Characterization of the REC114-MEI4-IHO1 complex regulating meiotic DNA double-strand break formation.

Meiotic recombination is initiated by the formation of DNA double-strand breaks (DSBs), essential for fertility and genetic diversity. In the mouse, DSBs are formed by the catalytic TOPOVIL complex consisting of SPO11 and TOPOVIBL. To preserve genome integrity, the activity of the TOPOVIL complex is finely controlled by several meiotic factors including REC114, MEI4, and IHO1, but the underlying mechanism is poorly understood. Here, we report that mouse REC114 forms homodimers, that it associates with MEI4 as a 2:1 heterotrimer that further dimerizes, and that IHO1 forms coiled-coil-based tetramers. Using AlphaFold2 modeling combined with biochemical characterization, we uncovered the molecular details of these assemblies. Finally, we show that IHO1 directly interacts with the PH domain of REC114 by recognizing the same surface as TOPOVIBL and another meiotic factor ANKRD31. These results provide strong evidence for the existence of a ternary IHO1-REC114-MEI4 complex and suggest that REC114 could act as a potential regulatory platform mediating mutually exclusive interactions with several partners.

Profiling wastewater characteristics in intra-urban catchments using online monitoring stations.

This study aims to investigate the differences in intra-urban catchments with different characteristics through real-time wastewater monitoring. Monitoring stations were installed in three neighbourhoods of Barcelona to measure flow, total chemical oxygen demand (COD), pH, conductivity, temperature, and bisulfide (HS-) for 1 year. Typical wastewater profiles were obtained for weekdays, weekends, and holidays in the summer and winter seasons. The results reveal differences in waking up times and evening routines, commuting behaviour during weekends and holidays, and water consumption. The pollutant profiles contribute to a better understanding of pollution generation in households and catchment activities. Flows and COD correlate well at all stations, but there are differences in conductivity and HS- at the station level. The article concludes by discussing the operational experience of the monitoring stations.

Development and application of metallo-phthalocyanines as potent G-quadruplex DNA binders and photosensitizers.

Metallo-phthalocyanines (MPc) are common photosensitizers with ideal photophysical and photochemical properties. Also, these molecules have shown to interact with non-canonical nucleic acid structures, such as G-quadruplexes, and modulate oncogenic expression in cancer cells. Herein, we report the synthesis and characterisation of two metallo-phthalocyanines containing either zinc (ZnPc) or nickel (NiPc) in the central aromatic core and four alkyl ammonium lateral chains. The interaction of both molecules with G-quadruplex DNA was assessed by UV-Vis, fluorescence and FRET melting experiments. Both molecules bind strongly to G-quadruplexes and stabilise these structures, being NiPc the most notable G-quadruplex stabiliser. In addition, the photosensitizing ability of both metal complexes was explored by the evaluation of the singlet oxygen generation and their photoactivation in cells. Only ZnPc showed a high singlet oxygen generation either by direct observation or by indirect evaluation using a DPBF dye. The cellular evaluation showed mainly cytoplasmic localization of ZnPc and a decrease of the IC50 values of the cell viability of ZnPc upon light activation of two orders of magnitude. Two metallo-phthalocyanines containing zinc and nickel within the aromatic core have been investigated as G-quadruplex stabilizers and photosensitizers. NiPc shows a high G4 binding but negligible photosensitizing ability while ZnPc exhibits a moderate binding to G-quadruplex together with a high potency to generate singlet oxygen and photocytotoxicity. The interaction with G4s and capacity to be photosensitized is associated with the geometry adopted by the central metal core of the phthalocyanine scaffold.

Modulating the G-Quadruplex and Duplex DNA Binding by Controlling the Charge of Fluorescent Molecules.

Two fluorescent and non-toxic spirobifluorene molecules bearing either positive (Spiro-NMe3) or negative (Spiro-SO3) charged moieties attached to the same aromatic structure have been investigated as binders for DNA. The novel Spiro-NMe3 containing four alkylammonium substituents interacts with G-quadruplex (G4) DNA structures and shows preference for G4s over duplex by means of FRET melting and fluorescence experiments. The interaction is governed by the charged substituents of the ligands as deduced from the lower binding of the sulfonate analogue (Spiro-SO3). On the contrary, Spiro-SO3 exhibits higher binding affinity to duplex DNA structure than to G4. Both molecules show a moderate quenching of the fluorescence upon DNA binding. The confocal microscopy evaluation shows the internalization of both molecules in HeLa cells and their lysosomal accumulation.

White Families' Communications About and Around Race: Conversations Between white Adolescents and Their Mothers.

Though there is substantial research on racial socialization in families of color, there is less on such socialization in white families. To investigate racial socialization in white families, the current study analyzed mixed-methods data from 46 mother-adolescent dyads. Though white parents and their adolescent children largely claimed to not talk about race, they in fact communicated about and around race through various strategies that in effect, maintained white privilege and failed to challenge systems of racial oppression. Very few families in our sample discussed racial discrimination or white privilege, and fewer rooted both at the systems level. Our results highlight situations that prompt conversations about race as well as the ways white families talk about and around race and white privilege.

Chest tomography for COVID-19 screening in head and neck cancer elective surgery. Is it enough?

INTRODUCTION: Head and neck cancer patients are at high risk of SARS-CoV-2 infection; surgery in them involves risk for patients, surgeons, health personnel, medical institutions and society, since it is associated with prolonged and inadvertent production of aerosols and emergency procedures that facilitate the breach of protective measures by health personnel. OBJECTIVE: To find out if pulmonary tomographic findings are sufficient to preoperatively identify patients with COVID-19. METHODS: Retrospective, cross-sectional, analytical study of patients with cervical-facial neoplasms who were candidates for surgery, preoperatively evaluated by simple chest computed tomography based on the CO-RADS classification. In CO-RADS ≥ 3 patients, surgery was suspended and PCR was performed using nasopharyngeal swab. RESULTS: 322 patients were included, all without COVID-19 symptoms. Tomography was positive in 35 (10.87%); in 30, nasopharyngeal swab was performed: 28 were negative and two were positive; none developed COVID-19 symptoms. CONCLUSIONS: Chest tomography is not useful as the only preoperative screening procedure for COVID-19, since its findings are nonspecific, with a high rate of false-positive results. Clinical evaluation, with PCR and tomography, is the best form of preoperative screening.

INTRODUCCIÓN: Los pacientes con cáncer de cabeza y cuello tienen alto riesgo de infección por SARS-CoV-2; la cirugía en ellos implica riesgo para pacientes, cirujanos, personal de salud, institución médica y sociedad, ya que se asocia a aerosolización prolongada e inadvertida y a procedimientos de urgencia que facilitan la ruptura de las medidas de protección del personal de salud. OBJETIVO: Conocer si los hallazgos tomográficos pulmonares son suficientes para identificar en forma preoperatoria a los pacientes con COVID-19. MÉTODOS: Estudio retrospectivo, transversal y analítico de pacientes con neoplasias cervicofaciales candidatos a cirugía, evaluados preoperatoriamente mediante tomografía axial computarizada simple de tórax con base en la clasificación CO-RADS. En los pacientes CO-RADS ≥ 3 se suspendió la cirugía y se realizó PCR por hisopado nasofaríngeo. RESULTADOS: Se incluyeron 322 pacientes, todos sin síntomas de COVID-19. La tomografía fue positiva en 35 (10.87 %); en 30 se efectuó hisopado nasofaríngeo: 28 fueron negativos y dos, positivos; ninguno desarrolló síntomas de COVID-19. CONCLUSIONES: La tomografía torácica no es útil como procedimiento único de tamizaje preoperatorio de COVID-19, ya que sus hallazgos son inespecíficos, con tasa alta de resultados falsos-positivos. La evaluación clínica, con PCR y tomografía es la mejor forma de pesquisa preoperatoria.

Features of Cytomegalovirus DNAemia Blips in Allogeneic Hematopoietic Stem Cell Transplant Recipients: Implications for Optimization of Preemptive Antiviral Therapy Strategies.

Cytomegalovirus (CMV) DNAemia occurs frequently in allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). There is limited information about the incidence, features, and clinical impact of CMV DNAemia blips (episodes defined by an isolated positive PCR result) in this setting. In this retrospective study, 225 consecutive adult patients undergoing any modality of allo-HSCT at our center between May 2012 and July 2019 were included. Plasma CMV DNA load was monitored using a highly sensitive real-time PCR assay. In all, 187 of 225 patients had CMV DNAemia through day 365 after allo-HSCT (total number of episodes, n = 379). Eighty-three of the 187 patients had 1 or more blips (n = 104). Blips occurred as a first episode of CMV DNAemia as opposed to prolonged CMV DNAemia (≥2 consecutive positive PCR results) in 47 patients; in 20 of these patients, blips represented the only documented episode throughout the study period, and in 27 patients, blips preceded a prolonged CMV DNAemia episode. In the remaining 36 patients, blips developed as recurrences. Blips presenting as initial episodes occurred more frequently (P < .001) in patients receiving an allograft from a CMV-seropositive donor. The cumulative incidence of recurrent CMV DNAemia following initial blips, self-resolving prolonged CMV DNAemia episodes, or CMV DNAemia episodes treated preemptively with antivirals was not significantly different (P = .34). Receiver operating characteristic curve analysis indicated that a CMV DNA load cutoff of 48 IU/mL yielded the highest combined sensitivity (66%) and specificity (70.2%) for predicting a prolonged CMV DNAemia episode. The practical implications of our data in the optimization of preemptive antiviral therapy strategies are discussed.

Assessment of users' acceptability of a mobile-based embodied conversational agent for the prevention and detection of suicidal behaviour.

The use of embodied conversational agents in mental health has increased in the last years. Several studies exist describing the benefits and advantages of this technology as a complement to psychotherapeutic interventions for the prevention and treatment of depression, anxiety, or post-traumatic stress disorder, to name a few. A small number of these works implement capabilities in the virtual agent focused on the detection and prevention of suicidality risks. The work presented in this paper describes the development of an embodied conversational agent used as the main interface in HelPath, a mobile-based application addressed to individuals detected with any of the suicidal behaviours: ideation, planning or attempt. The main objective of HelPath is to continuously collect user's information that, complemented with data from the electronic health record, supports the identification of risks associated with suicidality. Through the virtual agent, the users also receive information and suggestions based on cognitive behaviour therapy that would help them to maintain a healthy condition. The paper also presents the execution of an exploratory pilot to assess the acceptability, perception and adherence of users towards the virtual agent. The obtained results are presented and discussed, and some actions for further improvement of the embodied conversational agent are also identified.

Primary prophylaxis of invasive fungal infections with posaconazole or itraconazole in patients with acute myeloid leukaemia or high-risk myelodysplastic syndromes undergoing intensive cytotoxic chemotherapy: A real-world comparison.

This is an observational-retrospective study comparing the real-world outcomes associated with posaconazole vs itraconazole as prophylaxis treatments. Two hundred and ninety-three patient admissions attributable to 174 patients were included in the study. Patients were treated with itraconazole (n = 114 admissions; 39%) or posaconazole (n = 179; 61%). Antifungal prophylaxis failure (APF) due to treatment-related adverse events (in 34 out of 293 patient admissions; 11.6%) was more frequent in the posaconazole group (6.1% vs 15.1%; P = .024). There were 9 patient admissions for episodes of APF due to probable/proven breakthrough fungal infection (primary endpoint): 6 and 3 in the itraconazole and posaconazole group respectively (5.3% vs 1.7%; P = .095). All of them were associated with invasive pulmonary aspergillosis (IPA). APF was more frequent with itraconazole (65% vs 30%; P < .001), along with failure due to possible/probable/proven IPA (25% vs 10%; P = .002) and overall failure by any of the 3 different causes of prophylaxis failure (70% vs 38%; P < .001). In agreement with clinical trial data, this real-world evidence supports the use of posaconazole over itraconazole in AML or MDS patients undergoing intensive chemotherapy.

Crystal structure of a class-mu glutathione S-transferase from whiteleg shrimp Litopenaeus vannamei: structural changes in the xenobiotic binding H-site may alter the spectra of molecules bound.

Glutathione S-transferases (GSTs) are dimeric proteins that play a key role in phase II cellular detoxification. Here, the first crystal structure of a GST class-mu from marine crustacean shrimp Litopenaeus vannamei is reported at a resolution of 2.0 Å. The coordinates reported here have the lowest sequence identity with previously reported GSTs class-mu deposited at the Protein Data Bank (PDB), although they have subtle conformational differences. One key feature of GST class-mu from L. vannamei is the active site crevice markedly reduced when it is compared with other GSTs class-mu. This finding together with the chemical change of residues into the cavity (F112 and Y210) points to a particular specialization in which smallest xenobiotics with nonstandard chemical characteristics can be bound to the H-site. This suggests that marine organisms have evolved structural strategies to provide efficient selectivity toward xenobiotics to be disposed of by the phase II detoxification process.

Deep intronic mutation in OFD1, identified by targeted genomic next-generation sequencing, causes a severe form of X-linked retinitis pigmentosa (RP23).

X-linked retinitis pigmentosa (XLRP) is genetically heterogeneous with two causative genes identified, RPGR and RP2. We previously mapped a locus for a severe form of XLRP, RP23, to a 10.71 Mb interval on Xp22.31-22.13 containing 62 genes. Candidate gene screening failed to identify a causative mutation, so we adopted targeted genomic next-generation sequencing of the disease interval to determine the molecular cause of RP23. No coding variants or variants within or near splice sites were identified. In contrast, a variant deep within intron 9 of OFD1 increased the splice site prediction score 4 bp upstream of the variant. Mutations in OFD1 cause the syndromic ciliopathies orofaciodigital syndrome-1, which is male lethal, Simpson-Golabi-Behmel syndrome type 2 and Joubert syndrome. We tested the effect of the IVS9+706A>G variant on OFD1 splicing in vivo. In RP23 patient-derived RNA, we detected an OFD1 transcript with the insertion of a cryptic exon spliced between exons 9 and 10 causing a frameshift, p.N313fs.X330. Correctly spliced OFD1 was also detected in patient-derived RNA, although at reduced levels (39%), hence the mutation is not male lethal. Our data suggest that photoreceptors are uniquely susceptible to reduced expression of OFD1 and that an alternative disease mechanism can cause XLRP. This disease mechanism of reduced expression for a syndromic ciliopathy gene causing isolated retinal degeneration is reminiscent of CEP290 intronic mutations that cause Leber congenital amaurosis, and we speculate that reduced dosage of correctly spliced ciliopathy genes may be a common disease mechanism in retinal degenerations.

Whole exome sequencing detects homozygosity for ABCA4 p.Arg602Trp missense mutation in a pediatric patient with rapidly progressive retinal dystrophy.

BACKGROUND: A pediatric patient presented with rapidly progressive vision loss, nyctalopia and retinal dystrophy. This is the first report of homozygosity for the p.Arg602Trp mutation in the ABCA4 gene. The child became legally blind within a period of 2 years. CASE PRESENTATION: An eight year-old Hispanic female presented with bilateral decreased vision following a febrile gastrointestinal illness with nausea and vomiting. Extensive workup involved pediatric infectious disease and rheumatology consultations.Initial visual acuity was 20/60 at distance and 20/30 at near in both eyes. Rapidly progressive vision loss occurred during a 2-year period resulting in visual acuities of 20/200 at distance in both eyes. Fundus exam disclosed attenuated vessels and multiple subretinal blister-like elevations. Optical coherence tomography showed far more lesions than were clinically evident with different levels of elevation. Autofluorescence imagery showed dramatic and widespread geographic areas of atrophy. The deposits that appeared drusen-like on clinical exam were hyperfluorescent, consistent with lipofuscin deposits containing A2e (N-retinylidene-N-retinylethanolamine) indicative of RPE cell dysfunction. Electroretinography was consistent with cone dystrophy, with relative preservation of rod function. Blood analysis and rheumatology evaluation found no evidence of a diffuse post-infectious/inflammatory process. The unique and rapid progression of her subretinal blister-like lesions was documented by fluorescein angiography, optical coherence tomography, autofluorescence imagery, and fundus photography. Family pedigree history disclosed consanguinity, her parents being first cousins. DNA analysis by whole exomic sequencing revealed homozygosity of p.Arg602Trp in the ABCA4 gene. CONCLUSION: The pediatric patient presented with a striking clinical appearance and dramatic rate of progression that was clinically more characteristic of an infectious or inflammatory process. This case expands the diverse range of phenotypes attributed to ABCA4 mutations and further supports the role of whole exome sequencing as a powerful new tool available to aid clinicians in establishing diagnosis for challenging cases.

Two rhenium compounds with benzimidazole ligands: synthesis and DNA interactions.

Two rhenium compounds: cis-tetrachlorotetrabenzimidazoldirhenium(iii) chloride - I and tetrabenzimidazoldioxorhenium(v) - II have been synthesized and characterized. X-ray data are presented for the new complex II. I and II show strong emission that has been used to investigate their interaction with several non-canonical DNA structures. Both compounds have a quenching effect on the fluorescence intensity upon addition of the investigated oligonucleotides; I was more selective for binding G4-than II. Association constant values obtained for I and II with G-quadruplexes reached 106 M-1, which suggests a strong interaction between both complexes and these sequences. FRET-melting assays show that I and II have a rather high level of stabilization of ckit1 and ckit2 quadruplexes. I is toxic against macrophages RAW267.7 only in high concentrations, while complex II shows no toxicity against these cells. I and II accumulate inside cells in different degrees. Molecular dynamic simulation studies have provided insights into the binding modes of II with ckit1 and ckit2 G-quadruplexes. The results obtained show the DNA binding activity of the rhenium complexes and their ability to be players in the anti-cancer fight since they can bind to non-canonical DNA forms in oncogene promoters, accumulate in some cancer cells, and influence the cancer cells microenvironment.

Post-transplant cyclophosphamide compared to sirolimus/tacrolimus in reduced intensity conditioning transplants for patients with lymphoid malignancies.

Despite novel cellular and immunomodulatory therapies, allogeneic hematopoietic stem cell transplantation (HSCT) remains a treatment option for lymphoid malignancies. Post-transplant cyclophosphamide (PTCY) is increasingly employed for graft vs. host disease (GVHD) prophylaxis. This study aims to evaluate the safety and efficacy of PTCY in reduce intensity (RIC) HSCT for patients with lymphoid neoplasms compared to sirolimus with tacrolimus (SIR/TAC). The primary endpoint was to compare grade III-IV acute GVHD, severe chronic GVHD, and relapse-free survival (GRFS) between the two GVHD prophylaxis strategies. This study, conducted from January 2012 to December 2020, included 171 consecutive patients (82 in the PTCY and 89 in the SIR/TAC group). Results revealed a significantly decreased incidence of moderate and severe forms of chronic GVHD in PTCY cohort (5.8% [95% CI, 1.8 to 13.1]) versus the SIR/TAC cohort (39.6% [95% CI, 29.3 to 49.7] (p < 0.001)). Other outcomes, including GRFS (PTCY [45.9% (95% CI, 35.8-58.7)] and SIR/TAC groups [36.8% (95% CI, 28-48.4)], (p = 0.72)), non-relapse mortality (NRM), relapse and overall survival (OS) were similar in both groups. Interestingly, the failure to achieve GRFS was mainly attributed to GVHD in the SIR/TAC group, while disease relapse was the primary reason in the PTCY cohort.

REAL-WORLD EXPERIENCE OF ISAVUCONAZOLE IN ALLOGENEIC STEM CELL TRANSPLANTATION IN SPAIN.

BACKGROUND: Invasive fungal infections (IFI) pose a significant complication after hematopoietic stem cell transplantation (HSCT). Isavuconazole (ISV) is a new generation azole with a favourable adverse effect and interaction profile approved for the treatment of invasive aspergillosis and mucormycosis. OBJECTIVES: We analysed the indications, effectiveness, adverse event profile and drug interaction management of ISV in the real-world setting in adults who received allogeneic-HSCT (allo-HSCT) within the Spanish Group of HSCT and Cell Therapy (GETH-TC). MATERIAL AND METHODS: We conducted a multicenter retrospective study of all consecutive adult allo-HSCT recipients (≥18 years) who received ISV either for IFI treatment or prophylaxis, from December 2017 to August 2021, in 20 centers within the Spanish Group of Hematopoietic Stem Cell Transplantation and Cell Therapy (GETH-TC). RESULTS: 166 adult allografted patients who received ISV from 2017 to 2021 were included. Median age was 48 years with 43% females. In 81 (49%) patients, ISV was used for treatment of IFI, and in 85 (51%) for prophylaxis. Median duration of ISV administration for IFI treatment was 57 days (range 31-126) and 86 days (range 33-196) for prophylaxis. Most frequent indication for treatment was invasive aspergillosis (78%), followed by mucormycosis (6%). Therapeutic success (45%) was the most frequent reason for ISV withdrawal. In the prophylaxis group, the resolution of IFI risk factors was the most frequent reason for withdrawal (62%). Six (7%) breakthrough IFI were reported. The majority of patients (80%) presented pharmacological interactions. Twenty one patients (13%) reported adverse events related to ISV, mainly liver biochemistry abnormalities, that lead to ISV withdrawal in 7 patients (4%). CONCLUSIONS: ISV was effective and well tolerated for IFI treatment and prophylaxis, with a manageable interaction profile.

Detection and sequencing of defective viral genomes in C6/36 cells persistently infected with dengue virus 2.

Dengue virus is the most important arbovirus that affects humans, and it can establish persistent infections, especially in insect-derived cell cultures. Defective viral genomes have been implicated in the establishment and maintenance of persistent infections with several flaviviruses; however, there exists almost no information concerning defective dengue virus genomes. Here, we report the detection of defective dengue 2 virus genomes in persistently infected mosquito C6/36 cells. The defective viral genomes were detected at a low ratio compared with the wild-type genome. Deletions of approximately 147 residues (222-368) were found in the E protein, and these mainly affected domain III (73 %) of the protein; deletions of approximately 153 residues (4-156) and 228 residues (597-825) were found in the methyltransferase and polymerase domains, respectively, of the NS5 protein. The truncated versions of NS5 could be detected by western blot only in the protein extracts derived from persistently infected cells.

The phenotypic spectrum of epilepsy associated with periventricular nodular heterotopia.

BACKGROUND: Periventricular nodular heterotopia (PVNH) is a congenital brain malformation often associated with seizures. We aimed to clarify the spectrum of epilepsy phenotypes in PVNH and the significance of specific brain malformation patterns. METHODS: In this retrospective cohort study, we recruited people with PVNH and a history of seizures, and collected data via medical record review and a standardized questionnaire. RESULTS: One hundred individuals were included, aged 1 month to 61 years. Mean seizure onset age was 7.9 years. Ten patients had a self-limited epilepsy course and 35 more were pharmacoresponsive. Fifty-five had ongoing seizures, of whom 23 met criteria for drug resistance. Patients were subdivided as follows: isolated PVNH ("PVNH-Only") single nodule (18) or multiple nodules (21) and PVNH with additional brain malformations ("PVNH-Plus") single nodule (8) or multiple nodules (53). Of PVNH-Only single nodule, none had drug-resistant seizures. Amongst PVNH-Plus, 55% with multiple unilateral nodules were pharmacoresponsive, compared to only 21% with bilateral nodules. PVNH-Plus with bilateral nodules demonstrated the highest proportion of drug resistance (39%). A review of genetic testing results revealed eight patients with pathogenic or likely pathogenic single-gene variants, two of which were FLNA. Five had copy number variants, two of which were pathogenic. CONCLUSIONS: The spectrum of epilepsy phenotypes in PVNH is broad, and seizure patterns are variable; however, epilepsy course may be predicted to an extent by the pattern of malformation. Overall, drug-resistant epilepsy occurs in approximately one quarter of affected individuals. When identified, genetic etiologies are very heterogeneous.

G4-QuadScreen: A Computational Tool for Identifying Multi-Target-Directed Anticancer Leads against G-Quadruplex DNA.

The study presents 'G4-QuadScreen', a user-friendly computational tool for identifying MTDLs against G4s. Also, it offers a few hit MTDLs based on in silico and in vitro approaches. Multi-tasking QSAR models were developed using linear discriminant analysis and random forest machine learning techniques for predicting the responses of interest (G4 interaction, G4 stabilization, G4 selectivity, and cytotoxicity) considering the variations in the experimental conditions (e.g., G4 sequences, endpoints, cell lines, buffers, and assays). A virtual screening with G4-QuadScreen and molecular docking using YASARA (AutoDock-Vina) was performed. G4 activities were confirmed via FRET melting, FID, and cell viability assays. Validation metrics demonstrated the high discriminatory power and robustness of the models (the accuracy of all models is ~>90% for the training sets and ~>80% for the external sets). The experimental evaluations showed that ten screened MTDLs have the capacity to selectively stabilize multiple G4s. Three screened MTDLs induced a strong inhibitory effect on various human cancer cell lines. This pioneering computational study serves a tool to accelerate the search for new leads against G4s, reducing false positive outcomes in the early stages of drug discovery. The G4-QuadScreen tool is accessible on the ChemoPredictionSuite website.

Results of haploidentical transplant in patients with donor-specific antibodies: a survey on behalf of the Spanish Group of Hematopoietic Transplant and Cell Therapy.

Background: Donor-specific antibodies (DSAs) are IgG allo-antibodies against mismatched donor HLA molecules and can cause graft failure (GF) in the setting of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Our aim was to report the experience of the Spanish Group of Hematopoietic Transplant (GETH-TC) in DSA-positive patients who had undergone haplo-HSCT. Methods: We conducted a survey of patients who underwent haplo-HSCT in GETH-TC centers between 2012 and 2021. Data were collected on the DSA assay used, monitoring strategy, complement fixation, criteria for desensitization, desensitization strategies and transplant outcomes. Results: Fifteen centers from the GETH-TC responded to the survey. During the study period, 1,454 patients underwent haplo-HSCT. Seventy of the transplants were performed in 69 DSA-positive patients, all of whom lacked a suitable alternative donor; 61 (88%) patients were female (90% with prior pregnancies). All patients received post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis. Regarding baseline DSA intensity, 46 (67%) patients presented mean fluorescence intensity (MFI) >5,000, including 21 (30%) with MFI >10,000 and three (4%) with MFI >20,000. Six patients did not receive desensitization treatment, four of them with MFI <5,000. Of 63 patients receiving desensitization treatment, 48 (76%) were tested after desensitization therapy, and a reduction in intensity was confirmed in 45 (71%). Three patients (5%) experienced an increase in MFI after desensitization, two of whom experienced primary GF. Cumulative incidence of neutrophil engraftment at day 28 was 74% in a median of 18 days (IQR, 15─20); six patients died before engraftment due to toxicity or infection and eight patients had primary GF despite desensitization in seven of them. After a median follow-up of 30 months, two-year overall and event-free survival were 46.5% and 39%, respectively. The two-year cumulative incidence of relapse was 16% and non-relapse mortality (NRM) was 43%. Infection was the most frequent cause of NRM, followed by endothelial toxicity. Multivariate analysis identified baseline MFI >20,000 as an independent risk factor for survival and an increase in titers after infusion as an independent risk factor for GF. Conclusions: Haplo-HSCT is feasible in DSA-positive patients, with high rates of engraftment after desensitization guided by DSA intensity. Baseline MFI >20,000 and increased intensity after infusion are risk factors for survival and GF.