While measurable residual disease (MRD) in bone marrow (bmMRD) is a validated surrogate biomarker in multiple myeloma (MM), the clinical relevance of MRD in the apheresis product (aMRD) remains unclear. We retrospectively analysed 422 MM patients who underwent autologous stem cell transplantation (ASCT) between 2005 and 2023 at the University Hospital of Salamanca, all evaluated for aMRD by 8-colour flow cytometry. Overall, 45 patients (10%) were aMRD+ve and 377 (90%) were aMRD-ve, with similar baseline characteristics except for a higher frequency of t(11;14) in aMRD+ve cases. Patients with responses worse than a very good partial response before apheresis were six times more likely to be aMRD+ve (odds ratio [OR] 6.6, p = 0.006), and notably, no patients with bmMRD-ve status prior to apheresis were aMRD+ve. After ASCT, patients with aMRD+ve exhibited lower rates of complete response and bmMRD-ve than patients with aMRD-ve, leading to a shorter progression-free survival (hazard ratio 1.7, p = 0.006), and aMRD+ve status was identified as an independent predictor of early relapse (OR 9.75, p = 0.007). These findings may suggest that aMRD+ve serves as a critical early biomarker to identify suboptimal treatment responses, reflecting bmMRD persistence and predicting inferior clinical outcomes.

BACKGROUND:Common variable immunodeficiency (CVID) includes a heterogeneous group of disorders of predominantly antibody deficiencies featuring infectious and noninfectious complications that might lead to severe organ damage and shortened survival. Appropriate clinical management of CVID has been hampered by the lack of robust biomarkers to predict the development of clinical complications and patient outcome. OBJECTIVE:We investigated the association of individual serologic, cellular, and molecular biomarkers with disease behavior and outcome in CVID. METHODS:A multicenter cohort of 209 CVID patients was studied using age-matched reference values from 334 healthy donors to better define TCD4+-naive cell defects (late-onset combined immunodeficiency [LOCID]) and classify CVID-associated B-cell/plasma cell (PC) and natural killer (NK) cell defects. RESULTS:Globally, susceptibility to respiratory infections was strongly associated with low serum immunoglobulin (sIg), particularly sIgA, whereas noninfectious complications and disease severity mostly depended on TCD4+-naive cell, NK cell, and B-cell/PC defects. LOCID was independently associated with splenomegaly, lymphadenopathy, interstitial lung disease, cytopenia, and lymphoma. Milder B-cell/PC defects (MBC+/PC+/Ab-) protected from noninfectious complications, whereas a marked defect of classical CD27+ memory B cells (27MBC-) (with decreased NK cell and sIgM) was associated with enteropathy and (with LOCID and sIgA) liver disease. Together, lower sIgG, LOCID, and particularly 27MBC-, were strongly associated with shorter survival and early death in CVID. Conversely, CVID-associated pathogenic/risk alleles did not emerge as independent factors associated with disease behavior and outcome. CONCLUSION:Our results provide a new set of biomarkers closely associated with infectious and noninfectious complications of CVID, which together predict survival and might contribute to guide patient monitoring and clinical management.

BACKGROUND:The monoclonal gammopathy of uncertain significance (MGUS)-like model classifies multiple myeloma (MM) patients into 3 groups - MGUS-like, intermediate and MM-like--based on quantification of plasma cells (PCs) and clonal PCs in bone marrow, with distinct progression-free survival (PFS). We hypothesize that this model identifies patients with different characteristics that may influence the efficacy of autologous stem cell transplantation (ASCT). METHODS:A multicenter retrospective study was conducted including MM who underwent ASCT in the University Hospital of Salamanca between 2005 and 2023. The phenotypic profile was performed using the calculator available on the web site https://www.mgus-like.com/ RESULTS: Four hundred and fifteen patients who underwent ASCT between 2005 and 2023 were included: 39 MGUS-like (9.4%), 187 intermediate (45.1%) and 189 (45.5%) MM-like. MGUS-like patients more likely had low ISS/R-ISS, less BM infiltration, less secretory disease, less CRAB (except for lytic lesions) and had more bone-related plasmacytomas. Most patients received ASCT in the first line, with no differences in induction regimens among groups. The MGUS-like group achieved stronger responses after ASCT, defined as complete response and minimal residual disease negative (CR MRD-ve), 70.3%, than the intermediate (47.0%) and MM-like groups (40.6%). Additionally, the MGUS-like profile was identified as an independent predictor of CR MRD-ve and PFS, decreasing the likelihood of progression or death by 40% to 60% to the other phenotypic profiles. CONCLUSION:The MGUS-like profile is a baseline-evaluable feature that identifies a subset of patients with distinct clinical behavior and may predict greater benefit from high-dose melphalan, due to the high rate of CR MRD-ve resulting in longer survival.

Recommendations regarding the best time to start treatment in patients with relapsed/refractory multiple myeloma (RRMM) after biological relapse/progression (BR) are unclear. This observational, prospective, multicenter registry aimed to evaluate the impact on time to progression (TTP) of treatment initiation at BR versus at symptomatic clinical relapse (ClinR) based on the Spanish routine practice in adult patients with RRMM. Patients had two or less previous treatment lines and at least one previous partial response. Baseline characteristics and treatment outcomes were recorded, and survival was analyzed. Of 225 patients, 110 were treated at BR (TxBR group) and 115 at ClinR (TxClinR group) according to the investigators' criteria. The proportion of patients with higher ECOG, previous noncomplete remission (CR), and second relapse were significantly higher in the TxBR group compared to the TxClinR group. TheTxClinR group showed improved outcomes, including TTP, compared to the TxBR group. Progression-free survival increased in the TxClinR group (56.2 months) compared to the TxBR group (32.5 months) (p = 0.0137), and median overall survival also increased (p = 0.0897). Median TTP was significantly longer in patients relapsing from a CR (50.4 months) and in their first relapse (38.7 months) compared to those relapsing from a non-CR response (32.9 months) and in their second relapse (25.2 months). Physicians seemed to start treatment earlier in RRMM patients with poor prognosis features. Previous responses to anti-MM treatment and the number of prior treatment lines were identified as prognosis factors, whereby relapse from CR and first relapse were associated with a longer time to progression.

Immune thrombocytopenia (ITP) is a common autoimmune hematological disorder. Despite this, diagnosis is still challenging due to clinical heterogeneity and the lack of a specific diagnostic test. New findings in the pathology and the availability of new drugs have led to the development of different guidelines worldwide. In the present study, the Delphi methodology has been used to get a consensus on the management of adult patients with ITP in Spain and to help in decision-making. The Delphi questionnaire has been designed by a scientific ad hoc committee and has been divided into 13 topics, with a total of 127 items, covering the maximum possible scenarios for the management of ITP. As a result of the study, a total consensus of 81% has been reached. It is concluded that this Delphi consensus provides practical recommendations on topics related to diagnosis and management of ITP patients to help doctors to improve outcomes. Some aspects remain unclear, without consensus among the experts. Thus, more advances are needed to optimize ITP management.

Primary immune thrombocytopenia (ITP) is a complex autoimmune disease whose hallmark is a deregulation of cellular and humoral immunity leading to increased destruction and reduced production of platelets. The heterogeneity of presentation and clinical course hampers personalized approaches for diagnosis and management. In 2021, the Spanish ITP Group (GEPTI) of the Spanish Society of Hematology and Hemotherapy (SEHH) updated a consensus document that had been launched in 2011. The updated guidelines have been the reference for the diagnosis and management of primary ITP in Spain ever since. Nevertheless, the emergence of new tools and strategies makes it advisable to review them again. For this reason, we have updated the main recommendations appropriately. Our aim is to provide a practical tool to facilitate the integral management of all aspects of primary ITP management.

There are not many publications that provide a holistic view of the management of primary and secondary ITP as a whole, reflecting the similarities and differences between the two. Given the lack of major clinical trials, we believe that comprehensive reviews are much needed to guide the diagnosis and treatment of ITP today. Therefore, our review addresses the contemporary diagnosis and treatment of ITP in adult patients. With respect to primary ITP we especially focus on establishing the management of ITP based on the different and successive lines of treatment. Life-threatening situations, “bridge therapy” to surgery or invasive procedures and refractory ITP are also comprehensively reviewed here. Secondary ITP is studied according to its pathogenesis by establishing three major differential groups: Immune Thrombocytopenia due to Central Defects, Immune Thrombocytopenia due to Blocked Differentiation and Immune Thrombocytopenia due to Defective Peripheral Immune Response. Here we provide an up-to-date snapshot of the current diagnosis and treatment of ITP, including a special interest in addressing rare causes of this disease in our daily clinical practice. The target population of this review is adult patients only and the target audience is medical professionals.

Supplementary Tables Supplementary Table 1. Cytogenetic characteristics of MM samples Supplementary Table 2. Sequences of primers used in the study Supplementary Table 3. CCND2 mRNA FISH probes sequences Supplementary table 4. microRNAs predicted to target CCND1 or/and CCND2 Supplementary table 5. microRNAs expression in MM cell lines. Supplementary Figures Supplementary Figure 1. CCND2 mRNA level 24h after transfection of MM1S, RPMI and H929 cell lines with indicated miRNAs Supplementary Figure 2. Expression of miR-15a and miR-196b in H929 and MM1S cell lines after transfection Supplementary Figure 3. (A) Alignment of 3'RACE PCR product sequence from MM1S cell line with CCND2 mRNA (NM_001759.3). (B) Sequence of the 3'RACE PCR product withhighlighted APA signal. Supplementary Figure 4. CCND2 mRNA expression visualized with FISH probes Supplementary Figure 5. Luciferase activity in HEK923 cells cotransfected with various miRNAs, plasmid encoding GFP and plasmid containing luciferase and 3'UTR of CCND2 short isoform Supplementary Figure 6. Regulation of cyclin D2 level by CCND1/CCND3.

Introduction: The prognosis of relapsed B cell precursor acute lymphoblastic leukemia (B-ALL) is poor and few patients can be successfully rescued with conventional therapies. Inotuzumab ozogamicin (IO), an antibody against the CD22 antigen linked to calicheamicin, has been approved as a rescue treatment in relapsed/refractory (R/R) B-ALL. Patients and Methods: This was an observational, retrospective, multicenter study of adult patients included in the Spanish program of compassionate use of IO in centers from the PETHEMA group (Programa Espanol de Tratamientos en Hematologia). Results: Thirty-four patients with a median age of 43 years (range, 19-73) were included. Twenty patients (59%) were refractory to the last treatment, IO treatment was given as >= 3rd salvage treatment in 25 patients (73%) and 20 patients (59%) received allogeneic hematopoietic stem cell transplantation before IO treatment. After a median of 2 cycles of IO, 64% of patients achieved complete response (CR)/ complete response with incomplete recovery. The median response duration, progression-free survival and overall survival (OS) were 4.7 (95%CI, 2.4-7.0 months), 3.5 (95%CI, 1.0-5.0 months) and 4 months (95%CI, 1.9-6.1 months) respectively, with better OS for patients with relapsed B-ALL versus refractory disease (10.4 vs. 2.5 months, respectively) (p = .01). There was a trend for better OS for patients with first CR duration >12 months (7.2 months [95%CI, 3.2-11.2] vs. 3 months [95% CI, 1.8-4.2] respectively) (p = .054). There was no sinusoidal obstruction syndrome (SOS) event during IO treatment, but three patients (9%) developed grade 3-4 SOS during alloHSCT after IO treatment. Conclusions: Our study showed slightly inferior outcomes of the pivotal trial probably due to poorer risk factors and late onset of IO therapy of recruited patients. Our results support early use of IO in relapsed/refractory ALL patients.

(1) Background: New therapeutic strategies have improved the prognosis of multiple myeloma (MM), changing the accepted view of this disease from being incurable to treatable. (2) Methods: We studied 1001 patients with MM between 1980 and 2020, grouping patients into ten-year periods by diagnosis 1980-1990, 1991-2000, 2001-2010 and 2011-2020. (3) Results: After 65.1 months of follow-up, the median OS of the cohort was 60.3 months, and OS increased significantly over time: 22.4 months in 1980-1990, 37.4 months in 1991-2000, 61.8 months in 2001-2010 and 103.6 months in 2011-2020 (p < 0.001). Using novel agents in the front-line setting for myeloma patients yielded a significantly better OS than in those treated with conventional therapies, especially when combinations of at least two novel agents were used. The median OS of patients treated with the combination of at least two novel agents in induction was significantly prolonged compared to those treated with a single novel agent or conventional therapy in induction: 143.3 vs. 61.0 vs. 42.2 months (p < 0.001). The improvement was apparent in all patients regardless of age at diagnosis. In addition, 132 (13.2%) patients were long-term survivors (median OS ≥ 10 years). Some independent clinical predictors of long-term survival were identified: ECOG < 1, age at diagnosis ≤ 65 years, non-IgA subtype, ISS-1 and standard-risk cytogenetic. Achieving CR and undergoing ASCT were positively associated with >10 years of survival. (4) Conclusions: The combination of novel agents appears to be the main factor for the improvement in survival in MM, which is becoming a chronic and even curable disease in a subtype of patients without high-risk features.

Primary immune thrombocytopenia (ITP) is a complex autoimmune disease whose hallmark is a deregulation of cellular and humoral immunity leading to an increased destruction and a reduced production of platelets. The heterogeneity of presentation and clinical course hampers personalized approaches for diagnosis and management. In 2021, the Spanish ITP Group (GEPTI) of the Spanish Society of Hematology and Hemotherapy (SEHH) updated a consensus document which had been launched in 2011. The updated guidelines have been the reference for diagnosis and management of primary ITP in Spain ever since. Nevertheless, the emergence of new tools and strategies makes it advisable to review them again. For this reason, we have properly updated the main recommendations. Our aim is to provide a practical tool to enable the integral management of all the aspects concerning primary ITP management.

Book Citations: Authors, Title, HemaSphere, 2023;7(S3):pages. The individual abstract DOIs can be found at https://journals.lww.com/hemasphere/pages/default.aspx. Disclaimer: Articles published in the journal HemaSphere exclusively reflect the opinions of the authors. The authors are responsible for all content in their abstracts including accuracy of the facts, statements, citing resources, etc. 4036 In all patients who were in hemCR at transplant, the response was held up at day +100. High-tumor burden disease at diagnosis (>10% PC) was found in nearly half of them. Relapse was observed only in 2, at 37 and 44 months, respectively. Minimal residual diseased before ASCT was only assessed in one patient, which was negative and was maintained at +100. With a median follow-up of 71.3 months (3.3-210.1), median PFS from ASCT was 26.7 months (0.17-210.13). Patients who achieved hemCR at +100 had longer PFS (not reached vs. 23.1 months; p=0.023), and those with OR at +100 also had longer PFS (not reached vs. 6.2 months; p=0.027). Median OS from ASCT was 64.9 months (0.17-210.13). Four (13,3%) died within the first three months: 2 from septic shock and 2 from progression. Involvement of 3 o more organs significantly decreased OS (61.4 vs. 145.5 months; p=0.005). Summary/Conclusion: 1. Our series of transplant AL amyloidosis patients was carefully selected and early mortality was low. 2. Nowadays, the optimal response after ASCT is at least VGPR, which was achieved in 70% of patients at +100 days after ASCT. Among patients receiving induction, ASCT improved HR to VGPR or better in 40% and OR in 30% of them. Those in hemCR preASCT maintained the response at +100, and half of them would have undergone ASCT nowadays due to high-tumor burden at diagnosis. 3. PFS and OS results about transplantation are consistent with other series, with 46% of patients alive at 10 years and 25%, at 15 years. Factors which predict a better PFS were identified, as achieving hemCR and OR at +100. HemaSphere | 2023;7(S3) EHA2023 Hybrid Congress Copyright Information: (Online) ISSN: 2572-9241 © 2023 the Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the European Hematology Association. This is an open access Abstract Book distributed under the Attribution-NonCommercial-NoDerivs (CC BY-NC-ND) which allows third parties to download the articles and share them with others as long as they credit the author and the Abstract Book, but they cannot change the content in any way or use them commercially. Abstract Book Citations: Authors, Title, HemaSphere, 2023;7(S3):pages. The individual abstract DOIs can be found at https://journals.lww.com/hemasphere/pages/default.aspx.Book Citations: Authors, Title, HemaSphere, 2023;7(S3):pages. The individual abstract DOIs can be found at https://journals.lww.com/hemasphere/pages/default.aspx. Disclaimer: Articles published in the journal HemaSphere exclusively reflect the opinions of the authors. The authors are responsible for all content in their abstracts including accuracy of the facts, statements, citing resources, etc. 4037

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease with highly variable presentation, characteristics, and clinical course. Thrombocytopenia is a common complication of many viral infections, including SARS-CoV-2. In addition, both de novo ITP and exacerbation of ITP after vaccination against SARS-CoV-2 have been reported. Patients infected with SARS-CoV-2 develop a prothrombotic coagulopathy called COVID-19-associated coagulopathy (CAC). In addition, autoimmune hematological disorders secondary to SARS-CoV-2 infection, mainly ITP and autoimmune hemolytic anemia (AIHA), have been described. Furthermore, SARS-CoV-2 infection has been associated with exacerbation of autoimmune processes, including ITP. In fact, there is evidence of a high relapse rate in patients with preexisting ITP and COVID-19. As for vaccination against SARS-CoV-2, hematological adverse events (HAE) are practically anecdotal. The most common HAE is thrombocytopenia-associated thrombosis syndrome (TTS) linked to vectored virus vaccines. Other HAEs are very rare, but should be considered in patients with previous complement activation disease or autoimmunity. In patients with ITP who are vaccinated against SARS-CoV-2, the main complication is exacerbation of ITP and the bleeding that may result. In fact, this complication occurs in 12% of patients, with splenectomized and refractory patients with more than five lines of previous treatment and platelet counts below 50 × 10 9 /L being the most vulnerable. We conclude that, in general, there is no greater risk of severe SARS-CoV-2 infection in ITP patients than in the general population. Furthermore, no changes are advised in patients with stable ITP, the use of immunosuppressants is discouraged unless there is no other therapeutic option, and patients with ITP are not contraindicated for vaccination against COVID-19.

ABSTRACT To provide insight into the subclonal architecture and co-dependency patterns of the alterations in Waldenström's macroglobulinemia (WM), we performed single-cell mutational and protein profiling of eight patients. A custom panel was designed to screen for mutations and copy number alterations at the single-cell level in samples taken from patients at diagnosis (n=5) or at disease progression (n=3). Results showed that in asymptomatic WM at diagnosis, MYD88L265P was the predominant clonal alteration; other events, if present, were secondary and subclonal to MYD88L265P. In symptomatic WM, clonal diversity was more evident, uncovering combinations of alterations that synergized to promote clonal expansion and dominance. At disease progression, a dominant clone was observed, sometimes accompanied by other less complex minor clones, which could be consistent with a clonal selection process. Clonal diversity was also reduced, probably due to the effect of treatment. Finally, we combined protein expression with mutational analysis to map somatic genotype with the immunophenotype. Our findings provide a comprehensive view of the clonality of tumor populations in WM and how clonal complexity can evolve and impact disease progression.

SummaryImmunoparesis is the suppression of normal polyclonal immunoglobulins and is present in most patients with newly diagnosed multiple myeloma (MM). The association of immunoparesis at diagnosis, and particularly its recovery along with treatment, with survival in patients ineligible for autologous stem‐cell transplantation (ASCT) has not been well established. This retrospective study evaluated the impact of immunoparesis in 431 patients diagnosed with MM, ineligible for ASCT, with a median overall survival of 36 months [95% confidence interval (CI): 31–40]. Immunoparesis was present in 81.2% of patients at diagnosis and was associated with a trend to a worse overall response rate (ORR: 84.8% vs. 74.9%; OR 1.88 (95% CI: 0.97–3.63), shorter progression‐free survival (PFS) [22.0 vs. 18.2 months; hazard ratio (HR) 0.775; 95%CI: 0.590–1.018; p = 0.066], and overall survival (OS) (45.9 vs. 34.2 months; HR 0.746; 95% CI: 0.551–1.010; p = 0.057). Twenty‐four per cent of patients who had immunoparesis at diagnosis recovered polyclonal immunoglobulins in the follow‐up period. Interestingly, these patients had a better ORR (96.3% vs. 68.2%; OR 12.29 (95% CI: 3.77–40.06), PFS (HR 0.703; 95CI%: 0.526–0.941; p = 0.018) and OS (HR 0.678; 95 CI%: 0.503–0.913; p = 0.011) than patients who did not recover it. In summary, restoring a healthy immune system along with first‐line treatment in patients with MM, not receiving ASCT, is associated with better outcomes.

B-cell regeneration during therapy has been considered as a strong prognostic factor in multiple myeloma (MM). However, the effects of therapy and hemodilution in bone marrow (BM) B-cell recovery have not been systematically evaluated during follow-up. MM (n = 177) and adult (≥50y) healthy donor (HD; n = 14) BM samples were studied by next-generation flow (NGF) to simultaneously assess measurable residual disease (MRD) and residual normal B-cell populations. BM hemodilution was detected in 41 out of 177 (23%) patient samples, leading to lower total B-cell, B-cell precursor (BCP) and normal plasma cell (nPC) counts. Among MM BM, decreased percentages (vs. HD) of BCP, transitional/naïve B-cell (TBC/NBC) and nPC populations were observed at diagnosis. BM BCP increased after induction therapy, whereas TBC/NBC counts remained abnormally low. At day+100 postautologous stem cell transplantation, a greater increase in BCP with recovered TBC/NBC cell numbers but persistently low memory B-cell and nPC counts were found. At the end of therapy, complete response (CR) BM samples showed higher CD19− nPC counts vs. non-CR specimens. MRD positivity was associated with higher BCP and nPC percentages. Hemodilution showed a negative impact on BM B-cell distribution. Different BM B-cell regeneration profiles are present in MM at diagnosis and after therapy with no significant association with patient outcome.