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.

Primary lymphoma of the central nervous system: a clinical-pathological and immunohistochemical study of ten autopsy cases / Linfoma primário do sistema nervoso central: estudo clínico-patológico e imuno-histoquímico de dez casos de necropsia

CONTEXT: Primary central nervous system lymphomas (PCNSL) are a rare subgroup of lymphomas generally associated with HIV and EBV. OBJECTIVE: To study ten autopsy cases of PCNSL, to describe the neuropathological findings, to characterize the phenotype of the neoplastic cells, to detect EBV in the lesion and to compare the findings with the clinical and laboratory data of the patients. METHOD: The clinical, histological and immunohistochemical data of ten cases of PCNSL, eight cases from patients with AIDS, identified among 265 autopsies of these patients were analyzed. RESULTS: Seven patients were males and the mean age was 40.9 years. The most frequent symptomatology was focal neurologic deficit (70 percent). Six patients presented with only one lesion. Histologically, densely cellular and polymorphous neoplasms with angiocentrism were observed, in 90 percent of cases. An association with other diseases was observed in four cases. Most patients had diffuse large B cell non-HodgkinÆs lymphoma. EBV was detected by immunohistochemistry in only one case. The lack of detection of the virus might have been due to the long time of fixation of the brain which might have inactivate epitopes therefore compromising the testing. CONCLUSION: In the present series, PCNSL presented with focal symptoms, with unifocal or multifocal lesions, with a predominant B-cell CD20 positive phenotype, rarely associated with EBV.

CONTEXTO: Linfoma primário do sistema nervoso central (LP-SNC) é raro subgrupo de linfomas relacionado à AIDS, geralmente associado EBV. OBJETIVO: Identificar os achados clínico-patológicos dos pacientes com LP-SNC. MÉTODO: Foram analisados dados clínicos, histológicos e imuno-histoquímicos de dez necrópsias de LP-SNC, oito deles de pacientes com AIDS, identificados entre 265 autopsias destes. RESULTADOS: Sete pacientes foram masculinos e a idade média foi 40,9 anos. A sintomatologia neurológica mais freqüente era focal (70 por cento). Seis exibiram lesão única. Histologicamente, eram neoplasias densamente celulares e polimorfas, com angiocentrismo em 90 por cento dos casos. Em quatro casos, houve associação com outras afecções. A maioria dos casos foi de linfoma não-Hodgkin difuso de grandes células B. A pesquisa para EBV foi positiva em um caso. CONCLUSÃO: Predominaram os LP-SNC associados à AIDS, com sintomatologia focal, lesão em massa ou multifocal, com predominância de células B CD-20.

Clinical pathology an reactivation of human lymphotropic herpesviruses

Los virus linfotrópicos herpes humanos ejercen un efecto dual en el sistema inmune: estimulan como antígenos e interfieren funcionalmente debido a sulinfotropismo. En consecuencias, pueden resultar diferentes enfermedades, o verse éstas influenciadas en su evolución, posterior a la reactivación o persistencia de dichos virus. Los efectos son modulados por la edad del afectado y mediante la actividad variable del sistema de defensa humano. Los patrones de enfermedad asociados con estos virus van desde aproliferativos (aplásticos) hasta proliferativos (neoplásicos) y desórdenes autoinmunes. Esta revisión resume los conceptos e hipótesis actuales

Epstein-Barr virus and gastrointestinal lymphomas in Korea

To analyze the association of Epstein-Barr virus (EBV) with gastrointestinal non-Hodgkin's lymphomas arising in immunocompetent patients, 56 consecutive cases of gastrointestinal lymphomas (B-cell: 52-cases, T-cell: 3 cases, T/NK-cell: 1 case) occurring in the stomach (33 cases), intestine (22 cases) and esophagus (1 case) were investigated for the presence of EBV using polymerase chain reaction analysis as a screening method followed by EBER-1 RNA and DNA in situ hybridization (ISH) and immunohistochemistry for the expression of latent membrane protein 1 (LMP-1). Forty-seven cases demonstrated extractable DNA and EBV DNA was detected only in 4 cases. Among the, RNA (EBER-1) and DNA ISH analysis confirmed the presence of the EBV genome in tumor cells in 3 cases (T/NK-cell lymphoma of ileum, gastric high-grade B-cell lymphoma of mucosa-associated lymphoid tissue, gastric diffuse large B-cell lymphoma). Only the T/NK cell lymphoma showed diffuse positivity of tumor cells while 2 gastric B-cell lymphomas demonstrated a scattered positive reaction and no cases expressed LMP-1. Nine cases without extractable DNA by the PCR method showed no nuclear signal by EBER-1 ISH. These findings suggest that most sporadic primary gastrointestinal lymphomas in Korea are not associated with EBV.