In Hodgkin's disease Reed-Sternberg cells and normal B-lymphocytes are infected by related Epstein-Barr virus strains

In Hodgkin's disease (HD), both neoplastic Reed-Sternberg (RS) cells and bystander B-lymphocytes may be infected by Epstein-Barr virus (EBV). We postulated that if tumorigenic EBV strains did exist, they would be preferentially found in consistently EBV-associated tumors, such as RS cells, and differ significantly from the strains present in other, non-pathological sites of the same patients. In the present study we have compared LMP1-BNLF1 polymorphism of EBV strains infecting RS cells and B-lymphocytes in lymph nodes effected by HD on the one hand, and bystander B-lymphocytes in reactive lymph nodes on the other. It appeared that viral strains detected in HD tissues including RS cells and bystander B-lymphocytes were infected by different, but related EBV strains and were four times more polymorphic than EBV strains infecting bystander B-lymphocytes of reactive lymph nodes. The question arises as to the biological significance of these observations and the origin and chronology of multiple infections in the same patient. Since RS cells are derived from B-lymphocytes it is conceivable that the latter events could have occurred during the proliferation of bystander B-lymphocytes and their EBV episome following an antigenic stimulation.     

PCR analysis of immunoglobulin heavy chain (IgH) and TcR-gamma chain gene rearrangements in the diagnosis of lymphoproliferative disorders: results of a study of 525 cases.

This report summarizes a cumulative 4-year experience in polymerase chain reaction (PCR) analysis of immunoglobin heavy chain (IgH) and TcR-gamma chain gene rearrangements in 525 cases of lymphoproliferative disorders. Because the sensitivity of the PCR methodology was found to be tissue dependent, in the study of the presence of clonal cell population in tissues containing a small number of polyclonal lymphocytes, such as skin and gastrointestinal biopsy specimens, we used the multiple-PCR run approach. In this latter methodology, we repeat the PCR reaction from the same sample at least three times to confirm the reproducibility of the results. In the study of 273 cases of B- or T-cell lymphomas with characteristic immunomorphological and clinical features, a clonal IgH or TcR-gamma chain gene rearrangement was detected in approximately 80% of cases. A clonal rearrangement involving both IgH and TcR-gamma chain genes was found in 10% of cases of both B-cell and T-cell lymphomas. The study of 167 cases of nonneoplastic lymphoid tissue samples showed the presence of clonally rearranged cell populations for IgH or TcR-gamma genes in 3 and 9% of cases, respectively. We also applied PCR for the study of 85 cases of lymphoproliferations with no definite diagnosis (i.e., benign versus malignant) after immunomorphological analysis. In 65 cases (76%), the correlation of immunomorphological features with the presence (48 cases) or the absence (17 cases) of clonal lymphoid cell populations led to a definite diagnosis. In almost all these cases, the final diagnosis was found to be in agreement with the clinical course. In the 20 remaining cases (24%), no definite diagnosis could be made. We also assessed the value of PCR in detecting bcl-2/J(H) gene rearrangement as an additional clonal marker in the diagnosis of follicular lymphoma. Bcl-2/J(H) rearrangement and/or IgH gene rearrangement was found in approximately 85% (71/85) of follicular lymphoma cases studied.     

Measurement by the polymerase chain reaction of the Epstein-Barr virus load in infectious mononucleosis and AIDS-related non-Hodgkin's lymphomas

A polymerase chain reaction (PCR) assay for the detection of Epstein-Barr virus (EBV) sequences in various clinical samples, especially peripheral blood leukocytes (PBL) and serum, was carried out and the results obtained were compared with specific EBV serology. One hundred seventy patients were enrolled in the study: 89 healthy blood donors, 22 asymptomatic patients, 36 individuals with primary EBV infection (including 19 patients with infectious mononucleosis [IM]), 22 HIV-infected subjects (including 4 with hairy oral leukoplakia, 3 with central nervous disorders, and 15 with non-Hodgkin's lymphoma). All the serum samples from the healthy blood donors were negative, In patients with IM and in AIDS-non Hodgkin's lymphoma (ARNHL), PCR was strongly positive in leukocytes (>2, 000 genome equivalents/l 0⁴ cells), which was correlated with detectable amounts of EBV DNA in serum. The overall positivity rate of PCR in serum was 58.8%, 68%, and 73% of cases for non-IM primary EBV infections, IM, and ARNHL, respectively. In two cases of EBV primary infection, the viral DNA was detected in serum, respectively 1 month and 2 months before IgM positivity and IgG rise. In one case of ARNHL followed up for several months, PCR (viral load of 2, 000 genome equivalents/10⁴ cells) became positive concurrently with appearance of lymphoma. In immunocompromised individuals, PCR EBV, if carried out in larger prospective studies, could be considered as a tumor marker, useful for predicting EBV-driven lymphoma and follow-up therapy. © 1995 Wiley-Liss, Inc.     

Diagnosis of mycosis fungoides: a comparative immunohistochemical study of T-cell markers using a novel anti-CD7 antibody.

Mycosis fungoides (MF) is the most common form of primary cutaneous T-cell lymphoma. In its early stage it may mimic benign dermatoses both on a clinical and histologic basis. MF usually expresses CD3 and CD4 (T-cell) markers. CD7 is expressed on about 90% of CD4 T cells and is often deficient on malignant T cells. Thus, CD7 may be useful in evaluating the nature of dermal lymphoid infiltrates. The aim of this study was to evaluate the usefulness of immunohistochemical detection of T-cell markers on paraffin-embedded sections, CD3 and CD7 (clone CBC.37), in the differential diagnosis of MF and benign dermatoses. Forty-two patients with diffuse dermal T-lymphocytic infiltrates were selected. Previous clinicopathologic correlation and follow-up had established the diagnosis of MF in 31 patients and benign dermatoses in 11. The mean value of stained cells in MF was 86.45% for CD3 and 53.09% for CD7 (P<0.001); in benign dermatoses it was 79.09% for CD3 and 73.63% for CD7 (P=0.669). CD7 immunolabeling was significantly lower in the MF group (P=0.048). A semiquantitative evaluation revealed a considerable loss of CD7 immunolabeling in comparison with CD3 in patients with MF. The authors conclude that CD7 study may represent a valuable tool in the distinction between inflammation and neoplasia in T-lymphoproliferative skin disorders.     

Inflammatory Neutrophils Secrete Annexin 1 During Experimentally Induced Colitis in Rats

Immunoblotting and immunohistochemical analysiswere performed to identify the cells expressing andsecreting annexin 1 during experimental rat colitisinduced by trinitrobenzene sulfonic acid. Annexin 1 expression was increased during theinflammation. Likewise, annexin 1 secretion was inducedin inflamed colons at one, three, six, and nine daysafter trinitrobenzene sulfonic acid treatment but wasnot detected in colons from controls and rats at 12days. Immunohistochemistry showed that the rise inannexin 1 expression resulted from the infiltration oftwo types of leukocytes highly positive for annexin 1: neutrophils (the most abundant) andmacrophages. At day 1 after treatment, neutrophils ofthe inflammatory site, in mucosa and submucosa, are theonly cells expressing annexin 1. Immunoblotting showed that they secreted annexin 1 whereasneutrophils from blood or tunica muscularis did not.This indicates that, during this colitis, annexin 1 canbe secreted by neutrophils located in the inflammatorysite.     

Telomerase activity might persist in the human thymus throughout life.

Telomerase activity has been demonstrated at low levels in peripheral blood lymphocytes but at high levels in germinal centre B cells and thymocyte subpopulations. This study shows that telomerase is activated in the normal human thymus at different times of life. Telomerase activity was detected in thymic protein extracts from two newborn babies and from a 12 year old boy, as well as in extracts from two of six adult patients. The two positive cases were patients aged 54 and 66 years. These results suggest strongly that the thymus can remain functional despite involution in elderly patients.