RESUMO
Azacitidine is a mainstay of therapy for myelodysplastic syndrome (MDS)-related diseases. The purpose of our study is to elucidate the effect of gene mutations on hematological response and overall survival (OS), particularly focusing on their posttreatment clone size. We enrolled a total of 449 patients with MDS or related myeloid neoplasms. They were analyzed for gene mutations in pretreatment (n = 449) and posttreatment (n = 289) bone marrow samples using targeted-capture sequencing to assess the impact of gene mutations and their posttreatment clone size on treatment outcomes. In Cox proportional hazard modeling, multihit TP53 mutation (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.42-2.91; P < .001), EZH2 mutation (HR, 1.71; 95% CI, 1.14-2.54; P = .009), and DDX41 mutation (HR, 0.33; 95% CI, 0.17-0.62; P < .001), together with age, high-risk karyotypes, low platelets, and high blast counts, independently predicted OS. Posttreatment clone size accounting for all drivers significantly correlated with International Working Group (IWG) response (P < .001, using trend test), except for that of DDX41-mutated clones, which did not predict IWG response. Combined, IWG response and posttreatment clone size further improved the prediction of the original model and even that of a recently proposed molecular prediction model, the molecular International Prognostic Scoring System (IPSS-M; c-index, 0.653 vs 0.688; P < .001, using likelihood ratio test). In conclusion, evaluation of posttreatment clone size, together with the pretreatment mutational profile as well as the IWG response play a role in better prognostication of azacitidine-treated patients with myelodysplasia.
Assuntos
Síndromes Mielodisplásicas , Transtornos Mieloproliferativos , Neoplasias , Humanos , Prognóstico , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Resultado do Tratamento , AzacitidinaRESUMO
Donor lymphocyte infusion (DLI) is a therapeutic modality for relapsed hematological malignancies after allogeneic hematopoietic stem cell transplantation. We retrospectively analyzed non-infectious pulmonary complications (non-IPCs) following DLI therapy in 41 post-transplant patients with hematological malignancies, and found that 7 developed post-DLI non-IPCs. The 6-year cumulative incidence of non-IPCs was 18.0%. In these patients, non-IPCs were classified into three subtypes: acute respiratory distress syndrome (ARDS), nonspecific interstitial pneumonia (NSIP), and bronchiolitis obliterans syndrome (BOS). The median intervals from the last date of DLI to the development of ARDS and BOS were 12 days (range, 12-14) and 9.4 months (range, 2.6-61.8), respectively; the intervals between DLI and the development of NSIP were 3.5 and 24.7 in 2 patients. Regarding the status of GVHD before the diagnosis with ARDS, 2 out of 3 patients showed the progression of acute GVHD following DLI therapy. One out of 2 patients with NSIP and all 3 patients with BO had chronic GVHD symptoms prior to the development of non-IPCs. In our cohort, 1 patient died of the progression of NSIP. In conclusion, the present study showed the clinical features of non-IPCs following DLI, suggesting the importance of careful follow-ups for non-IPCs in post-DLI patients.
Assuntos
Doença Enxerto-Hospedeiro , Neoplasias Hematológicas , Transplante de Células-Tronco Hematopoéticas , Síndrome do Desconforto Respiratório , Humanos , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/terapia , Transfusão de Linfócitos , Estudos Retrospectivos , Recidiva Local de Neoplasia/complicações , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Neoplasias Hematológicas/terapia , Linfócitos , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/terapiaRESUMO
Chronic disseminated candidiasis (CDC) is a type of invasive candidiasis. CDC commonly appears in the neutrophil recovery phase after chemotherapy in patients with hematologic malignancies, and immune reconstitution inflammatory syndrome (IRIS) is thought to play a major role in CDC development. This report describes the case of a 33-year-old man with CDC as a complication of acute myeloid leukemia. We describe the clinical course, body temperature, therapy, and (1,3)-ß-D-glucan (BDG) levels over the course of 22 months. He was initially treated with antifungals, but corticosteroids were added because of a persistently elevated body temperature, which we attributed to IRIS. After starting corticosteroids, his clinical condition improved, but his BDG levels became markedly elevated. We hypothesize that the suppression of the excessive immune response by corticosteroids lead to granuloma collapse, fungal release, and hematogenous dissemination, resulting in elevated BDG levels. The patient's condition gradually improved over the course of follow-up.
Assuntos
Candidíase Invasiva , beta-Glucanas , Corticosteroides/uso terapêutico , Adulto , Antifúngicos/uso terapêutico , Candidíase Invasiva/tratamento farmacológico , Humanos , Masculino , ProteoglicanasRESUMO
Objective The standard treatment for chronic myeloid leukemia (CML) is the continuous use of tyrosine kinase inhibitors (TKIs), which results in a favorable prognosis for the majority of patients. Recent studies have identified cardiovascular diseases (CVDs) as late adverse events (AEs) related to TKIs. In this study, we evaluated the long-term efficacy and AEs of TKIs, focusing on CVDs. Methods We performed a retrospective survey of CML patients (diagnosed from 2001 to 2016) treated with TKIs in Nagasaki Prefecture. Clinical data were obtained from their medical records. We analyzed the survival, estimated cumulative incidence of CVDs, and risk factors for CVD among CML patients treated with TKIs. Results The overall survival rate of 264 CML patients treated with TKIs (median age 58 years old) was 89.6% [95% confidence interval (CI), 84.9-92.9%], and 80.5% (95% CI, 73.4-85.9%) at 5 and 10 years after the CML diagnosis, respectively. CVD events occurred in 26 patients (9.8%, median age 67.5 years old) with a median 65.5 months of TKI treatment. The cumulative incidences at 2 and 5 years was 2.4% (95% CI, 1.0-4.8%) and 5.2% (95% CI, 2.8-8.6%), respectively. Hypertension and a high SCORE chart risk at the diagnosis of CML were associated with CVD events during TKI treatment. Conclusion TKI treatment contributed to the long-term survival of CML patients in Nagasaki Prefecture in a "real-world" setting, but the incidence of CVDs seemed to be increased in these patients. A proper approach to managing risk factors for CVD is warranted to reduce CVD events during TKI treatment.
Assuntos
Doenças Cardiovasculares , Leucemia Mielogênica Crônica BCR-ABL Positiva , Idoso , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/efeitos adversos , Estudos Retrospectivos , Fatores de RiscoRESUMO
The efficacy of azacitidine (AZA) on survival of lower risk (LR) - myelodysplastic syndromes (MDS) is controversial. To address this issue, we retrospectively evaluated the long-term survival benefit of AZA for patients with LR-MDS defined by International Prognostic Scoring System (IPSS). Using data from 489 patients with LR-MDS in Nagasaki, hematologic responses according to International Working Group 2006 and overall survival (OS) were compared among patients that received best supportive care (BSC), immunosuppressive therapy (IST), erythropoiesis-stimulating agents (ESA), and AZA. Patients treated with AZA showed complete remission (CR) rate at 11.3%, marrow CR at 1.9%, and any hematologic improvement at 34.0%, with transfusion independence (TI) of red blood cells in 27.3% of patients. and platelet in 20% of patients, respectively. Median OS for patients received IST, ESA, BSC, and AZA (not reached, 91 months, 58 months, and 29 months, respectively) differed significantly (P < .001). Infection-related severe adverse events were observed in more than 20% of patients treated with AZA. Multivariate analysis showed age, sex, IPSS score at diagnosis, and transfusion dependence were significant for OS, but AZA treatment was not, which maintained even response to AZA, and IPSS risk status at AZA administration was added as factors. We could not find significant survival benefit of AZA treatment for LR-MDS patients.
Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Hematínicos/uso terapêutico , Imunossupressores/uso terapêutico , Síndromes Mielodisplásicas/tratamento farmacológico , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Azacitidina/efeitos adversos , Causas de Morte , Transfusão de Eritrócitos/mortalidade , Feminino , Humanos , Quimioterapia de Indução/métodos , Japão , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Síndromes Mielodisplásicas/mortalidade , Transfusão de Plaquetas/mortalidade , Prognóstico , Análise de Regressão , Estudos Retrospectivos , Fatores Sexuais , Resultado do Tratamento , Adulto JovemRESUMO
Secondary pulmonary alveolar proteinosis (sPAP) is a complication of myelodysplastic syndrome (MDS). A 60-year-old woman was diagnosed with MDS with excess blasts-1. Fifty-four months after the initial diagnosis, treatment with azacitidine was initiated. Seventy-three months after the diagnosis, a bone marrow examination revealed increased myeloblasts, at which time computed tomography showed diffuse ground-glass opacities and interlobular septal thickening in the bilateral lower lung fields. A lung biopsy revealed the presence of PAP; therefore, the clinical diagnosis of MDS/sPAP was confirmed. Careful attention should be paid to the development of sPAP in MDS patients with pulmonary lesions during azacitidine treatment.
Assuntos
Azacitidina/uso terapêutico , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/tratamento farmacológico , Proteinose Alveolar Pulmonar/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
A 68-year-old male was diagnosed with acute promyelocytic leukemia (APL). A G-banding chromosomal analysis revealed the co-existence of two clones: one with del(20q) and t(15;17)(q22;q12) and another with del(20q) alone. During the remission of APL following treatment with all-trans-retinoic acid, del(20q) was persistently identified, indicating a diagnosis of cytogenetic abnormalities of undetermined significance (CCAUS) with isolated del(20q). Bicytopenia developed 48 months after the remission of APL. The presence of isolated del(20q) was detected in the G-banding analysis, whereas morphological dysplasia of hematopoietic cells was not confirmed. This case showed indolent progression from CCAUS after the remission of APL to clonal cytopenia of undetermined significance (CCUS). CCUS with isolated del(20q) persisted for 24 months without any finding of hematological malignancies. At the most recent follow-up, targeted capture sequencing showed the U2AF1 S34F mutation. Considerable attention needs to be paid in follow-ups for CCAUS with del(20q) after the treatment of leukemia.
Assuntos
Aberrações Cromossômicas , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/genética , Idoso , Células Clonais , Seguimentos , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Masculino , Indução de Remissão , Tretinoína/uso terapêuticoRESUMO
Ionizing radiation is a risk factor for myeloid neoplasms including myelodysplastic syndromes (MDS), and atomic bomb survivors have been shown to have a significantly higher risk of MDS. Our previous analyses demonstrated that MDS among these survivors had a significantly higher frequency of complex karyotypes and structural alterations of chromosomes 3, 8, and 11. However, there was no difference in the median survival time between MDS among survivors compared with those of de novo origin. This suggested that a different pathophysiology may underlie the causative genetic aberrations for those among survivors. In this study, we performed genome analyses of MDS among survivors and found that proximally exposed patients had significantly fewer mutations in genes such as TET2 along the DNA methylation pathways, and they had a significantly higher rate of 11q deletions. Among the genes located in the deleted portion of chromosome 11, alterations of ATM were significantly more frequent in proximally exposed group with mutations identified on the remaining allele in 2 out of 5 cases. TP53, which is frequently mutated in therapy-related myeloid neoplasms, was equally affected between proximally and distally exposed patients. These results suggested that the genetic aberration profiles in MDS among atomic bomb survivors differed from those in therapy-related and de novo origin. Considering the role of ATM in DNA damage response after radiation exposure, further studies are warranted to elucidate how 11q deletion and aberrations of ATM contribute to the pathogenesis of MDS after radiation exposure.
Assuntos
Sobreviventes de Bombas Atômicas , Síndromes Mielodisplásicas , Aberrações Cromossômicas , Humanos , Síndromes Mielodisplásicas/etiologia , Síndromes Mielodisplásicas/genética , Fatores de Risco , SobreviventesRESUMO
Ectopic soft tissue calcification (ESTC), a rare clinical condition, causes tissue and organ damage. It is associated with chronic renal failure, hyperparathyroidism, and malignant neoplasms, including multiple myeloma, and it is reportedly resistant to treatment. Here, we present the case of a 71-year-old male with multiple myeloma who had rapid ESTC in the lung. He had developed hypoparathyroidism secondary to thyroidectomy. During the course of our observation, he rapidly developed ectopic pulmonary calcification approximately 2 weeks after acquiring an infection. There was no evidence of further progression of multiple myeloma after the onset of ESTC, and treatment with ferric citrate hydrate and precipitated calcium resulted in immediate improvement of his pulmonary signs. We recommend cautious monitoring for patients with multiple myeloma and hypoparathyroidism to detect the onset of ectopic calcification. In addition, low blood phosphorus levels should be effectively treated.
Assuntos
Calcinose/etiologia , Mieloma Múltiplo/complicações , Paratireoidectomia/efeitos adversos , Idoso , Humanos , MasculinoRESUMO
A 62-year-old male was diagnosed with blastic plasmacytoid dendritic cell neoplasm (BPDCN) with a MYC rearrangement. Four months after the first unrelated bone marrow transplantation (BMT), he developed the relapsed BPDCN. After the achievement of partial remission following re-induction therapy, he underwent a second BMT from another unrelated donor, and experienced complete remission with grade II acute graft-versus-host disease and moderate chronic graft-versus-host disease. He remains alive in complete remission more than 71 months after the second BMT. These results suggested that donor change at the second transplantation may represent a considerable therapeutic option for patients with relapsed BPDCN.
RESUMO
In acute myeloid leukemia (AML), patients may harbor pre-leukemic hematopoietic stem cells (HSCs) containing some, but not all, of the mutations observed in the leukemic cells. These pre-leukemic HSCs may survive induction chemotherapy and contribute to AML relapse by obtaining additional mutations. We report here an acute monoblastic leukemia (AMoL) patient who later developed an unclassifiable myeloproliferative neoplasm (MPN-U). Whole-exome sequencing and cluster analysis demonstrated the presence of three distinct major clones during the clinical course: (1) an AMoL clone with ASXL1, CBL, and NPM1 somatic mutations, likely associated with the pathogenesis, and GATA2, SRSF2, and TET2 mutations, (2) an AMoL remission clone, with mutated GATA2, SRSF2, and TET2 only (possibly the founding clone (pre-leukemic HSC) that survived chemotherapy), (3) a small subclone which had JAK2 mutation during the AMoL remission, appearing at MPN-U manifestation with additional mutations. These findings suggest that pre-leukemic HSCs in AML patients may give rise to non-AML myeloid malignancies. This is the first report to analyze the clonal evolution from AMoL to MPN-U, which may provide new insight into the development of myeloid malignancies.
Assuntos
Evolução Clonal/genética , Leucemia Monocítica Aguda/genética , Leucemia Monocítica Aguda/patologia , Transtornos Mieloproliferativos/etiologia , Transtornos Mieloproliferativos/genética , Idoso , Evolução Clonal/fisiologia , Células-Tronco Hematopoéticas/patologia , Humanos , Quimioterapia de Indução , Leucemia Monocítica Aguda/sangue , Leucemia Monocítica Aguda/complicações , Masculino , Mutação , Recidiva Local de Neoplasia , Nucleofosmina , Sequenciamento do ExomaRESUMO
The myelodysplastic syndromes (MDS) are clonal haematopoietic disorders that develop de novo and also secondary to chemotherapy and/or radiation therapy. We previously demonstrated that the risk of MDS is increased among atomic bomb survivors with significant correlation to radiation dose; however, the clinical characteristics of these survivors have not been well analysed. In this study, we investigated chromosomal abnormalities of MDS among survivors. The frequency of abnormal karyotypes was significantly higher, with more very poor risk karyotypes, according to the revised International Prognostic Scoring System, among those exposed close to the hypocentre compared with unexposed cases. However, abnormal karyotype frequency did not reflect the prognosis of exposed cases with respect to distance from the hypocentre. In addition, there was no difference in prognosis between exposed and unexposed cases. Among proximally exposed cases (<1·5 km from the hypocentre), chromosomal translocations and inversions were more frequent, and the frequency of structural alterations in chromosomes 3, 8, and 11 was significantly increased compared with unexposed cases. These results suggest that chromosomal alterations in MDS among survivors have different features compared with those in de novo or therapy-related MDS. Detailed molecular study is warranted.
Assuntos
Aberrações Cromossômicas , Vítimas de Desastres , Síndromes Mielodisplásicas/epidemiologia , Síndromes Mielodisplásicas/genética , Armas Nucleares , Sobreviventes , Adulto , Idoso , Idoso de 80 Anos ou mais , Contagem de Células Sanguíneas , Medula Óssea/patologia , Análise Citogenética , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/terapia , Avaliação de Resultados da Assistência ao Paciente , Sistema de Registros , Análise de SobrevidaRESUMO
An adult woman developed polymorphic post-transplant lymphoproliferative disorder (PTLD) 58 months after unrelated cord blood transplantation. She was treated successfully with chemotherapy and radiation therapy but presented with lymphadenopathy and splenomegaly 74 months after transplantation. A lymph node biopsy confirmed the diagnosis of nodular sclerosis type Hodgkin lymphoma (classical Hodgkin lymphoma [CHL]-type PTLD). After salvage therapy and hematopoietic stem cell harvesting, she was subsequently treated with consolidative high-dose chemotherapy with melphalan followed by stem cell rescue, which resulted in durable remission. High-dose chemotherapy using stem cell rescue has potential as a therapeutic option for subsequent CHL-type PTLD.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Doença de Hodgkin/terapia , Transtornos Linfoproliferativos/terapia , Melfalan/uso terapêutico , Terapia de Salvação/métodos , Feminino , Sangue Fetal , Doença de Hodgkin/complicações , Humanos , Transtornos Linfoproliferativos/complicações , Transtornos Linfoproliferativos/etiologia , Melfalan/administração & dosagem , Pessoa de Meia-IdadeAssuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Sangue Fetal/fisiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Leucemia-Linfoma de Células T do Adulto/terapia , Doadores de Tecidos , Adulto , Sangue Fetal/transplante , Humanos , Doença Iatrogênica , Leucemia-Linfoma de Células T do Adulto/sangue , Masculino , Indução de Remissão , Transplante Homólogo/efeitos adversos , Doadores não RelacionadosAssuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Receptores CCR4/genética , Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos/farmacologia , Citometria de Fluxo , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia-Linfoma de Células T do Adulto/genética , Masculino , Pessoa de Meia-Idade , Patologia Molecular , Reação em Cadeia da Polimerase , Interferência de RNA/efeitos dos fármacosRESUMO
Myelodysplastic syndrome (MDS) is a disorder of hematopoietic stem cells (HSCs) that is often treated with DNA methyltransferase 1 (DNMT1) inhibitors (5-azacytidine [AZA], 5-aza-2'-deoxycytidine), suggesting a role for DNA methylation in disease progression. How DNMT inhibition retards disease progression and how DNA methylation contributes to MDS remain unclear. We analyzed global DNA methylation in purified CD34+ hematopoietic progenitors from MDS patients undergoing multiple rounds of AZA treatment. Differential methylation between MDS phenotypes was observed primarily at developmental regulators not expressed within the hematopoietic compartment and was distinct from that observed between healthy hematopoietic cell types. After AZA treatment, we observed only limited DNA demethylation at sites that varied between patients. This suggests that a subset of the stem cell population is resistant to AZA and provides a basis for disease relapse. Using gene expression data from patient samples and an in vitro AZA treatment study, we identified differentially methylated genes that can be activated following treatment and that remain silent in the CD34+ stem cell compartment of high-risk MDS patients. Haploinsufficiency in mice of one of these genes (NR4A2) has been shown to lead to excessive HSC proliferation, and our data suggest that suppression of NR4A2 by DNA methylation may be involved in MDS progression.
Assuntos
Metilação de DNA/genética , Células-Tronco Hematopoéticas/metabolismo , Síndromes Mielodisplásicas/genética , Antígenos CD34/metabolismo , Azacitidina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Humanos , Estudos Longitudinais , Síndromes Mielodisplásicas/tratamento farmacológico , Reação em Cadeia da Polimerase , TranscriptomaRESUMO
An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment.
Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/genética , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Benzamidas/efeitos adversos , Benzamidas/uso terapêutico , Análise Mutacional de DNA , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Regulação Leucêmica da Expressão Gênica , Humanos , Mesilato de Imatinib , Japão , Leucemia Mieloide de Fase Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Estudos Prospectivos , Inibidores de Proteínas Quinases/efeitos adversos , Pirimidinas/efeitos adversos , Pirimidinas/uso terapêutico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco , Resultado do Tratamento , Adulto JovemAssuntos
Proliferação de Células , Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma de Células T do Adulto/patologia , Leucemia-Linfoma de Células T do Adulto/terapia , Linfócitos/patologia , Humanos , Leucemia-Linfoma de Células T do Adulto/imunologia , Masculino , Pessoa de Meia-Idade , Transplante HomólogoRESUMO
Dispersions of image potential states on a graphite surface (denoted IPS1) and on 1 monolayer (ML) film (denoted IPS2) of lead phthalocyanine (PbPc) are investigated by the micro-spot angle-resolved two-photon photoemission (micro-AR-2PPE) spectroscopy. On the graphite surface, whole dispersions of the two members of IPS1 (n = 1 and 2) are observed. The n = 1 IPS1 peak is weakly visible at energy higher than the vacuum level. The effective mass of an electron in the n = 1 IPS1 becomes slightly light at the high momentum region, suggesting the interaction between the IPS1 and the unoccupied σ-band of graphite. On the PbPc film, the IPS2 band forms a band gap and back-folds at the boundary of the Brillouin zone. A 1-dimensional Kronig-Penny model is used to reproduce the effective mass and the shift of binding energy.
RESUMO
Under programs organized by the government of Thailand, HIV-1-infected patients have been treated since 2002 with several regimens, including a tablet known as GPOvir, which contains lamivudine, stavudine, and nevirapine. The aim of this study was to establish an effective assay, based on mutagenically separated PCR (MS-PCR), with the goal of surveying GPOvir-resistant HIV-1 cases. To determine the target mutation point for the assay, we analyzed the patterns of acquired drug resistance in plasma samples from GPOvir-failed cases. Of 428 HIV-1-infected individuals treated with GPOvir at Lampang Hospital in northern Thailand from 2002 to 2004, 66 had detectable viral loads after 3 months of treatment. The HIV-1 sequences of these 66 GPOvir-failed cases and 55 pre-GPOvir baseline samples were analyzed. The most prevalent drug resistance mutation among the samples was the lamivudine resistance M184I/V mutation. Based on this finding, we developed a new MS-PCR assay to detect the M184I/V mutation, and evaluated the assay performance for detecting GPOvir-resistant CRF01_AE cases. Comparing the results of M184I/V MS-PCR and sequence analyses, we found a concordance rate of 95% and an overall sensitivity of the M184I/V MS-PCR for detecting GPOvir-resistant cases of 79%. Considering the relatively low price of the assay, approximately $12.50 per sample, M184I/V MS-PCR may be a candidate for monitoring a large number of GPOvir-treated patients, particularly in developing nations.