AIDS-related B-cell non-Hodgkin's lymphomas in direct blood-stream HIV-infected patients: pathogenesis and differentiation features

EBV detection in HIV-related oral plasmablastic lymphoma

OBJECTIVES

Plasmablastic lymphoma (PBL) of the oral cavity is an aggressive neoplasm derived from B cell, considered to be the second more common among human immunodeficiency virus (HIV)-associated malignancies. As Epstein-Barr virus (EBV) infection has been associated with this neoplasm, the aim of the present study was to assess the presence of EBV in 11 cases of oral HIV-related PBL and investigate the controversial issue of the presence of Human herpesvirus-8 (HHV-8) in these tumors.

METHODS

DNA was extracted from nine cases of HIV-associated oral lymphomas, diagnosed as PBL, and genomic material was amplified by polymerase chain reaction to verify the presence of EBV. In situ hybridization (ISH) for EBV was performed in five cases. Immunohistochemical analysis was conducted to confirm previous diagnosis and verify HHV-8 infection.

RESULTS

The 11 cases had diagnosis confirmed by immunohistochemical analysis. Only nine cases presented an adequate amount of DNA for analysis, and EBV was detected in seven of them. The five cases tested for EBV viral infection by ISH showed positive signals. All 11 cases were negative for HHV-8.

CONCLUSION

The presence of EBV in all cases studied favors a direct role of this virus in the development of HIV-related PBL, and this finding could be considered when dealing with HIV patients.

Immunophenotypic and molecular analyses of acquired immune deficiency syndrome-related and Epstein-Barr virus-associated lymphomas: a comparative study

Limited information is current available on the molecular and immunophenogenotypic characteristics of CD30-positive anaplastic large cell (ALC) lymphomas occurring in human immunodeficiency virus (HIV)-infected individuals. To address this issue, the authors have undertaken a combined analysis of these lymphomas in a comparison with other Epstein-Barr virus (EBV)-associated tumors in the setting of HIV infection. Twenty-one AIDS-related lymphomas, including five CD30-positive ALC and 11 small noncleaved cell (SNCC) lymphomas, and five Hodgkin's disease (HD) specimens were characterized regarding the immunophenogenotypic features, the frequency and subtype distribution of EBV (as defined by in situ hybridization [ISH], Southern blot, and a polymerase chain reaction [PCR] amplification of the EBV nuclear antigen-2 [EBNA-2] region) antigen expression (latent membrane protein-1 [LMP-1], EBNA-2, and for alterations of the tumor suppressor gene p53. Combined immunophenotypic and immunogenotypic analyses showed a derivation from anomalously matured B cells in four of five CD30-positive ALC lymphomas, whereas SNCC showed features of mature B cells; no evidence of immunoglobulin or TCR gene rearrangement could be obtained in HD cases. Combined ISH and Southern blot analyses revealed that EBV was more strictly associated with HD (five of five) and CD30-positive ALC lymphomas (four of five) than with SNCC lymphomas (four of 11). EBV-positive samples from CD30-positive ALC lymphomas carried type 1 EBV (two of two specimens tested), whereas both EBV subtypes were observed in SNCC lymphomas and HD samples. All three forms of viral latent gene expression were found in the EBV positive CD30-positive ALC lymphomas. SNCC specimens did not express LMP-1 or EBNA-2, whereas HD specimens expressed LMP-1 (four of five tested) but no EBNA-2. Immunostaining for ZEBRA was consistently negative. HHV-6 DNA sequences were detected by PCR in one SNCC of the 19 specimens analyzed. Three out of five CD30-positive ALC lymphoma specimens and six of 10 SNCC showed nuclear staining for p53. No mutation was detected in any of the three CD30-positive Alc lymphoma analyzed, whereas an aberrant SSCP pattern was found in all the four SNCC samples tested. At variance with SNCC lymphomas, AIDS-related B-cell CD30- positive ALC lymphomas are strictly associated with EBV infection and may also express the broad lymphoblastoid cell line-like (LMP-1-positive, EBNA-2-positive) pattern, and lack p53 genetic lesions. Unlike EBV, HHV-6 probably does not represent a relevant factor involved in the pathogenesis of CD30-positive ALC and other HIV related lymphomas.

Genotypic and immunohistological demonstration of the progression of an unusual reactive-like B-cell lymphoproliferative disorder to a high grade diffuse lymphoma

In the present study the clinical and pathological evolution of a reactive-like B-cell lymphoproliferative disorder with an unusually high content of T cells is described. Immunogenotypic analysis showed that the same phenotypically atypical B-cell clone, characterized by the unusual presence of an immunoglobulin (Ig)K gene rearrangement, with the heavy chain (IgH) gene in germline configuration, was invariantly present in all phases of the disease. The disorder showed an indolent course for a long period of time during which the clonal B-cell population coexisted with an abundant, reactive T-cell component in different locations of the disease. These findings, together with the observation of spontaneous progression and regression phases of the disorder and its responsiveness to corticosteroids, suggest that functional interactions between the B-cell clone and the polyclonal infiltrating T cells probably were involved in the pathogenesis of the disease. After the administration of the antiblastic treatment, a progressive reduction of the reactive T-cell component was observed with the concomitant evolution to a diffuse large cell (immunoblastic) B-cell lymphoma and the appearance of an IgH gene rearrangement. The biological characteristics and the clinical evolution of the case described here are similar to those reported for the so-called "T-cell-rich B-cell lymphomas" (TCRBCLs). These findings suggest that the T-cell-rich pattern may identify a group of B-cell lymphoproliferations with common pathogenetic mechanisms and clinical behavior.

Subtypes of Epstein-Barr virus in HIV-1-associated and HIV-1-unrelated Hodgkin's disease cases

Epstein-Barr virus (EBV) type 2 is considered to be a much less potent transformer of lymphocytes than type 1. However, type-2 EBV may be involved in the pathogenesis of non-Hodgkin's lymphomas (NHLs) arising in immunocompromised patients, i.e., subjects with malaria or HIV-1 infection. To determine whether type-2 EBV may also play a role in Hodgkin's disease (HD) developing in immunocompromised patients, we characterized EBV subtypes in EBV-positive HD samples from 10 HIV-1-positive patients as well as from a control population of 24 HIV-1-negative patients. Type-2 EBV was detected in 5/10 HD samples from the HIV-1-positive group (1 case showed concomitant type-1 EBV positivity), but only in 1/20 HD samples from the HIV-1-negative group, indicating that, during HIV-1-induced immunodepression, type-2 EBV may be pathogenetically involved also in HD, as previously reported for HIV-associated NHLs.

High incidence of monoclonal EBV episomes in Hodgkin's disease and anaplastic large-cell KI-1-positive lymphomas in HIV-1-positive patients

A series of selected lymphoid malignancies (LMs) occurring in Italian HIV-1-infected (HIV+) patients, principally intravenous drug users, was investigated. In addition to small non-cleaved-cell (SNCC) and large-cell immunoblastic (LCI) non-Hodgkin's lymphomas (NHLs), a relatively high occurrence of anaplastic large-cell Ki-I-positive (ALC Ki-I+) lymphomas and Hodgkin's disease (HD) was observed, at variance with other reported series of HIV+ patients. Combined results of in situ hybridization and Southern-blot analyses, in conjunction with immunohistochemical detection of Epstein-Barr virus (EBV)-encoded latent membrane protein-I (LMP-I), showed an almost complete association of ALC Ki-I+ lymphomas and HD cases with EBV. The neoplastic cells of both these LMs also showed common immunophenotypic features such as frequent absence of B- and T-cell differentiation markers and expression of the Ki-I activation marker, while SNCC and LCI lymphomas were mainly of mature B-cell origin and Ki-I-. The concomitant high incidence of ALC Ki-I+ lymphomas and HD in a specific group of HIV+ patients, their almost complete association with EBV in clonal and episomal form and the great similarity in differentiation, activation and virological markers which they display suggest that these LMs are pathological variants of a continuous spectrum of HIV-I-associated disorders etiopathologically linked to EBV.

Co-expression of Epstein-Barr virus latent membrane protein and vimentin in "aggressive" histological subtypes of Hodgkin's disease

The presence of Epstein-Barr virus (EBV) genome in Hodgkin's and Reed-Sternberg (HRS) cells, as detected using in situ hybridization (ISH) with biotinylated BamHI "V" probes, along with the expression of EBV-encoded latent membrane protein (LMP) and vimentin was examined in paraffin-embedded sections of 39 immunomorphologically characterized cases of Hodgkin's disease (HD). ISH demonstrated EBV in HRS cells in 15 of 39 cases, whereas LMP expression was detected in 11 of 39 cases, only in the presence of EBV genome detection. With the exception of 1 case, in which HRS cells expressed B-cell-associated antigens, the LMP-positive cases included specimens in which HRS cells were of non-B, non-T phenotype. LMP expression showed a stronger association with lymphocyte depletion (LD) (3/3) and mixed cellularity (MC) (6/11) than with lymphocyte predominance (0/5) or nodular sclerosis (2/20) subtypes. Vimentin expression on HRS cells was found in all the LMP-expressing cases and only in a fraction (13/28) of LMP-negative cases. This study supports the view that HD represents a heterogeneous group of diseases also in terms of EBV association, LMP expression being strongly related to the "aggressive" LD and MC histological subtypes. In light of the supposed interactions between vimentin and LMP, their co-expression on HRS cells, as detected in this study, provides further evidence for a significant role of EBV in the development of a proportion of HD cases.

Cancer morbidity in blood recipients--results of a cohort study

Blood transfusions involve the transfer of relatively large volumes of body fluids and cellular material between individuals. A variety of pathogens like viruses, some of which are associated with development of certain tumours, are known to be transmitted by this route. Blood recipients were identified during 1981-1982 in the register of the hospital blood centre, and in-patients by the in-patient and discharge register of the hospital. Tumour occurrence and vital status were determined by means of the population-based regional tumour register. Age, gender and calendar-year specific rates from the general population were used to calculate expected values. In a cohort study of 3177 blood recipients, increased numbers of malignant lymphomas [13 vs. 4.8 expected, standard morbidity ratio (SMR) 2.70 95% confidence interval (CI) 1.44-4.62] and skin cancers [12 vs. 5.2 expected, SMR 2.29, 95% CI 1.19-4.01] were seen 3 to 9 years after transfusion. In a second cohort study of 29,910 hospitalised patients, a total of 37 (29.8 expected) malignant lymphomas was found in 28,338 patients with no transfusion and 10 (2.73 expected) in 1572 patients with a transfusion, 3 to 9 years after the hospitalisation. The incidence rate ratio between these groups was 3.11 (95% CI 1.56-6.20) using a Mantel-Haenszel estimator with age stratification. Non-melanomatous skin cancers had an incidence ratio of 2.74 (95% CI 1.25-6.00). We conclude that, in the cohorts discussed here, malignant lymphomas and skin cancer occur more often in blood recipients than in controls. It remains to be established whether this is due to factors covariating with transfusion or by the transfusion itself. Further studies on these putative associations are warranted, as are analytical studies of the epidemiology of malignant lymphomas, especially non-Hodgkin's lymphoma, whose aetiology is still poorly understood.

Malignant lymphoma associated with human AIDS and with SIV-induced immunodeficiency in macaques

Malignant lymphomas associated with human (HIV) and simian (SIV) immunodeficiency virus infections are reviewed and compared. Recent observation of a high frequency of lymphomas in a series of cynomolgus macaques, highly immunodeficient after infection with SIVsm(smm3) are described. In addition to the increased frequency in human and monkey AIDS, SIV and HIV lymphomas share several important features. Clinically and by histology they present as aggressive high-grade malignant tumors with a predilection for extranodal growth in viscera, skin, central nervous system, testis, and retroorbitally. Most malignant lymphomas are of B-cell origin. AIDS lymphomas in humans are heterogeneous with regard to Epstein-Barr virus (EBV) association. Similarly, most lymphomas in monkeys experimentally infected with SIV tested to date were shown to be associated with an EBV-like simian herpes virus. These observations point to the possibility of using SIV-immunodeficient macaques for study of EBV and other oncogenic and immunosuppressive factors in AIDS-associated lymphomagenesis.