Etiology and pathogenesis of AIDS-related non--Hodgkin's lymphoma

Primary colorectal diffuse large B-cell lymphoma: A report of eighteen cases in a tertiary care center

Primary colorectal diffuse large B-cell lymphoma (DLBCL) is very rare colon malignancy. It is important to know the main demographic and clinical characteristics of these patients. We conducted a retrospective analysis of 18 patients diagnosed with primary colorectal DLBCL during a 17-year period at the National Cancer Institute of Brazil (INCA) between 2000 and 2018. Demographic characteristics, tumor localization, HIV status, lactate dehydrogenase (LDH) levels, treatment modality and follow-up status were obtained from medical records. Survival was estimated from the date of diagnosis until death. There were 11 male and seven female patients in our cohort, the median age at diagnosis was 59.5 years and four patients were HIV positive. Tumor was mainly localized in the right colon. Patients were treated with chemotherapy (CT) and/or surgical resection. Eleven patients died during a median follow-up of 59 months and the median survival time was 10 months. Six or more cycles of CT (HR=0.19; CI 95% 0.054-0.660, p = 0.009), LDH levels below 350 U/L (HR=0.229; CI 95% 0.060-0.876, p = 0.031) and surgical resection (HR=0.23; CI 95% 0.065-0.828, p = 0.030) were associated with reduced risk of death in univariate analysis. Patient's age and DLBCL right colon localization should be considered at diagnosis to distinguish between DLBCL and other diseases for differential diagnosis. Six cycles of CT, LDH levels below 350 U/L and surgical resection were associated with better survival. Our results are consistent with previous publications and address the importance of correct colorectal DLBCL diagnosis and treatment.

Stable Incidence and Poor Survival for HIV-Related Burkitt Lymphoma Among the US Veteran Population During the Antiretroviral Era

BACKGROUND

Despite advances in diagnosis and treatment of both HIV and Burkitt lymphoma (BL), persons living with HIV remain at high risk for BL. We conducted this study to evaluate if there have been any changes in the risk of or survival after BL diagnosis among persons living with HIV during the antiretroviral era.

SETTING

Veterans living with HIV (VLWH) and age-matched HIV-negative controls receiving care between 1999 and 2016 were retrospectively identified using Veterans Health Administration electronic medical records.

METHODS

We identified BL diagnoses through Veterans Health Administration Cancer Registry review and International Classification of Diseases, Ninth/Tenth Revisions, codes, and we extracted demographic, lifestyle, and clinical variables from electronic medical record. We estimated hazard ratios (HR) and 95% confidence intervals (CIs) for BL risk and survival using Cox proportional models.

RESULTS

We identified 45,299 VLWH. Eighty-four developed BL (incidence rate = 21.2 per 100,000 person years; CI: 17.1 to 26.3). Median CD4 count at BL diagnosis was 238 cells per milliliter (SD: 324.74) and increased over time. Survival was truncated in VLWH with BL (P < 0.05). The risk of BL in VLWH was 38% less in blacks compared with whites (HR: 0.620; CI: 0.393 to 0.979; P = 0.0401). VLWH with an undetectable viral load for at least 40% of follow-up were 74% less likely to develop BL (HR: 0.261; CI: 0.143 to 0.478; P < 0.0001) and 86% less likely to die after diagnosis (HR: 0.141; CI: 0.058 to 0.348; P < 0.0001).

CONCLUSIONS

BL incidence among VLWH did not improve between 2000 and 2016. Survival after BL diagnosis in VLWH remains dismal as compared with their HIV-negative counterparts, although veterans with prolonged periods of undetectable viral load had improved prognosis.

AIDS-Associated Cardiac Lymphoma-A Review: Apropos a Case Report

Despite treatment with potent and effective combination antiretroviral medications, the incidence of non-Hodgkin lymphoma (NHL) in the population living with HIV/AIDS remains significantly higher than that in noninfected individuals. The majority of the HIV-infected patients with NHL present with advanced stage extranodal disease of the B-cell phenotype. Lymphomas are the second most common tumors involving the heart in HIV-infected patients. Although the heart may serve as the primary focus of the lymphoma, in most HIV-related cases, cardiac lymphomatous involvement is part of a metastatic process that originated elsewhere.

Gastrointestinal B-cell lymphomas: From understanding B-cell physiology to classification and molecular pathology

The gut is the most common extranodal site where lymphomas arise. Although all histological lymphoma types may develop in the gut, small and large B-cell lymphomas predominate. The sometimes unexpected finding of a lymphoid lesion in an endoscopic biopsy of the gut may challenge both the clinician (who is not always familiar with lymphoma pathogenesis) and the pathologist (who will often be hampered in his/her diagnostic skill by the limited amount of available tissue). Moreover, the past 2 decades have spawned an avalanche of new data that encompasses both the function of the reactive B-cell as well as the pathogenic pathways that lead to its neoplastic counterpart, the B-cell lymphoma. Therefore, this review aims to offer clinicians an overview of B-cell lymphomas in the gut, and their pertinent molecular features that have led to new insights regarding lymphomagenesis. It addresses the question as how to incorporate all presently available information on normal and neoplastic B-cell differentiation, and how this knowledge can be applied in daily clinical practice (e.g., diagnostic tools, prognostic biomarkers or therapeutic targets) to optimalise the managment of this heterogeneous group of neoplasms.

AIDS malignancies

Among individuals with HIV-infection, coinfection with oncogenic viruses including EBV, HHV-8, and HPV cause significant cancer-related morbidity and mortality. It is clear that these viruses interact with HIV in unique ways that predispose HIV-infected individuals to malignant diseases. In general, treatment directed specifically against these viruses does not appear to change the natural history of the malignant disease, and once the malignancy develops, if their health permits, HIV-infected patients should be treated using similar treatment protocols to HIV-negative patients. However, for the less frequent HIV-related malignancies, such as PEL, or MCD, optimal treatments are still emerging. For certain AIDS-defining malignancies, it is clear that the widespread access to HAART has significantly decreased the incidence, and improved outcomes. However, for other cancers, such as the HPV-related tumors, the role of HAART is much less clear. Further research into prevention and treatment of these oncogenic virally mediated AIDS-related malignancies is necessary.

Reciprocal transactivation between HIV-1 and other human viruses

A variety of rare clinical syndromes are seen with strikingly increased prevalence in HIV-1-infected individuals, many with underlying viral etiologies. The emergence of these diseases in AIDS reflects a reduction in the ability of the immune system to mount an adequate defense against viruses in general due to the damage inflicted to the immune system by HIV-1 infection. However, in many cases, it has been found that HIV-1 can enhance the level of expression and hence the life cycle of other viruses independently of immunosuppression through specific interactions with the viruses. This can occur either directly by HIV-1 proteins such as Tat enhancing the activity of heterologous viral promoters, and/or indirectly by HIV-1 inducing the expression of cytokines and activation of their downstream signaling that eventually promotes the multiplication of the other virus. In a reciprocal manner, the effects of other viruses can enhance the pathogenicity of HIV-1 infection in individuals with AIDS through stimulation of the HIV-1 promoter activity and genome expression. The purpose of this review is to examine the cross-interactions between these viruses and HIV-1.

Epstein-Barr virus DNA loads in adult human immunodeficiency virus type 1-infected patients receiving highly active antiretroviral therapy

Patients with human immunodeficiency virus type 1 (HIV-1) infection are at high risk of developing Epstein-Barr virus (EBV)-associated lymphoma. However, little is known of the EBV DNA loads in patients receiving highly active antiretroviral therapy (HAART). Using a real-time quantitative polymerase chain reaction assay, we demonstrated that significantly more HIV-1-infected patients receiving HAART than HIV-1-uninfected volunteers had detectable EBV DNA in blood (57 [81%] of 70 vs. 11 [16%] of 68 patients; P=.001) and saliva (55 [79%] of 68 vs. 37 [54%] of 68 patients; P=.002). The mean EBV loads in blood and saliva samples were also higher in HIV-1-infected patients than in HIV-1-uninfected volunteers (P=.001). The frequency of EBV detection in blood was associated with lower CD4+ cell counts (P=.03) among HIV-1-infected individuals, although no differences were observed in the EBV DNA loads in blood or saliva samples in the HIV-1-infected group. Additional studies are needed to determine whether EBV-specific CD4+ and CD8+ cells play a role in the pathogenesis of EBV in HIV-1-infected patients receiving HAART.

Biology and management of AIDS-associated non-Hodgkin's lymphoma

The treatment of HIV-related lymphomas is evolving in the era of HAART. Standard-dose chemotherapy and dose-intensive therapies appear to be feasible. Whether outcomes are improved with combination chemotherapy and HAART remains unclear. Efforts aimed at developing pathogenic-based therapies will continue as the mechanisms of HIV lymphomagenesis are elucidated.

Update on the Pathogenesis, Diagnosis, and Therapy of AIDS-related Lymphoma

AIDS-related non-Hodgkin's lymphoma (ARL) is an opportunistic malignancy that foreshortens life more than any other commonly occurring HIV-associated cancer. Treatment strategies include low-dose chemotherapy, chemotherapy given with antiretroviral therapy, and infusional chemotherapy regimens. Rituximab, an anti-CD20 monoclonal antibody, has been found to be useful in non-HIV-associated lymphomas and is of interest in ARL as well. Since the advent of highly active antiretroviral therapy, the ARL incidence and survival has changed. This paper reviews the epidemiologic, biologic, and clinical features of ARL with the aim of presenting a cohesive overview of these elements.

Role of endogenous retroviruses in autoimmune diseases

Endogenous retroviruses (ERVs) correspond to the integrated proviral form of infectious retroviruses that are trapped within the genome by mutations. Endogenous retroviruses represent a key molecular link between the host genome and infectious viral particles. Proteins encoded by ERVs are recognized by antiviral immune responses and become targets of autoreactivity. Activation of ERVs, such as human ERV-K or a human T-cell lymphotropic virus-related endogenous sequence, may also mediate pathogenicity of Epstein-Barr virus. Endogenous retrovirus peptides can directly regulate immune responses. Thus, molecular mimicry and immunomodulation by ERVs may account for self-reactivity and abnormal T- and B-cell functions in autoimmune disorders.

The incidence of lymphoma in the UK haemophilia population between 1978 and 1999

OBJECTIVE

To determine the incidence of non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD) in the UK haemophilia population during the 22 year period 1978-1999.

DESIGN AND METHODS

An analysis of patient data included on the UK Haemophilia Centre Doctors' Organisation lymphoma register. The number of cases of NHL and HD occurring in HIV-positive and negative patients in each 3-year period were compared with the expected incidence in the general male population.

RESULTS

Eighty-nine cases of lymphoma were identified. Seventy-two cases (81%) occurred in HIV-positive patients (67 NHL, five HD), and 17 cases (19%) in HIV-negative patients (nine NHL, eight HD). The incidence of NHL in the HIV-positive cohort was significantly increased, with a ratio of observed to expected cases of 83.92 (P < 0.001) in the period 1985-1996. The ratio reduced to 42.15 during the period 1997-1999, presumably as a consequence of the introduction of highly active antiretroviral therapy (HAART). There was a significant excess of HD in HIV-positive patients, with an observed to expected ratio of 10.50 between 1985 and 1999 (based on five cases, P < 0.001). During the whole observation period, there was a significant excess of HD in HIV-negative patients, with an observed to expected ratio of 2.66 (based on eight cases, P < 0.05).

CONCLUSION

The incidence of lymphoma is significantly higher in HIV-positive UK haemophilia patients compared with HIV-negative individuals. Since the introduction of HAART, the incidence of lymphoma has tended to fall in the HIV-positive group.

High Epstein-Barr virus (EBV) DNA loads in HIV-infected patients: correlation with antiretroviral therapy and quantitative EBV serology

OBJECTIVE

To study Epstein-Barr virus (EBV) DNA loads in peripheral blood of HIV carriers to determine base-line values and diagnostic relevance of viral load in relation to quantitative serology; to compare EBV presence in parallel plasma and unfractionated whole blood samples; and to correlate EBV DNA load to HIV, CD4 T-cell counts and HAART.

DESIGN

One-hundred and nine random patients receiving highly active antiretroviral therapy (HAART) during 1999 and 99 patients on anti-HIV monotherapy during 1993-1996 were included.

METHODS

EBV DNA load was determined by quantitative competitive PCR. EBV serology was determined by immunoblot profile and quantitative enzyme-linked immunosorbent assay for responses against VCA-p18 and EBNA-1.

RESULTS

Twenty-two out of 109 patients receiving HAART and 28 out of 99 of patients on anti-HIV monotherapy showed elevated EBV DNA loads in whole blood (> 2000 copies/ml), without elevated loads in parallel plasma. EBV DNA load distribution did not differ between the two groups (P = 0.78) and did not correlate with HIV or CD4 T-cell count. In three patients with high EBV DNA loads EBV RNA was virtually absent. Patients with high EBV DNA loads (3610-89 400 copies/ml) had higher anti-VCA-p18 IgG levels than patients with undetectable EBV DNA (P < 0.0001) but lower anti-EBNA-1 IgG levels (P = 0.005).

CONCLUSION

Absolute values of EBV DNA load may have poor diagnostic value for defining HIV patients at risk for developing EBV-associated disease. Elevated EBV DNA loads are cell-associated and are not influenced by HAART. Increased anti-p18-VCA and decreased anti-EBNA-1 IgG levels in patients with high EBV loads indicate impaired latency control and increased lytic replication suggesting disturbed overall immunosurveillance against EBV.

Lymphoid neoplasms in HIV-positive individuals in India

The HIV epidemic in the Asian subcontinent has a significant impact on India. Patients with AIDS have an increased risk of developing non-Hodgkin lymphoma (NHL). In this study, we have investigated the pattern of distribution of lymphoid neoplasms and also studied the Epstein-Barr virus (EBV)-association and p53 expression in 35 HIV-positive patients from India. The biopsy samples were studied for histology and for expression of CD20, CD3, CD15, CD30, light chains, CD138, bcl-6, epithelial membrane antigen, EBV-latent membrane protein-1, and p53 protein. In situ hybridization was performed with digoxigenin-labeled anti-sense EBV-encoded nuclear RNA-1 (EBER-1) probe. Polymerase chain reaction (PCR) was performed on DNA extracted from paraffin sections for EBV-subtype analysis. The 35 cases included 7 cases of Hodgkin disease (HD), 4 cases of plasmacytoma (PL), and 24 cases of NHL. Among the cases of NHL, 3 were Burkitt lymphoma (BL), 4 were diffuse large B-cell lymphoma (DLBL) of centroblastic type (CBL), 10 were DLBL of immunoblastic type (IBL), 4 were high-grade B-cell lymphoma (unspecified) and the rest were other subtypes. EBV-association was noted in all cases of HD, 2 of 3 BL, and 3 of 10 IBL. PCR analysis of the EBNA-3C gene revealed amplimers corresponding to type A. A p53 protein overexpression was noted in 6 of 10 IBLs, 1 of 3 BLs, 2 of 3 CBLs, and 5 of 7 cases of HD. This is the first reported study of lymphoid malignancies in HIV-positive individuals from India.

Pulmonary manifestations of HIV infection in the era of highly active antiretroviral therapy

STUDY OBJECTIVES

To determine whether the spectrum of HIV-related pulmonary disease seen by a university medical center Pulmonary and Critical Care Medicine Service has changed since the introduction of highly active antiretroviral therapy (HAART).

DESIGN

Retrospective chart review.

SETTING

A tertiary care university hospital.

PATIENTS

All HIV-infected patients referred to the Pulmonary and Critical Care Medicine Service from January 1, 1993, through December 31, 1995 (era 1) and from July 1, 1997, through June 30, 2000 (era 2).

INTERVENTIONS

Inpatient and outpatient charts were reviewed for data regarding patient demographics, CD4 cell counts, viral load levels, duration of HIV seropositivity, history of opportunistic infections, and final diagnosis.

RESULTS

Pneumocystis carinii pneumonia (PCP) was less common in the HAART era than in the pre-HAART era, whereas bacterial pneumonia and non-Hodgkin's lymphoma (NHL) were more common in the HAART era than in the pre-HAART era. HAART was protective against PCP (odds ratio [OR], 0.37; confidence interval [CI], 0.16 to 0.89) in a manner dependent on the CD4 cell count. Patients receiving HAART were at increased risk for the development of bacterial pneumonia (OR, 2.41; CI, 1.12 to 5.17) and NHL (OR, 15.11; CI, 3.14 to 28.32). A history of PCP indicated a risk factor for bacterial pneumonia (OR, 2.14; CI, 1.13 to 4.04). A history of cytomegalovirus infection indicated a risk factor for NHL (OR, 6.0; CI, 1.27 to 28.32).

CONCLUSIONS

There have been significant changes in the spectrum of HIV-related pulmonary complications seen by our Pulmonary and Critical Care Medicine Service in the HAART era.

Interleukin-7: master regulator of peripheral T-cell homeostasis?

Recent evidence has implicated interleukin-7 (IL-7) as a master regulator of T-cell homeostasis, based upon its essential role in the homeostatic expansion of naive T-cell populations in response to low-affinity antigens (Ags) and its capacity to enhance dramatically the expansion of peripheral T-cell populations in response to high-affinity Ags. Furthermore, T-cell-depleted humans have a unique inverse relationship between the peripheral CD4(+) T-cell count and the level of circulating IL-7. Together, these data suggest that increased amounts of IL-7 become available following T-cell depletion, thus, enhancing the high- and low-affinity Ag-driven expansion of the population of residual, mature T cells and boosting thymic regenerative capacity, as a means to restore T-cell homeostasis.

Risk factors for non-Hodgkin's lymphoma according to family history of haematolymphoproliferative malignancies

BACKGROUND

Aetiological profiles of non-Hodgkin's lymphoma (NHL) may differ depending upon whether the disease is inheritance-related or sporadic. Because familial risk (a probable surrogate of inheritance-relatedness) of NHL is influenced by haematolymphoproliferative malignancies (HLPM), we evaluated whether non-familial risk factors differ between NHL with and without a family history of HLPM, using the Selected Cancers Study data.

METHODS

Cases were 1511 men aged 31-59 and diagnosed with NHL during 1984-1988. Controls were men without NHL, frequency-matched to cases by age range and cancer registry (n = 1910). These groups were compared: cases with a family history of HLPM and without, and controls without such a family history.

RESULTS

Polytomous logistic regression analyses showed that the odds ratio (OR) estimates of homosexual behaviour were 18.2 (95% confidence interval (CI) : 4.8-69.4) and 5.6 (95% CI : 3.3-9.5) for NHL with and without a family history of HLPM, respectively. The corresponding estimates were 3.9 (95% CI : 1.7-8.9) and 2.2 (95% CI : 1.5-3.1) for history of enlarged lymph nodes. Variables only related to NHL with a family history were use of heroin (OR = 15.6, 95% CI : 3.4-70.4), exposure to a chlorinated hydrocarbon pesticide (OR = 2.3, 95% CI : 1.0-5.0), occupational exposure to plywood, fibreboard or particleboard (OR = 2.0, 95% CI : 1.2-3.4) and history of liver diseases (other than hepatitis or cirrhosis) (OR = 6.5, 95% CI : 1.2-36.2). The association between homosexual behaviour and NHL among men with a family history was stronger for those aged 31-44, especially for B-cell type of the disease.

CONCLUSIONS

This study suggests differences in the risk factor profiles between NHL with and without a family history of HLPM. The higher risks of NHL for homosexual behaviour and heroin use, surrogates of HIV infection, in men with a family history of HLPM imply that genetic susceptibility may be influential on the occurrence of HIV-related NHL.

Lymphoma immunophenotyping: a new era in paraffin-section immunohistochemistry

Recent advances in immunohistochemistry have made it possible to investigate lymphomas for the expression of a wide range of antigens in fixed tissues. Epitope retrieval, sensitive detection methods, and the availability of new monoclonal antibodies have all contributed to one's ability to perform detailed immunophenotyping that previously could only be done in cryostat sections or by flow cytometry. Current lymphoma classifications make use of characteristic immunophenotypic profiles that aid in the reproducible diagnosis and subcassification of these neoplasms. The following is a review of the current state of immunophenotyping for lymphoid neoplasms in fixed tissues.

Current issues in the biology of AIDS-related lymphoma

Three important issues have been the focus of much recent attention in the biology of AIDS-related lymphomas. The altered epidemiology in the era of highly active antiretroviral therapy, the role of herpesviruses including human herpesvirus 8 and the molecular genetics of HIV-associated T-cell lymphomas. These topics are covered in this article and their potential application to the clinical management of AIDS-related lymphomas are discussed.

Non-Hodgkin lymphoma in Uganda: a case-control study

BACKGROUND

Lymphomas are a relatively common complication of AIDS in western countries, but little is known of the impact of the AIDS epidemic in Africa on the risk of these tumours.

OBJECTIVE

To investigate the types of non-Hodgkin lymphoma (NHL) occurring in Kampala, Uganda, their association with Epstein-Barr virus (EBV), and how their risk is modified by HIV and other variables.

METHODS

A case-control study comparing NHL cases with age/sex-matched controls. Lymphoma cases included 50 histologically diagnosed adults (31 with validation and phenotyping) and 132 histologically diagnosed children (61 with validation and phenotyping). Controls were adults with cancers unrelated to HIV and children with non-infectious diseases.

RESULTS

Most (90%) childhood lymphomas were EBV-positive Burkitt's lymphoma (BL), with no association with HIV. Adult lymphoma cases were mainly BL (mostly EBV positive) or diffuse B cell lymphomas (71%). Only a weak association was found with HIV infection; a more precise estimate was obtained with the total series (OR 2.2, 95% CI 0.9-5.1) than validated/phenotyped cases (OR 2.1, 95% CI 0.3-6.7). Higher socioeconomic status adults, who travelled away from home, or had a history of sexually transmitted diseases, appeared to have a moderately increased risk of lymphoma.

CONCLUSION

Childhood lymphomas were predominantly endemic BL, the risk of which was not modified by HIV. In adults, the risk associated with HIV was much lower in Uganda than in western countries, possibly because of the poor survival of immunosuppressed HIV-positive individuals. Future studies will require careful attention to subtyping of lymphomas, to investigate the possible differences between them.

AIDS oncology

Kaposi's sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease, and squamous cell carcinoma are among the malignancies seen with increased frequency in patients infected with HIV. The outlook for patients with these malignancies has improved significantly with the utilization of highly active antiretroviral therapy (HAART) and more aggressive cytotoxic therapies. Novel biologic therapies with lesser side effects are currently being evaluated. This article reviews the current knowledge about HIV malignancies, their epidemiology, pathogenesis, clinical manifestations, and treatment.

Peripheral T-cell lymphoma complicated by a proliferation of large B cells

We studied 14 cases that showed a morphologic appearance of peripheral T-cell lymphoma and contained substantial numbers of CD20+ large B cells. In all but 2 cases, the CD20+ large cells showed a mix of kappa and lambda light chain expression. Two cases showed a focal predominance of kappa expression. In situ hybridization using the EBER1 probe for detection of Epstein-Barr virus (EBV) RNA was performed on every case. EBV RNA was present in 10 cases. Of 8 cases with EBV RNA stained by immunohistochemistry for the latent membrane protein of EBV, 6 were positive. Double-labeling immunohistochemistry and in situ hybridization confirmed that EBV was present in the large B cells. Polymerase chain reaction (PCR) analysis showed a clonal rearrangement of the T-cell receptor (TCR)-gamma chain gene in 12 of 13 cases tested. One additional case showed a clonal rearrangement of the TCR-beta chain gene by Southern blot hybridization. PCR analysis showed a clonal immunoglobulin gene rearrangement in 5 cases, a suggestion of a clonal rearrangement in 1, an oligoclonal pattern in 4, and a polyclonal pattern in 4. The finding of large B and T cells may result in a misdiagnosis of a reactive process or of T-cell-rich B-cell lymphoma. The presence of EBV in some cases could cause further confusion with the reactive T- and B-immunoblastic proliferation of infectious mononucleosis.

Comparative genomic analyses of primary effusion lymphoma

BACKGROUND

A rare subset of human immunodeficiency virus (HIV) lymphomas, known as primary effusion lymphomas (PELs), are high-grade tumors carrying human herpes virus 8. Mechanisms postulated to contribute to lymphomagenesis include impaired immune surveillance, alterations in hemopoietic regulatory pathways due to expressed viral genes, and acquisition of genomic alterations in regions of the genome that contain regulatory genes. In PEL, limited information exists about the nature of genome-wide aberrations in these rare lymphomas.

METHODS

We used comparative genomic hybridization to detect regions of sequence gain and loss throughout the genome of 8 PEL cases. Regions of DNA sequence loss or gain were confirmed using forward and reverse hybridization and t-statistic analyses.

RESULTS

Genomic aberrations were identified in 6 of 8 cases, including recurrent gain of sequence in chromosomes 12 [ish enh (12q22;12q23, 12q12;12q23)] in 3 of 8 cases and X [ish enh (X, Xp)] in 2 of 8 cases.

CONCLUSIONS

DNA copy number changes occurred in a majority of PEL cases and are consistent with changes observed in other HIV lymphomas. These observations suggest that common genetic events may occur in HIV-associated lymphoid malignancies, but they probably do not contribute to the unique markers and morphology of PEL. Although individual genetic loci have been evaluated previously in a few PEL cases, to our knowledge this study represents the first reported genome-wide scan of copy number changes in these rare HIV-associated tumors.

Evidence that immunoglobulin specificities of AIDS-related lymphoma are not directed to HIV-related antigens

Chronic B-cell stimulation may be a predisposing event in the early pathogenesis of the acquired immunodeficiency syndrome (AIDS)-related lymphoma (ARL). ARL-derived immunoglobulin (Ig) genes are significantly diversified from germline, suggesting that antigenic stimulation via Ig receptors may occur prior to malignant transformation. We have evaluated 6 ARL-derived antibodies for binding to human immunodeficiency virus (HIV) and cell surface epitopes. Five cases expressed IgM, and 1 case expressed IgG. Expressed V genes were significantly diversified (3%-15%) from known germline V genes. A non-Ig producing mouse myeloma cell line was transfected with expression vectors containing the lymphoma-derived V genes. By enzyme-linked immunosorbent assay and Western blot assay, the lymphoma-derived Ig's showed no reactivity against HIV recombinant proteins. Also, no specific HIV reactivity was observed by flow cytometry with lymphoma-derived Ig's against the T-cell line infected with T-tropic HIV-1 or peripheral blood mononuclear cells infected with M-tropic HIV strains, indicating lack of binding to native HIV epitopes. However, 2 of the lymphoma-derived Ig's (ARL-7 and ARL-14) bound strongly to non–HIV-infected cells of various tissue origins. Thus, these findings suggest that the transformed B cells of AIDS-associated lymphomas may not arise from the pool of anti-HIV specific B cells but, rather, may develop from B cells responding to other antigens, including self-antigens.

Molecular and virologic characteristics of lymphoid malignancies in children with AIDS

PURPOSE

To characterize AIDS-associated lymphoid malignancies in children.

PATIENTS AND METHODS

We studied lymphomas and B-cell leukemias from 25 children with AIDS for immunoglobulin heavy chain gene clonality, c-myc oncogene abnormalities, and presence of HIV and Epstein-Barr virus.

RESULTS

Monoclonal immunoglobulin gene rearrangements were identified in 22 of 23 cases tested, the single exception being one of mucosa-associated lymphoid tissue. Immunoglobulin gene/c-myc translocations were found in 3 of 4 cases of B (surface immunoglobulin-positive)-acute lymphoblastic leukemia, 8 of 11 small noncleaved cell lymphomas, and 1 of 5 large cell lymphomas. Mutations of c-myc were found in 2 of 13 small noncleaved cell lymphomas, 1 of 2 Epstein-Barr virus-positive mucosa-associated lymphoid tissue neoplasms, and 1 of 4 Epstein-Barr virus-negative B-acute lymphoblastic leukemia. Six small noncleaved cell lymphomas, both mucosa-associated lymphoid tissue neoplasms and one of large cell lymphoma had high levels of Epstein-Barr virus in tumor tissue. Hodgkin's disease tissue and B-acute lymphoblastic leukemia tumors were negative for EBV. Proviral HIV-1 was not detected in any tumor.

CONCLUSIONS

AIDS-associated lymphoid malignancies in children appear to have a different distribution of histologic subtypes than adult HIV-infected individuals, fewer large cell lymphomas occur in children. The small noncleaved cell lymphomas exhibit a lower frequency as well as different locations of c-myc mutations than AIDS-associated small noncleaved cell lymphomas in adults.

Infection, immunity, and cancer

A significant percentage of human cancers worldwide are associated with infections due to known viruses, including human papillomaviruses (cervical cancer and other skin cancers), human T-lymphotropic viruses (adult T-cell leukemias and lymphomas in endemic areas), hepatitis B virus (liver cancer), and Epstein-Barr virus (Burkitt lymphoma and nasopharyngeal carcinoma). The fraction of human cancers attributable to infection may now need to be revised in light of the fact that new viral associations have been discovered and other nonviral associations have been identified. This article addresses the increasingly recognized role of infectious agents as precipitants of human neoplasia and the possibility that novel diagnostic, therapeutic, and chemopreventive strategies may emanate directly from research directed at identifying and understanding these agents.

Comparison of molecular changes in cervical intraepithelial neoplasia in HIV-positive and HIV-indeterminate subjects

OBJECTIVE

HIV infection is associated with an increased incidence of cervical malignancy and its precursor lesions (CIN, cervical intraepithelial neoplasia) compared with the general population. We studied the molecular abnormalities in the development of HIV-associated CIN and compared them with those present in CINs arising in HIV-indeterminate subjects ("sporadic CIN").

METHODS

We investigated the presence of human papilloma virus (HPV) sequences, loss of heterozygosity (LOH), and microsatellite alterations (MAs) at five 3p chromosomal regions using 17 polymorphic markers in precisely microdissected archival tissues from 16 HIV-positive CINs and compared them with those present in 39 sporadic CINs.

RESULTS

HPV sequences were detected in 36 of 55 (66%) CIN lesions, and high-risk oncogenic strains (HPV 16 and 18) accounted for 15 of them. No differences in the HPV frequencies were found between HIV-associated and sporadic CINs. Allelic losses at one or more chromosome 3p regions were frequently detected in CIN lesions (49%). The overall frequency of 3p LOH and the frequencies at all individual regions were similar in HIV-associated and sporadic CINs. The frequency of MA present in the HIV-associated CIN cases (0.093) was sixfold greater than in sporadic CINs (0.014; P = 0.0001). At least 1 MA was present in 11 (69%) of 16 HIV-associated vs. 5 of 39 (13%) sporadic CIN (P = 0.0006). Molecular changes were independent of the presence of HPV sequences.

CONCLUSION

Chromosome 3p deletions are frequently detected in the precursor lesions of cervical carcinoma (CIN) and there are no differences in the 3p LOH frequencies between HIV-associated and sporadic CIN lesions. Microsatellite alterations, which reflect widespread genomic instability, occur at greatly increased frequency in HIV-associated CIN. Although the mechanism underlying the development of increased MAs is unknown, it may play a crucial role in the development of many HIV-associated neoplasias.

Pathogenesis of non-AIDS-defining cancers: a review

As the AIDS epidemic advances, the number of HIV-infected subjects developing AIDS-related neoplasms is rapidly increasing, and the spectrum of malignancies encountered is expanding. Several non-AIDS-defining cancers are being reported at an increasing incidence in HIV-infected individuals, including anal, skin, oral mucosa, head and neck and lung carcinomas, testicular tumors, and pediatric soft-tissue sarcoma. There appears to be an emerging role for various concurrent viral infections in the HIV-infected host that are likely implicated in the pathogenesis of some nondefining-AIDS neoplasms. Our recent findings in HIV-associated lung cancers and in the precursor lesions of cervical carcinoma suggest that wide-spread genomic instability, as manifested by the development of increased numbers of microsatellite alterations (MAs), may occur frequently in HIV-associated tumors and they may play an important role in the pathogenesis of those neoplasms. Although the mechanism underlying the development of increased MAs is unknown, it may play a crucial role in the development of many HIV-associated tumors. It will be important to track the epidemiological and biological features of non-AIDS-defining cancers in HIV-infected patients, and compare them to those tumors in the general population. It is likely that further clues about malignant transformation and oncogenesis unraveled in the HIV setting will have broad clinical implications.

MYC oncogenes and human neoplastic disease

c-myc, N-myc and L-myc are the three members of the myc oncoprotein family whose role in the pathogenesis of many human neoplastic diseases has received wide empirical support. In this review, we first summarize data, derived mainly from non-clinical studies, indicating that these oncoproteins actually serve quite different roles in vivo. This concept necessarily lies at the heart of the basis for the observation that the deregulated expression of each MYC gene is reproducibly associated with only certain naturally occurring malignancies in humans and that these genes are not interchangeable with respect to their aberrant functional consequences. We also review evidence implicating each of the above MYC genes in specific neoplastic diseases and have attempted to identify unresolved questions which deserve further basic or clinical investigation. We have made every attempt to review those diseases for which significant and confirmatory evidence, based on studies with primary tumor material, exists to implicate MYC members in their causation and/or progression.

Epstein-Barr virus-associated polymorphic B-cell lymphoproliferative disorders in the lungs of children with AIDS: a report of two cases

Patients infected with HIV experience a spectrum of lymphoproliferative disorders, including generalized reactive lymphadenopathy to atypical lymphoproliferative lesions and lymphomas. Polymorphic B-cell lymphoproliferative disorders are rare and not well documented. We studied lung lesions from two children infected with HIV: an atypical polymorphic B-cell hyperplasia in a 14-year-old boy and a malignant polymorphic B-cell lymphoma in a 21-month-old girl. Morphologically, both lung lesions revealed similar polymorphic lymphoid infiltrations with numerous mitoses in case 1 and extensive necrosis and architectural distortion in case 2. Immunophenotypic examination showed no predominance of kappa or lambda light chain in case 1 and a predominance of kappa light chain in case 2. Genotypic analysis demonstrated an absence of immunoglobulin and T-cell receptor gene rearrangements in case 1 and the presence of biallelic immunoglobulin heavy chain rearrangement and a single clonal Epstein-Barr virus (EBV) in case 2. The clinical course was indolent in case 1 and aggressive in case 2. The clinicopathologic features were similar to those of posttransplantation lymphoproliferative disorders suggesting that these lung lesions might represent an immunosuppression-related spectrum of benign to malignant diseases. EBV infection may play a role in the pathogenesis of these lesions. This study highlights the importance of the molecular characterization of AIDS-associated lymphoproliferative disorders in children in establishing a definitive diagnosis.

Epstein-Barr virus-associated intravascular lymphomatosis within Kaposi's sarcoma in an AIDS patient

Intravascular lymphomatosis (IL) is an unusual neoplasm characterized by multifocal proliferation of lymphoma cells exclusively within the blood vessels. We report here a patient with acquired immunodeficiency syndrome (AIDS) and disseminated Kaposi's sarcoma. A 233-bp amplification product of HHV-8 was detected in the DNA extracted from specimens of Kaposi's sarcoma at different sites by polymerase chain reaction (PCR). At autopsy, the vessels within the Kaposi's sarcoma were dilated and filled with atypical large mononuclear cells. No such feature was seen in the vessels of non-Kaposi's sarcomatous regions. Immunohistochemically, the spindle cells of Kaposi's sarcoma were positive for CD31 (endothelial cell marker). The intravascular tumor cells were positive for CD45 (leukocyte common antigen) but negative for others, including chloroacetate esterase, CD45-RO (UCHL-1, Pan-T), CD3, CD43, CD20 (L26, Pan-B), CD30 (Ki-1), immunoglobulin heavy chains and light chains, CD56 (natural killer cell antigen), and CD31. Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in the DNA extracts from fresh tissue of Kaposi's sarcoma by PCR, which indicated that the lymphoma cells within the Kaposi's sarcoma were of monoclonal B cell origin. In situ hybridization revealed that EBER-1 transcripts were present in the lymphoma cells of IL but not in the spindle cells of Kaposi's sarcoma. To the authors' best knowledge, this is the first instance of IL in an AIDS patient with direct evidence of EBV association.

Plasmablastic lymphoma: a new subcategory of human immunodeficiency virus-related non-Hodgkin's lymphoma

A patient with human immunodeficiency virus-related non-Hodgkin's lymphoma arising in the oral cavity is reported. The tumour had an unusual immunohistochemical profile that was negative for leucocyte common antigen and the B-cell antigen CD20 but positive for the plasma cell-reactive antibody VS38c. The features of this type of tumour, which has recently been categorized, are presented and discussed.

B cells malignantly transformed by human immunodeficiency virus are polyclonal

The roles that human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) play in the genesis of acquired immune deficiency syndrome (AIDS)-related lymphomas are not understood. A human B cell line (B-HIV), developed to study AIDS-related lymphomagenesis, contains EBV and HIV genomes and is malignantly transformed. This line was produced by exposing B cells from an EBV-seropositive donor to HIV. To investigate the number of independent transformation events that took place at the time of HIV infection, we sought to determine how many transformed lineages are present in this cell line. B-HIV was found to have multiple different sites of HIV integration (> or = 25) as determined by fluorescence in situ hybridization. As a control, we analyzed a clonal cell line of HIV-infected human T cells, 8E5, and found HIV sequences located exclusively at band q22 in chromosome 13. We conclude that B-HIV is polyclonal, and viral sequences are located at multiple variable chromosomal sites in different B-HIV cells.

Lymphomas and reactive lymphoid lesions in HIV infection

Infection by the human immunodeficiency virus (HIV) causes depletion of CD4-positive lymphocytes with consequent immunodeficiency. HIV infection also causes, by direct or indirect mechanisms, both reactive and neoplastic changes in lymphoid tissues. In primary infection reactive changes are a direct response to HIV. Later in the course of the disease there are reactive changes in lymph nodes and extranodal lymphoid tissues which are likely to be largely an indirect effect of HIV infection, being a response to opportunistic infection by other organisms. There is also an increased incidence of autoimmune phenomena in HIV-infected subjects which is likely to be consequent, at least in part, on impaired control of the proliferation of self-reactive B-cell clones. A second mechanism of immune damage of blood cells, probably operating in the case of HIV-related immune thrombocytopenic purpura, is that of cellular damage by immune complexes containing antiviral antibodies. Lymphoid neoplasms associated with HIV infection include non-Hodgkin's lymphoma, Hodgkin's disease and, uncommonly, plasma cell dyscrasias. HIV-associated lymphomas have distinct clinicopathological features and generally a poor prognosis. As for reactive lymphoid lesions, induction of neoplasia is likely, in the majority of cases, to be an indirect rather than a direct effect of the virus. The combination of chronic B-cell stimulation and impaired T-cell function is important, and interaction of lymphoid cells with virus-infected stromal cells may also play a role. Infection by oncogenic viruses such as the Epstein-Barr virus and human herpes virus 8 is also aetiologically important. In rare cases of T-cell lymphoma, HIV may be directly oncogenic.

Abdominal presentation of Burkitt's lymphoma in an HIV-positive patient

The incidence of non-Hodgkin's lymphoma (NHL) has greatly increased in the AIDS population. It has been estimated that 8% to 27% of newly diagnosed cases of NHL are related to AIDS. The vast majority are clinically aggressive B cell-derived lymphomas. AIDS-associated NHLs are classified according to their anatomic site of location into three classes: (1) systemic (both nodal as well as extranodal), (2) primary central nervous system, and (3) body cavity-based lymphomas. We present a case report of a patient with HIV infection who presented with abdominal pain and distension and was found to have an intraabdominal type of Burkitt's lymphoma. This case underlines the following points: 1. In the evaluation of acute abdominal disease in a patient with AIDS, both AIDS-related infections as well as malignancies should be sought in the differential diagnosis. 2. Computed tomographic scanning of the abdomen is the modality of choice for characterization of disease as well as direction of appropriate therapy. 3. AIDS-related NHL remains an important biologic model for investigating the development and progression of lymphomas in the immune-deficient host. 4. With the improved survival of patients with AIDS secondary to better prevention and treatment of infections, there may be an increase in AIDS-associated malignancies; therefore, further research pertaining to the development and characterization of therapy modalities of such malignant tumors is mandatory.

Pathology of human immunodeficiency virus infection: noninfectious conditions

Diagnostic anatomic pathologists play a crucial role in the battle against acquired immunodeficiency syndrome (AIDS). Not only are they intimately involved in the treatment of individual patients with human immunodeficiency virus (HIV) infection, but also they make important observations that result in the expansion of the scientific understanding of its pathogenesis. Pathologists studying tissue from patients with HIV infection should be familiar with the conditions to which these patients are susceptible. Although opportunistic infections are important causes of morbidity and mortality, noninfectious conditions frequently make substantial contributions to the disease course. Patients with HIV infection may be at increased risk for neoplastic disease. They do not, however, have an increased incidence of the most common tumors affecting the general population, such as breast, colon, and prostate carcinoma. Immunodeficiency results in increased susceptibility to malignant neoplasms, both by decreased immunologic response to abnormal cells and increased susceptibility to infection by viruses. All of the malignant neoplastic diseases that are Centers for Disease Control and Prevention (CDC) AIDS indicator conditions have been shown to have an association with a virus: Kaposi sarcoma (KS) with herpes hominis virus 8 (HHV-8), malignant lymphoma with Epstein-Barr virus (EBV), and cervical carcinoma with human papilloma virus (HPV). Patients with HIV infection also can develop reactive processes that are attributable to direct effects of HIV or immune system alterations. Such conditions include salivary gland cystic lymphoepithelial lesion, lymphadenopathy, lymphocytic interstitial pneumonitis, encephalopathy, enteropathy, nephropathy, hepatic conditions, dermatologic conditions and anemia.