Influencia de los polimorfismos genéticos en la Leucemia Mieloide Crónica

La leucemia mieloide crónica (LMC) es una neoplasia mieloproliferativa crónica de carácter clonal con origen en una célula madre pluripotencial común a las tres series hematopoyéticas. La historia natural de la LMC progresa desde una fase crónica relativamente benigna a la aparición de una fase terminal o de crisis blástica caracterizada por un cuadro de insuficiencia medular, similar al de las leucemias agudas y generalmente refractario al tratamiento. La enfermedad se caracteriza por la presencia de una alteración citogenética, el cromosoma Filadelfia (Ph), producto de una translocación recíproca entre los cromosomas 9 y 22 en las células hematopoyéticas, que genera el oncogén BCR/ABL, dando lugar a la síntesis de una proteína con actividad tirosinacinasa aumentada (la proteína BCR/ABL). En la patogénesis de la LMC parece desempeñar un papel relevante la actividad de la oncoproteína BCR/ABL. De hecho su actividad es considerada fundamental en la proliferación neoplásica de la LMC y, por ello, la mayoría de los fármacos utilizados en su tratamiento basan su acción terapéutica en la inhibición específica de la proteína tirosinocinasa BCR/ABL. Uno de estos inhibidores, el imatinib mesilato, constituye en la actualidad el tratamiento de elección de primera línea para los pacientes con LMC, tras demostrarse su superioridad terapéutica respecto a otros tratamiento. A pesar de la gran eficacia del imatinib, algunos enfermos con LMC no responden adecuadamente al tratamiento de entrada o, lo que es más frecuente, tras presentar una respuesta terapéutica inicial. Las alteraciones estructurales derivadas de la formación de la proteína BCR-ABL (dimerización proteica, localización citoplasmática exclusiva) tienen como consecuencia una desregulación del efecto tirosinacinasa, de forma que la enzima está activada continuamente. El resultado de ello es la activación anómala de una serie de vías de transmisión intracelular de señales en los progenitores Ph positivos, que conduce a un incremento de su actividad proliferativa, a una alteración de su adhesión al estroma medular, y a una disminución de la apoptosis celular, siendo estos procesos la base de la patogénesis de la LMC. Con todo, es preciso conocer con mayor profundidad los mecanismos implicados en la génesis y en la evolución clínica de la LMC. En este sentido, falta información acerca de la influencia de la variabilidad genética interindividual en la susceptibilidad a desarrollar una LMC y en la respuesta al tratamiento. Entre los factores que determinan dicha variabilidad genética se encuentran los polimorfismos de un único nucleótido (SNPs). Los SNPs son variaciones de un solo nucleótido en una posición determinada de la secuencia del ADN que originan variantes alélicas de cada gen que se distribuyen ampliamente en la población general y se les considera responsables en parte de la variabilidad interindividual en la susceptibilidad genética a desarrollar enfermedades, entre ellas el cáncer, o en la probabilidad de responder al tratamiento.Por tanto cabría esperar que los polimorfismos genéticos de los distintos componentes implicados en la vía de señalización de BCR-ABL y en la distribución del imatinib influyesen en la susceptibilidad a desarrollar una LMC, y en la respuesta al tratamiento. La población total a estudio La población total a estudio incluye una serie de 190 pacientes diagnosticados de LMC (BCR-ABL positivos) Además, para el estudio de la predisposición genética a desarrollar una LMC se ha incluido un grupo control compuesto por 370 individuos sanos.Para el estudio de la respuesta al tratamiento con imatinib se seleccionaron 105 pacientes que cumplían los siguientes criterios: Sujetos afectos de LMC en fase crónica inicial o de menos de un año de evolución, en tratamiento con imatinib, a las dosis de 400 mg/día, durante un período mínimo de seis meses;disponibilidad de los datos clínicos, hematológicos iniciales y evolutivos (edad, sexo, tamaño del bazo, cifra de hemoglobina, leucocitos, plaquetas, porcentaje de basófilos y eosinófilos, porcentaje de blastos en sangre periférica, porcentaje de blastos en médula ósea, índice de Sokal [272], presencia o no de alteraciones citogenéticas adicionales al cromosoma Ph y tipo de tránscrito BCR/ABL), y disponibilidad de muestras de ADN genómico para realizar los estudios de genotipado. El estudio fue aprobado por el comité ético local (de acuerdo con la Declaración de Helsinki) y el consentimiento informado se obtuvo de todos los pacientes.Las muestras de ADN que se utilizaron para el análisis de los polimorfismos procedían de extracciones de células mononucleadas de sangre periférica obtenidas en cualquier momento del curso evolutivo de la LMC.Los criterios para la selección de los polimorfismos de estos genes fueron: En primer lugar SNP en genes conocidos en las vías dependientes de BCR_ABL así como aquellos que tiene un papel en el mantenimiento de la integridad del ADN y en la farmacocinética a imatinib, la región genética y el grado de heterocigosidad,la funcionalidad y la información de estudios previos. El genotipado de los polimorfismos se realizó mediante la utilización de la PCR alelo específica con sondas Taqman. Con los resultados obtenidos, se puede afirmar que existen datos que apoyan la influencia de los polimorfismos genéticos en la susceptibilidad a desarrollar LMC, en su perfil clínico al diagnóstico y en la respuesta al tratamiento, al menos con imatinib. Sin embargo, el grado de evidencia es aún insuficiente para tomar en consideración esta información en la práctica clínica habitual. Se requieren más estudios antes de que nuestros resultados puedan ser aplicados a la práctica clínica

Monitoring of Trough Plasma Ganciclovir Levels and Peripheral Blood Cytomegalovirus (CMV)-Specific CD8+ T Cells To Predict CMV DNAemia Clearance in Preemptively Treated Allogeneic Stem Cell Transplant Recipients

It is uncertain whether monitoring plasma ganciclovir (GCV) levels is useful in predicting cytomegalovirus (CMV) DNAemia clearance in preemptively treated allogeneic stem cell transplant recipients. In this observational study, including 13 episodes of CMV DNAemia treated with intravenous (i.v.) GCV or oral valganciclovir, we showed that monitoring trough plasma GCV levels does not reliably predict response to therapy. Rather, immunological monitoring (pp65 and immediate-early [IE]-1-specific gamma interferon [IFN-γ]-producing CD8+ T cells) appeared to perform better for this purpose

Performance of the QuantiFERON-Cytomegalovirus (CMV) Assay for Detection and Estimation of the Magnitude and Functionality of the CMV-Specific Gamma Interferon-Producing CD8+ T-Cell Response in Allogeneic Stem Cell Transplant Recipients

The performance of the QuantiFERON-cytomegalovirus (CMV) assay was compared to that of a flow cytometry intracellular cytokine staining (ICS) method for the detection of CMV-specific gamma interferon (IFN-γ)-producing CD8+ T-cell responses in allogeneic stem cell transplant (allo-SCT) recipients and for estimations of their magnitude and functionality. A total of 90 whole-blood specimens from 23 allo-SCT recipients was analyzed by both methods. Overall, the percentage of specimens that yielded concordant results by both methods was 68.8% (κ = 0.691; 95% confidence interval [CI], 0.548 to 0.835), and the sensitivity of the QuantiFERON-CMV assay for the detection of positive IFN-γ T-cell responses (>0.2 IU/ml), taking the ICS method as the reference, was 76.3%. The magnitude of IFN-γ-producing CD8+ T-cell responses to CMV-specific peptides measured with the QuantiFERON-CMV assay correlated significantly (σ = 0.695; P = 0.001]) CMV-specific CD8+ T-cell responses, as quantitated by ICS. In summary, the data indicated that the QuantiFERON-CMV assay is less sensitive than the ICS method for the detection of CMV-specific IFN-γ-producing CD8+ T-cell responses in the allo-SCT setting. Nevertheless, it allowed the estimation of the total and polyfunctional CMV-specific IFN-γ-producing CD8+ T-cell responses in specimens that tested positive by both methods

NLRP3 inflammasome activation and symptom burden in KRAS-mutated CMML patients is reverted by IL-1 blocking therapy

Chronic myelomonocytic leukemia (CMML) is frequently associated with mutations in the rat sarcoma gene (RAS), leading to worse prognosis. RAS mutations result in active RAS-GTP proteins, favoring myeloid cell proliferation and survival and inducing the NLRP3 inflammasome together with the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), which promote caspase-1 activation and interleukin (IL)-1(3 release. Here, we report, in a cohort of CMML patients with mutations in KRAS, a constitutive activation of the NLRP3 inflammasome in monocytes, evidenced by ASC oligomerization and IL-1(3 release, as well as a specific inflammatory cytokine signature. Treatment of a CMML patient with a KRASG12D mutation using the IL-1 receptor blocker anakinra inhibits NLRP3 inflammasome activation, reduces monocyte count, and improves the patient's clinical status, enabling a stem cell transplant. This reveals a basal inflammasome activation in RAS-mutated CMML patients and suggests potential therapeutic applications of NLRP3 and IL-1 blockers

Analysis of vitamin C content of fruits from five pepper varieties showing different pungency levels and antimicrobial potentiality of capsaicin

In this work, the nutritional properties and antimicrobial activity of five pepper varieties, including dulce italiano (bell pepper), boiro (a Padron-type pepper), green jalapeño, red chilli, and habanero, have been investigated. The dry matter provided by each of these varieties was analyzed, and their caloric content were withdrawn from searches in databases. Thus, it was found the following caloric contents: Habanero and red chilli provided 40 kcal/100 g; jalapeño green, 29 kcal/100 g; dulce italiano, 23 kcal/100 g; and boiro (padrón), 21 kcal/100 g. On the other hand, an easy and simple method was set up to determine vitamin C (ascorbic acid, ascorbate) in crops, using lugol and starch. The data provided by the application of this method indicated that red chili was the variety with the highest vitamin C content, and boiro the one with the lowest. The antimicrobial activity of both crude extracts from pepper fruits and pure capsaicin was probed against five bacterial species: Escherichia coli, Bacillus subtilis, Xanthomonas campestris, Dickeya dadantii and Ralstonia solanacearum. Solid (Petri dishes with agar) and liquid media were used for the assays. Our data indicated that capsaicin is able to inhibit the growth of B. subtilis, but not that of E. coli, perhaps this latter case due to the great adaptation of this species to environmental conditions.Peer reviewe

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

Torque Teno Virus plasma DNA load: a novel prognostic biomarker in CAR-T therapy

Torque Teno Virus (TTV) is a single-stranded circular DNA virus which has been identified as a surrogate marker of immune competence in transplantation. In this study we investigated the dynamics of plasma TTV DNAemia in 79 adult patients undergoing chimeric antigen receptor T-cell (CAR-T) therapy for relapsed or refractory large B-cell lymphoma, also evaluating the impact of TTV on immunotoxicities, response and survival outcomes. After lymphodepleting therapy, TTV DNA load was found to decrease slightly until reaching nadir around day 10, after which it increased steadily until reaching maximum load around day 90. TTV DNA load < 4.05 log10 copies/ml at immune effector cell-associated neurotoxicity syndrome (ICANS) onset identified patients at risk of progressing to severe forms of ICANS (OR 16.68, P = 0.048). Finally, patients who experienced falling or stable TTV DNA load between lymphodepletion and CAR-T infusion had better progression-free survival than those with ascending TTV DNA load (HR 0.31, P = 0.006). These findings suggest that TTV monitoring could serve as a surrogate marker of immune competence, enabling predictions of CAR-T efficacy and toxicity. This could pave the way for the development of TTV-guided therapeutic strategies that modulate clinical patient management based on plasma TTV load, similar to suggested strategies in solid organ transplant recipients

NLRP3 inflammasome activation and symptom burden in KRAS-mutated CMML patients is reverted by IL-1 blocking therapy

Chronic myelomonocytic leukemia (CMML) is frequently associated with mutations in the rat sarcoma gene (RAS), leading to worse prognosis. RAS mutations result in active RAS-GTP proteins, favoring myeloid cell proliferation and survival and inducing the NLRP3 inflammasome together with the apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), which promote caspase-1 activation and interleukin (IL)-1β release. Here, we report, in a cohort of CMML patients with mutations in KRAS, a constitutive activation of the NLRP3 inflammasome in monocytes, evidenced by ASC oligomerization and IL-1β release, as well as a specific inflammatory cytokine signature. Treatment of a CMML patient with a KRAS mutation using the IL-1 receptor blocker anakinra inhibits NLRP3 inflammasome activation, reduces monocyte count, and improves the patient's clinical status, enabling a stem cell transplant. This reveals a basal inflammasome activation in RAS-mutated CMML patients and suggests potential therapeutic applications of NLRP3 and IL-1 blockers

Assessment of the potential value of plasma Torque Teno virus DNA load monitoring to predict cytomegalovirus DNAemia in patients with hematological malignancies treated with small molecule inhibitors: A proof-of-concept study

It is unknown whether Torque Teno virus (TTV) DNA load monitoring could anticipate the development of infectious events in hematological patients undergoing treatment with small molecular targeting agents. We characterized the kinetics of plasma TTV DNA in patients treated with ibrutinib or ruxolitinib and assessed whether TTV DNA load monitoring could predict the occurrence of Cytomegalovirus (CMV) DNAemia or the magnitude of CMV-specific T-cell responses. Multicenter, retrospective, observational study, recruiting 20 patients treated with ibrutinib and 21 with ruxolitinib. Plasma TTV and CMV DNA loads were quantified by real-time PCR at baseline and days +15, +30, +45, +60, +75, +90, +120, +150, and +180 after treatment inception. Enumeration of CMV-specific interferon-γ (IFN-γ)-producing CD8+ and CD4+ T-cells in whole blood was performed by flow cytometry. Median TTV DNA load in ibrutinib-treated patients increased significantly (p = 0.025) from baseline (median: 5.76 log10 copies/mL) to day +120 (median: 7.83 log10 copies/mL). A moderate inverse correlation (Rho = -0.46; p < 0.001) was found between TTV DNA load and absolute lymphocyte count. In ruxolitinib-treated patients, TTV DNA load quantified at baseline was not significantly different from that measured after treatment inception (p ≥ 0.12). TTV DNA load was not predictive of the subsequent occurrence of CMV DNAemia in either patient group. No correlation was observed between TTV DNA loads and CMV-specific IFN-γ-producing CD8+ and CD4+ T-cell counts in either patient group. The data did not support the hypothesis that TTV DNA load monitoring in hematological patients treated with ibrutinib or ruxolitinib could be useful to predict either the occurrence of CMV DNAemia or the level of CMV-specific T-cell reconstitution; nevertheless, due to the small sample size, further studies involving larger cohorts are warranted to elucidate this issue. Keywords: CMV; CMV DNAemia; CMV-specific T-cells; Ibrutinib; TTV DNA load; ruxolitinib

Reconstitution of cytomegalovirus-specific T-cell immunity following unmanipulated haploidentical allogeneic hematopoietic stem cell transplantation with posttransplant cyclophosphamide

Abstract Cytomegalovirus (CMV) DNAemia and CMV disease have been reported as more frequent in patients undergoing haploidentical allogeneic hematopoietic stem cell transplantation (Haplo-HSCT) than in those receiving HLA-matched allografts. This could be due to impaired CMV-specific T-cell reconstitution. Here, we conducted a multicenter observationalstudy to assess CMV pp65 and IE-1-specific T cells kinetics in patients undergoing unmanipulated Haplo-HSCT with posttransplant cyclophosphamide (PT/Cy-haplo) and compared it with patients allografted with HLA-matched donors. PlasmaCMV DNA load was monitored by real-time PCR and enumeration of CMV-specific IFN-γ-producing CD8+ and CD4+T cells was performed by flow cytometry for intracellular cytokine staining at days +30, +60, +90, and +180 aftertransplantation. CMV DNAemia developed in 62 patients, occurring with comparable frequency in PT/Cy-haplo and MRD/ MUD recipients (P =0.14). There were no significant differences across groups in the number of patients either displayingdetectable CMV-specific CD8+ and CD4+ T-cell responses or acquiring CMV-specific T-cell levels conferring protectionagainst subsequent infection. CMV-specific T-cell counts were comparable between groups at most time points examined,irrespective of whether CMV DNAemia occurred or not prior to monitoring. Collectively the data suggest that PT/Cy-haplorecipients may reconstitute CMV-specific T-cell immunity to the same extent as patients undergoing HLA-matched allo-HSCT.Depto. de EnfermeríaFac. de Enfermería, Fisioterapia y PodologíaTRUEpubPagado por el auto