Epstein-Barr virus load in transplant patients: Early detection of post-transplant lymphoproliferative disorders / Carga de virus Epstein-Barr en pacientes trasplantados: detección temprana de desórdenes linfoproliferativos postrasplante

High levels of circulating EBV load are used as a marker of post-transplant lymphoproliferative disorders (PTLD). There is no consensus regarding the threshold level indicative of an increase in peripheral EBV DNA. The aim of the study was to clinically validate a developed EBV quantification assay for early PTLD detection. Transversal study: paired peripheral blood mononuclear cells (PBMC), plasma and oropharyngeal lymphoid tissue (OLT) from children undergoing a solid organ transplant with (n = 58) and without (n = 47) PTLD. Retrospective follow-up: 71 paired PBMC and plasma from recipients with (n = 6) and without (n = 6) PTLD history. EBV load was determined by real-time PCR. The diagnostic ability to detect all PTLD (categories 1-4), advanced PTLD (categories 2-4) or neoplastic PTLD (categories 3 and 4) was estimated by analyzing the test performance at different cut-off values or with a load variation greater than 0.5 log units. The higher diagnostic performance for identifying all, advanced or neoplastic PTLD, was achieved with cut-off values of 1.08; 1.60 and 2.47 log EBV gEq/10(5) PBMC or 2.30; 2.60; 4.47 log gEq/10(5) OLT cells, respectively. EBV DNA detection in plasma showed high specificity but low (all categories) or high (advanced/neoplastic categories) sensitivity for PTLD identification. Diagnostic performance was greater when: (1) a load variation in PBMC or plasma was identified; (2) combining the measure of EBV load in PBMC and plasma. The best diagnostic ability to identify early PTLD stages was achieved by monitoring EBV load in PBMC and plasma simultaneously; an algorithm was proposed.

La carga alta del virus Epstein-Barr se utiliza como un marcador de desórdenes linfoproliferativos postrasplante (post-transplant lymphoproliferative disorders [PTLD]). El objetivo de este estudio fue validar clínicamente un ensayo de cuantificación del virus Epstein-Barr para la detección temprana de PTLD. Se efectuó un estudio transversal en el que se analizaron muestras pareadas de células mononucleares periféricas (CMP), de plasma y de tejido linfoide orofaríngeo de niños con trasplante de órgano sólido, con PTLD (n = 58) y sin PTLD (n = 47). En el seguimiento retrospectivo se incluyeron 71 muestras pareadas de CMP y de plasma de trasplantados, con PTLD (n = 6) y sin PTLD (n = 6). La carga viral se determinó por PCR en tiempo real. Se estimó la capacidad diagnóstica para detectar PTLD (categorías: todas vs. avanzadas vs. neoplásicas) analizando diferentes valores de corte o una variación de carga mayor de 0,5 logaritmos. El mayor desempeño diagnóstico para identificar todos los PTLD, los avanzados y los neoplásicos, se obtuvo con valores de corte de 1,08; 1,60 y 2,47 log copias/10(5) en CMP y de 2,30; 2,60 y 4,48 log copias/10(5) en células de tejido linfoide orofaríngeo, respectivamente. La detección del ADN del virus Epstein-Barr en el plasma mostró una especificidad alta, pero una sensibilidad baja (todas las categorías) o alta (categorías avanzadas o neoplásicas) para identificar PTLD. Se observó el desempeño diagnóstico más alto en las siguientes condiciones: 1) al identificar una variación de carga en CMP o en plasma; 2) combinando la medición de la carga viral en CMP y en plasma. La mejor capacidad diagnóstica para identificar las etapas tempranas de los PTLD se logró mediante el seguimiento simultáneo de la carga viral en CMP y en plasma; se propone un algoritmo.

Evaluation of GBV-C / HVG viremia in HIV-infected women / Avaliação da viremia por GBV-C/HGV em mulheres infectadas pelo HIV

The present study aimed at standardizing a real-time quantitative polymerase chain reaction assay to evaluate the presence of GBV-C/HGV RNA. A "TaqMan" assay using primers and probe derived from the 5¢ NCR region was developed and validated. Two hundred and fifty-three plasma samples from HIV-infected women were tested for GBV-C viremia and antibody against the envelope protein 2. GBV-C RNA was detected in 22.5 percent of the patients whereas the antibody was identified in 25.3 percent of the cohort. Detection of viral RNA and of antibodies was mutually exclusive. Viral loads showed a mean of 1,777 arbitrary units / mL, being 1.1 and 13,625 arbitrary units / mL respectively the lowest and highest values measured. We conclude that the real-time quantitative polymerase chain reaction method developed is appropriate for the investigation of GBV-C RNA since it was shown to be highly specific and sensitive, as well as requiring few steps, preventing contamination and providing additional information as to the relative viremia of carriers, a parameter that must be included in studies evaluating the co-factors influencing the clinical outcome of HIV/AIDS.

Este estudo teve como objetivo o desenvolvimento de método de PCR em Tempo Real para a determinação da viremia do vírus GBV-C. Ensaio baseado em primers e sonda "TaqMan" derivados da região 5' não-codificante deste vírus foi padronizado, validado e aplicado em uma série de 253 amostras de plasma de pacientes HIV+. Além do PCR em tempo real, as amostras foram submetidas a um ensaio imunoenzimático anti-E2 e a um nested-PCR. Das 253 amostras testadas, 64 foram positivas para o anticorpo anti-E2 (25,3 por cento), enquanto 57 amostras foram concordantemente RNA positivas pelo nested-PCR e PCR em tempo real (22,5 por cento), perfazendo um índice total de exposição de 48 por cento (25.3 + 22.5). A carga viral teve média de 1.777 UA/mL (13.625 - 1.1UA/mL). Foi obtida metodologia simples, rápida e de boa sensibilidade e especificidade, permitindo a quantificação do RNA do vírus GBV-C com reprodutibilidade. A metodologia permite a análise simultânea de grande número de amostras, sendo apropriada para estudos clínicos. A prevalência de exposição a este agente na população feminina HIV+ estudada é alta, provavelmente decorrente da via sexual comum de transmissão dos agentes.

24 Weeks Treatment with Pegylated Interferon Alfa Plus Ribavirin May Be Possible in Genotype 1 Chronic Hepatitis C Patients with Rapid Virological Response Who Have Low Pretreatment Viremia / 대한소화기학회지

BACKGROUND/AIMS: The standard treatment for chronic hepatitis C infected with hepatitis C virus (HCV) genotype 1 is a combination of pegylated interferon alfa and ribavirin over a 48 weeks period. It is unclear if 24 weeks treatment is possible for patients showing a rapid virological response (RVR) without compromising the sustained virological response (SVR) in Korea. METHODS: Between June 2005 and September 2008, among patients chronically infected with the HCV genotype 1 who were treated with pegylated interferon alfa subcutaneously once weekly plus ribavirin based on body weight, 55 patients who had low pretreatment viral load (<600,000 IU/mL) and RVR were enrolled. A total of 55 patients were divided into 24 weeks treatment group (n=29) and the standard treatment group (n=26). The HCV RNA was quantitatively assessed before treatment, and after 12 weeks of treatment, and also qualitatively assessed after 4 weeks of treatment, at end of treatment (24 weeks), and 24 weeks after end of treatment. RVR was defined as undetectable HCV RNA at the 4 weeks of treatment. RESULTS: Among the 55 patients, SVR was achieved in 100% (29/29) of the patients in 24 weeks treatment and 96.2% (25/26) of the patients in the standard treatment (p=0.473). CONCLUSIONS: HCV genotype 1 infected patients with a low baseline HCV RNA concentration who become HCV RNA negative at week 4 may be treated for 24 weeks without compromising sustained virlolgical response. However, an additional trial will be needed to optimize the treatment duration.

Detection of equid herpesvirus 1 DNA by Polymerase Chain Reaction after experimental inoculation of horses with a Brazilian A4/72 strain / Detecção do DNA do herpesvírus eqüino 1 pela reação em cadeia pela polimerase em cavalos inoculados com a estirpe brasileira A4/72

Seven conventional adult horses were inoculated intranasally with a Brazilian A4/72 strain of equid herpesvirus-1 (EHV-1). In the first ten days after the inoculation, they showed signs of a mild, self limitin gupper respiratory tract infection. In spite of the presence of neutralizing antibodies before the trial, seroconversion was observed in some horses. The virus was not isolated from nasal swabs and peripheral blood leukocytes (PBL) of any of the horses. However,the EHV-1 was detected through the polymerase chain reaction (PCR)from PBL of all horses in the experiment within the third to the eighth day after the inoculation that illustrated the viremia. In addition,the PCR assay also detected the virus in bronchoalveolar lavage fluid samples starting on the ninth day after the experimental infection in most of horses. For that reason, as a diagnostic tool, the PCR assay showed higher sensitivity and specificity than the conventional laboratorial methods in detection of EHV-1.

Sete cavalos adultos de status sanitário convencional foram inoculados por via intranasal com a estirpe brasileira A4/72 do herpesvírus eqüino tipo 1 (EHV-1). Nos primeiros dez dias após a inoculação viral, todos os cavalos apresentaram manifestações de infecção respiratória leve erestrita às vias aéreas anteriores. Apesar de possuírem títulos de anticorpos neutralizantes antes da inoculação, alguns cavalos apresentaram soroconversão após o desafio viral. O EHV-1 não foi isolado a partir das secreções nasais e leucócitos sanguíneos periféricos(PBL) de nenhum animal. Entretanto, o DNA viral foi detectado pela reação em cadeia pela polimerase (PCR) nos PBL entre o terceiro e o oitavo dias pós-inoculação (d.p.i.) em todos os animais, indicando a ocorrência de viremia. Além disso, a prova de PCR detectou o vírus nas amostras do lavado broncoalveolar a partir do nono d.p.i. na maioria dos animais. Com base nos resultados obtidos, foi possível concluir que a PCR é uma técnica com alta sensibilidade e especificidade para o diagnóstico do EHV-1, capaz de detectar a presença do DNA viral mesmo quando não ocorre a constatação do agente pelos métodos tradicionais.

Anti-HCV Signal-to-Cutoff Ratio in Predicting Hepatitis C Viremia

No abstract available.

Significance of Anti-HCV Signal-to-Cutoff Ratio in Predicting Hepatitis C Viremia

BACKGROUND/AIMS: Hepatitis C virus (HCV) RNA testing can be performed using qualitative or quantitative assays, and it is still unclear which is more useful as a primary test in patients positive for anti-HCV. The present study evaluated the usefulness of anti-HCV signal-to-cutoff ratio (S/CO ratio) for predicting HCV RNA results. METHODS: Patients on whom a qualitative HCV RNA test was performed due to a positive anti-HCV enzyme immunoassay were enrolled. Patients were divided into viremia and no-viremia groups according to HCV RNA results. Receiver-operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO for a diagnosis of viremia. RESULTS: In total, 487 patients were enrolled. HCV RNA was positive in 301 subjects (61.8%). Age, serum ALT level, and anti-HCV S/CO ratio were significantly different between the viremia and no-viremia groups. By ROC curve analysis, anti-HCV S/CO ratio (area, 0.989; 95% confidence interval, 0.981 to 0.998) accurately predicted the presence of viremia, with a cutoff value of 10.9 (sensitivity, 94.4%; specificity, 97.3%). CONCLUSIONS: Anti-HCV S/CO ratio was found to be highly accurate at predicting HCV viremia. The anti-HCV S/CO ratio can be used to determine whether a quantitative or qualitative HCV RNA test should be used to confirm HCV viremia in patients with a positive anti-HCV by the following criteria: if the anti-HCV S/CO ratio is or =10.9 a quantitative HCV RNA test can be performed.

Assessment of two quantitative techniques for hepatitis C viraemia

In Egypt, chronic hepatitis due to Hepatitis C Virus is an important public health problem. 40 patients with chronic hepatitis C were randomly selected. The aim of this study was the quantitative measurement of serum hepatitis C virus [HCV] RNA. We compared two commercial available assays, Roche Amplicor HCV Monitor kits and Chiron branched DNA signal amplification [bDNA] assay, in quantitative measurement of serum HCV RNA virus. In this study [84.4%] of the samples positive by Roche Amplicor were positive by bDNA assay. Our results were consistent with previous reports. Amplicor test kit was more sensitive than bDNA assay but the difference was not statistically significant. The statistical correlation between the two quantitative techniques was highly significant using Chi-square and Spearman's correlation. The two assays were highly correlated and the relationship between the log values obtained by both assays generated the following equation: log10 bDNA = 0.47x log10 Roche [PCR] + 3.86. In conclusion, Roche Amplicor HCV Monitor kits and the Chiron branched DNA signal amplification assay are equally sensitive in the quantitative measurement of serum HCV RNA in patients with chronic hepatitis C. Both assays are suitable for assessing patients with chronic hepatitis C before therapy and for evaluating treatment regimens. This new approach of serum HCV RNA quantification will lead to a better standardization and comparison of controlled trials of chronic hepatitis C treatments

La causa del SIDA es el VIH: evidencias clínicas, etiopatogénicas, epidemiológicas y experimentales / HIV is cause of sida: clinic evidence, etiopathogenic, epidemiologist and experimental

Los primeros casos del Síndrome de Inmunodeficiencia Adquirida (SIDA) fueron identificados en los Estados Unidos en 1981 y rapidamente esta enfermedad se ha convertido en una de las mayores amenazas para la salud pública mundial. El virus de la inmunodeficiencia humana (VIH) fue aislado por primera vez en 1983. Numerosas investigaciones posteriores confirmaron su papel etiológico en el SIDA, aunque todavía existen algunas interrogates en relación a varios aspectos clínicos, etiopatogénicos y epidemiológicos de dicha enfermedad. Esas interrogantes llevaron a un reducido número de científicos a dudar de la relación etiológica VIH/SIDA. En este artículo se describe brevemente dicha controversia y se discuten las evidencias clínicas, etiopatogénicas, epidemiológicas y experimentales que apoyan esta relación etiológica. Esas evidencias se analizan a la luz de los postulados de Koch, concluyéndose que la asociación VIH/SIDA es probablemente más sólida que otras enfermedades virales, y que hoy en día no es justificable ninguna duda sobre el papel etiológico del VIH en el SIDA

Five cases of cytomegalovirus infection detected by in situ hybridization and antigenemia assay

We report five cases of cytomegalovirus infection in immunocompromised patients which were detected by either cytomegalovirus antigenemia assay or in situ hybridization. Four cases had leukemia and the other had chronic renal failure. All the three BMT recipients suffered from GvHD. Interestingly, there was an unique case of CMV disease without a history of BMT, which reminded us that CMV could attack immunocompromised patients who had not undergone transplantation, too. Four out of five cases died. We think that cytomegalovirus infection or disease should not be regarded as a minor problem in post-transplantation infection in Korea.