ABSTRACT
BACKGROUND: Our study focuses on the role that human Cytomegalovirus (CMV) genotypes play in the development of disease. OBJECTIVES: (1) To analyze the frequency of various genotype envelope proteins (gB, gH) in a group of solid organ transplant (SOT) recipients; (2) to assess their correlation with CMV disease; (3) to study the association between any of the genotypes and viral loads. STUDY DESIGN: A retrospective observational study conducted by analyzing CMV gB and gH genotypes detected with real-time polymerase chain reaction (PCR)-specific assays in 162 CMV-positive blood samples from 62 SOT recipients. Demographic, clinical, and microbiological data were recorded. RESULTS: Mixed gB genotypes were associated with viral syndrome (70%, p = .004), earlier presentation of symptoms (48.27 ± 27.03 versus 74.33 ± 47.25 days, respectively, p = .001), and higher median of the plasma viral load log10 (UI/ml) than infection with a single genotype (p = .004). Furthermore, the gB3 genotype was detected more frequently in patients who presented with asymptomatic viremia (77.27%, p < .0001). The gH1 genotype was more frequent (65%) in patients who presented with asymptomatic viremia (p = .003), and it caused infection later than gH2 or the mixed genotype (84.88 ± 48.10 versus 57.91 ± 39.18 days, respectively, p < .001). CONCLUSIONS: Patients who presented mixed gB genotypes more frequently developed clinical manifestations and earlier, higher, plasma viral loads. The detection of gB and gH genotypes by real-time PCR can provide relevant information to stratify the risk of SOT recipients to develop symptomatic infection by CMV.
Subject(s)
Cytomegalovirus Infections/virology , Cytomegalovirus/genetics , Transplant Recipients , Viral Envelope Proteins/genetics , Adult , Cytomegalovirus/classification , Cytomegalovirus Infections/blood , Cytomegalovirus Infections/complications , DNA, Viral/blood , DNA, Viral/genetics , Female , Genotype , Humans , Male , Middle Aged , Prognosis , Real-Time Polymerase Chain Reaction , Retrospective Studies , Sequence Analysis, DNA , Viral LoadABSTRACT
BACKGROUND: Cytomegalovirus (CMV) remains an important pathogen to immunocompromised patients even in the era of HAART. The present study aimed at evaluating the influence of CMV viral load and its gB genotypes on AIDS patients' outcome. METHODS: Blood samples of 101 AIDS patients were collected and tested for HIV load, CD4 - cell count and opportunistic pathogens, including CMV. Semi-nested PCRs were run to detect CMV genome and in the positive samples, gB genotyping and CMV load were established using enzymatic restriction and real time PCR, respectively. All patients were clinically followed for four years. RESULTS: In thirty patients (31 percent) CMV was detected and all fatal cases (n = 5) occurred in this group of patients (p = 0.007), but only two patients had CMV disease (1.9 percent). However, viral load was not statistically associated with any analyzed parameter. The most frequently observed CMV genotype was gB2 (45.16 percent) followed by gB3 (35.48 percent). gB2 genotype was more frequently found in patients with CD4-cell counts under 200 cells/mm³ (p = 0.0017), and almost all fatal cases (80 percent) had gB2 genotype. CONCLUSIONS: Our study suggests that CMV and its polymorphisms in biologically relevant genes, such as the gB encoding ORF, may still influence the prognosis and outcome of AIDS patients. The gB2 genotype was associated to patient's bad outcome.
ANTECEDENTES: O citomegalovírus (CMV) permanece um importante patógeno para pacientes imunocomprometidos, mesmo na era da HAART. O presente estudo teve como objetivo avaliar a influência da carga viral do CMV e seu genótipo gB sobre a evolução de pacientes com AIDS. MÉTODOS: Amostras de sangue de 101 pacientes com AIDS foram coletadas e testadas para carga viral de HIV, a contagem de células CD4 e patógenos oportunistas, incluindo o CMV. Um sistema de PCRs seminested foi utilizado para detectar o genoma do CMV e em amostras positivas a carga viral de CMV e genotipagem foram estabelecidos por restrição enzimática e PCR em tempo real, respectivamente. Todos os pacientes foram acompanhados clinicamente durante quatro anos. RESULTADOS: Trinta pacientes (31 por cento) tiveram CMV detectado e todos os casos fatais (n = 5) ocorreram em pacientes deste grupo (p = 0,007), porém apenas dois pacientes tinham doença por CMV (1,9 por cento). No entanto, a carga viral não foi associada estatisticamente a nenhum dos parâmetros analisados. O genótipo de CMV mais freqüentemente observado foi gB2 (45,16 por cento), seguido por gB3 (35,48 por cento). O genótipo gB2 foi mais freqüente em pacientes com contagens abaixo de 200 células/mm³ CD4cell (p = 0,0017), e quase todos os casos fatais (80 por cento) tinham o genótipo gB2. CONCLUSÃO: Nosso estudo sugere que CMV e seu polimorfismo em genes relevantes biologicamentes, como a gB, pode ainda influenciar no prognóstico e evolução de pacientes com AIDS. O genótipo gB2 foi associado ao mau prognóstico do paciente.
