Microenvironment and HIV-related lymphomagenesis

Research progress of nanoparticle targeting delivery systems in bacterial infections

Bacterial infection is a huge threat to the health of human beings and animals. The abuse of antibiotics have led to the occurrence of bacterial multidrug resistance, which have become a difficult problem in the treatment of clinical infections. Given the outstanding advantages of nanodrug delivery systems in cancer treatment, many scholars have begun to pay attention to their application in bacterial infections. However, due to the similarity of the microenvironment between bacterial infection lesions and cancer sites, the targeting and accuracy of traditional microenvironment-responsive nanocarriers are questionable. Therefore, finding new specific targets has become a new development direction of nanocarriers in bacterial prevention and treatment. This article reviews the infectious microenvironment induced by bacteria and a series of virulence factors of common pathogenic bacteria and their physiological functions, which may be used as potential targets to improve the targeting accuracy of nanocarriers in lesions.

Hemophagocytic Lymphohistiocytosis Secondary to Hodgkin's Lymphoma with Isolated Bone Marrow Involvement in a Newly Diagnosed HIV Patient

Human immunodeficiency virus (HIV) infection is known to be associated with the development of Hodgkin's lymphoma (HL). Exclusive extranodal bone marrow involvement is less common. Co-infection by other viruses, such as the Epstein-Barr virus (EBV), increases the incidence of a frequent complication denominated by hemophagocytic lymphohistocytosis (HLH). We present the case of a 50-year-old patient with the above clinical spectrum who develops several serious complications during treatment.

Primary Effusion Lymphoma, Multicentric Castleman's Disease, and Kaposi's Sarcoma in an HHV-8 and HIV-Positive Patient: A Case Report

Primary effusion lymphoma (PEL), Kaposi's sarcoma (KS), and multicentric Castleman's disease (MCD) is an uncommon group of diseases included in the same spectrum with related characteristics. The coexistence of all of them in the same individual is a rare occurrence. We present the case of a 25-year-old patient diagnosed with human immunodeficiency virus (HIV) and the development of all these related pathologies. Despite the use of intensive treatment according to the latest recommendations, the evolution was unfavorable. This case reflects the need for new therapies and research in this field.

Co-Infection of the Epstein-Barr Virus and the Kaposi Sarcoma-Associated Herpesvirus

The two human tumor viruses, Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV), have been mostly studied in isolation. Recent studies suggest that co-infection with both viruses as observed in one of their associated malignancies, namely primary effusion lymphoma (PEL), might also be required for KSHV persistence. In this review, we discuss how EBV and KSHV might support each other for persistence and lymphomagenesis. Moreover, we summarize what is known about their innate and adaptive immune control which both seem to be required to ensure asymptomatic persistent co-infection with these two human tumor viruses. A better understanding of this immune control might allow us to prepare for vaccination against EBV and KSHV in the future.

Hematological cancers in individuals infected by HIV

HIV infection increases cancer risk and is linked to cancers associated to infectious agents classified as carcinogenic to humans by the International Agency for Research on Cancer. Lymphomas represent one of the most frequent malignancies among individuals infected by HIV. Diffuse large B-cell lymphoma remains a leading cancer after the introduction of combined antiretroviral therapy (cART). The incidence of other lymphomas including Burkitt lymphoma, primary effusion lymphomas, and plasmablastic lymphoma of the oral cavity remain stable, while the incidence of Hodgkin lymphoma and Kaposi sarcoma-associated herpesvirus (KSHV)-associated Multicentric Castleman Disease has increased. The heterogeneity of lymphomas in individuals infected by HIV likely depends on the complexity of involved pathogenetic mechanisms, i.e. HIV-induced immunosuppression, genetic abnormalities, cytokine dysregulation, co-infection with the gamma-herpesviruses, Epstein Barr virus and KSHV, and the dysregulation of the immune responses controlling these viruses. In the modern cART era, standard treatments for HIV-associated lymphoma including stem cell transplantation in relapsed/refractory disease, mirrors that of the general population. The combination of cART and anti neoplastic treatments has resulted in remarkable prolongation of long-term survival. However, oncolytic and immunotherapic strategies, and therapies targeting specific viral oncogenes will need to be developed primarily.

EBV-associated primary CNS lymphoma occurring after immunosuppression is a distinct immunobiological entity

Primary central nervous system lymphoma (PCNSL) is confined to the brain, eyes, and cerebrospinal fluid without evidence of systemic spread. Rarely, PCNSL occurs in the context of immunosuppression (eg, posttransplant lymphoproliferative disorders or HIV [AIDS-related PCNSL]). These cases are poorly characterized, have dismal outcome, and are typically Epstein-Barr virus (EBV)-associated (ie, tissue-positive). We used targeted sequencing and digital multiplex gene expression to compare the genetic landscape and tumor microenvironment (TME) of 91 PCNSL tissues all with diffuse large B-cell lymphoma histology. Forty-seven were EBV tissue-negative: 45 EBV- HIV- PCNSL and 2 EBV- HIV+ PCNSL; and 44 were EBV tissue-positive: 23 EBV+ HIV+ PCNSL and 21 EBV+ HIV- PCNSL. As with prior studies, EBV- HIV- PCNSL had frequent MYD88, CD79B, and PIM1 mutations, and enrichment for the activated B-cell (ABC) cell-of-origin subtype. In contrast, these mutations were absent in all EBV tissue-positive cases and ABC frequency was low. Furthermore, copy number loss in HLA class I/II and antigen-presenting/processing genes were rarely observed, indicating retained antigen presentation. To counter this, EBV+ HIV- PCNSL had a tolerogenic TME with elevated macrophage and immune-checkpoint gene expression, whereas AIDS-related PCNSL had low CD4 gene counts. EBV-associated PCNSL in the immunosuppressed is immunobiologically distinct from EBV- HIV- PCNSL, and, despite expressing an immunogenic virus, retains the ability to present EBV antigens. Results provide a framework for targeted treatment.

The Role of Coinfections in the EBV-Host Broken Equilibrium

The Epstein–Barr virus (EBV) is a well-adapted human virus, and its infection is exclusive to our species, generally beginning in the childhood and then persisting throughout the life of most of the affected adults. Although this infection generally remains asymptomatic, EBV can trigger life-threatening conditions under unclear circumstances. The EBV lifecycle is characterized by interactions with other viruses or bacteria, which increases the probability of awakening its pathobiont capacity. For instance, EBV infects B cells with the potential to alter the germinal center reaction (GCR)—an adaptive immune structure wherein mutagenic-driven processes take place. HIV- and Plasmodium falciparum-induced B cell hyperactivation also feeds the GCR. These agents, along with the B cell tropic KSHV, converge in the ontogeny of germinal center (GC) or post-GC lymphomas. EBV oral transmission facilitates interactions with local bacteria and HPV, thereby increasing the risk of periodontal diseases and head and neck carcinomas. It is less clear as to how EBV is localized in the stomach, but together with Helicobacter pylori, they are known to be responsible for gastric cancer. Perhaps this mechanism is reminiscent of the local inflammation that attracts different herpesviruses and enhances graft damage and chances of rejection in transplanted patients. In this review, we discussed the existing evidence suggestive of EBV possessing the potential to synergize or cooperate with these agents to trigger or worsen the disease.

[EBV and immunodeficiency]

Epstein-Barr virus (EBV), discovered in 1964, is a double-stranded DNA virus belonging to the Herpesviridae family. EBV has a lymphoid tropism with transforming capacities using different oncogenic viral proteins. This virus has two replication cycles: a lytic cycle mainly occuring during primary infection and a latent cycle allowing viral persistence into host memory B cells. More than 90% of adults are seropositive for EBV worldwide, with a past history of asymptomatic or mild primary infection. EBV infection can sometimes cause life-threatening complications such as hemophagocytic lymphohistiocytosis, and lead to the development of lymphoproliferative disorders or cancers. Risk factors associated with these phenotypes have been recently described through the study of monogenic primary immune deficiencies with EBV susceptibility. We here review the virological and immunological aspects of EBV infection and EBV-related complications with an overview of current available treatments.

The role of EBV in haematolymphoid proliferations: emerging concepts relevant to diagnosis and treatment

Epstein-Barr virus (EBV) is a ubiquitous gammaherpesvirus with >90% of the adult population worldwide harbouring latent infection. A small subset of those infected develop EBV-associated neoplasms, including a range of lymphoproliferative disorders (LPD). The diagnostic distinction of these entities appears increasingly relevant as our understanding of EBV-host interactions and mechanisms of EBV-driven lymphomagenesis improves. EBV may lower the mutational threshold for malignant transformation, create potential vulnerabilities related to viral alteration of cell metabolism and allow for improved immune targeting. However, these tumours may escape immune surveillance by affecting their immune microenvironment, limiting viral gene expression or potential loss of the viral episome. Methods to manipulate the latency state of the virus to enhance immunogenicity are emerging as well as the potential to detect so-called 'hit and run' cases where EBV has been lost. Finally, measurement of EBV DNA remains an important biomarker for screening and monitoring of LPD. Methods to distinguish EBV DNA derived from virions during lytic activation from latent, methylated EBV DNA present in EBV-associated neoplasms may broaden the utility of this testing, particularly in patients with compromised immune function. We highlight some of these emerging areas relevant to the diagnosis and treatment of EBV-associated LPD with potential applicability to other EBV-associated neoplasms.

Immunodeficiency-Related Lymphoid Proliferations: New Insights With Relevance to Practice

PURPOSE OF REVIEW

Our understanding of risk factors and mechanisms underlying immunosuppression-related lymphoproliferative disorders continues to evolve. An increasing number of patients are living with altered immune status due to HIV, solid organ or hematopoietic stem cell transplant, treatment of autoimmune disease, or advanced age. This review covers advances in understanding, emerging trends, and revisions to diagnostic guidelines.

RECENT FINDINGS

The tumor microenvironment, including interactions between the host immune system and tumor cells, is of increasing interest in the setting of immunosuppression. While some forms of lymphoproliferative disease are associated with unique risk factors, common mechanisms are also emerging. Indolent forms, such as Epstein-Barr virus positive mucocutaneous ulcer, are important to recognize. As methods to modulate the immune system evolve, more data are needed to understand and minimize lymphoproliferative disease risk. A better understanding of individual risk factors and common mechanisms underlying immunosuppression-related lymphoproliferations will ultimately enable improved prevention and treatment of these disorders.

Identifying transcriptional profiles and evaluating prognostic biomarkers of HIV-associated diffuse large B-cell lymphoma from Malawi

Lymphoma incidence in sub-Saharan Africa (SSA) is increasing due to HIV and population aging. Diffuse Large B-cell lymphoma (DLBCL), the most common lymphoma in SSA and worldwide, is highly associated with HIV, but molecular studies of HIV-associated DLBCL are scarce globally. We describe profiling of DLBCL from Malawi, aiming to elucidate tumor biology and identify clinically meaningful biomarkers specifically for SSA. Between June 1, 2013 and June 1, 2016, 59 cases of DLBCL (32 HIV+/27 HIV-) enrolled in the Kamuzu Central Hospital Lymphoma Study were characterized, of which 54 (92%) were negative for Epstein-Barr virus. Gene expression profiling (GEP) by whole transcriptome sequencing was performed on the first 36 cases (22 HIV+/14 HIV-). Immunohistochemistry (IHC) and GEP results were compared with published data and correlated to clinical outcome and pathologic features. Unsupervised clustering strongly segregated DLBCL by HIV status (p = 0.0003, Chi-squared test), indicating a marked contribution of HIV to expression phenotype. Pathway analysis identified that HIV-associated tumors were enriched in hypoxia, oxidative stress, and metabolism related gene expression patterns. Cell-of-origin subtype, determined by sequencing and IHC, did not associate with differences in overall survival (OS), while Ki-67 proliferation index ≥80% was associated with inferior OS in HIV+ DLBCL only (p = 0.03) and cMYC/BCL2 co-expression by IHC was negatively prognostic across the entire cohort (p = 0.01). This study provides among the first molecular characterizations of DLBCL from SSA, demonstrates marked gene expression differences by HIV status, and identifies genomic and immunophenotypic characteristics that can inform future basic and clinical investigations.

EBNA2-deleted Epstein-Barr virus (EBV) isolate, P3HR1, causes Hodgkin-like lymphomas and diffuse large B cell lymphomas with type II and Wp-restricted latency types in humanized mice

EBV transforms B cells in vitro and causes human B-cell lymphomas including classical Hodgkin lymphoma (CHL), Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). The EBV latency protein, EBNA2, transcriptionally activates the promoters of all latent viral protein-coding genes expressed in type III EBV latency and is essential for EBV's ability to transform B cells in vitro. However, EBNA2 is not expressed in EBV-infected CHLs and BLs in humans. EBV-positive CHLs have type II latency and are largely driven by the EBV LMP1/LMP2A proteins, while EBV-positive BLs, which usually have type I latency are largely driven by c-Myc translocations, and only express the EBNA1 protein and viral non-coding RNAs. Approximately 15% of human BLs contain naturally occurring EBNA2-deleted viruses that support a form of viral latency known as Wp-restricted (expressing the EBNA-LP, EBNA3A/3B/3C, EBNA1 and BHRF1 proteins), but whether Wp-restricted latency and/or EBNA2-deleted EBV can induce lymphomas in humanized mice, or in the absence of c-Myc translocations, is unknown. Here we show that a naturally occurring EBNA2-deleted EBV strain (P3HR1) isolated from a human BL induces EBV-positive B-cell lymphomas in a subset of infected cord blood-humanized (CBH) mice. Furthermore, we find that P3HR1-infected lymphoma cells support two different viral latency types and phenotypes that are mutually exclusive: 1) Large (often multinucleated), CD30-positive, CD45-negative cells reminiscent of the Reed-Sternberg (RS) cells in CHL that express high levels of LMP1 but not EBNA-LP (consistent with type II viral latency); and 2) smaller monomorphic CD30-negative DLBCL-like cells that express EBNA-LP and EBNA3A but not LMP1 (consistent with Wp-restricted latency). These results reveal that EBNA2 is not absolutely required for EBV to form tumors in CBH mice and suggest that P3HR1 virus can be used to model EBV positive lymphomas with both Wp-restricted and type II latency in vivo.

Risk, Diagnostic and Predictor Factors for Classical Hodgkin Lymphoma in HIV-1-Infected Individuals: Role of Plasma Exosome-Derived miR-20a and miR-21

The incidence of classical Hodgkin lymphoma (cHL) in the HIV-1 setting has increased 5–25-fold compared to that observed in the general population. This study aimed to determine whether selected micro RNAs (miRs) and other soluble biomarkers and cellular subsets are dysregulated in cHL and could be used as biomarkers. This was a retrospective and longitudinal matched case-control study of 111 Caucasian, HIV-1-infected adult individuals, including 37 individuals with cHL and 74 with no type of cancer. Immunovirological data, plasma exosome-derived miR-16, miR-20a, miR-21, miR-221, miR-223, miR-106a, miR-185, miR-23, miR-30d, miR-222, miR-146a and miR-324, plasma IL-6, sCD14, sCD27, sCD30, sIL-2R, TNFR1, and cell phenotyping of T and B lymphocytes and natural killer (NK) cells were analyzed. Before cHL diagnosis, miR-20a, miR-21, and sCD30 were higher in cHL (p = 0.008, p = 0.009 and p = 0.042, respectively), while miR-16 was down-regulated (p = 0.040). miR-20a and miR-21 were independently associated with cHL (p = 0.049 and p = 0.035, respectively). The combination of miR-20a and miR-21 showed a good AUC value of 0.832 with a moderate likelihood ratio positive (LR+) value of 5.6 and a slight likelihood ratio negative (LR−) value of 0.23. At cHL diagnosis, miR-20a, miR-21 and miR-324 were overexpressed in cHL (p = 0.005, p = 0.024, and p = 0.001, respectively), while miR-223, miR-16, miR-185 and miR-106a were down regulated (p = 0.042, p = 0.007, p = 0.006, and p = 0.002, respectively). In addition, sCD14, sCD27, sCD30 and IL2R levels were higher in these individuals (p = 0.038, p = 0.010, p = 0.030, p = 0.006, respectively). miR-20a was independently associated with cHL (p = 0.011). The diagnostic value of miR-20a showed good AUC value of 0.754 (p = 0.074) with a slight LR+ value of 2 and a slight LR− of 0.25. After chemotherapy, miR-20a was higher in those individuals who had an adverse outcome (p < 0.001), while sCD14 and sCD30 were higher (p < 0.001). A specific signature of miRs and cytokines associated with a subsequent cHL diagnosis was found in this study, especially miR-20a and miR-21. Also, another biomarker signature was found at cHL diagnosis, with a relevant discriminant disease value for miR-20a. Of note, miR-20a expression was higher in those individuals who had an adverse clinical outcome after chemotherapy.

In the South African setting, HIV-associated Burkitt lymphoma is associated with frequent leukaemic presentation, complex cytogenetic karyotypes, and adverse clinical outcomes

South Africa (SA) has a high prevalence of human immunodeficiency virus (HIV) infection. People living with HIV are at markedly increased risk of developing Burkitt lymphoma (BL), which is characterized by the MYC translocation. There is a paucity of survival data of HIV-associated Burkitt lymphoma/leukaemia (HIV-BL) cases from SA, and the relationship between karyotype and outcomes has not been widely reported. Here we report the clinico-pathological characteristics of a cohort of cytogenetically confirmed HIV-BL cases. A retrospective, descriptive review was conducted of clinico-pathological features of HIV-BL patients newly diagnosed and treated between 2005 and 2014 at our tertiary academic institution in Cape Town. Only HIV-BL patients with cytogenetic evidence of a MYC translocation were included for analysis. A multivariable Cox proportional hazards model assessed the impact of variables on overall survival (OS). Forty-nine patients met inclusion criteria. Their median age was 37 years (IQR 30-43 years) and 57% (n = 28) were females. Their median CD4 count was 240 cells/μl (IQR 103-423 cells/μl). The majority, 61% (n = 30), had leukaemic presentation, and 20% (n = 10) had a complex karyotype on conventional karyotyping. Seventy-seven percent (n = 36) received various protocols of combination intensive chemotherapy, excluding rituximab. Their OS was 64% (95% CI 45-77%) at 6 months, and 34% (95% CI 17-51%) at 5 years. Leukaemic presentation and a complex karyotype gave a 2.7-fold (95% CI 1.0-6.7) and 2.6-fold (95% CI 1.1-6.6) increased risk of mortality respectively, which were statistical significant (p < 0.05). We report 49 newly diagnosed, cytogenetically confirmed HIV-BL patients at our institution over a 10-year period. There was a high proportion of complex karyotypes and leukaemic presentation, which both independently adversely affected survival. This may be due to differences in the pathobiology of HIV-BL that requires further study and could lead to therapeutic advances in this patient group.

Effects of HIV on the Tumor Microenvironment

Oncomodulatory viruses can affect the tumor microenvironment (TME) by triggering inflammation, suppressing apoptosis, initiating angiogenesis, altering tumor metabolism, and stimulating tumor cell signaling pathways, leading to tumor growth, proliferation, and invasion. The higher incidence of malignancies among people with HIV (PWH), despite the widespread use of antiretroviral therapy (ART), suggests a more complex relation than HIV-associated immune deregulation. Viral cooperation can have synergistic effect on tumorigenesis. The most relevant oncogenes involved in viral cooperation include the HIV-1-related Tat and Vpu genes, EBV LMP-1 and EBNA-2 genes, and Kaposi's sarcoma herpesvirus (KSHV) KIE2, Rta, and LANA genes. The TME in HIV-related malignancies is highly angiogenic and characterized by high microvessel density compared to sporadic cases. Tat protein, found in patients with HIV infection regardless of their immune status, has been widely implicated in the increased angiogenesis and has been a target of interest for therapeutic strategies. Similarly, HIV-1 matrix protein p17 can be detected in the plasma and tissues of PWH, including those treated with ART. Studies have found that p17 can cause dysregulation of the biological activity of different immune cells, is involved in aberrant angiogenesis, and exhibits an IL8 chemokine activity, activating multiple intracellular signaling pathways, promoting angiogenic responses in endothelial cells, and forming capillary like structures. In addition, several studies have demonstrated difference in the cellular immune components within the TME in patients with or without HIV infection, as well as cases in pre- and post-ART era. In this chapter, we review the existing literature about the role tumor microenvironment plays in the pathogenesis of HIV-related malignancies. Understanding the functions of each component of the TME and determining how these cellular and noncellular components contribute to tumorigenesis will impact the advancement of interventions and treatment in clinical oncology among PWH.

Human Immunodeficiency Virus-Associated Lymphoproliferative Disorders

HIV infection is associated with an increased risk for developing B-cell lymphoproliferative disorders. The spectrum of disease differs in HIV-infected versus HIV-uninfected persons, with aggressive B-cell non-Hodgkin lymphomas constituting a higher proportion of all lymphoproliferative disorders in the HIV-positive population. Although antiretroviral therapy (ART) has significantly changed the landscape of lymphomas arising in HIV-infected persons, population growth and aging are reflected in the steady increase in non-AIDS-defining cancers. In the ART era, outcomes for HIV-infected lymphoma patients are similar to those of HIV-negative patients. This article reviews the diagnostic features and summarizes current biologic understanding of HIV-associated lymphomas.

Formation of the Immunosuppressive Microenvironment of Classic Hodgkin Lymphoma and Therapeutic Approaches to Counter It

Classic Hodgkin lymphoma (cHL) is characterized by a few tumor cells surrounded by a protective, immunosuppressive tumor microenvironment composed of normal cells that are an active part of the disease. Hodgkin and Reed-Sternberg (HRS) cells evade the immune system through a variety of different mechanisms. They evade antitumor effector T cells and natural killer cells and promote T cell exhaustion. Using cytokines and extracellular vesicles, they recruit normal cells, induce their proliferation and "educate" (i.e. reprogram) them to become immunosuppressive and protumorigenic. Therefore, alternative treatment strategies are being developed to target not only tumor cells but also the tumor microenvironment. Here we summarize current knowledge on the ability of HRS cells to build their microenvironment and to educate normal cells to become immunosuppressive. We also describe therapeutic strategies to counteract formation of the tumor microenvironment and related processes leading to T cell exhaustion and repolarization of immunosuppressive tumor-associated macrophages.

The Tumor Microenvironment in Post-Transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLDs) cover a broad spectrum of lymphoproliferative lesions arising after solid organ or allogeneic hematopoietic stem cell transplantation. The composition and function of the tumor microenvironment (TME), consisting of all non-malignant constituents of a tumor, is greatly impacted in PTLD through a complex interplay between 4 factors: 1) the graft organ causes immune stimulation through chronic antigen presentation; 2) the therapy to prevent organ rejection interferes with the immune system; 3) the oncogenic Epstein-Barr virus (EBV), present in 80% of PTLDs, has a causative role in the oncogenic transformation of lymphocytes and influences immune responses; 4) interaction with the donor-derived immune cells accompanying the graft. These factors make PTLDs an interesting model to look at cancer-microenvironment interactions and current findings can be of interest for other malignancies including solid tumors. Here we will review the current knowledge of the TME composition in PTLD with a focus on the different factors involved in PTLD development.

Survival and predictors of death in people with HIV-associated lymphoma compared to those with a diagnosis of lymphoma in general population

OBJECTIVES

to compare overall survival in HIV-associated lymphoma (HIV-L) and lymphoma raising in HIV-negative population (nHIV-L) and to identify predictors of increased risk of death.

METHODS

All HIV+ patients with HIV-associated lymphoma (Hodgkin lymphoma, HL; non-Hodgkin Lymphoma, NHL) observed between 1.2000 and 12.2013 in the ICONA Foundation Study cohort or in three collaborating centres, and, as control group, nHIV-L individuals followed in one of the four collaborating centres over the same time period, were included. Survival estimates were calculated by use of Kaplan-Meier (KM) and multivariable Cox regression models.

RESULTS

1,331 pts were included (465 HIV-L, 866 nHIV-L): 909 (68%) NHL, 422 (32%) HL. 3 years-cumulative probability (95% confidence interval, CI) of death was higher in HIV-L compared to nHIV-L in NHL (38% (33-44) vs. 22% (19-26); p<0.001), and HL (22% [15-29] vs. 10% (6-13), p<0.001). Among HL, HIV was associated with an increased risk of death (hazard ratio [HR] = 2.37 [95% CI: 1.24-4.55], p = 0.009) independently of calendar year, age, gender, type of chemotherapy and stage; in NHL, HIV was no longer an independent predictor of death after controlling for rituximab use and IPI (HR = 1.26 (0.97-1.63), p = 0.08).

CONCLUSIONS

Our analysis shows a reduced overall survival in HIV+ patients diagnosed with lymphoma compared to HIV-negative controls. Whereas in HIV people with HL, the increased risk of death was confirmed even after adjustment for main confounders, the association between HIV status and survival in NHL appears to be somewhat attenuated after controlling for more aggressive presentation and lower frequency of rituximab use in HIV-+ people.

Epstein-Barr virus associated lymphomas in people with HIV

PURPOSE OF REVIEW

The present review summarizes the association of the different histotypes of Epstein-Barr virus (EBV)-associated lymphomas with known genetic lesions and/or oncogenic viruses. A more comprehensive understanding of the complex interplay existing between genetic abnormalities of tumor cells and the viral contribution to the development of EBV-associated lymphomas is pivotal for the development of more effective treatments.

RECENT FINDINGS

Recent evidence indicates that HIV may contribute to lymphomagenesis by acting directly on B lymphocytes as a critical microenvironmental factor. The pathogenesis of EBV-associated lymphomas in patients with HIV infection is considered the result of the concerted action of different factors, mainly including impaired immune surveillance, genetic alterations, and concomitant viral infection (EBV and HIV).

SUMMARY

Immunodeficiency states usually increase susceptibility to cancer as a result of reduced immune surveillance and enhanced chances for virus-driven oncogenesis. Lymphoma remains the most frequent neoplastic cause of death among patients infected with HIV. Several of the HIV-associated lymphomas are related to EBV infection. EBV-associated lymphomas in patients infected with HIV are heterogeneous, not only pathologically but also in terms of pathogenetic pathways and cellular derivation.

Multiple viral infections in primary effusion lymphoma: a model of viral cooperation in lymphomagenesis

INTRODUCTION

Primary effusion lymphoma (PEL) is a rare B-cell lymphoid neoplasm mainly associated with HIV infection, presenting as pleural, peritoneal, and pericardial effusions. A defining property of PEL is its consistent association with Kaposi sarcoma associated herpesvirus (KSHV) infection, and, in most cases, Epstein Barr virus (EBV) co-infection. On these grounds, a review of the literature related to viral cooperation and lymphomagenesis can help to understand the complex interplay between KSHV and EBV in PEL pathogenesis. Areas covered: In this review, the authors highlight clinical, pathologic, genetic and proteomic features of PEL, in the context of viral cooperation in PEL lymphomagenesis. Expert commentary: Tumour cells are characterized by the overexpression of genes that are involved in inflammation and invasion. Coherently, PEL secretomes are enriched in proteins probably responsible for the particular tropism (cell adhesion and migration) of PEL cells. The development of PEL in HIV+ patients is multifactorial and involves a complex interplay among co-infection with oncogenic viruses (EBV and KSHV), inflammatory factors, and environmental conditions.

[Immune-checkpoint and hemopathies]

Immune-checkpoint inhibitors represent potent new therapies for most lymphomas, particularly for refractory diseases. Contrasting with solid tumors the majority of lymphoma are sensitive to conventional therapies and immunotherapies such as anti-CD20 or anti-CD30. But relapsing lymphoma or refractory disease have a very poor prognosis and new drugs are mandatory. Immune-checkpoint inhibitors targeting CTLA4, PD-1 et PD-L1 demonstrated efficiency with prolonged survivals even after bone marrow allograft for aggressive disease. Lymphomas differ from solid tumors as tumor cells belong to the immune compartment and therefore molecules targeting immune cells may act on both immune environment and tumor cells. Furthermore, PD-L1 expression in most lymphomas is related to tumor cell molecular alterations such as PD-L1 gene amplification or mutation. PD-L1 protein expression on tumor cells and immune cells, particularly it frequency and distribution vary according to different lymphoma subtype and it may help to assess diagnosis as it may predict therapeutical response.

Stage IV advanced diffuse large B-cell lymphoma in human immunodeficiency virus infection with achieving cure by using highly active antiretroviral therapy alone: a case report

After the introduction of highly active antiretroviral therapy (HAART), there has been a decrease in the incidence of lymphoma among the HIV-infected population and also significantly improved survival rates. We describe a remarkable case of an HIV-infected patient with advanced stage IV diffuse large B-cell lymphoma (DLBCL), completely regressed with the use of HAART alone. He remained disease-free for 6 years and he achieved cure without chemotherapy. Although several cases of low-grade lymphoma with complete regression were reported, we could not find any case of stage IV high-grade malignant lymphoma with HAART alone in complete remission for over 5 years from our review of the literature. This unique case shows the importance of HAART in improving survival and achieving cure in HIV-high-grade malignant lymphoma.

A lymphomagenic role for HIV beyond immune suppression?

Despite the immune reconstitution promoted by combined antiretroviral therapy (cART), lymphomas still represent the most common type of cancer in HIV-infected individuals. Cofactors related to immunodeficiency such as oncogenic viruses, chronic antigenic stimulation, and cytokine overproduction are thought to be the main drivers of HIV lymphomagenesis, although the current scenario does not convincingly explain the still-high incidence of lymphomas and the occurrence of peculiar lymphoma histotypes in HIV-infected patients under cART. Recent findings are challenging the current view of a mainly indirect role of HIV in lymphoma development and support the possibility that HIV may directly contribute to lymphomagenesis. In fact, mechanisms other than immune suppression involve biologic effects mediated by HIV products that are secreted and accumulate in lymphoid tissues, mainly within lymph node germinal centers. Notably, HIV-infected patients with lymphomas, but not those not affected by these tumors, were recently shown to carry HIV p17 protein variants with enhanced B-cell clonogenic activity. HIV p17 protein variants were characterized by the presence of distinct insertions at the C-terminal region of the protein responsible for a structural destabilization and the acquisition of novel biologic properties. These data are changing the current paradigm assuming that HIV is only indirectly related to lymphomagenesis. Furthermore, these recent findings are consistent with a role of HIV as a critical microenvironmental factor promoting lymphoma development and pave the way for further studies that may lead to the design of more effective strategies for an early identification and improved control of lymphomas in the HIV setting.