RESUMO
Acute promyelocytic leukemia (APL) is a subtype of acute myelogenous leukemia (AML) that is characterized by peculiar clinical and biologic features, including severe hemorrhagic diathesis, specific recurrent chromosomal aberration, and distinct morphologic features with predominant pathologic promyelocytes. A reciprocal translocation involving chromosomes 15 and 17, t(15;17)(q22;q21), is a characteristic feature of APL that represents approximately 5-8% of AML. The rearranged gene created by this translocation encodes a chimeric protein PML-RARA that is a transcriptional repressor. In contrast to other AML subtypes, APL is particularly sensitive to treatment with all trans-retinoic acid (ATRA) combined with chemotherapy, converting this once fatal leukemia to a highly curable disease. Nonetheless, therapy-related myelodysplastic syndrome-acute myelogenous leukemia (t-MDS/AML) has been reported as a rare complication of chemotherapy in APL. Of 30 APL cases described as t-MDS/AML in the literature, only 1 case relapsed as acute leukemia with t(3;21)(q26;q22). Here we describe a rare case of APL relapsing as secondary AML with t(3;21)(q26;q22) and clinically characterize this patient using the RUNX1 (previously AML1)-MDS1-EVI1 fusion transcript (with follow-up for 55 months), and review the relevant literature.
Assuntos
Leucemia Mieloide Aguda/genética , Leucemia Promielocítica Aguda/genética , Segunda Neoplasia Primária/genética , Proteínas de Fusão Oncogênica/genética , Translocação Genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Medula Óssea/ultraestrutura , Coloração Cromossômica , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 3/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Cariotipagem , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/patologia , Proteína do Locus do Complexo MDS1 e EVI1 , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Segunda Neoplasia Primária/patologia , Proto-Oncogenes/genética , Análise de Sequência de DNA , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tretinoína/uso terapêuticoRESUMO
The aim of this study was to investigate antimicrobial susceptibilities and macrolide resistance mechanisms of beta-hemolytic viridans group streptococci (VGS) in a tertiary Korean hospital. Minimum inhibitory concentrations (MICs) of seven antimicrobials were determined for 103 beta-hemolytic VGS isolated from various specimens. The macrolide resistance mechanisms of erythromycin-resistant isolates were studied by the double disk test and polymerase chain reaction (PCR). The overall resistance rates of beta-hemolytic VGS were found to be 47.5% to tetracycline, 3.9% to chloramphenicol, 9.7% to erythromycin, and 6.8% to clindamycin, whereas all isolates were susceptible to penicillin G, ceftriaxone, and vancomycin. Among ten erythromycin-resistant isolates, six isolates expressed a constitutive MLS(B) (cMLS(B)) phenotype, and each of the two isolates expressed the M phenotype, and the inducible MLS(B) (iMLS(B)) phenotype. The resistance rates to erythromycin and clindamycin of beta-hemolytic VGS seemed to be lower than those of non-beta-hemolytic VGS in our hospital, although cMLSB phenotype carrying erm(B) was dominant in beta-hemolytic VGS.
Assuntos
Infecção Hospitalar/genética , Farmacorresistência Bacteriana , Macrolídeos/farmacologia , Estreptococos Viridans/genética , Estreptococos Viridans/metabolismo , Ceftriaxona/farmacologia , Cloranfenicol/farmacologia , Clindamicina/farmacologia , Eritromicina/farmacologia , Humanos , Técnicas Imunoenzimáticas , Coreia (Geográfico) , Penicilina G/farmacologia , Fenótipo , Reação em Cadeia da Polimerase , Tetraciclina/farmacologia , Vancomicina/farmacologiaRESUMO
PURPOSE: Erythromycin-resistant beta-hemolytic streptococci (BHS) has recently emerged and quickly spread between and within countries throughout the world. In this study, we evaluate the antimicrobial susceptibility patterns and erythromycin resistance mechanisms of BHS during 2003-2004. MATERIALS AND METHODS: The MICs of seven antimicrobials were determined for 204 clinical isolates of BHS from 2003 to 2004. Resistance mechanisms of erythromycin-resistant BHS were studied by the double disk test as well as by polymerase chain reaction (PCR). RESULTS: Compared with our previous study, resistance among Streptococcus pyogenes isolates to a variety of drugs decreased strikingly: from 25.7% to 4.8% in erythromycin; 15.8% to 0% in clindamycin; and 47.1% to 19.0% in tetracycline. The prevalent phenotypes and genotypes of macrolide-lincosamide-streptograminB (MLSB) resistance in Streptococcus pyogenes isolates have been changed from the constitutive MLSB phenotype carrying erm(B) to the M phenotype with mef(A) gene. In contrast with Streptococcus pyogenes, resistance rates to erythromycin (36.7%), clindamycin (43.1%), and tetracycline (95.4%) in Streptococcus agalactiae isolates did not show decreasing trends. Among the Streptococcus dysgalactiae subsp. equisimilis isolates (Lancefield group C, G), resistance rates to erythromycin, clindamycin, tetracycline and chloramphenicol were observed to be 9.4%, 3.1%, 68.8%, and 9.4%, respectively. CONCLUSION: Continual monitoring of antimicrobial resistance among large-colony-forming BHS is needed to provide the medical community with current data regarding the resistance mechanisms that are most common to their local or regional environments.
Assuntos
Antibacterianos/farmacologia , Eritromicina/farmacologia , Streptococcus/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Genes Bacterianos , Genótipo , Hospitais , Humanos , Incidência , Coreia (Geográfico) , Testes de Sensibilidade Microbiana , Streptococcus/genética , Streptococcus/isolamento & purificação , Streptococcus agalactiae/efeitos dos fármacos , Streptococcus agalactiae/genética , Streptococcus agalactiae/isolamento & purificação , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/genética , Streptococcus pyogenes/isolamento & purificaçãoRESUMO
Massive intravascular hemolysis secondary to Clostridium perfringens septicemia is rare but often fatal. We report a case of a fatal clostridial hemolytic complication in a 71-year-old woman with probable refractory anemia. The patient was admitted to the emergency room due to a comatose mental state and a high fever. Laboratory analysis showed massive hemolysis. She died from severe anemia two hours after admission. The next day, blood cultures grew gram positive cocci and boxcarshaped gram positive rods, which were identified as coagulase-negative staphylococci and C. perfringens, respectively.
