Ceftazidime/avibactam resistance is associated with PER-3-producing ST309 lineage in Chilean clinical isolates of non-carbapenemase producing Pseudomonas aeruginosa.

Introduction: Ceftazidime/avibactam (CZA) is indicated against multidrug-resistant Pseudomonas aeruginosa, particularly those that are carbapenem resistant. CZA resistance in P. aeruginosa producing PER, a class A extended-spectrum ß-lactamase, has been well documented in vitro. However, data regarding clinical isolates are scarce. Our aim was to analyze the contribution of PER to CZA resistance in non-carbapenemase-producing P. aeruginosa clinical isolates that were ceftazidime and/or carbapenem non-susceptible. Methods: Antimicrobial susceptibility was determined through agar dilution and broth microdilution, while bla PER gene was screened through PCR. All PER-positive isolates and five PER-negative isolates were analyzed through Whole Genome Sequencing. The mutational resistome associated to CZA resistance was determined through sequence analysis of genes coding for PBPs 1b, 3 and 4, MexAB-OprM regulators MexZ, MexR, NalC and NalD, AmpC regulators AmpD and AmpR, and OprD porin. Loss of bla PER-3 gene was induced in a PER-positive isolate by successive passages at 43°C without antibiotics. Results: Twenty-six of 287 isolates studied (9.1%) were CZA-resistant. Thirteen of 26 CZA-resistant isolates (50%) carried bla PER. One isolate carried bla PER but was CZA-susceptible. PER-producing isolates had significantly higher MICs for CZA, amikacin, gentamicin, ceftazidime, meropenem and ciprofloxacin than non-PER-producing isolates. All PER-producing isolates were ST309 and their bla PER-3 gene was associated to ISCR1, an insertion sequence known to mobilize adjacent DNA. PER-negative isolates were classified as ST41, ST235 (two isolates), ST395 and ST253. PER-negative isolates carried genes for narrow-spectrum ß-lactamases and the mutational resistome showed that all isolates had one major alteration in at least one of the genes analyzed. Loss of bla PER-3 gene restored susceptibility to CZA, ceftolozane/tazobactam and other ß-lactamsin the in vitro evolved isolate. Discussion: PER-3-producing ST309 P. aeruginosa is a successful multidrug-resistant clone with blaPER-3 gene implicated in resistance to CZA and other ß-lactams.

A real life use of ruxolitinib in patients with acute and chronic graft versus host disease refractory to corticosteroid treatment in Latin American patients

Abstract Introduction: Graft-versus-host disease (GVHD) is a serious complication in allogeneic transplantation. The first-line treatment is high doses of corticosteroids. In the absence of response to corticosteroids, several immunosuppressive drugs can be used, but they entail an elevated risk of severe infections. Added to this, there are patients who do not improve on any immunosuppressive treatment, with subsequent deteriorated quality of life and high mortality. Ruxolitinib has been shown to induce responses in refractory patients. In this study we have presented our real-life experience. Methods: A retrospective analysis was performed on patients with severe GVHD refractory to corticosteroids. Demographic, previous treatment, response and mortality data were collected. Results: Since 2014, seventeen patients with GVHD were treated with ruxolitinib due to refractoriness to corticosteroids and immunosuppressants and a few to extracorporeal photopheresis, 8 with acute GVHD (1 pulmonary, 4 cutaneous grade IV and 3 digestive grade IV) and 9 with chronic GHVD (5 cutaneous sclerodermiform, 2 pulmonary and 1 multisystemic). The overall response to ruxolitinib treatment for acute GVHD was 80%, 40% with partial response and 40% with complete remission. Global response in chronic GVHD was 79%. The GVHD mortality was only seen in acute disease and was 40%. Causes of mortality in those patients were severe viral pneumonia, post-transplantation hemophagocytic syndrome and meningeal GVHD refractory to ruxolitinib. Conclusions: In our series, the use of ruxolitinib as a rescue strategy in acute or chronic GVHD was satisfactory. Ruxolitinib treatment in patients with a very poor prognosis showed encouraging results. However, the GVHD mortality remains high in refractory patients, showing that better therapeutic strategies are needed.

[Age does not affect the outcome of allogeneic hematopoietic precursor transplantation for acute myeloid leukemia]. / Resultados a largo plazo de una cohorte chilena: la edad del paciente no incide en el resultado del trasplante alogénico de precursores hematopoyéticos para leucemia mieloide aguda.

BACKGROUND: In our country, transplantation centers differ in the age limit for allogeneic hematopoietic transplantation (ALOHT). In our program, transplants with age- adjusted conditioning are performed in patients until 70 years old. Currently more than 60% of ALOHT reported to the Center for International Bone Marrow Transplantation Research (CIBMTR) are performed in patients older than 40 years. AIM: To report our experience with ALOHT in acute myelogenous leukemia (AML), analyzing patient age at transplantation in different periods and transplant results in different age groups. MATERIAL AND METHODS: A retrospective analysis of the database of adult hematopoietic transplants in AML patients was performed. Demographic data, disease characteristics, transplant data, survival and relapse times, and mortality were collected. RESULTS: In our program, 1030 transplants were performed in adults and 119 ALOHT were performed in AML patients, between 1990 and 2020. The median age of patients in all periods was 41 years, (range 16-69). The median age was 33 and 45 years, in the periods 1990-2000 and 2000-2020 respectively (p < 0.01). Seventy-eight patients received myeloablative conditioning (median age 44 years) and 41 reduced intensity conditioning (median age 53 years). Five-year overall survival was 44.6% (confidence intervals (CI) 41-48). Non relapse mortality of all periods was 19% (CI 17 - 40%) and relapse rate was 17 % (CI 16-22). No difference in five years overall survival among patients younger than 40, 41 to 50 and over 51 years was observed. CONCLUSIONS: Overall Survival, non-relapse mortality and relapse rate were similar in younger and older patients in our program and similar to those previously reported in other centers.

Resultados a largo plazo de una cohorte chilena: la edad del paciente no incide en el resultado del trasplante alogénico de precursores hematopoyéticos para leucemia mieloide aguda / Age does not affect the outcome of allogeneic hematopoietic precursor transplantation for acute myeloid leukemia

BACKGROUND: In our country, transplantation centers differ in the age limit for allogeneic hematopoietic transplantation (ALOHT). In our program, transplants with age- adjusted conditioning are performed in patients until 70 years old. Currently more than 60% of ALOHT reported to the Center for International Bone Marrow Transplantation Research (CIBMTR) are performed in patients older than 40 years. AIM: To report our experience with ALOHT in acute myelogenous leukemia (AML), analyzing patient age at transplantation in different periods and transplant results in different age groups. MATERIAL AND METHODS: A retrospective analysis of the database of adult hematopoietic transplants in AML patients was performed. Demographic data, disease characteristics, transplant data, survival and relapse times, and mortality were collected. RESULTS: In our program, 1030 transplants were performed in adults and 119 ALOHT were performed in AML patients, between 1990 and 2020. The median age of patients in all periods was 41 years, (range 16-69). The median age was 33 and 45 years, in the periods 1990-2000 and 2000-2020 respectively (p < 0.01). Seventy-eight patients received myeloablative conditioning (median age 44 years) and 41 reduced intensity conditioning (median age 53 years). Five-year overall survival was 44.6% (confidence intervals (CI) 41-48). Non relapse mortality of all periods was 19% (CI 17 - 40%) and relapse rate was 17 % (CI 16-22). No difference in five years overall survival among patients younger than 40, 41 to 50 and over 51 years was observed. Conclusions: Overall Survival, non-relapse mortality and relapse rate were similar in younger and older patients in our program and similar to those previously reported in other centers.

A real life use of ruxolitinib in patients with acute and chronic graft versus host disease refractory to corticosteroid treatment in Latin American patients.

INTRODUCTION: Graft-versus-host disease (GVHD) is a serious complication in allogeneic transplantation. The first-line treatment is high doses of corticosteroids. In the absence of response to corticosteroids, several immunosuppressive drugs can be used, but they entail an elevated risk of severe infections. Added to this, there are patients who do not improve on any immunosuppressive treatment, with subsequent deteriorated quality of life and high mortality. Ruxolitinib has been shown to induce responses in refractory patients. In this study we have presented our real-life experience. METHODS: A retrospective analysis was performed on patients with severe GVHD refractory to corticosteroids. Demographic, previous treatment, response and mortality data were collected. RESULTS: Since 2014, seventeen patients with GVHD were treated with ruxolitinib due to refractoriness to corticosteroids and immunosuppressants and a few to extracorporeal photopheresis, 8 with acute GVHD (1 pulmonary, 4 cutaneous grade IV and 3 digestive grade IV) and 9 with chronic GHVD (5 cutaneous sclerodermiform, 2 pulmonary and 1 multisystemic). The overall response to ruxolitinib treatment for acute GVHD was 80%, 40% with partial response and 40% with complete remission. Global response in chronic GVHD was 79%. The GVHD mortality was only seen in acute disease and was 40%. Causes of mortality in those patients were severe viral pneumonia, post-transplantation hemophagocytic syndrome and meningeal GVHD refractory to ruxolitinib. CONCLUSIONS: In our series, the use of ruxolitinib as a rescue strategy in acute or chronic GVHD was satisfactory. Ruxolitinib treatment in patients with a very poor prognosis showed encouraging results. However, the GVHD mortality remains high in refractory patients, showing that better therapeutic strategies are needed.

[Cytarabine and hematopoietic cell transplantation for mantle cell lymphoma. Analysis of 20 patients]. / Resultados de pacientes con linfoma del manto: impacto de terapias basadas en citarabina y trasplante hematopoyético.

BACKGROUND: Mantle cell lymphoma (MCL) has high relapse and mortality rates. There is a survival benefit when treatment is intensified with cytarabine (AraC), hematopoietic cell transplantation (HCT) and maintenance with rituximab. AIM: To assess the outcomes of patients with MCL treated in a university hospital. MATERIAL AND METHODS: Review of an oncology center database and medical records identifying patients with MCL treated between 2006 and 2017. Death dates were obtained from the death certificate database of the National Identification Service. We analyzed the response rate, overall survival (OS) and progression-free survival (PFS). As a secondary objective, the survival impact of AraC, HCT and maintenance with rituximab, was also analyzed. RESULTS: Information on 20 patients aged 62 ± 11 years, followed for a median of 45 months was retrieved. Eighty-five percent were diagnosed at an advanced stage. The most used first-line regime was R-CHOP in 11 patients, followed by R-HyperCVAD in five. Only 47% achieved complete response. 4-year PFS and OS were of 30 and 77% respectively. Mantle Cell Lymphoma International Prognostic Index (MIPI) significantly predicted PFS and OS. Maintenance with rituximab or HCT was associated with better PFS (48 vs 21 months, p < 0.01). The exposure to AraC or HCT, in refractory or relapsed disease, was associated with an increase in PFS from 9 to 28 months (p = 0,02) and 4-year OS from 40 to 100% (p = 0.05). OS increased even more, from 25 to 100% in those with high-risk MIPI (p = 0.04). CONCLUSIONS: The incorporation of AraC, HCT and maintenance with rituximab in the therapeutic backbone of MCL, especially for high-risk cases, was associated with improved survival.

Resultados de pacientes con linfoma del manto: impacto de terapias basadas en citarabina y trasplante hematopoyético / Cytarabine and hematopoietic cell transplantation for mantle cell lymphoma: analysis of 20 patients

Background: Mantle cell lymphoma (MCL) has high relapse and mortality rates. There is a survival benefit when treatment is intensified with cytarabine (AraC), hematopoietic cell transplantation (HCT) and maintenance with rituximab. Aim: To assess the outcomes of patients with MCL treated in a university hospital. Material and Methods: Review of an oncology center database and medical records identifying patients with MCL treated between 2006 and 2017. Death dates were obtained from the death certificate database of the National Identification Service. We analyzed the response rate, overall survival (OS) and progression-free survival (PFS). As a secondary objective, the survival impact of AraC, HCT and maintenance with rituximab, was also analyzed. Results: Information on 20 patients aged 62 ± 11 years, followed for a median of 45 months was retrieved. Eighty-five percent were diagnosed at an advanced stage. The most used first-line regime was R-CHOP in 11 patients, followed by R-HyperCVAD in five. Only 47% achieved complete response. 4-year PFS and OS were of 30 and 77% respectively. Mantle Cell Lymphoma International Prognostic Index (MIPI) significantly predicted PFS and OS. Maintenance with rituximab or HCT was associated with better PFS (48 vs 21 months, p < 0.01). The exposure to AraC or HCT, in refractory or relapsed disease, was associated with an increase in PFS from 9 to 28 months (p = 0,02) and 4-year OS from 40 to 100% (p = 0.05). OS increased even more, from 25 to 100% in those with high-risk MIPI (p = 0.04). Conclusions: The incorporation of AraC, HCT and maintenance with rituximab in the therapeutic backbone of MCL, especially for high-risk cases, was associated with improved survival.

[Response to ABVD chemotherapeutic protocol in patients with early stage Hodgkin’s lymphoma]. / Excelente respuesta a tratamiento con ABVD en pacientes con linfoma de Hodgkin localizado.

BACKGROUND: Recent trials show that > 90% of patients with early stage Hodgkin`s Lymphoma (ESHL) can be cured, especially when using the ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapeutic (CT) protocol. The use of radiotherapy (RT) is variable and can be selected according to the presence of specific risk factors, including PET-CT, as recently reported. AIM: To report the experience in the treatment of ESHL. MATERIAL AND METHODS: Retrospective and descriptive analysis of patients with ESHL treated at the Red de Salud UC-Christus between 2011-2015. RESULTS: Twenty-two patients were treated. In 73%, the tumor was of nodular sclerosis histologic type. Most patients (95%) were in stage II, and 78% had a favorable prognosis according to the Deutsche Hodgkin Studiengruppe (GHSG) criteria. All patients were stratified using PET-CT and treated using the ABVD CT protocol, for 4-6 cycles. Only 5 patients received RT. There was no change of conduct after interim-PET-CT results. Ninety one percent of patients achieved complete response and there were two cases of refractory disease. Both cases underwent hematopoietic stem cell transplantation. After 17 months of median follow-up, 91% of patients are relapse-free, and only one patient died (5%). CONCLUSIONS: ABVD offers excellent results for ESHL patients. The benefit of PET-CT should be evaluated with prospective protocols, aiming to select patients needing RT or to reduce the number of CT cycles.

Excelente respuesta a tratamiento con ABVD en pacientes con linfoma de Hodgkin localizado / Response to ABVD chemotherapeutic protocol in patients with early stage Hodgkin’s lymphoma

Background: Recent trials show that > 90% of patients with early stage Hodgkin`s Lymphoma (ESHL) can be cured, especially when using the ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapeutic (CT) protocol. The use of radiotherapy (RT) is variable and can be selected according to the presence of specific risk factors, including PET-CT, as recently reported. Aim: To report the experience in the treatment of ESHL. Material and Methods: Retrospective and descriptive analysis of patients with ESHL treated at the Red de Salud UC-Christus between 2011-2015. Results: Twenty-two patients were treated. In 73%, the tumor was of nodular sclerosis histologic type. Most patients (95%) were in stage II, and 78% had a favorable prognosis according to the Deutsche Hodgkin Studiengruppe (GHSG) criteria. All patients were stratified using PET-CT and treated using the ABVD CT protocol, for 4-6 cycles. Only 5 patients received RT. There was no change of conduct after interim-PET-CT results. Ninety one percent of patients achieved complete response and there were two cases of refractory disease. Both cases underwent hematopoietic stem cell transplantation. After 17 months of median follow-up, 91% of patients are relapse-free, and only one patient died (5%). Conclusions: ABVD offers excellent results for ESHL patients. The benefit of PET-CT should be evaluated with prospective protocols, aiming to select patients needing RT or to reduce the number of CT cycles.