Casos atípicos e14a3 (b3a3) en el gen de fusión BCR-ABL de la leucemia mieloide crónica en Cuba / Rare cases of e14a3 (b3a3) BCR-ABL fusion in chronic myeloid leukemia in Cuba

Introducción: La leucemia mieloide crónica es un desorden clonal maligno de células madres hematopoyéticas pluripotentes que se caracteriza por la presencia del cromosoma Filadelfia, consecuencia de la traslocación cromosómica recíproca entre los brazos largos de los cromosomas 9 y 22. El resultado de esta alteración cromosómica es un gen de fusión que contiene las uniones b2a2 (e13a2) o b3a2 (e14a2). En la mayor parte de los casos, las células de la leucemia mieloide crónica expresan uno de los dos transcritos (b2a2 o b3a2); sin embargo, el 5 por ciento de los pacientes tienen ambos tipos de ARNm como resultado de empalmes alternativos. Se han encontrado otros transcriptos como e19a2, e2a2, e1a3, e6a2, e13a3(b2a3), y e14a3(b3a3), que ocurren con menos frecuencia. Objetivo: Describir el comportamiento de dos pacientes con leucemia mieloide crónica que presentan un trascripto BCR/ABL atípico. Casos clínicos: En el estudio molecular por reacción en cadena de la polimerasa cualitativo realizado a los dos pacientes, se observó un punto de ruptura del gen de fusión BCR/ABL poco frecuente, el cual se correspondía al transcripto e14a3 (b3a3). Estos pacientes iniciaron tratamiento con mesilato de imatinib a dosis de 400 mg diarios. Al primer paciente a los dos meses de tratamiento se le detectó crisis blástica, por lo que se le cambió el tratamiento a nilotinib 400 mg diarios que mantiene hasta la actualidad. La segunda paciente mantuvo igual tratamiento, aunque en ocasiones ha sido necesario incorporar tratamiento citorreductor con hidroxiurea por presentar leucocitosis. Conclusiones: Los pacientes con BCR/ABL a3 presentan un curso más benigno de la enfermedad. Aunque en los pacientes estudiados no se observó una respuesta satisfactoria al tratamiento pues presentaron diversas complicaciones(AU)

Introduction: Chronic myeloid leukemia is a malignant clonal disorder of pluripotent hematopoietic stem cells and characterized by the presence of the Philadelphia chromosome, which is the product of a reciprocal translocation between the long arms of chromosomes 9 and 22. The result of this chromosomal alteration is a fusion gene that contains the e13a2 (b2a2) and e14a2 (b3a2) junctions. In most cases, chronic myeloid leukemia cells express one of the two transcripts (b2a2 or b3a2); however, 5 percent of patients have both types of mRNA, as a result of alternative junctions. Other transcripts have been identified, such as e19a2, e2a2, e1a3, e6a2, e13a3 (b2a3), and e14a3 (b3a3), which occur less frequently. Objective: To describe the behavior of two patients with chronic myeloid leukemia who have an atypical BCR-ABL transcript. Clinical cases: In a qualitative molecular study of polymerase chain reaction carried out with two patients, a BCR-ABL fusion gene breakpoint was observed, which corresponded to the e14a3 (b3a3) transcript. These patients started treatment with imatinib mesylate at a dose of 400mg/d. At two months, the first patient had a diagnose of blast crisis, so the treatment was changed to nilotinib at a dose of 400mg/d, which the patient maintained to date. The second patient maintained the same treatment, although it was sometimes necessary to incorporate cytoreductive treatment with hydroxyurea due to leukocytosis. Conclusions: Patients with BCR-ABL a3 present a more benign evolution of the disease. However, a satisfactory response to treatment was not observed in the patients studied, as long as they presented various complications(AU)

Six‑year susceptibility trends and effect of revised Clinical Laboratory Standards Institute breakpoints on ciprofloxacin susceptibility reporting in typhoidal Salmonellae in a tertiary care paediatric hospital in Northern India.

The antimicrobial trends over 6 years were studied, and the effect of revised Clinical Laboratory Standards Institute (CLSI) breakpoints (2012) for ciprofloxacin susceptibility reporting in typhoidal Salmonellae was determined. A total of 874 (95.4%) isolates were nalidixic acid‑resistant (NAR). Using the CLSI 2011 guidelines (M100‑S21), 585 (66.9%) isolates were ciprofloxacin susceptible. The susceptibility reduced to 11 (1.25%) isolates when interpreted using 2012 guidelines (M100‑S22). Among the forty nalidixic acid susceptible (NAS) Salmonellae, susceptibility to ciprofloxacin decreased from 37 isolates (M100‑S21) to 12 isolates (M100‑S22). The 25 cases which appeared resistant with newer guidelines had a minimum inhibitory concentration (MIC) range between 0.125 and 0.5 μg/ml. MIC50 for the third generation cephalosporins varied between 0.125 and 0.5 μg/ml over 6 years whereas MIC90 varied with a broader range of 0.19–1 μg/ml. The gap between NAR and ciprofloxacin‑resistant strains identified using 2011 guidelines has been reduced; however, it remains to be seen whether additional NAS, ciprofloxacin‑resistant isolates are truly resistant to ciprofloxacin by other mechanisms of resistance.

Diversity of breakpoints of variant Philadelphia chromosomes in chronic myeloid leukemia in Brazilian patients

Background: Chronic myeloid leukemia is a myeloproliferative disorder characterized by the Philadelphia chromosome or t(9;22)(q34.1;q11.2), resulting in the break-point cluster regionAbelson tyrosine kinase fusion gene, which encodes a constitutively active tyrosine kinase protein. The Philadelphia chromosome is detected by karyotyping in around 90% of chronic myeloid leukemia patients, but 5-10% may have variant types. Variant Philadelphia chromosomes are characterized by the involvement of another chromosome in addition to chromosome 9 or 22. It can be a simple type of variant when one other chromosome is involved, or complex, in which two or more chromosomes take part in the translocation. Few studies have reported the incidence of variant Philadelphia chromosomes or the breakpoints involved among Brazilian chronic myeloid leukemia patients. Objective: The aim of this report is to describe the diversity of the variant Philadelphia chromosomes found and highlight some interesting breakpoint candidates for further studies. Methods: the Cytogenetics Section Database was searched for all cases with diagnoses of chronic myeloid leukemia during a 12-year period and all the variant Philadelphia chromosomes were listed. Results: Fifty (5.17%) cases out of 1071 Philadelphia-positive chronic myeloid leukemia were variants. The most frequently involved chromosome was 17, followed by chromosomes: 1, 20, 6, 11, 2, 10, 12 and 15. Conclusion: Among all the breakpoints seen in this survey, six had previously been described: 11p15, 14q32, 15q11.2, 16p13.1, 17p13 and 17q21. The fact that some regions get more fre- quently involved in such rare rearrangements calls attention to possible predisposition that should be further studied. Nevertheless, the pathological implication of these variants remains unclear. .

SUSCEPTIBILITY OF Candida spp. ISOLATED FROM BLOOD CULTURES AS EVALUATED USING THE M27-A3 AND NEW M27-S4 APPROVED BREAKPOINTS / Suscetibilidade de Candida spp. isoladas de hemocultivos, avaliadas pelos breakpoints dos documentos M27-A3 e M27-S4 do CLSI

The high mortality rates associated with candidemia episodes and the emergence of resistance to antifungal agents necessitate the monitoring of the susceptibility of fungal isolates to antifungal treatments. The new, recently approved, species-specific clinical breakpoints (SS-CBPs)(M27-S4) for evaluating susceptibility require careful interpretation and comparison with the former proposals made using the M27-A3 breakpoints, both from CLSI. This study evaluated the susceptibility of the different species of Candida that were isolated from candidemias based on these two clinical breakpoints. Four hundred and twenty-two isolates were identified and, among them, C. parapsilosis comprised 46.68%, followed by C. albicans (35.78%), C. tropicalis (9.71%), C. glabrata (3.55%), C. lusitaniae (1.65%), C. guilliermondii (1.65%) and C. krusei (0.94%). In accordance with the M27-A3 criteria, 33 (7.81%) non-susceptible isolates were identified, of which 16 (3.79%) were resistant to antifungal agents. According to SS-CBPs, 80 (18.95%) isolates were non-susceptible, and 10 (2.36%) of these were drug resistant. When the total number of non-susceptible isolates was considered, the new SS-CBPs detected 2.4 times the number of isolates that were detected using the M27-A3 interpretative criteria. In conclusion, the detection of an elevated number of non-susceptible species has highlighted the relevance of evaluating susceptibility tests using new, species-specific clinical breakpoints (SS-CBPs), which could impact the profile of non-susceptible Candida spp. to antifungal agents that require continuous susceptibility monitoring.

As elevadas taxas de mortalidade associadas com episódios de candidemia e a emergência da resistência aos antifúngicos, requerem o monitoramento da suscetibilidade de Candida spp., isoladas das candidemias, frente aos agentes antifúngicos. Os novos breakpoints, chamados “espécie-específicos,” foram recentemente aprovados (M27-S4) requerendo, pois, cuidadosa interpretação e comparações com aqueles até agora utilizados (M27-A3); ambos são propostos pelo Clinical Laboratory Standard Institute (CLSI). O presente estudo avaliou a suscetibilidade de espécies de Candida isoladas de candidemias baseando-se nestes dois breakpoints. Quatrocentos e vinte e dois isolados de Candida foram identificados e assim distribuídos: C. parapsilosis (48,68%), C. albicans (35,78%), C. tropicalis (9,71%), C. glabrata (3,55%), C. lusitaniae (1,65%), C. guilliermondii (1,65%), C. krusei (0,94%). Com base nos critérios do M27-A3, um total de 33 (7,81%) isolados foram julgados não-sensíveis, dos quais 16 (3,79%) como resistentes aos antifúngicos. De acordo com os breakpoints espécie-específicos (M27-S4) um total de 80 (18,95%) isolados foram considerados não-sensíveis, dos quais 10 (2,36%) resistentes a algum dos antifúngicos testados. Com base nos novos breakpoints espécie-específicos, o número de isolados não-sensíveis foi 2,4 vezes maior do que o número de não-sensíveis detectado pelos breakpoints do documento M27-A3. A detecção de um elevado número de isolados não-sensíveis através dos breakpoints propostos pelo M27-S4 destaca a importância dos testes de suscetibilidade, os quais trarão impactos no reconhecimento de isolados de Candida spp. não-sensíveis em episódios de candidemias, requerendo, portanto, continua avaliação.

Susceptibilidad de candida spp, aislados de sangre, a fluconazol, voriconazol, anfotericina B, y caspofungina, por los métodos de microdilución en caldo (EUCAST) y el método de difusión en agar (ETEST) / Susceptibility of candida spp; blood isolates to fluconazole, voriconazole, amphotericin B, and caspofungin by broth microdilution methods (EUCAST) and the agar diffusion method (ETEST)

La Candidiasis invasora es una de las principales infecciones Nosocomiales. El desarrollo de los triazoles, inició el uso masivo de la profilaxis antifúngica y de la terapia empírica. Estas prácticas terapéuticas han generado cambios epidemiológicos, entre los que destacan la aparición de cepas que han desarrollado resistencia secundaria a los antifúngicos y la sustitución de algunas especies sensibles por otras con resistencia intrínseca. En este estudio se evaluaron 189 aisladas de sangre de la Red de Candidemia del INHRR determinando la Concentración Mínima Inhibitoria (CMI) a fluconazol, voriconazol, caspofungina y anfotericina b por los métodos Microdilución en caldo EUCAST y Etest, de cada una de las levaduras, siguiendo los procedimientos del método documento E. Dis. 7.1 del EUCAST y del fabricante. Se utilizaron las cepas C. parapsilosis ATCC 22019 y C. krusei ATCC 6258 como control de calidad. Los aislados fueron 89% sensibles para fluconazol por EUCAST y 87% por Etest, para voriconazol por ambos métodos 97% sensibles y para caspofungina y anfotericina B tasas muy bajas de resistencia se obtuvier. Se obtuvo una Concordancia del 94,8% y una Especificidad de 82,4%. Voriconazol 88,4% de Concordancia con unos límites de confianza de 82,9 a 92,5% y una Especificidad del 100%. Caspofungina se obtuvo un Concordancia de 98,4%y Sensibilidad del 100%. Se obtuvo una excelente concordancia entre los métodos evaluados, de manera que pueden ser utilizados indistintamente en la detección de susceptibilidad y/o resistencia antifúngica. Se determinaron puntos de corte epidemiológicos locales para fluconazol, voriconazol, caspofungina y anfotericina B en las especies de Candida frecuentemente aisladas mucho más sensible para detectar la posible emergencia de cepas resistente en nuestro medio.

Invasive candidiasis is a major nosocomial infections. With the development of the triazoles, began the widespread use of antifungal prophylaxis and empiric therapy, which has generated epidemiological changes. In this study, we evaluated 189 blood isolates from Network Candidemia INHRR of determining the minimum inhibitory concentration (MIC) to fluconazole, voriconazole, amphotericin B and caspofungin by EUCAST broth microdilution methods and ETEST. Strains were used C. parapsilosis ATCC 22019 and C. krusei ATCC 6258 as quality control. The group was 16.4% C. albicans and 83.6% C no albicans. C. parapsilosis (48%) the most frequently isolated species. The susceptibility of the total was isolated by EUCAST and Etest of 89/87% 97/97%, m99.5/98% 98/99% to fluconazole, voriconazole, amphotericin B and caspofungin respectively. General resistance to fluconazole was 9% and 11% EUCAST Etest for voriconazole amphotericin B, and caspofungin resistance did not exceed 4% of the total. Were determined epidemiological cutoff value (ECV) local to fluconazole, voriconazole, caspofungin and amphotericin B for C. albicans, C. parapsilosis and C. tropicalis which accounted for 89% of the total. The ECV is more sensitive to detect the possible emergence of resistant strains in our setting. The agreement obtained for the 4 antifungal was between 97.4 and 100% with a sensitivity of 95.9 to 100%. The data obtained are recommended ETEST for their sensitivity and consistency with respect to the reference method proving to be even more effective in detecting resistance. With the support of our local data allow the clinician to establish early and adequate therapy to finally benefit the patient.

Resistencia a cefalosporinas de espectro extendido en enterobacterias sin AmpC inducible: Evaluación de los nuevos puntos de corte / Resistance to extended-spectrum cephalosporins in non-inducible AmpC enterobacteria: Evaluation of the new MIC breakpoints

Los objetivos de este estudio fueron determinar la actividad in vitro de las cefalosporinas de espectro extendido frente a aislamientos clínicos de enterobacterias sin AmpC inducible y evaluar la utilidad de las normativas propuestas por el CLSI 2009 y de los puntos de corte recomendados por el CLSI 2010 y el EUCAST 2010. El análisis incluye la caracterización feno y genotípica de los mecanismos de resistencia. En todos los aislamientos se realizó un antibiograma semicuantitativo y se determinó la CIM por dilución en agar. Asimismo, se realizó la detección fenotípica de p-lactamasas de espectro extendido (BLEE), de AmpC plasmídica (AmpCp) y de carbapenemasas de tipo KPC. En los aislamientos que fueron resistentes a las cefalosporinas de espectro extendido (CEE) se evaluó, mediante PCR múltiple para b/aSHV y b/aCTX-M y PCR con cebadores específicos, el tipo de p-lactamasa pre-valente y la presencia de KPC. Se recuperaron de pacientes 169 aislamientos resistentes a CEE: 95 de K/ebsie//a pneumoniae, 55 de Escherichia co/i y 19 de Proteus mirabi/is. La resistencia a CEE se verificó en el 56,2 %; 32,6 % y 11,2 % de estos conjuntos de aislamientos, respectivamente. Se detectó el fenotipo BLEE en 152 aislamientos (90 %), el fenotipo AmpCp en 12 (7 %) y el KPC en 5 (3 %). Las recomendaciones del CLSI 2009 y los puntos de corte del CLSI 2010 y del EUCAST 2010 para la ceftriaxona permitieron detectar eficientemente las BLEE, mientras que para la ceftacidima, con los puntos de corte del CLSI 2010 solo se detectó el 55 % de las BLEE. Esta discrepancia en los porcentajes de resistencia a ceftriaxona y a ceftacidima se relaciona con la presencia de CTX-M en nuestro medio. Los nuevos puntos de corte detectaron con mayor eficiencia las enzimas de tipo AmpCp.

The aims of this study were to evaluate the in vitro activity of extended-spectrum cephalosporins (ESC) in non-inducible AmpC enterobacteria throµgh phenotypic and genotypic characterization of the mechanisms of resistance (ESBL, plasmid-mediated AmpC and KPC) and to evaluate the interpretation criteria proposed by the existing recommendations and the new breakpoints established by the CLSI and the EUCAST. Susceptibility tests and PCR multiplex for b/aSHV and b/aCTX-M and amplification using specific primers was performed. One hundred sixty nine resistant isolates: K/ebsie//a pneumoniae (95), Escherichia co/i (55), and Proteus mirabi/is (19) were recovered. ESC resistance was 56.2 %, 32.6%, and 11.2 %, respectively. ESBL was detected in 152 (90 %) isolates, plasmid-mediated AmpC in 12 (7 %) and KPC in 5 (3 %). The CLSI 2009 recommendations and the breakpoints sµggested by the CLSI 2010 and the EUCAST for ceftriaxone were efficacious to detect ESBL, whereas the different breakpoints for ceftazidime presented discrepancies. The CLSI 2010 breakpoints only detected 55 % of the ESBL-producing isolates due to the endemic presence of CTX-M ESBLs in our country. Regarding the plasmid-mediated AmpC producers, the recommendations of the CLSI 2010 and the EUCAST 2010 proved to be more efficient than the old ones.

CHROMOSOMAL FRAGILE SITES AND LEUKEMIA / 重庆医科大学学报

The fragile sites was induced to express, in PHA-stimulated lymphocytes chromosome of leukemic patients by low concentrations of folic acid and thymidine in 199 medium. 12 patients and 9 normal controls were examined. The results showed that both rates of the freguencies of fragile sites and the chromosome aberrations in patients were much higher than those in normal controls (20.42% :3.30%). There was significant correlation between the two groups.We found that there are 57 Fra in chromosome. These patients carried 7 of 57 Fra, which were located at the bands of oncogenes loci and cancer breakpoints, these 7 Fra are Ip36(src2),3p24(rafl)(raf2),6p23 (krasip), 8q22(mos), 14q24(fos), 22qll(bcr), 22.ql3 (sis). This observation suggests that the fragile sites may associate with leukemia