndrome characterized by increased chromosomal breakage, congenital anomalies, bone marrow failure and an increased tendency to develop malignancies. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment for bone marrow failure and the hematologic malignancies these patients develop. Given the sensitivity of FA patients to chemotherapy and radiation, as to the clinical symptoms of graft versus host disease (GvHD), HSCT in these patients is challenging. Since the mid-nineties, HSCT for FA patients is performed in our center by using the fludarabine based reduced-intensity protocol. AIMS: To summarize the results of HSCT for patients with FA using a fludarabine based reduced-intensity conditioning regimen at the Hadassah Medical Center. METHODS: This retrospective research is based on the collection and analysis of clinical and laboratory data from the medical records of patients. RESULTS: Since June 1996 up till February 2020, 39 patients with FA underwent 43 HSCTs with a fludarabine based protocol at the Hadassah Medical Center. Four patients required a second transplant due to primary engraftment failure. Nine patients (23%) suffered from acute GvHD, four of them severe. Eight patients (20%) developed chronic GvHD, two with an extensive and debilitating disease. Thirty-three (85%) of the patients survived and six died, five shortly after the transplant, and one twenty years later from malignancy. CONCLUSIONS: Our results show high survival rates with low rates of engraftment failure and reasonable rates of GvHD. DISCUSSION: As of today, there is an effective and safe treatment for patients with FA who require HSCT by using a fludarabine-based reduced-intensity conditioning regimen, with high survival rates and few complications.

Mesenchymal stroma/stem cells: Haematologists' friend or foe?

Mesenchymal stromal cells (MSCs) are non-haematopoietic cells found in fetal and adult organs, that play important roles in tissue repair, inflammation and immune modulation. MSCs residing in the bone marrow interact closely with haematopoietic cells and comprise an important component of the microenvironment supporting haematopoiesis, in both health and disease states. Since their identification in 1970, basic scientific and preclinical research efforts have shed light on the role of MSCs in the regulation of haematopoiesis and evoked interest in their clinical application in haematopoietic stem cell transplantation (HSCT) and malignant haematology. Over the last two decades, these research efforts have led to numerous clinical trials, which have established the safety of MSC therapy; however, the optimal mode of administration and the benefit remain inconclusive. In this paper, we will review the clinical experience with use of MSCs in HSCT for enhancement of engraftment, prevention and treatment of graft-versus-host disease and haemorrhagic cystitis. Then, we will discuss the contradictory evidence regarding tumour-promoting versus tumour-suppressing effects of MSCs in haematological malignancies, which may have relevance for future clinical applications.

Toxicity and efficacy of chimeric antigen receptor T-cell therapy in patients with diffuse large B-cell lymphoma above the age of 70 years compared to younger patients - a matched control multicenter cohort study.

Data regarding efficacy and toxicity of chimeric antigen receptor T (CAR-T) cell therapy in the elderly, geriatric population are insufficient. In 2019, tisagenlecleucel and axicabtagene-ciloleucel were commercially approved for relapsed/refractory diffuse large B-cell lymphoma. From May 2019 onwards, 47 relapsed/refractory diffuse large Bcell lymphoma patients, ≥70 years underwent lymphopharesis in three Israeli centers. Elderly (n=41, mean age 76.2 years) and young (n=41, mean age 55.4 years) patients were matched based on ECOG performance status and lactose dehydrogenase levels. There were no differences in CD4/CD8 ratio (P=0.94), %CD4 naive (P=0.92), %CD8 naive (P=0.44) and exhaustion markers (both HLA-DR and PD-1) between CAR-T cell products in both cohorts. Forty-one elderly patients (87%) received CAR-T cell infusion. There were no differences in the incidence of grade ≥3 cytokine-release-syndrome (P=0.29), grade≥3 neurotoxicity (P=0.54), and duration of hospitalization (P=0.55) between elderly and younger patients. There was no difference in median D7-CAR-T cell expansion (P=0.145). Response rates were similar between the two groups (complete response 46% and partial response 17% in the elderly group, P=0.337). Non-relapse mortality at 1 and 3 months was 0 in both groups. With a median follow-up of 7 months (range, 1.3-17.2 months), 6- and 12-months progression-free and overall survival in elderly patients were 39% and 32%, and 74% and 69%, respectively. EORTC QLQ-C30 questionnaires, obtained at 1 month, showed worsening of disability and cancer-related-symptoms in elderly versus younger patients. We conclude that outcomes of CAR-T cell therapy are comparable between elderly, geriatric and younger patients, indicating that age as per se should not preclude CAR-T cell administration. Longer rehabilitation therapy is essential to improve disabilities and long-term symptoms.

Allogeneic hematopoietic cell transplantation for acute myeloid leukemia in first complete remission after 5-azacitidine and venetoclax: a multicenter retrospective study.

The combination of hypomethylating agents and venetoclax has revolutionized the therapeutic landscape of acute myeloid leukemia (AML), especially for patients previously deemed unfit for curative-intent treatment. Some of these patients undergo allogeneic hematopoietic cell transplant (alloHCT); yet, there are scarce data regarding transplantation outcomes. We conducted a multicenter nationwide retrospective cohort study, including patients with AML who underwent alloHCT in CR1 after frontline treatment with azacitidine plus venetoclax only (aza-ven group). We collected a historical control group of patients who achieved CR1 after first-line intensive chemotherapy only, followed by alloHCT (intensive group). Patients in the aza-ven group (n = 24) were transplanted between 2019 and 2021. Compared to the intensive group, patients in the aza-ven group were older (median age 71.7 vs. 58.4 years), had higher incidence of therapy-related AML and AML with antecedent hematologic disorder and had more often adverse cytogenetics. They had a higher percentage of allografts from matched-unrelated donors, and reduced intensity conditioning was more commonly used. The estimated 12 months non relapse mortality was 19.1% in the aza-ven group and 11.8% in the intensive group. The estimated 12 months relapse-free survival and overall survival were 58% and 63% in the aza-ven group and 54% and 70% in the intensive group, respectively. The cumulative incidence of acute GVHD at 6 months and of chronic GVHD at 12 months were 58% and 40% in the aza-ven group and 62% and 42% in the intensive group, respectively. Analysis of the aza-ven group revealed that HCT-CI score and ELN risk category were predictive of RFS in both univariate analysis as well as multivariate analysis. Our data suggests that alloHCT for AML patients achieving first CR with aza-ven appears feasible, with short-term post-transplant outcomes similar to those expected after traditional intensive chemotherapy.

Monitoring Minimal Residual Disease in RUNX1-Mutated Acute Myeloid Leukemia.

INTRODUCTION: Mutated RUNX1 is considered a poor prognostic factor and usually is mutually exclusive with NPM1 mutations. Monitoring of molecular markers for minimal residual disease provides a powerful tool to assess remission and guide clinical decisions. METHODS: Newly diagnosed RUNX1-mutated AML patients, designated to intensive chemotherapy-based treatment or nonintensive regimens, were monitored for mutated RUNX1 transcript levels by qPCR with patient-specific primers. Samples were obtained along the treatment course and follow-up. RESULTS: A clear correlation was observed between mutated RUNX1 levels and response to treatment as observed by flow cytometry and STR-based assessment. CONCLUSION: We demonstrate the feasibility of RUNX1-based MRD to correlate with the clinicopathological status of leukemia. We further suggest how RUNX1 qPCR monitoring can influence clinical decision-making and contribute to improved personalized patient care.

Photobiomodulation (low-level laser) therapy for immediate pain relief of persistent oral ulcers in chronic graft-versus-host disease.

PURPOSE: To determine the immediate pain-relieving effect of photobiomodulation therapy (PBMt) in patients with oral ulcers of chronic graft-versus-host disease (cGVHD) refractory to first line therapy with topical corticosteroids. METHODS: This retrospective study included all patients who underwent PBMt for pain relief of refractory oral cGVHD lesions. PBMt was applied using an intraoral approach to all sites with mucosal lesions, using a 940 nm InGaAsP diode laser device, with the following parameters: pulsed modulation (duty cycle of 50%), power 0.7 W, illuminated spot size 7.1 cm2, irradiance 98.6 mW/cm2, and irradiation time 90 s per point. Pain was self-assessed using a 0-to-10 scale immediately before and after PBMt. RESULTS: Data from eleven patients with a total of 56 PBMt sessions were analyzed. In 48 (85.7%) sessions, the patients reported less pain immediately after treatment, with a reduction of ≥ 50% of the initial pain level in 43 (76.8%) sessions. Mean pre- and post-treatment pain levels were 5.20 ±2.7 and 1.38 ±2.1, respectively (p < 0.001), i.e., a post-treatment reduction of 73.4% of the initial pain level. The benefits of the treatment remained for a mean of 6.50 ±5.4 days (range of 2 to 14 days). No adverse effects were reported. CONCLUSIONS: PBMt seems to be a promising treatment modality for refractory oral cGVHD lesions as a rapid pain reliever with relatively long-lasting effects.

Oral verruciform xanthoma in chronic graft-versus-host disease patients.

BACKGROUND: Verruciform xanthoma (VX) is an uncommon benign epithelial lesion which mainly appears in inflamed oral epithelium. In this study, our aim was to present new cases of oral VX (OVX) in chronic graft-versus-host disease (cGVHD) and review the literature. METHODS: We conducted a retrospective chart review of cGVHD patients (2012-2019) to reveal cases of OVX. The demographics, medical background, clinical presentation, treatment provided, and follow-up were obtained. Additionally, Medline was searched using the terms "graft-versus-host disease," "verruciform xanthoma," and "oral." Of the articles, the above-mentioned demographic and clinical features were retrieved. RESULTS: The patient pool included 133 oral cGVHD patients. Three cGVHD patients (males, aged 15-49 years, post-hematologic malignancy) were diagnosed with OVX. All patients had oral mucosal lichenoid lesions, but not in close proximity to the VX lesion. Medline searches revealed 9 cases of OVX in cGVHD patients reported in the literature. Eleven of the 12 patients had oral mucosal lichenoid lesions. Four patients had multiple OVX lesions. All lesions were asymptomatic. Six patients had lesions in the masticatory mucosa (hard palate and gingiva) and 4 patients had lesions in the buccal mucosa. CONCLUSIONS: To the best of our knowledge, this is the largest published OVX in cGVHD series, including 12 patients. It appears that despite the higher prevalence in cGVHD patients relative to the general population, OVXs do not necessarily develop in sites with lichenoid lesions. It is advised that clinicians be familiar with the clinical and histological features in order to consider OVX in the differential diagnosis of oral lesions in cGVHD patients.

Daratumumab resistance is frequent in advanced-stage multiple myeloma patients irrespective of CD38 expression and is related to dismal prognosis.

OBJECTIVE: Daratumumab is a promising new antimyeloma agent. We report a single center "real-world" series of multiple myeloma (MM) and amyloidosis (AL) patients treated with daratumumab. METHODS: Forty-one patients were included: 7 second-line MM, 30 heavily pretreated (median number of therapies of 5) advanced MM, and 4 with AL. RESULTS: Second-line patients and advanced AL showed high rate of durable overall responses. However, advanced MM patients had a dismal prognosis with an overall response rate (ORR) of 36%, and a short median progression-free and overall survival of 2.3 and 6.6 months, respectively. Responses were particularly poor in patients with extramedullary plasmacytomas. Neither the addition of another agent to daratumumab nor changing to the next line of therapy produced significant durable responses in this patient population. Flow cytometry analysis demonstrated that CD38 expression level was not predictive of response. We show that CD38 expression dynamics by a commercially available anti-CD38 antibody after daratumumab administration was hindered by competitive binding of daratumumab. CONCLUSIONS: Responses to daratumumab and combinations in patients with advanced MM, particularly with extramedullary disease, are low and short-lived, stressing the administration of this agent should be early in the course of the disease.

Fludarabine-based reduced toxicity yet myeloablative conditioning is effective and safe particularly in patients with high-risk thalassemia undergoing allogeneic transplantation.

INTRODUCTION: Thalassemia major (TM) is an inherited disorder caused by ineffective erythropoiesis. At the present time, allogeneic stem cell transplantation (allo-SCT) is a curative option. Conventional busulfan and cyclophosphamide based myeloablative conditioning regimens are limited by increased toxicity, especially in high-risk patients. Replacement of cyclophosphamide with fludarabine has reduced toxicity and nonrelapse mortality (NRM), thus improving outcomes. We analyzed long-term data of our fludarabine-based myeloablative, reduced toxicity protocol, specifically in high-risk patients. METHODS: We retrospectively analyzed a cohort of 47 consecutive patients with TM undergoing allo-SCT from matched donors, using the fludarabine-based regimen (reduced toxicity regimen). The median age of the cohort was 10 years. Thirty-eight patients (80%) were in the high-risk and nine patients (20%) were in the low-risk category. The primary aim of this analysis was thalassemia-free survival (TFS). RESULTS: The rejection rate was 11% within high-risk patients with NRM of 2%. With a median follow-up period of 7 years (1-15 years), the 10-year TFS in the entire cohort was 87%, and the overall survival (OS) was 97%. The 10-year TFS and OS among the low-risk and high-risk groups were 90% versus 84%, respectively (P = 0.45) and 100% versus 96%, respectively (P = 0.5), and both subsets of patients did equally well. CONCLUSION: In conclusion, replacement of high-dose cyclophosphamide with fludarabine is well tolerated with minimal regimen-related toxicity and acceptable rejection rates, especially in high-risk patients.

Successful hematopoietic stem cell transplantation for osteopetrosis using reduced intensity conditioning.

BACKGROUND: Infantile malignant osteopetrosis (IMO) is an autosomal recessive condition characterized by defective osteoclast activity, with hematopoietic bone marrow transplant being the only available cure. Over the past several years, new conditioning regimes and donor options have emerged, thus extending the possibility of cure to a greater number of patients and improving the outcomes of bone marrow transplant. Here we detail the outcomes of bone marrow transplant in a cohort of 31 patients treated with a combination of fludarabine, treosulphan, thiotepa, and antithymocyte globulin. PROCEDURES: Thirty-one patients with IMO who underwent hematopoietic stem cell transplantation with fludarabine, treosulphan, thiotepa, and antithymocyte globulin at our center from 2012 to 2017 are retrospectively reviewed in this study. Twenty-six patients were transplanted from 10/10 matched donors (13 from siblings, 11 from unrelated, and two from extended family donors), four from 9/10 matched unrelated donors, and one from a 9/10 matched family donor. RESULTS: Overall survival was 100% with a median follow-up of 363 days (range 74-1891). There were 12 cases of acute graft versus host disease (GvHD) (38.7%), no cases of veno-occlusive disease, and eight cases of hypercalcemia (25.8%). Almost 80% of patients suffered viral reactivations with two cases of Epstein-Barr-virus-driven post-transplant lymphoproliferative disease. All cases of GvHD and viral reactivation were successfully treated. CONCLUSIONS: We conclude that transplantation in children with IMO using fludarabine, treosulphan, thiotepa, and antithymocyte globulin is safe and effective and should be performed as early as possible following diagnosis, prior to the development of severe disease sequelae.