Molecular characterization of Epstein-Barr virus variants detected in the oral cavity of adolescents in Cali, Colombia / [Caracterización molecular de las variantes del virus de Epstein-Barr detectadas en la cavidad oral de adolescentes de Cali, Colombia].

Introduction: The Epstein-Barr virus (EBV) is an ubiquitous and oncogenic virus associated with the development of diseases such as infectious mononucleosis, Burkitt's lymphoma, nasopharyngeal carcinoma, and other neoplasms. Currently, two types are recognized: EBV-1 and EBV-2, which have genetic differences with their EBNA nuclear antigens. Likewise, due to the high degree of heterogeneity and variability found in the LMP1 protein of the virus, variants associated with pathogenesis or specific geographic regions have been described. Objective: To identify and characterize molecularly EBV variants detected in the oral cavity of 84 adolescents in Cali, Colombia. Materials and methods: Conventional PCR amplification, purification, and sequencing of the gen EBNA3C were carried out to typify the virus and the C-ter domain of the LMP1 protein to identify variants. We also conducted a phylogenetic and nucleotide variant analysis of the obtained sequences versus pathogenic or geographic variants reported in GenBank-NCBI. Results: The predominant viral subtype was EBV-1 (79%); 72.6% was grouped with the pathogenic variant Raji, derived from B lymphocytes of a patient with Burkitt>s lymphoma, 13.7% was related to a variant of Mediterranean origin, and 13.7% was not grouped with any of the reference variants. Conclusions: This is the first time that variants of LMP1-EBV have been identified in Cali, Colombia. Additional studies are necessary to characterize the unidentified variant and to determine if it is pathogenic or if it is just an isolate present in the city of Cali.

Introducción. El virus de Epstein-Barr (EBV) es un virus ubicuo y oncogénico, asociado con el desarrollo de enfermedades como la mononucleosis infecciosa, el linfoma de Burkitt, el carcinoma nasofaríngeo y otras neoplasias. Actualmente, se reconocen dos subtipos: EBV-1 y EBV- 2, que tienen diferencias genéticas con sus antígenos nucleares (Epstein-Barr Nuclear Antigens, EBNA). Debido a la gran heterogeneidad y variabilidad encontradas en la proteína LMP1 del virus, se han descrito variantes asociadas con ciertas enfermedades o con regiones geográficas específicas. Objetivo. Identificar y caracterizar molecularmente las variantes del EBV detectadas en la cavidad oral de 84 adolescentes de Cali, Colombia. Materiales y métodos. Se hizo la amplificación por reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) convencional, así como la purificación y la secuenciación del gen EBNA3C se realizó para subtipificar el virus y del dominio C-ter de la proteína LMP1 para identificar variantes. Además, se llevó a cabo un análisis filogenético y de variantes nucleotídicas de las secuencias obtenidas comparadas con variantes patogénicas y geográficas reportadas en el GenBank (National Center for Biotechnology Information, NCBI). Resultados. El subtipo viral predominante fue el EBV-1 (79 %); el 72,6 % se agrupó con la variante patogénica Raji, derivada de linfocitos B de un paciente con linfoma de Burkitt; el 13,7 % se relacionó con una variante de origen geográfico del Mediterráneo y otro 13,7 % no se agrupó con ninguna de las variantes de referencia. Conclusiones. Este es el primer estudio que reporta variantes del gen LMP1-EBV en Cali, Colombia. Se requieren nuevos estudios para caracterizar la variante sin identificar y determinar si es patogénica o si es una variante geográfica presente exclusivamente en la ciudad.

The interplay between local immune response and Epstein-Barr virus-infected tonsillar cells could lead to viral infection control.

Epstein Barr virus (EBV) gains access to the host through tonsillar crypts. Our aim was to characterize microenvironment composition around EBV+ cells in tonsils from pediatric carriers, to disclose its role on viral pathogenesis. LMP1 expression, assessed by immunohistochemistry (IHC), was used to discriminate EBV + and - zones in 41 tonsil biopsies. Three regions were defined: Subepithelial (SE), interfollicular (IF) and germinal center (GC). CD8, GrB, CD68, IL10, Foxp3, PD1, CD56 and CD4 markers were evaluated by IHC; positive cells/100 total cells were counted. CD8+, GrB+, CD68+ and IL10+ cells were prevalent in EBV+ zones at the SE region (p < 0.0001, p = 0.03, p = 0.002 and p = 0.002 respectively, Wilcoxon test). CD4+ and CD68+ cell count were higher in EBV + GC (p = 0.01 and p = 0.0002 respectively, Wilcoxon test). Increment of CD8, GrB and CD68 at the SE region could indicate a specific response that may be due to local homing at viral entry, which could be counterbalanced by IL10, an immunosuppressive cytokine. Additionally, it could be hypothesized that CD4 augment at the GC may be involved in the EBV-induced B-cell growth control at this region, in which macrophages could also participate.

Human cytomegalovirus detection by real-time PCR and pp65-antigen test in hematopoietic stem cell transplant recipients: a challenge in low and middle-income countries.

AIM: Cytomegalovirus (CMV) infection is one of the most common complications in patients submitted to hematopoietic stem cell transplant (HSCT). Pre-emptive therapy has been indicated in patients with laboratory evidence of CMV replication. The aims of this study were to compare real-time PCR or pp65 antigen assay methodologies to detect CMV replication in HSCT patients, define a viral load threshold for initiation of pre-emptive therapy, and assess the feasibility of its implementation in hospitals of countries with low and middle income. MATERIAL AND METHODS: Human CMV detection by real-time PCR and pp65 antigen assay was carried out in blood and plasma samples of HSCT patients collected weekly during 3 months. Pre-emptive therapy was based on CMV antigenemia results. RESULTS: Twenty-one patients were monitored with a total of 227 samples collected; 13 (62%) patients were children. A poor correlation was observed between qualitative results, though quantitative results showed statistically significant difference, with higher viral loads detected in patients with positive antigenemia. Compared to a positive antigenemia, a cutoff value of 1067·5 copies/ml, 3·03 log10/ml, for viral load was obtained with 100% sensitivity and 71% specificity. CONCLUSION: CMV real-time PCR in whole blood was suitable for monitoring HSCT patients. However, its high cost is a limiting factor, and it could be used to monitor selected patients, those with prolonged leukopenia and underweight children, and subsequently switched to pp65 antigen test. Further studies involving larger numbers of patients should be performed to confirm this statement.

Geographic variation in the prevalence of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly: a comparative analysis of a Mexican and a German population.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma of the elderly was included as a provisional entity in the 2008 WHO lymphoma classification. Most reports of this disease come from Asia and little is known about it in other regions of the world, including Latin America. Therefore, in this study, 305 diffuse large B-cell lymphomas in patients above 50 years were analyzed, 136 from Mexico and 169 from Germany. EBV was detected by Epstein-Barr early RNA (EBER) in situ hybridization. Only cases with EBER+ in the majority of tumor cells were regarded as EBV+ diffuse large B-cell lymphoma. The prevalence of EBV+ diffuse large B-cell lymphoma in Mexican patients was found to be 7% (9 of 136), whereas only 2% (4 of 169) of the German cases were positive. The median age at diagnosis was 66 years in the Mexican cohort, as opposed to 77 years in the German group. The site of presentation was in both groups predominantly nodal in nine cases (70%) and extranodal in four cases (30%). Of the 13 EBV+ cases, 10 (77%) were classified as polymorphic and 3 (23%) as monomorphic type. The polymorphic cases showed a non-germinal center B-cell immunophenotype (CD10- MUM1+). Twelve cases (92%) were LMP1 positive and two (15%) expressed EBNA2. An interesting finding was the high frequency of EBV type B with the LMP1 30 bp deletion found in the Mexican cases (50%). Eight of the 11 evaluable cases were B-cell monoclonal by polymerase chain reaction. In summary, we found a similar prevalence of EBV+ diffuse large B-cell lymphoma of the elderly in a Mexican population compared with what has been reported in Asian countries, and in contrast to the low frequency in Western populations (1-3%). However, compared with the Asian series, the Mexican patients were younger at diagnosis, presented predominantly with nodal disease and rarely expressed EBNA2 protein.

Mapping of the self-interaction domains in the simian immunodeficiency virus Gag polyprotein.

To gain a better understanding of the assembly process in simian immunodeficiency virus (SIV), we first established the conditions under which recombinant SIV Gag lacking the C-terminal p6 domain (SIV GagΔp6) assembled in vitro into spherical particles. Based on the full multimerization capacity of SIV GagΔp6, and to identify the Gag sequences involved in homotypic interactions, we next developed a pull-down assay in which a panel of histidine-tagged SIV Gag truncation mutants was tested for its ability to associate in vitro with GST-SIVGagΔp6. Removal of the nucleocapsid (NC) domain from Gag impaired its ability to interact with GST-SIVGagΔp6. However, this Gag mutant consisting of the matrix (MA) and capsid (CA) domains still retained 50% of the wild-type binding activity. Truncation of SIV Gag from its N-terminus yielded markedly different results. The Gag region consisting of the CA and NC was significantly more efficient than wild-type Gag at interacting in vitro with GST-SIVGagΔp6. Notably, a small Gag subdomain containing the C-terminal third of the CA and the entire NC not only bound to GST-SIVGagΔp6 in vitro at wild-type levels, but also associated in vivo with full-length Gag and was recruited into extracellular particles. Interestingly, when the mature Gag products were analyzed, the MA and NC interacted with GST-SIVGagΔp6 with efficiencies representing 20% and 40%, respectively, of the wild-type value, whereas the CA failed to bind to GST-SIVGagΔp6, despite being capable of self-associating into multimeric complexes.

Saliva as a source of HCMV DNA in allogeneic stem cell transplantation patients.

OBJECTIVE: The purpose of this study was to investigate the use of saliva for the identification of human cytomegalovirus (HCMV) in allogeneic hematopoietic stem cell transplant patients by real time PCR compared with blood. MATERIALS AND METHODS: Saliva and blood samples were sampled weekly in 30 allogeneic hematopoietic stem cell transplant patients until 100 days after transplant. Total genomic DNA, extracted from saliva and whole-blood samples, was used for HCMV real time PCR. Nonparametric tests were performed, and P value

[Detection of Epstein-Barr virus in recurrent tonsillitis].

UNLABELLED: Recurrent tonsillitis has been the subject of frequent investigation. Misuse of antibiotic therapy in acute tonsillitis, changes to the tonsillar microflora, structural changes to the tonsillar crypts, and viral infections have been listed as predisposing or causal factors for recurrent tonsillitis. Epstein-Barr virus (EBV) infection usually occurs in early childhood and may persist in tonsillar lymphocytes, thus leading to the onset of recurrent tonsillitis. Little is known about the persistence and reactivation of EBV strains in immunocompetent patients. Methods such as in situ hybridization, polymerase chain reaction (PCR), and immunochemistry have been used to study the pathogenesis of the EBV. AIM: this study aims to characterize the association between EBV and recurrent tonsillitis by investigating the presence of EBV through PCR and immunohistochemistry, using viral protein LMP-1 as a target. STUDY DESIGN: this is a cross-sectional study with analysis of sample prevalence. MATERIALS AND METHOD: twenty-four paraffin-embedded tonsil specimens from the Pathology Service were selected. The specimens were removed from children aged between 2 and 12 years diagnosed with recurrent tonsillitis. RESULTS: EBV genome was detected in 13 (54.1%) specimens, whereas viral protein LMP-1 was found in 9 (37.5%) specimens. CONCLUSION: children's tonsils can be colonized by EBV and such colonies may be associated with the pathogenesis of recurrent tonsillitis.

Comparison of immunoperoxidase and immunofluorescence assays for pp65 cytomegalovirus antigen in immunocompromised patients

We compared the pp65 antigen detection by an in house method (immunoperoxidase assay) and by a commercial kit (immunofluorescence assay) available for cytomegalovirus infection diagnosis in immunocompromised patients. Sixty-four blood samples were analyzed in duplicate for both techniques. Eight-six percent of the samples had concordant qualitative results. The discordant results occurred more frequently in samples with low quantity of positive cells. There were no significant differences with qualitative and quantitative results of the methods.

Detecção do vírus Epstein-Barr em tonsilites recorrentes / Detection of Epstein-Barr virus in recurrent tonsillitis

As tonsilites recorrentes têm sido objeto de muitos estudos. Eventos considerados na predisposição e causa incluem a utilização errônea de antibióticos em crises agudas, alterações da microflora, mudanças estruturais nas criptas epiteliais tonsilares e infecções virais. A infecção pelo vírus Epstein-Barr (EBV) ocorre freqüentemente na infância persistindo em linfócitos de tonsilas, podendo causar tonsilites recorrentes. Pouco se conhece sobre a persistência e reativação do EBV em pacientes imunocompetentes. Alguns métodos como a hibridização in situ, a reação em cadeia da polimerase (PCR) e a imuno-histoquímica têm sido utilizados no estudo da patogenia do vírus. OBJETIVO: Para caracterizar a associação do vírus Epstein-Barr com tonsilites recorrentes examinamos a presença do EBV pela PCR e por imuno-histoquímica usando como alvo a proteína viral LMP-1. FORMA DE ESTUDO: Estudo transversal com análise de prevalência amostral. MATERIAL E MÉTODOS: Foram selecionados 24 blocos parafinados de tonsilas, provenientes do Serviço de Anatomia Patológica, removidas de crianças de 2 a 12 anos com diagnóstico de tonsilite recorrente. Resultados: O genoma do EBV foi detectado em 13 (54,1%) e a LMP-1 em 9 (37,5%) dos casos. CONCLUSÃO: As tonsilas das crianças podem ser colonizadas pelo EBV e este pode estar associado à patogenia das tonsilites recorrentes.

Recurrent tonsillitis has been the subject of frequent investigation. Misuse of antibiotic therapy in acute tonsillitis, changes to the tonsillar microflora, structural changes to the tonsillar crypts, and viral infections have been listed as predisposing or causal factors for recurrent tonsillitis. Epstein-Barr virus (EBV) infection usually occurs in early childhood and may persist in tonsillar lymphocytes, thus leading to the onset of recurrent tonsillitis. Little is known about the persistence and reactivation of EBV strains in immunocompetent patients. Methods such as in situ hybridization, polymerase chain reaction (PCR), and immunochemistry have been used to study the pathogenesis of the EBV. AIM: this study aims to characterize the association between EBV and recurrent tonsillitis by investigating the presence of EBV through PCR and immunohistochemistry, using viral protein LMP-1 as a target. STUDY DESIGN: this is a cross-sectional study with analysis of sample prevalence. MATERIALS AND METHOD: twenty-four paraffin-embedded tonsil specimens from the Pathology Service were selected. The specimens were removed from children aged between 2 and 12 years diagnosed with recurrent tonsillitis. RESULTS: EBV genome was detected in 13 (54.1%) specimens, whereas viral protein LMP-1 was found in 9 (37.5%) specimens. CONCLUSION: children's tonsils can be colonized by EBV and such colonies may be associated with the pathogenesis of recurrent tonsillitis.

Comparison of immunoperoxidase and immunofluorescence assays for pp65 cytomegalovirus antigen in immunocompromised patients.

We compared the pp65 antigen detection by an in house method (immunoperoxidase assay) and by a commercial kit (immunofluorescence assay) available for cytomegalovirus infection diagnosis in immunocompromised patients. Sixty-four blood samples were analyzed in duplicate for both techniques. Eight-six percent of the samples had concordant qualitative results. The discordant results occurred more frequently in samples with low quantity of positive cells. There were no significant differences with qualitative and quantitative results of the methods.

Flow cytometry characterization of leukemic phase of nasal NK/T-cell lymphoma in tumor biopsies and peripheral blood.

We report the findings of the immunophenotypic profile of three cases of nasal T/NK cell lymphoma in leukemic phase. Flow cytometry analysis was carried out using cell suspensions of tumor nasal biopsies and peripheral blood. Tumor samples were composed by a mixture of a predominant subset of medium-size true NK cytCD3epsilon-, sCD3epsilon-, CD56+ cells mixed with a minor subset of medium-size T/NK sCD3epsilon+, CD56+ cells. Both subsets were also detected in peripheral blood. In addition, an infiltration of small-size sCD3epsilon+, CD56- normal T lymphocytes was also present.

Antigenemia for cytomegalovirus in renal transplantation: choosing a cutoff for the diagnosis criteria in cytomegalovirus disease.

Cytomegalovirus (CMV) infection is a frequent complication in transplant recipients, causing a high level of morbidity and mortality. We studied 203 consecutive renal transplant recipients performed between January 2000 and December 2001. Patients underwent weekly measurements of CMV pp65 antigen to assess CMV activity from the 4th to the 12th week posttransplantation. The results were reported as number of cells positive for the pp65 antigen among 10(5) granulocytes. In order to define a best cutoff to diagnose CMV disease with desirable sensitivity and specificity, we used a receiver operator characteristics (ROC) curve. The cutoff of four positive cells corresponded to a sensitivity of 93% and specificity of 60% (AUC = 0.87) for the diagnosis of CMV disease. The chosen cutoff for starting antiviral treatment was 10 cells, since this was associated with a sensitivity of 92% and specificity of 70% (AUC = 0.90). In conclusion, the highly sensitive cutoff points for the diagnosis of antigenemia was four cells and 10 cells for initiation of antiviral therapy.

High frequency of Epstein Barr virus latent membrane protein-1 30 bp deletion in a series of pediatric malignancies in Argentina.

UNLABELLED: Epstein Barr virus widely infects human populations and remains mostly asymptomatic; however, it has been associated with several malignancies. The EBV-encoded latent membrane protein-1 has been involved in neoplasic transformation; a 30-bp deletion and several mutations in the COOH-terminal domain have been associated with histopathological and clinical disease features. OBJECTIVE: To analyze and correlate the presence of mutations and a 30-bp deletion with the influence of LMP-1 on tumorigenicity in a population of EBV+ pediatric malignancies. METHODS: We studied EBV presence by LMP-1 immunohistochemistry, EBERs in situ hybridization and PCR in fresh and formalin-fixed paraffin-embedded tissue samples from 10 Hodgkin's lymphomas, 6 non-Hodgkin's lymphomas, 4 undifferentiated nasopharyngeal carcinomas. Eighteen out of 20 samples were sequenced. Eight fresh normal lymphoid tissue samples and 3 peripheral blood samples were analyzed. RESULTS: All cases were EBV positive. EBV typing rendered 12 EBV-1 and 8 EBV-2. Del-LMP-1 was detected in 15/20 EBV related malignancies, as well as in 4/11 control tissues. A high percentage of patients showed point mutations previously described. The presence of del-LMP-1 and point mutations failed to correlate with clinical course. CONCLUSIONS: We found a marked incidence of del-LMP-1 (75%) in our series. However, we failed to find any correlation between histological aggressiveness of malignancies and the presence of del-LMP-1 and point mutations.

Epstein-Barr virus in biopsies from patients with Hodgkin and non-Hodgkin lymphoma at the University of Puerto Rico immunohistochemistry laboratory.

OBJECTIVES: We aimed to determine the Epstein-Barr Virus (EBV) presence rate in our laboratory's lymphoma tissue biopsies for comparison with that reported in literature. BACKGROUND: The presence of EBV has been established in Hodgkin lymphoma (HL), endemic Burkitt Lymphoma and some non-Hodgkin lymphomas (NHL). It has been linked to geographic, ethnic and socioeconomic factors, with a lower rate in developed countries. METHODS: We used the immunoperoxidase technique to determine the rate of the EBV LMP-1 in eighty-seven biopsies diagnosed as lymphoma. Tissue slides were stained using the Ventana Automated Slide Stainer with the DAKO EBV LMP-1 primary antibody and the results were analyzed with the SYSTAT program. RESULTS: We found an LMP-1 positive rate of 50% for 22 cases of HL and 35% for 63 cases of NHL. Among HL, 5 were children and 16 were adults, with LMP-1 positive rates of 60% and 50% respectively. Among NHL, 3 were children and 59 were adults, with equal LMP-1 positive rates of 33%. The sex LMP-1 positive rates for HL were 42% for 12 males and 60% for 10 females. Among NHL, the sex LMP-1 positive rates were 39% for 38 males and 28% for 27 females. NHL was further subdivided into subtypes and LMP-1 primary antibody positive rates were reported. CONCLUSIONS: We found a similar presence rate of EBV in the HL biopsies to that of developed countries, but a similar presence rate of EBV in NHL biopsies to that of developing countries.

Histopathological analysis and demonstration of EBV and HIV p-24 antigen but not CMV expression in labial minor salivary glands of HIV patients affected by diffuse infiltrative lymphocytosis syndrome.

BACKGROUND: The diffuse infiltrative lymphocytosis syndrome (DILS) in HIV patients is characterized by the persistence of CD8-circulating lymphocytes and lymphocytic infiltration, predominantly in salivary glands. METHODS: We examined seven HIV-positive patients with bilateral parotid enlargement and sicca symptoms. Minor labial salivary gland biopsies were performed in all patients and submitted for histopathological analysis and immunohistochemistry for CD4, CD8, cytomegalovirus (CMV), LMP-EBV protein, and HIV p-24 protein. RESULTS: In all cases, lymphocytic infiltration of the minor salivary glands, mainly periductal, was found. Acinar atrophy, ductal ectasia, and mild to moderate fibrosis were also observed. We noticed strong immunohistochemical reaction for LMP-EBV and p-24 proteins in ductal cells in all cases, while staining for CMV was consistently negative. The lymphocytes were positive for CD8, but consistently negative for CD4. CONCLUSIONS: A role of Epstein-Barr virus (EBV) and HIV, but not CMV, in the pathogenesis of DILS, is suggested by our immunohistochemical findings.

Epstein-Barr virus in biopsies from patients with Hodgkin and non-Hodgkin lymphoma at the University of Puerto Rico immunohistochemistry laboratory

OBJECTIVES: We aimed to determine the Epstein-Barr Virus (EBV) presence rate in our laboratory's lymphoma tissue biopsies for comparison with that reported in literature. BACKGROUND: The presence of EBV has been established in Hodgkin lymphoma (HL), endemic Burkitt Lymphoma and some non-Hodgkin lymphomas (NHL). It has been linked to geographic, ethnic and socioeconomic factors, with a lower rate in developed countries. METHODS: We used the immunoperoxidase technique to determine the rate of the EBV LMP-1 in eighty-seven biopsies diagnosed as lymphoma. Tissue slides were stained using the Ventana Automated Slide Stainer with the DAKO EBV LMP-1 primary antibody and the results were analyzed with the SYSTAT program. RESULTS: We found an LMP-1 positive rate of 50 per cent for 22 cases of HL and 35 per cent for 63 cases of NHL. Among HL, 5 were children and 16 were adults, with LMP-1 positive rates of 60 per cent and 50 per cent respectively. Among NHL, 3 were children and 59 were adults, with equal LMP-1 positive rates of 33 per cent. The sex LMP-1 positive rates for HL were 42 per cent for 12 males and 60 per cent for 10 females. Among NHL, the sex LMP-1 positive rates were 39 per cent for 38 males and 28 per cent for 27 females. NHL was further subdivided into subtypes and LMP-1 primary antibody positive rates were reported. CONCLUSIONS: We found a similar presence rate of EBV in the HL biopsies to that of developed countries, but a similar presence rate of EBV in NHL biopsies to that of developing countries.

The prognostic relevance of apoptosis-related proteins in classical Hodgkin's lymphomas.

Neoplastic cells in classical Hodgkin's lymphomas (cHL) seem to correspond to defective germinal center B-cells, which escape from apoptosis. Epstein-Barr virus (EBV) may be implicated in this protective mechanism. The aim of the present study was to determine the expression of apoptosis-related proteins in cHL among adult patients and correlate them with EBV expression, clinical findings and survival. EBV was detected by in situ hybridization (Epstein-Barr Encoded RNA, EBER, probe). Immunohistochemistry was used on paraffin sections to detect LMP-1/EBV, CD15 and the apoptosis-related proteins (bcl-2, bax, bcl-X, mcl-1 and CD95). Seventy-eight patients seen at our Institution were studied: 36 male and 42 female. Median age was 31 years (15-75 years). Histological types of cHL were: 61 nodular sclerosis (47 NS1 and 14 NS2), 15 mixed cellularity (MC), 1 lymphocyte depletion and 1 unclassified. In 50 cases there was EBV expression (64%). At least one apoptosis-associated protein was expressed in 92% and CD15 in 57.7% of the cases. In the univariate analysis, the following variables were related to a better overall survival: expression of CD15 (p = 0.023), expression of mcl-1 protein (p = 0.029), expression of bcl-2 protein (p = 0.028, only in a Cox model after stratification for histology) and expression of LMP-1 (p = 0.042). EBV expression presented a borderline inverse correlation with bcl-2. A prognostic index (PI) developed in the present study revealed that simultaneous expression of bcl-2, mcl-1 and LMP-1 was significant and independently correlated with an excellent survival.

Assessment of Epstein-Barr virus association with pediatric non-hodgkin lymphoma in immunocompetent and in immunocompromised patients in Argentina.

CONTEXT: Epstein-Barr virus (EBV) has been classically associated with 3 malignancies, Burkitt lymphoma, B-cell lymphoproliferative syndromes, and nasopharyngeal carcinoma, and more recently with Hodgkin disease, T-cell lymphomas, and gastric and breast carcinomas, as well as with leiomyosarcoma and leiomyoma associated with immunosuppression. OBJECTIVE: To compare EBV expression in Argentine tumor samples with those reported elsewhere, we analyzed EBV expression in an Argentine pediatric population with non-Hodgkin lymphoma and correlated these results with clinical course and outcome. METHODS: We studied EBV presence by latent membrane protein-1 protein labeling by immunohistochemistry, by in situ hybridization, and by polymerase chain reaction for Epstein-Barr-encoded RNAs (EBERs) in formalin-fixed and paraffin-embedded non-Hodgkin lymphoma tissue samples (collected retrospectively) from 32 pediatric patients at Ricardo Gutiérrez Children's Hospital from 1993 to 2000. RESULTS: Eight out of the 32 (25%) non-Hodgkin lymphoma cases showed latent membrane protein-1 and EBERs by in situ hybridization positive staining in tumor cells. Among EBERs and latent membrane protein-1-positive cases, there were 5 immunocompromised patients, with either human immunodeficiency virus infection or primary immunodeficiency. The EBERs in situ hybridization results were confirmed by EBERs polymerase chain reaction in good-quality DNA from 11 samples, with 3 proving positive and 8 negative. CONCLUSIONS: The association of EBV with non-Hodgkin lymphoma in the Argentine pediatric population was low (25%), and this figure rose to 100% when only the immunocompromised patients subgroup was considered, confirming that the virus is probably a cofactor in the lymphomagenesis of some but not all pediatric non-Hodgkin lymphoma. So far, no differences in clinical outcome are discernible between EBV-positive and EBV-negative non-Hodgkin lymphoma patients.

Juvenile xanthogranuloma: case report with immunohistochemical identification of early and late cytomegalovirus antigens.

Juvenile xanthogranuloma (JXG) is a dermatological condition of unknown etiology that rarely affects the oral mucosa. There are conflicting reports suggesting that it may represent a reactive virally-induced lesion associated with cytomegalovirus (CMV) infection. The present paper reports an additional case of oral JXG and discusses its possible association with CMV infection. The biotin-streptavidin system was used to detect early and late CMV antigens. Positive immunolabelling for both antigens was demonstrated in some histiocytes in the lesion. These findings suggest that JXG may be associated with CMV infection.

Hodgkin's disease in Costa Rica: a report of 40 cases analyzed for Epstein-Barr virus.

We studied 40 cases of Hodgkin's disease (HD) from Costa Rica for evidence of Epstein-Barr virus (EBV) in the Reed-Sternberg and Hodgkin (RS-H) cells. We also compared the epidemiologic features of these patients with previous reports of HD in industrialized and developing nations. Because Costa Ricans enjoy a relatively higher standard of living than the residents of other developing Central American nations yet live in the same general geographic region and are genetically similar, we believed that this comparison might shed additional light on the hypothesis that the prevalence of EBV in HD and the epidemiologic factors of HD are influenced by socioeconomic factors. In 16 (40%) of 40 cases, immunohistochemical studies demonstrated that the RS-H cells were positive for EBV latent membrane protein (LMP), including 1 case of lymphocytic depletion analyzed, 12 (86%) of 14 cases of mixed cellularity, and 3 (15%) of 20 cases of nodular sclerosis. All five cases of lymphocytic predominance were negative. In the 16 EBV LMP-positive cases, polymerase chain reaction studies revealed that the virus was type A in 12 cases and type B in 4 cases. Nodular sclerosis was the most common type of HD, accounting for 20 cases (50%), followed by mixed cellularity, with 14 cases (35%). The relatively low prevalence of EBV in the RS-H cells of HD and the high incidence of nodular sclerosis in Costa Rica are similar to industrialized nations and are unlike HD in neighboring Central American countries. These findings further support the hypothesis that the prevalence of EBV in HD and the epidemiologic features of HD are most closely linked with socioeconomic conditions, and geographic location or ethnic heritage are of relatively less importance.