ALBERT

Description: A set of linear second-order differential equations is converted into a semigroup, whose algebraic structure is used to generate novel equations. The Lagrangian formalism based on standard, null, and nonstandard Lagrangians is established for all members of the semigroup. For the null Lagrangians, their corresponding gauge functions are derived. The obtained Lagrangians are either new or generalization of those previously known. The previously developed Lie group approach to derive some equations of the semigroup is also described. It is shown that certain equations of the semigroup cannot be factorized, and therefore, their Lie groups cannot be determined. A possible solution of this problem is proposed, and the relationship between the Lagrangian formalism and the Lie group approach is discussed.

Description: Glucose 6-phosphate dehydrogenase (G6PD) deficiency is 1 of the commonest human enzymopathies, caused by inherited mutations of the X-linked gene G6PD. G6PD deficiency makes red cells highly vulnerable to oxidative damage, and therefore susceptible to hemolysis. Over 200 G6PD mutations are known: approximately one-half are polymorphic and therefore common in various populations. Some 500 million persons with any of these mutations are mostly asymptomatic throughout their lifetime; however, any of them may develop acute and sometimes very severe hemolytic anemia when triggered by ingestion of fava beans, by any of a number of drugs (for example, primaquine, rasburicase), or, more rarely, by infection. Approximately one-half of the G6PD mutations are instead sporadic: rare patients with these mutations present with chronic nonspherocytic hemolytic anemia. Almost all G6PD mutations are missense mutations, causing amino acid replacements that entail deficiency of G6PD enzyme activity: they compromise the stability of the protein, the catalytic activity is decreased, or a combination of both mechanisms occurs. Thus, genotype-phenotype correlations have been reasonably well clarified in many cases. G6PD deficiency correlates remarkably, in its geographic distribution, with past/present malaria endemicity: indeed, it is a unique example of an X-linked human polymorphism balanced through protection of heterozygotes from malaria mortality. Acute hemolytic anemia can be managed effectively provided it is promptly diagnosed. Reliable diagnostic procedures are available, with point-of-care tests becoming increasingly important where primaquine and its recently introduced analog tafenoquine are required for the elimination of malaria.

Description: Introduction Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by hematopoietic/stem cell-derived clonal myeloproliferation leading to cytopenia/cytosis, splenomegaly and bone marrow (BM) fibrosis. The alteration of haematopoiesis associted with BM fibrosis is deeply associated with profound modifications of the BM microenvironment, as a consequence of a defective balance between the vascular niche and the endosteal niche, associated to megakaryocytes, endothelial and mesenchymal stromal cells (MSC) dysfunction through the production of a variety of profibrotic, angiogenic, and pro-inflammatory cytokines, including megakaryocyte-derived PDGF, TGF-beta and osteoprotegerin, IL-6, PDGF, RANTSs, BMP-2, and which can trigger auto-immune mechanisms, chronic inflammation and oxidative stress status. It is well-known that oncogenic lesions can switch the bioenergetics of malignant cells from OXPHOS to glycolysis (Warburg effect) with lactate production, a phenomenon clinically relevant, particularly in PMF where the amount of the enzyme lactate dehydrogenase (LDH) is an established biomarker of leucocyte turnover and an independent biomarker of overall and leukemia-free survival. The shuttling of the main LDH metabolite lactate is implicated in the interplay of cancer cells with neighboring stromal cells which become glycolytic and export lactate. In turn, lactate is taken up by cancer cells and used for oxidative metabolism, to drive angiogenesis in endothelial cells and to inhibit T- cell function. Moreover, there are evidences that lactate may be involved in the promotion of the fibrosis increasing the TGF-beta levels. In this work we aimed to investigate the role of lactate in the BM myelofibrosis. Results. From microarray datasets, we selected 34 PMF patients carrying the JAK2V617F mutation, 28 JAK2 wild-type patients and 16 healthy donors (HD). Our analysis showed that SLC16A1 (MCT1), SLC16A3(MCT2) and SLC16A7 (MCT4) genes were upregulated in patients in respect to healthy donors in a JAK2V617F mutation independent manner. Furthermore, we demonstrated a significant increase of lactate concentration in PB sera from PMF patients compared to HD, associated to higher percentage of circulating granulocyte- and monocyte-myeloid derived suppressor cells (Gr- and Mo-MDSCs), and Treg. Moreover, IDO, LAG3, BTLA, PDL-2, TIM-3 and CD152 levels were significantly increased in PMF sera compaterd to HD ones. To demonstrate that lactate could play a role in driving cancer immune evasion in PMF, healthy peripheral blood mononucleated cells (PBMCs) were incubated in presence of lactate. After 3 days we observed a significant increase of the percentage of Mo-MDSCs, Treg, CD4+PD1+ and CD8+PD1+ lymphocytes. The same results were obtained after incubation of PBMCs with sera from PMF patients. No effects were observed using HD sera. Interestingly, the percentages of Treg and Mo-MDSCs increased after exposure to PMF sera were significantly reduced in presence of the inhibitor of lactate transporter AZD3965. To investigate the role of lactate in the PMF microenvironment, we next exposed healthy MSCs to lactate for 48h. Treated MSCs assumed a CAF-like phenotype increasing expression of aSMA, FAP1 and TGF-beta. Moreover, Masson's trichrome staining showed an increase of collagen deposits in BM-MSCs associated to increased release of IL6, TGF-beta, MMP2, MMP9 and RANTES. Also, exposure to PMF sera induced higher collagen deposits in MSCs and this effect was reverted adding AZD3965. As BM fibrosis is frequently accompanied by osteosclerosis, we also investigated the effects of lactate on ostegenic differentiation of BM-MSCs. After 10 days of treatment with lactate, the BM-MSCs showed a morphological change associated to increased osteogenic gene markers such as BMP2, RUNX2 and SPARC (osteonectin), and higher released levels of calcitonin, BMP-2, MCP-1, sRANKL and osteoprotegerin. Conclusion Our results demonstrate that lactate might be involved in the immune impairment and BM fibrosis of PMF. The inhibition of lactate production and shuttles in myelofibrosis may be a strategy not only to inhibit invasive and metastatic behavior of cancer cells, but also to restore the anti-cancer immune response improving the results of therapy in MF patients. Disclosures Romano: Novartis: Honoraria; Takeda: Honoraria. Di Raimondo:Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen, Takeda, Novartis: Honoraria; Celgene: Consultancy, Honoraria; GILEAD, Incyte: Research Funding. Palumbo:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: INTRODUCTION: Several studies have disclosed the predictive role of tumor microenvironment (ME) in diffuse large B cell lymphoma (DLBCL). However, there is limited data regarding the prognostic impact of immune cells (IC) in the bone marrow (BM) of DLBCL patients (pts). Regulatory molecules secreted from primary tumor sites may induce a pro-tumorigenic ME within BM, resulting in an impaired systemic immune response that could promote lymphoma survival. AIMS: -To determine the prognostic impact on survival and risk of early relapse (ER) of the % of T lymphocytes (TL), monocytes (Mo), neutrophils, NK cells and polyclonal B lymphocytes (BL) measured by flow cytometry (FC) in pre-treatment BM aspirates of DLBCL pts. METHODS: We selected pts with DLBCL and available BM aspiration FC data at the time of diagnosis who received treatment at our institution between 2012 and 2019. Clinical information was collected from medical records. FC analysis was performed with 8-color FC panels according to international Euroflow protocols. % of TL, Mo, neutrophils, NK cells and polyclonal BL by FC were compared to the normal values determined by Matarraz et al. (Cytometry part B, 2010). All parameters were analyzed as ordinal variables in 3 categories: low, normal and high. Odds ratio for ER (relapse within a year) was calculated using logistic regression. The survival analysis was estimated with Kaplan-Meier method. The comparison between variables was performed through log-rank test and multivariate analysis with Cox regression. RESULTS: A total of 119 pts were included in this retrospective study. Pts characteristics are summarized in Table 1. All pts were treated with immunochemotherapy regimens. Median PFS and OS were not reached, 75th percentile of 12.7 and 27.8 months (m), respectively; with a median follow up time of 30.7 m (range: 3.4-60). ER was documented in 25 pts. Regarding BM IC, pts with normal TL, polyclonal BL and Mo % were significantly associated with superior PFS and OS (figure 1A and table 2). No correlation between BM NK cells or neutrophils levels and outcome was observed. Moreover, BM IC levels did not statistically differ in involved vs not involved BM. In our cohort, the R-IPI was able to discriminate outcomes in poor and good-very good (G-VG) risk (median OS of 48 m vs. not reached, p

Description: Introduction: Trauma-induced coagulopathy (TIC) is a multifactorial condition secondary to severe trauma. In TIC, early fibrinogen (FI) replacement and low dose of recombinant activated factor VII (rFVIIa) may positively impact outcome. Factor XIII (FXIII), on the other hand, may stimulate in vitro clot formation and clot stability. We hypothesized that combination of FI, rFVIIa and FXIII might normalize clot formation more effectively than the isolated use of each concentrate in a model of TIC. Aim: Evaluation of the procoagulant effect of isolated or combined use of FI, rFVIIa and FXIII in a model of TIC. Methods: TIC in vitro model was obtained by dilution of whole blood from seven healthy controls with isotonic saline (NaCl 0.9%) (2:3 whole blood:saline ratio). FI, rFVIIa and FXIII were spiked in combination or alone until obtaining final levels of 2 g/L, 1 μg/mL and 100 IU/dL respectively. Procoagulant effects of the different concentrates or their mixtures were evaluated by Rotational Thromboelastometry (ROTEM®, Werfen) triggered using starTEM® (calcium chloride 0,2 M) and exTEM® reagent (source of tissue factor) diluted with saline up to 1:100.000 (final dilution) for a better evaluation of both the extrinsic and intrinsic pathways of coagulation. The values of clotting time (CT: time until 2 mm of amplitude, in seconds), amplitude (parameter proportional to the clot strength) at 5 minutes (A5, in mm) and clot formation time (CFT: time from CT to 20 mm of amplitude, in seconds) were evaluated. Statistical analysis of differences was performed by One-Way ANOVA test assuming no paring of data and using the Holm-Sidak's correction for multiple comparisons with a family-wise significance and confidence level of 0.01. Statistical significance was set at p〈 0.05. Results/Discussion: Data are summarized in Table I and Figure 1. CT needed the combination of two of more concentrates to reach the normal range suggesting that the administration of FI alone in TIC may not be enough to restore the patients' hemostatic potential. In regard to the clot strength evaluated by A5, the addition of FXIII or rFVIIa alone or in combination did not improve the value of A5 that was only normalized by the addition of FI. This effect of FI was increased in the presence of FXIII or rFVIIa which indicated that normal levels of FI might be required for rFVIIa or FXIII to be effective emphasising the possible benefit of the combinatory therapy. Like observed in A5, the velocity of clot formation evaluated by the CFT was normalised only by the addition of FI. However, the combination of FI plus FXIII + rFVIIa had a stronger effect on CFT compared with the combination of FI + FXIII or FI + rFVIIa, indicating that the improvement of thrombin generation due to rFVIIa plus an increment of fibrin formation and net stabilization through the contribution of higher levels of FI and FXIII respectively, might provide a beneficial synergistic procoagulant effect in TIC. Conclusion: The use of FI in TIC may contribute to increase the patient's hemostatic potential but might not be enough. Combinatory therapies based on the administration of FI, rFVIIa and FXIII might be of better benefit in this setting. Ex-vivo studies using blood of patients with stablished TIC might bring new insights on the possible advantages of this combinatory therapy to design more effective protocols to treat this frequent and life-threatening acquired condition. Disclosures Canales: Sandoz: Honoraria; iQone: Honoraria; Janssen: Speakers Bureau; Janssen: Honoraria; Roche: Speakers Bureau; Karyopharm: Honoraria; Sandoz: Speakers Bureau; Novartis: Honoraria; Takeda: Speakers Bureau; Roche: Honoraria; Sandoz: Honoraria; Janssen: Speakers Bureau; Roche: Speakers Bureau; Sandoz: Speakers Bureau; Takeda: Speakers Bureau; Janssen: Honoraria; Karyopharm: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Roche: Honoraria; Gilead: Honoraria. Butta:NovoNordisk: Speakers Bureau; Takeda: Research Funding, Speakers Bureau; SOBI: Speakers Bureau; Pfizer: Speakers Bureau; ROCHE: Research Funding, Speakers Bureau; Novartis: Speakers Bureau; Grifols: Research Funding. Alvarez Román:NovoNordisk,: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; SOBI,: Consultancy, Research Funding, Speakers Bureau; Pfizer,: Research Funding, Speakers Bureau; Roche: Speakers Bureau; Novartis: Speakers Bureau; Bayer: Consultancy; Grifols: Research Funding. Jiménez-Yuste:F. Hoffman-La Roche Ltd, Novo Nordisk, Takeda, Sobi, Pfizer: Consultancy; Grifols, Novo Nordisk, Takeda, Sobi, Pfizer: Research Funding; F. Hoffman-La Roche Ltd, Novo Nordisk, Takeda, Sobi, Pfizer, Grifols, Octapharma, CSL Behring, Bayer: Honoraria.

Description: In March 2020, COVID-19 was declared a pandemic by the WHO. Since then, efforts have been made to increase our knowledge of the disease. The convalescent plasma (CP) donation involves a series of criteria for donor eligibility, such as pre-donation and serological tests. Currently, the antibody response against SARS-CoV-2 remains poorly understood and the usefulness of serological tests is unclear (Long, et al. Nature Medicine, 2020). Based on donor eligibility, one can better assess the antibody response to SARS-CoV-2 from post-infection candidates. This is an observational, prospective study, without intervention. From 06/26/2020 to 07/31/2020, serological data of candidates for CP donation were collected. Recovered COVID-19 patients who had been previously tested were interviewed. RT-PCR and serological test (chemiluminescence immunoassays) for SARS-CoV-2 were carried out to verify their eligibility for CP collection. The data were related to the time of the onset of symptoms and the collection of the material. Subjects with non-detectable RT-PCR and reagent IgG were considered eligible. Reference values were IgM 〉 1.2 AU/mL and IgG 〉 1.4 AU/mL. The characteristics of the candidates are summarized in Table 1. Of 234 interviewed subjects, 70 were screened for pre-collection tests, 49 were male. The average age was 36 (20 - 57). After serological screening, 44/70 (62.8%) were considered eligible for CP donation. The reasons for ineligibility were: 17/70 (24.3%) non-reagent IgG, 4/70 (5.7%) with detectable RT-PCR and 5/70 (7.1%) due to reasons in clinical screening. The median between the onset of symptoms and the serology sample collection was 32.5 (21 - 77) days, (IQR 28.75 to 37.25). Those who were more likely to be eligible to donate were the subjects who had a longer time interval between the symptoms onset and the sample collection (p

Description: Introduction: Treatment-free remission (TFR) is an emerging treatment goal for chronic myeloid leukemia (CML) patients in deep molecular response (DMR). Current evidence shows that 40%-60% of patients relapse while in TFR; and nearly all regain response once tyrosine kinase inhibitors (TKIs) treatment are reinitiated. However a robust predictor of prolonged TFR has not been reported yet. Considering real-life setting, 2 key factors may affect TFR outcome if not properly done: Access to serial molecular monitoring at optimal timepoints and quality laboratory terms as accuracy, sensitivity and rapid results. This motivated the creation of the AST study in our region to guarantee adequate molecular monitoring for TFR in Argentina and characterize new prognostic biomarkers helpful to identify more accurately patients who will be able to sustain TFR. We aimed to assess the proportion of patients with sustained major molecular response (MMR) after TKIs discontinuation and define precise conditions for stopping treatment. Methods: This prospective, multicentre Argentina Stop Trial (AST) trial is recruiting chronic phase CML patients under TKI treatment for at least ≥ 4 years, in DMR (≥MR4.0) sustained for ≥ 2 years in standardized laboratory, confirmed typical BCR-ABL1 transcripts b3a2 and/or b2a2 and aged 〉 18 years. Molecular tests are centralized in 2 harmonized laboratories and performed monthly for the first 6 months, every 2 months until the first year, and every 3 months during the second year. If patients lost MMR, TKI was restarted immediately. Molecular relapse Free Survival was estimated by Kaplan-Meier method. Difference between survival variables was evaluated through log-rank test. Multivariate analysis was performed through Cox proportional hazards model. The cutoffs of the numerical variables were considered according to the log-rank test. Results: Between February 2019 and July 2020, we evaluated 50 CML patients of whom 46 were enrolled from 7 centers in Argentina and 4 were screening failures. Recruitment was interrupted due to COVID-19 pandemic. Patient median age was 57.5 years (range 24-85). Before discontinuation, TKI treatment was as follows: Imatinib 37/46 (80%), Nilotinib 5/46 (11%) and Dasatinib 4/46 (9%), 2G-TKI as 1st line, 11% of the patients received non-branded treatment. Sokal risk score showed to be low in 22 patients (48%), intermediate in 14 (30%) and high in 10 (22%). Median follow-up was 10 months (range 4-17) and the estimated molecular relapse-free survival was 80.2% (95%CI 69-93) at 6 months Fig 1. Longer DMR durations before discontinuation were associated with increased probability of maintaining response at 6 and 12 months: 83.2% for patients who had 〉54 months in DMR vs 70% with

Description: Background:Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and fatal myeloid malignancy characterized by clonal proliferation of immature plasmacytoid dendritic cells. BDCN has been frequently described in men and age above 60 years, and usually involves the skin and bone marrow. Immunophenotyping is based on CD123+, CD4+ and CD56+ expression and is necessary rule out other myeloid malignancies. Objective: We aimed to describe the clinical characteristics and immunophenotype of BPDCN cases diagnosed at two tertiary Peruvian cancer institutions between 2018-2019. Methods: We retrospectively reviewed medical records of patients diagnosed of BPDCN at two tertiary Peruvian cancer centers (Instituto Nacional de Enfermedades Neoplasicas and Oncosalud-AUNA, Lima-Peru) between 2008 and 2019. Clinical characteristics, treatments, outcomes and immunophenotype by pathology or flow cytometry review, were collected. Patients were classified according to their maturation stage using CD34 and CD117 expression into three subgroups: Immature-Intermediate blastic (IIB-BPDCN; partial expression of CD117 and absence or minimal expression of CD34), mature (M-BPDCN; absence of CD34 and CD117) and unknown(U-BPDCN). Overall survival (OS) and event-free survival (EFS) curves were estimated using the Kaplan-Meier method and compared with the Log-rank test to determine the impact of immunophenotype. Results: Thirty-eight cases were included during the study period. The median age at diagnosis was 38 years (7-82), only six (16%) were older than 65 years, and a notorious female predominance (F/M ratio: 1.7:1) was observed. Twenty-four cases had CD34/117 expression available and were classified according to the maturation stage in IIB-BPDCN (13) and M-BPDCN(11), additionally 14 cases had unknown stage (U-BPDCN). Table 1 summarizes clinical characteristics, treatment and outcomes according to their immunophenotype. Bone marrow infiltration was more frequent in immature phenotypes (92% IIB-BPDCN vs 73% M-BPDCN, p=0.001), as well as skin infiltration was more common in mature phenotype (72% vs 31%, p=0.008). CNS infiltration at diagnosis was 15% and 55% in IIB-BPDCN and M-BPDCN, respectively. Sixteen patients received treatment based on ALL-like protocols, 8 AML-like, 5 CHOP-like and 9 patients only palliative care. At 5 years median follow-up, median EFS and OS was 12 and 16 months, respectively. IIB-BPDCN had the lowest survival (4 months EFS and 6 months OS). Conclusions: We describe a Peruvian cohort of BPDCN patients with younger age at diagnosis and female predominance than reported previously by other series, however further studies in Latino population are required to confirm these results. Immature phenotypes based on CD34 and CD117 expression were associated with high rate of bone marrow infiltration and fatal outcomes. New successful target therapies must be warranted for this rare and fatal condition. Disclosures No relevant conflicts of interest to declare.

Description: In Brazil, until the 1980s, the context of blood as transfusion therapy was marked by paid donations. Thus, self-interest has surpassed solidarity as a motivator to donate. Recruiting donors involves advising the population due to the difficulties related to the myths around donation. With the COVID-19 pandemic, recruiting convalescent plasma (CP) donors has been a hard. This is an observational, prospective and non-interventionist study carried out in a hemotherapy unit of the Unified Health System, in central-western Brazil. Data collection was carried out from 06/19/2020 to 07/31/2020. The subjects were contacted by the Recruitment and Collection (CR) sector, through an active search, using lists of patients previously diagnosed with COVID-19. The study was also published on social and traditional networks, which resulted in self-reference. Convalescent COVID-19 patients tested, of both genders, aged between 18 and 60 years, weight over 60 kg, without symptoms for more than 14 days, and nulliparous donors were invited to the study. Those who met the criteria were scheduled for clinical and serological screening. The subjects eligible for donation, with IgG reagent, signed the Free and Informed Consent Form. Individuals with positive RT-PCR and / or non-reactive IgG were excluded. During the study period, RC made 308 and received 1,797 calls (2,105 contacts), generating 242 (11.5%) screening appointments, 173 (8.2%) of which resulted from self-referral and 69 (3.2%) from active search. Of these, 131 (6.2%) subjects attended the appointment. After clinical screening, 37 (28.25%) subjects were ineligible, 37 (28.25%) after serological tests and 57 (43.5%) were eligible for donation. The ineligibility causes in clinical and serological screening are described in table 1. Many countries face difficulties in meeting the demand for blood and its components during the pandemic (Barone & DeSimone. Transfusion, 2020), especially in those where blood commercialization is prohibited, as in Brazil. The purpose of recruiting donors is to make blood donation habitual to Brazilians, as it occurs in developed countries. Figure 2 shows self-referral rates after dissemination in traditional media. The ads focused on the donor's ability to save lives by encouraging altruism (Ronse, et al. 2018).On the other hand, despite attracting more people, most were not eligible for donation, demonstrating a great capacity to raise awarenessamong the population, but it was necessary to improve criterias and demonstrate them clearly for the likely donor. Of the 26 donors, 22 (84.6%) are older than 29. For these, awareness-raising occurred mainly through the television media 9(34.6%) and 5(19.3%) through personal contact. In the youngest 4(15.4%), the stimulus was social networks (Sümnig, et al. Transfusion, 2018). Marketing was important for recruitment. As blood donation is not usual for most brazilians, it is essential to plan, develop, evaluate strategies, enabling new forms of collection. Another difficulty encountered was the logistics for this donation type. As the donor is convalescent, the recruitment, screening, and collection was restricted to a physical space, isolated from conventional donos (Bloch, et al. J Clin Invest. 2020). In conclusion, the COVID-19 pandemic has become a public health challenge worldwide. Many recovered patients could donate CP. However, it is necessary to define the ideal requirements for donor selection to ensure the therapeutic viability and efficacy of PC transfusion. Blood collection teams need to strengthen strategies to inform the population about blood donation needs. The information available in the traditional and digital media about the donation process can increase the donation rate and guarantee a safe blood component. Strategies such as a greater number of insertions in social networks with well-defined criteria for donating plasma from a convalescent donor, clarification of exclusion criteria in the means of greater reach, creation of easily accessible channels to the donor (registrations, central doubts),in addition to stratifying by age group and proposing different dissemination strategies and thanksgiving for the donation, forming a network of donations. The combined efforts of these actions will contribute with expert advice and experience, technical guidance and additional support to potentially save more lives. Disclosures No relevant conflicts of interest to declare.