Indicación de amigdalectomía en pacientes pediátricos por sospecha de trastorno linfoproliferativo postrasplante / Indication for tonsillectomy in pediatric patients with suspected post-transplant lymphoproliferative disorder

Un sitio común de hiperplasia linfoidea en los trastornos linfoproliferativos postrasplante (TLPT) son las amígdalas palatinas. Sin embargo, la hipertrofia amigdalina es extremadamente común en niños, lo que dificulta la sospecha de estos trastornos. Se realizó un estudio de una serie de casos de pacientes trasplantados intervenidos de amigdalectomía por sospecha de TLPT en un hospital pediátrico de alta complejidad en Argentina desde enero de 2014 hasta diciembre de 2021. El objetivo de este trabajo es exponer las características clínicas de los pacientes trasplantados a los que se les indicó amigdalectomía con fin diagnóstico de TLPT.

A common site of lymphoid hyperplasia in post-transplant lymphoproliferative disorders (PTLD) is the palatine tonsils. However, tonsillar hypertrophy is extremely common in children, which hinders the suspicion of PTLD. A case series of transplanted patients undergoing tonsillectomy for suspected PTLD was conducted at a tertiary care children's hospital in Argentina between January 2014 and December 2021. The objective of this study is to expose the clinical characteristics of transplanted patients who underwent a tonsillectomy to diagnose PTLD

Análise dos Critérios Imunofenotípicos por Citometria de Fluxo para Definição das Doenças Linfoproliferativas Crônicas de Células B / Analysis of Immunophenotypic Criteria by Flow Cytometry to Define B-Cell Chronic Lymphoproliferative Diseases / Análisis de Criterios Inmunofenotípicos por Citometría de Flujo para Definir Enfermedades Linfoproliferativas Crónicas de Células B

Introdução: A citometria de fluxo é uma metodologia importante para o diagnóstico das doenças linfoproliferativas crônicas de células B (DLPCB), contudo, por vezes, o citometrista não encontra subsídios suficientes para a definição exata da entidade patológica envolvida. Objetivo: Analisar os laudos emitidos a pacientes com doenças linfoproliferativas crônicas (DLPC) atendidos em um laboratório particular de Belém-PA, segundo os critérios de classificação estabelecidos pelos estudos de Matutes et al. e Craig e Foon. Método: Estudo retrospectivo com laudos de pacientes que realizaram imunofenotipagem por citometria de fluxo para diagnóstico de DLPCB no período entre setembro de 2015 a dezembro de 2019. Resultados: Depois de aplicados os critérios de Matutes et al. e Craig e Foon para os laudos analisados, observou-se concordância em: 45,24% casos de leucemia linfoide crônica de células B/linfoma linfocítico de pequenas células B; 14,29% casos de linfoma folicular; 4,76% casos de leucemia de células pilosas; e 21,43% de casos definidos como "outras DLPCB não classificáveis por citometria de fluxo". Entretanto, o teste de hipóteses de Hotelling (p=0,0409) mostrou haver diferença estatística para a definição das DLPCB segundo os critérios aplicados. Conclusão: Os resultados ressaltam que, mesmo sendo a citometria de fluxo importante para a caracterização das DLPCB, por vezes, o citometrista necessita incluir no laudo a categoria "outras doenças linfoproliferativas crônicas de células B não classificadas por citometria de fluxo" para induzir o prescritor a solicitar mais exames complementares.

Introduction: Flow cytometry is an important methodology for the diagnosis of chronic B-cell lymphoproliferative diseases (CBCLPD), however, sometimes the cytometrist does not find sufficient elements for the exact definition of the pathological entity involved. Objective: To analyze the reports issued to patients with chronic lymphoproliferative diseases (CLPD) tested at a private laboratory in Belém-PA, according to the classification criteria established by the studies by Matutes et al. and Craig and Foon. Method: Retrospective study with reports of patients who underwent immunophenotyping by flow cytometry for the diagnosis of CBCLPD from September 2015 to December 2019. Results: After applying the criteria by Matutes et al. and Craig and Foon to the reports analyzed, agreement was reached for 45.24% of the cases of chronic b-cell lymphocytic leukemia/small B-cell lymphocytic lymphoma, 14.29% of the cases of follicular lymphoma, 4.76% of the cases of hairy cell leukemia and 21.43% of the cases defined as "other CBCLPDs not classifiable by flow cytometry". However, Hotelling's hypothesis test (p=0.0409) showed a statistical difference for the definition of CBCLPD according to the criteria adopted. Conclusion: The results emphasize that even though flow cytometry is important for the characterization of CBCLPD, sometimes the cytometrist needs to include the category "other chronic B-cell lymphoproliferative diseases not classified by flow cytometry" in the report to induce the prescriber to request additional complementary exams.

Introducción. La citometría de flujo es una metodología importante para el diagnóstico de enfermedades linfoproliferativas crónicas de células B (ELPCB), sin embargo, en ocasiones el citometrista no encuentra suficientes subsidios para la definición exacta de la entidad patológica involucrada. Objetivo: Analizar los informes emitidos a pacientes con enfermedades linfoproliferativas crónicas (ELPC) tratados en un laboratorio privado en Belém-PA, de acuerdo con los criterios de clasificación establecidos por los estudios de Matutes et al. y Craig y Foon. Método: Retrospectivo con relatos de pacientes que se sometieron a inmunofenotipificación por citometría de flujo para el diagnóstico de ELPC de septiembre de 2015 a diciembre de 2019. Resultados: Tras aplicar los criterios de Matutes et al. y Craig y Foon a los informes analizados, se observó concordancia en: 45,24% de los casos de leucemia linfocítica crónica de células B/linfoma linfocítico de células B pequeñas; 14,29% casos de linfoma folicular; 4,76% casos de leucemia de células peludas; y 21,43% de los casos definidos como "otros ELPCB no clasificables por citometría de flujo". Sin embargo, la prueba de hipótesis de Hotelling (p=0,0409) mostró diferencia estadística para la definición de ELPCB según los criterios aplicados. Conclusión: Nuestros resultados enfatizan que si bien la citometría de flujo es importante para la caracterización de ELPCB, en ocasiones el citometrista necesita incluir en el informe la categoría "otras enfermedades linfoproliferativas crónicas de células B no clasificadas por citometría de flujo" para inducir al prescriptor a solicitar más exámenes complementarios.

Pérdida de agudeza visual progresiva en paciente con proptosis. Caso clínico y revisión de la literatura / Progressive visual impairment in a patient with proptosis. Case report and review of the literature.

Introducción: a raíz del siguiente reporte de caso clínico se pretende repensar el diagnóstico diferencial de los tumores orbitales y revisar la literatura existente al respecto. Caso: paciente de 54 años, fumadora, acude a nuestro centro por una pérdida de agudeza visual progresiva de dos años de evolución en el ojo derecho, que se acompañaba de proptosis. Las pruebas de imagen basadas en resonancia magnética y tomografía por emisión de positrones ­ tomografía computarizada (PET-TC) realizadas describían una lesión intraconal derecha de morfología indefinida, que rodeaba el nervio óptico. El estudio inmunohistoquímico y molecular anatomopatológico confirmó la sospecha de síndrome linfoproliferativo extranodal de bajo grado. Discusión: el manejo endoscópico de estas lesiones puede resultar en una menor comorbilidad en comparación con el abordaje externo tradicional. El papel de la cirugía radica en la obtención de una muestra de la lesión que permita un correcto diagnóstico. Conclusiones: el abordaje multidisciplinar con oftalmólogos, hematólogos y expertos en radioterapia permite obtener buenos resultados quirúrgicos y clínicos en la inmensa mayoría de casos.

Introduction: as result of the following clinical case report, we intend to review the differential diagnosis of orbital tumors and review the existing literature in this regard. Case report: a 54-year-old smoking patient, consulted to our department due to a progressive visual impairment over the last two years in her right eye. She presented proptosis in her clinical examination. Imaging studies based on MRI and PET-CT described a right intraconal lesion with an undefined morphology surrounding the optic nerve. Orbital tumors differential diagnosis is delicate. Nevertheless, Non-Hodgkin lymphomas followed by metastasis are the two most common found in this location. The immunohistochemistry and molecular studies, confirmed the suspected diagnosis of extranodal low-grade lymphoproliferative syndrome. Discussion: endoscopic management of these lesions may result in a lower comorbidity compared to traditional external approaches. Role of surgery lays in obtainment of a quality sample which allows a proper diagnosis. Conclusions: multidisciplinary approach with ophthalmologists, hematologists and radiotherapy experts enhance good surgical and clinical results in the vast majority of cases.

Polyclonal CD5+/CD19+ B1a lymphocytes after allogeneic stem cell transplantation: a potential diagnostic pitfall

In adults, B-lymphocytes comprise approximately 10% of circulating lymphocytes. The majority of peripheral B cells are B2 cells ("Mature" B-cells), which function as part of the humoral adaptive immune system. B1 cells ("Innate-like" B cells) are another sub-class of B lymphocytes, considered as innate immune cells with a characteristic phenotype (CD20+, CD27+, CD43+, CD70-, CD11b+, sIgM++, sIgD+) which can be divided into two subtypes; B1a (CD5+): spontaneously produce broadly reactive natural IgM, and B1b (CD5-): can generate T-cell independent, long-lasting IgM. There is very limited data available, indicating a correlation between allogeneic bone marrow transplantation and an increase in B1a cells. Here we present a case of a 17-year-old female with homozygous sickle cell disease (HbSS disease) who underwent hematopoietic stem cell transplant (HSCT). Approximately seven months post-transplant, she was found to have 16% immature mononuclear cells on complete blood count (CBC)-differential report. A follow-up peripheral blood flow cytometry showed that these cells were polyclonal CD5+/CD20+ B-cells, and comprised 66% of lymphocytes. Further workup and follow up failed to reveal any lymphoproliferative disorders. It is important not to misdiagnose these cells as an atypical CD5+ lymphoproliferative disorder. The presence of B1a cells has not been widely reported in non-neoplastic post-stem cell transplanted patients. This case also adds to and expands our knowledge regarding the presence of increased circulating B1a cells after stem cell transplant in a patient with no history of hematological malignancy.

Neoplasia blástica de células dendríticas plasmocitoides variante leucemia aguda: reporte de un caso / Blastic plasmacytoid dendritic cell neoplasm variant acute leukemia: case report

RESUMEN La neoplasia blástica de células dendríticas plasmocitoides (NBCDP) es una malignidad hematológica poco frecuente y generalmente agresiva, por lo cual se requiere su reconocimiento precoz. A continuación, se describe el curso clínico prolongado de un paciente masculino de 60 años con NBCDP procedente de Venezuela, en cuyos hallazgos más relevantes destacó la presencia de lesiones cutáneas, organomegalias, infiltración de la médula ósea y del sistema nervioso central. Posterior al diagnóstico se indicó quimioterapia sistémica, no obstante, el paciente falleció por complicaciones respiratorias durante la fase de inducción del tratamiento. En esta enfermedad es necesario establecer el diagnóstico diferencial con trastornos linfoproliferativos, leucemias linfoides y mieloides agudas, constituyendo el análisis morfológico de las células neoplásicas un aspecto importante para una adecuada orientación diagnóstica.

ABSTRACT Blastic plasmacytoid dendritic cell blast neoplasm (BPDCN) is a rare and generally aggressive hematologic malignancy, requiring early recognition. Below is a description of the prolonged clinical course of a 60-year-old male patient with BPDCN from Venezuela, whose most relevant findings highlighted the presence of skin lesions, organomegaly, infiltration of the bone marrow and central nervous system. Systemic chemotherapy was prescribed after diagnosis; however, the patient died of respiratory complications during the induction phase of treatment. In this disease, it is necessary to establish the differential diagnosis with lymphoproliferative disorders, acute lymphoid and myeloid leukemias. The morphological analysis of neoplastic cells is, thus, an important aspect toward proper diagnostic guidance.

Síndromes linfoproliferativos gastrointestinales / Gastrointestinal lymphoproliferative syndrome

The gastrointestinal lymphoid system plays a relevant role. The daily and continuous interaction between gastrointestinal lymphocytes with food and intestinal microbes requires precise functioning. The pathologic spectrum of lymphocyte malfunction results in lymphomas. MALT lymphoma is the most frequently diagnosed lymphoma, but there are other lymphoproliferative diseases such as diffuse large B cell lymphoma, mantle cell lymphoma and T associated lymphoma. The gastroenterologist and the endoscopist need to know these diseases in detail to achieve early diagnosis and treatment.

El sistema linfoide de defensa abdominal tiene un relevante rol en el buen funcionamiento sistémico. La interacción diaria y continua con patógenos alimentarios y microbios comensales intestinales precisa un estrecho funcionamiento. Las alteraciones linfoides clonales favorecen el desarrollo de linfomas de diversos tipos. Si bien, el linfoma asociado a tejido linfoide de mucosas (MALT) es el más conocido en contexto de su asociación con Helicobacter pylori, el tracto gastrointestinal se puede ver afectado por otros linfomas como el linfoma difuso de células grandes B y linfomas indolentes como el linfoma folicular, el linfoma del manto y el linfoma T asociado a enteropatía. El gastroenterólogo y endoscopista precisan conocer en detalle estas entidades para un oportuno diagnóstico y adecuado tratamiento.

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.

Advances in the diagnosis and control of lymphomas / Avances en el diagnóstico y control de linfomas

Abstract Lymphoproliferative disorders have increased in last decades. Immunohistochemistry analysis is required to categorize them in different clinical entities, as has been stablished by WHO. Advances in imaging have set the PET-CT as a standard staging procedure in most cases. Knowledge of the biology of these malignancies has allowed therapeutic advances with different approaches, including development of monoclonal antibodies, conjugated antibodies, immunomodulatory agents, as well as inhibition of specific pathways. Although new drugs are promising, the cost-benefit impact requires to be evaluated in pharmacoeconomic clinical trials.

Resumen Los padecimientos linfoproliferativos han incrementado en las últimas décadas. Es fundamental la evaluación con inmunohistoquímica para clasificarlos en las diferentes entidades que establece la clasificación de la OMS. Los avances en técnicas de imagen han colocado al PET-CT como un procedimiento de estadificación estándar. El conocimiento de la biología de estas neoplasias ha permitido avances terapéuticos con el desarrollo de anticuerpos monoclonales solos o conjugados, como agentes inmunomoduladores, así como a través de la inhibición de vías específicas. Aun cuando los resultados con estos nuevos fármacos son promisorios, el impacto costo-beneficio requiere evaluarse en estudios prospectivos con análisis farmacoeconómico.

EBV-driven B-cell lymphoproliferative disorders: from biology, classification and differential diagnosis to clinical management

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, affecting >90% of the adult population. EBV targets B-lymphocytes and achieves latent infection in a circular episomal form. Different latency patterns are recognized based on latent gene expression pattern. Latent membrane protein-1 (LMP-1) mimics CD40 and, when self-aggregated, provides a proliferation signal via activating the nuclear factor-kappa B, Janus kinase/signal transducer and activator of transcription, phosphoinositide 3-kinase/Akt (PI3K/Akt) and mitogen-activated protein kinase pathways to promote cellular proliferation. LMP-1 also induces BCL-2 to escape from apoptosis and gives a signal for cell cycle progression by enhancing cyclin-dependent kinase 2 and phosphorylation of retinoblastoma (Rb) protein and by inhibiting p16 and p27. LMP-2A blocks the surface immunoglobulin-mediated lytic cycle reactivation. It also activates the Ras/PI3K/Akt pathway and induces Bcl-xL expression to promote B-cell survival. Recent studies have shown that ebv-microRNAs can provide extra signals for cellular proliferation, cell cycle progression and anti-apoptosis. EBV is well known for association with various types of B-lymphocyte, T-lymphocyte, epithelial cell and mesenchymal cell neoplasms. B-cell lymphoproliferative disorders encompass a broad spectrum of diseases, from benign to malignant. Here we review our current understanding of EBV-induced lymphomagenesis and focus on biology, diagnosis and management of EBV-associated B-cell lymphoproliferative disorders.

Epstein Barr virus-associated lymphoproliferative diseases: the virus as a therapeutic target

Epstein Barr virus (EBV)-associated lymphoproliferative diseases (LPDs) express all EBV latent antigens (type III latency) in immunodeficient patients and limited antigens (type I and II latencies) in immunocompetent patients. Post-transplantation lymphoproliferative disease (PTLD) is the prototype exhibiting type III EBV latency. Although EBV antigens are highly immunogenic, PTLD cell proliferation remains unchecked because of the underlying immunosuppression. The restoration of anti-EBV immunity by EBV-specific T cells of either autologous or allogeneic origin has been shown to be safe and effective in PTLDs. Cellular therapy can be improved by establishing a bank of human leukocyte antigen-characterized allogeneic EBV-specific T cells. In EBV+ LPDs exhibiting type I and II latencies, the use of EBV-specific T cells is more limited, although the safety and efficacy of this therapy have also been demonstrated. The therapeutic role of EBV-specific T cells in EBV+ LPDs needs to be critically reappraised with the advent of monoclonal antibodies and other targeted therapy. Another strategy involves the use of epigenetic approaches to induce EBV to undergo lytic proliferation when expression of the viral thymidine kinase renders host tumor cells susceptible to the cytotoxic effects of ganciclovir. Finally, the prophylactic use of antiviral drugs to prevent EBV reactivation may decrease the occurrence of EBV+ LPDs.

Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorders

Epstein-Barr virus, a ubiquitous human herpesvirus, can induce both lytic and latent infections that result in a variety of human diseases, including lymphoproliferative disorders. The oncogenic potential of Epstein-Barr virus is related to its ability to infect and transform B lymphocytes into continuously proliferating lymphoblastoid cells. However, Epstein-Barr virus has also been implicated in the development of T/natural killer cell lymphoproliferative diseases. Epstein-Barr virus encodes a series of products that mimic several growth, transcription and anti-apoptotic factors, thus usurping control of pathways that regulate diverse homeostatic cellular functions and the microenvironment. However, the exact mechanism by which Epstein-Barr virus promotes oncogenesis and inflammatory lesion development remains unclear. Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases often have overlapping clinical symptoms as well as histologic and immunophenotypic features because both lymphoid cell types derive from a common precursor. Accurate classification of Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases is a prerequisite for appropriate clinical management. Currently, the treatment of most T/natural killer cell lymphoproliferative diseases is less than satisfactory. Novel and targeted therapies are strongly required to satisfy clinical demands. This review describes our current knowledge of the genetics, oncogenesis, biology, diagnosis and treatment of Epstein-Barr virus-associated T/natural killer cell lymphoproliferative diseases.

Pseudolinfoma cutâneo: relato de caso / Cutaneous pseudolymphoma: case report

Os pseudolinfomas cutâneos representam um grupo heterogêneo de reações linfoproliferativas benignos que podem simular clinica e histologicamente linfomas cutâneos. O objetivo deste estudo foi relatar a apresentação anatomoclínica de um caso de pseudolinfoma cutâneo para o aperfeiçoamento do seu diagnóstico diferencial com linfomas cutâneos. Paciente do gênero masculino, 66 anos procurou atendimento médico relatando história de nódulos em região superior do dorso há seis anos. Ao exame físico foram observados sete nódulos com aproximadamente 0,5 cm de diâmetro e sem sinais de linfonodomegalias. A biópsia de pele mostrava um denso infiltrado de linfócitos e histiócitos na derme. A análise imuno-histoquímica revelou uma população mista de linfócitos B (CD 20) e linfócitos T (CD 3). O diagnóstico diferencial entre as lesões benignas e malignas é a principal prioridade nesses casos. Tanto o pseudolinfoma, quanto o linfoma cutâneo se manifestam como nódulos solitários, pápulas e placas decorrentes de infiltração linfocitária. Para o diagnóstico diferencial, estão indicadas a avaliação imuno-histoquímica e técnicas de biologia molecular...

Cutaneous pseudolymphoma represents heterogeneous groups of benign lymphoproliferative reactions that may simulate clinically and histologically cutaneous lymphomas. The aim of this study was to report a case of cutaneous pseudolymphoma. Male patient, 66-year-old, came to us reporting a 6-year history of nodules on the upper back. On physical examination we noticed 7 nodules with 0.5 cm of diameter and no sign of adenopathy. The skin biopsy showed a dense infiltrate of lymphocytes and histiocytes in the dermis. The immunohistochemical analysis revealed a mixed population of B lymphocytes (CD 20) and T lymphocytes (CD 3). Differential diagnosis between benign and malignant lesions is the main concern in these cases. In some cases, pseudolymphoma manifests as solitary nodules, papules and plaques that are clinically indistinguishable from cutaneous lymphomas. The differentiation process can be further facilitated by immunohistochemical and molecular biological techniques...

Duplex realtime PCR method for Epstein-Barr virus and human DNA quantification: its application for post-transplant lymphoproliferative disorders detection

INTRODUCTION: The quantification of circulating Epstein-Barr virus (EBV) DNA is used to monitor transplant patients as an early marker of Post-Transplant Lymphoproliferative Disorders (PTLD). So far no standardized methodology exists for such determination. OBJECTIVE: Our purpose was to develop and validate a real-time PCR assay to quantify EBV DNA in clinical samples from transplant recipients. METHODS: A duplex real-time PCR method was developed to amplify DNA from EBV and from a human gene. The EBV load was determined in peripheral blood mononuclear cells (PBMC), plasma and oropharyngeal tissue from 64 non-transplanted patients with lymphoid-hypertrophy (Non-Tx), 47 transplant recipients without PTLD (Tx), 54 recipients with PTLD (Tx-PTLD), and 66 blood donors (BD). WinPEPI, version 11.14 software was used for statistical analysis. RESULTS: Analytical validation: the intra and inter-assays variation coefficients were less than 4.5% (EBV-reaction) and 3% (glyceraldehyde 3-phosphate dehydrogenase - GAPDH reaction). Linear ranges comprised 107-10 EBV genome equivalents (gEq) (EBV-reaction) and 500,000-32 human gEq (GAPDH-reaction). The detection limit was 2.9 EBV gEq (EBV-reaction). Both reactions showed specificity. Application to clinical samples: higher levels of EBV were found in oropharyngeal tissue from transplanted groups with and without PTLD, compared to Non-Tx (p < 0.05). The EBV load in PBMC from the groups of BD, Non-Tx, Tx and Tx-PTLD exhibited increasing levels (p < 0.05). In BD, PBMC and plasma, EBV loads were undetectable. CONCLUSIONS: The performance of the assay was suitable for the required clinical application. The assay may be useful to monitor EBV infection in transplant patients, in particular in laboratories from low-income regions that cannot afford to use commercial assays. .

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for the Diagnosis of Central Lung Parenchymal Lesions

PURPOSE: The purpose of this study was to evaluate the usefulness of convex probe endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for detecting malignancy in parenchymal pulmonary lesions located adjacent to the central airways. MATERIALS AND METHODS: We retrospectively reviewed the diagnostic performance of EBUS-TBNA in consecutive patients with high clinical suspicion of a centrally located primary lung cancer who had undergone EBUS-TBNA at the Samsung Medical Center between May 2009 and June 2011. RESULTS: Thirty-seven patients underwent EBUS-TBNA for intrapulmonary lesions adjacent to the central airways. Seven lesions were located adjacent to the trachea and 30 lesions were located adjacent to the bronchi. Cytologic and histologic samples obtained via EBUS-TBNA were diagnostic in 32 of 37 (86.4%) of patients. The final diagnosis was lung cancer in 30 patients (7 small cell lung cancer, 23 non-small cell lung cancer), lymphoma in one and malignant fibrous histiocytoma in one patient. The diagnostic sensitivity of EBUS-TBNA in detecting malignancy and detecting both malignancy and benignity was 91.4% and 86.5%, respectively. Two patients experienced minor complications. CONCLUSION: EBUS-TBNA is an effective and safe method for tissue diagnosis of parenchymal lesions that lie centrally close to the airways. EBUS-TBNA should be considered the procedure of choice for patients with centrally located lesions without endobronchial involvement.

Clonality assessment of lymphoproliferative lesions using the polymerase chain reaction: An analysis of two methods.

Background: Lymphoid malignancies are a heterogeneous group of disorders which may be difficult to differentiate from reactive proliferations even after immunohistochemistry. Polymerase chain reaction (PCR) is believed to be a good adjunct tool for diagnosis. Materials and Methods: We examined 24 cases of neoplastic and non-neoplastic lymphoproliferative lesions in this study and evaluated the PCR as an additional tool in the confirmation of the diagnosis. Two different PCR methodologies were evaluated. Results: In the evaluation of the T-cell PCR, it was seen that the correlation using both the commercial kits and the custom-synthesized primers was highly significant at a P value of <0.05. In the evaluation of the B-cell PCR, it was seen that the correlation using both the commercial kits and the custom-synthesized primers was not significant using either method (P > 0.05). Conclusions: Both the methods showed an excellent concordance for T-cell γ gene rearrangements, However, the same was not seen in the B-cell receptor rearrangements. This may be because of the small sample size or the inability of consensus V primers to recognize complementary DNA sequences in all of the V segments.

Fulminant Epstein-Barr Virus-associated T-cell Lymphoproliferative Disorder in an Immunocompetent Middle-aged Man Presenting with Chronic Diarrhea and Gastrointestinal Bleeding

The World Health Organization (WHO) recently defined systemic Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disorders (LPD) of childhood as a life-threatening illness. However, this rare disease has not been extensively studied. Here we report a case of systemic EBV-positive T-cell LPD in a previously healthy middle-aged man with a chief complaint of chronic diarrhea. The initial colon biopsy showed focal infiltration of EBV-positive small lymphocytes without any atypia. However, the disease rapidly progressed and the patient required a total colectomy due to severe gastrointestinal bleeding. Three and half months after admission, the patient died from a complication of disseminated intravascular coagulation. The resected colon showed diffuse infiltration of EBV-positive atypical lymphocytes with ischemic change. Most atypical lymphocytes were CD3+ or CD5+. The monoclonality of EBV was demonstrated by sequence variation analysis of the latent membrane protein 1 (LMP1) gene in the colectomy specimen as well as in the initial biopsy.

Enfermedad linfroproliferativa en trasplante renal y hepático / Lymproproliferative disease in kidney and liver transplantation

La enfermedad linfoproliferativa post trasplante (PTLD) es la neoplasia más frecuente observada en receptores pediátricos de órganos sólidos. Analizamos 883 pacientes trasplantados: 547 trasplantes renales (TxR) y 336 trasplantes hepáticos (TxH). 44 de ellos desarrollaron un PTLD luego de estos procedimientos. La incidencia en TxR fue del 4.02 por ciento (22 de 547) y en TxH de 5.75 por ciento (22 de 336). El tiempo medio de la aparición del PTLD fue de 37.47 más menos 35 meses. Localización: cavun 50 por ciento, adenopatías cervicales 14.4 por ciento, masa abdominal 11.4 por ciento, adenopatías axilares e inguinales 9 por ciento, compromiso del SNC 4.5 por ciento, piso de la boca 4.5 por ciento , higado ortótopico 2.3 por ciento, páncreas 2.3 por ciento, injerto renal 2.3 por ciento. Los diagnósticos histopatológicos obtenidos fueron: hiperplasia plasmocitica 52.3 por ciento, lesiones polimorfas 20.5 por ciento, y lesiones monomorgas (linforma B o Linfoma de células grandes) 27.2 por ciento de los pacientes. El tratamiento indicado incluyó reducción de la inmunosupresión de mantenimiento en todos los pacientes, excéresis en 22 pacientes, anticuerpos antCD20 en 17 de ellos y quimioterapia (régimen de CHOP) en 6 pacientes. La sobrevida fue del 79 por ciento (IC 64 por ciento-88 por ciento) a 5 años de seguimiento. Conclusión: En nuestra serie la incidencia de PTLAD es similar a la de otros autores. La respuesta al tratamiento con disminución de la inmunosupresón, empleo de monoclonales, ha sido satisfactoria. El seguimiento cercano, el alto índice de sospecha para el diagnóstico precóz y la individualización de la inmunosupresión para cada paciente, fueron conductas eficaces.