Epstein-Barr virus-associated extranodal non-Hodgkin's lymphoma of the sinonasal tract and nasopharynx in Thailand.

Epstein-Barr virus (EBV) infection is highly associated with specific subtypes of malignant lymphoma. In our previous report on nodal malignant lymphoma in Thailand, we found that 64% of classical Hodgkin's lymphoma (cHL), 51% of non-Hodgkin's lymphoma, T-cell (NHL-T), and 13% of non-Hodgkin's lymphoma, B-cell (NHL-B) were EBV-related. In the present research, we conducted a retrospective study of primary extranodal non-Hodgkin's lymphoma of the sinonasal tract (e-NHL-ST) and primary extranodal non-Hodgkin's lymphoma of the nasopharynx (e-NHL-NP) in Southern Thailand, between 1997 and 2004. EBV-encoded RNA (EBER) expression by in situ hybridization was performed in all cases and a T-cell receptor (TCR)-g gene rearrangement study was performed in NHL-T cases. There were 18 cases of e-NHL-ST and 42 cases of e-NHL-NP detected by histologic and immunohistochemistry examinations. The percentages of e-NHL-ST and e-NHL-NP as compared to nodal malignant lymphoma were 3.7% and 6.8%, respectively. Sixteen cases (88.9%) of e-NHL-ST and 7 cases (16.7%) of e-NHL-NP were NHL-T, and the remainder were NHL-B. All of the NHL-T cases in both sites were EBER-positive. Two (5.4%) of the NHL-B cases in the nasopharynx showed EBER positive. Monoclonal bands of the TCR-gamma gene were detected in 71.4% of the extranodal NK/T-cell lymphomas, nasal type, patients; 50.0% of peripheral T-cell lymphoma, unspecified, patients; and one case of angioimmunoblastic T-cell lymphoma. This study indicates a very strong association of NHL-T in the sinonasal tract or nasopharynx with EBV infection, the link apparently being weaker in NHL-B patients. The study also indicates that most cases of extranodal NK/T-cell lymphoma, nasal type, are not the germline configuration of the TCR genes.

A prospective evaluation of four immunodiagnotic assays for human leptospirosis.

This was a prospective evaluation of four immunodiagnostic assays for human leptospirosis, including the indirect immunofluorescence test (IFA), the microscopic agglutination test (MAT), the LEPTO dipstick, and the latex agglutination (LA) test. Four hundred ninety-two serum samples were collected from 348 patients who presented with acute fever without localizing signs. The sensitivities of the IFA, MAT, Dipstick, and LA were 91.9, 76.6, 77.4, and 83.1%, respectively. The specificities of these assays were 100.0, 100.0, 89.3, and 83.5, respectively. Even though IFA showed the highest overall sensitivity and specificity, when acute sera were considered, the LA was the most sensitive (28.7%). All 3 genus specific antibody assays had broad reactivity against various serogroups. The MAT is best suited for the reference laboratory, where it can be maintained with the battery of live antigens; the IFA is suited for a laboratory with sophisticated equipment and technical expertise; the Dipstick and LA are suitable for peripheral laboratories which lack expensive equipment and expertise.

Epstein-Barr virus-associated nodal malignant lymphoma in Thailand.

Specific subtypes of malignant lymphoma are highly associated with Epstein-Barr virus (EBV) infection. In the present study, the authors evaluated EBV-encoded RNA (EBER) expression by in situ hybridization in 300 cases of malignant lymphomas diagnosed by lymph node biopsy, with 100 cases of reactive lymphoid hyperplasia in lymph nodes as controls, for comparison. There were 100 consecutive cases of classical Hodgkin's lymphoma (cHL), 100 consecutive cases of non-Hodgkin's lymphoma, B cell (NHL-B), and 100 consecutive cases of non-Hodgkin's lymphoma, T cell (NHL-T). EBER expression was detected in 46% of reactive lymphoid hyperplasia cases, but the positively stained cells in those cases constituted less than 5 percent of the total cell populations. When using the presence of EBER in 5 percent or more of the cell population and/or the presence of EBER in the Hodgkin's Reed-Sternberg's cells as indicators of positivity, 64% of cHL, 13% of NHL-B, and 51% of NHL-T were found to be positive. The study indicates a strong association of cHL and NHL-T with EBV infection, the link apparently being weaker for NHL-B except for the subtypes of Burkitt's lymphoma and diffuse large B cell lymphoma.

Epstein-Barr virus-associated peripheral T-cell lymphoma with gastrointestinal tract involvement.

Peripheral T-cell lymphoma (PTCL) is a group of diseases which are common in Asia and areas of South and Central America. They are highly associated with the Epstein-Barr virus (EBV) infection. In the present study the authors evaluated patients with gastrointestinal involvement of PTCL with respect to clinical findings and outcome, pathologic features, and molecular analysis for EBV infection and the clonality of tumor cells. From January 1997 through December 2000, 7 patients with gastrointestinal tract involvement of PTCL were identified. The frequency of gastrointestinal tract involvement in the various types of PTCL was 5.4 per cent (7 of 129 cases). The pertinent clinical features were prolonged fever, weight loss, anemia, hepatosplenomegaly, lymphadenopathy, multiorgan involvement, and gastrointestinal bleeding. Laboratory results showed a significantly high serum level of alkaline phosphatase and lactate dehydrogenase, and abnormal coagulograms. Five patients died within 4 months after onset of illness, while two were in complete remission after chemotherapy. The tumor cell morphology was classified into three categories: small-sized cells, mixed medium- and large-sized cells, and large-sized cells. The antigenic phenotypes of the tumor cells were LCA+, CD3+, CD15-, CD16-, CD30-, CD45R0+, CD57-, CD68-, EMA-, betaF1-, granzyme B+, TIA-1+, and p53+. The expression of CD4, CD8, CD56 and CD20 was variable. EBV-RNA expression by in situ hybridization (EBER-ISH) study was positive and T-cell receptor (TCR) beta and/or gamma gene rearrangements were detected in all patients. DNA sequence analysis showed high identity to the human TCR germline gene. PTCL with gastrointestinal tract involvement was associated with EBV infection. The tumor cells were mature T cells with some NK-cell antigenic expression and all demonstrated TCR gene rearrangements.

The etiology of acute pyrexia of unknown origin in children after a flood.

Acute pyrexia of unknown origin (PUO) is a major public health problem in Thailand. We studied the etiology of 180 cases of acute PUO in children after a sudden severe flood in Hat Yai city in 2000. Dengue infection and leptospirosis accounted for more than half of the total cases. Dengue hemorrhagic fever was the most common (29.4%) followed by leptospirosis (27.2%) and scrub typhus infection (1.1%). Five serovars of leptospires were involved in this study. Leptospira interrogans bataviae was the most common (86.5%). Acute serum antibody testing could detect only 52.8% and 40.8% of dengue and leptospirosis cases, respectively. This study showed both should be included in the presumptive diagnosis of acute PUO in patients after flooding.

Epstein-barr virus-associated non-Hodgkin's lymphoma of B-cell origin, Hodgkin's disease, acute leukemia, and systemic lupus erythematosus: a serologic and molecular analysis.

Parallel studies of (a) patients with Epstein-Barr virus (EBV)-associated peripheral T-cell proliferative disease/lymphomas and (b) a group of patients with a prolonged fever from other causes were conducted at Songklanagarind University Hospital from 1997 through 2000. (Reports on EBV-associated peripheral T-cell and NK-cell proliferative disease/lymphomas have been published elsewhere) In this study, the authors identified 58 patients; 14 were non-Hodgkin's lymphoma of B-cell origin (NHL-B), 8 were Hodgkin's disease, 6 were acute leukemia, 9 were systemic lupus erythematosus (SLE), and 21 were patients with other diseases. Serologic tests for the EBV infection, the study of EBV genome in circulating non-T-cells (CD3-cells) and T-cells (CD3+ cells), and the EBV-RNA study in the tumor cells were performed. EBV internal repeat-1 region (IR-1) in peripheral blood CD3+ cells was detected in 10 of 14 patients (71.5%) with NHL-B, 3 of 8 patients (37.5%) with Hodgkin's disease, 1 of 6 patients (16.7%) with acute leukemia, 4 of 9 patients (44.5%) with SLE, and was not detected in any of the 21 patients with other diseases. Anti-viral capsid antigen-IgG was significantly elevated in hematologic malignancy patients with EBV IR-1 genome in the peripheral blood CD3+ cells when compared to hematologic malignancy patients with a negative result, whereas there was no significant difference in anti-EBV nuclear antigen among these two groups. EBV-RNA expression in tumor cells by in situ hybridization was detected in 4 of 13 patients (31%) with NHL-B (all showed EBV IR-1 genome in peripheral blood CD3+ cells), and 3 of 5 patients (60%) with Hodgkin's disease (only two showed EBV IR-1 genome in peripheral blood CD3+ cells). These data support the theory that chronic EBV infection is often found in association with cases of NHL-B, Hodgkin's disease, acute leukemia, and SLE.