Overview of the management of AIDS-related Kaposi's sarcoma

Bone Marrow Culture Yield for the Diagnosis of Opportunistic Diseases in Patients with AIDS and Disseminated Kaposi Sarcoma

BACKGROUND

Disseminated Kaposi sarcoma (DKS) is present in patients with advanced HIV infection in whom co-infection with other opportunistic pathogens can occur. Bone marrow (BM) aspirate and biopsy comprise a robust diagnostic tool in patients with fever, cytopenias, and abnormal liver tests. However, the yield in patients with DKS has not been determined.

OBJECTIVE

The aim of this study was to evaluate the utility of BM aspirate and biopsy in patients with DKS.

METHODS

We included 40 male patients with a recent diagnosis of DKS. BM aspirate and biopsy was performed as part of the workup to rule out co-infections.

RESULTS

In four patients, Mycobacterium avium complex (MAC) was recovered from culture. In other four patients, intracellular yeasts were observed in the Grocott stain, diagnosed as Histoplasma. The yield of BM was calculated in 20%. Only 12 patients (30%) had fever and 11 (27.5%) had pancytopenia. Alkaline phosphatase (ALP) above normal values and C-reactive protein (CRP) were higher in patients with positive results for BM than in those with negative results (63% vs. 21.9%, and 3.0 vs. 1.2 mg/L; p = 0.03 in both comparisons). No differences were found when complete blood-count abnormalities were compared.

CONCLUSION

We recommend performing a BM aspirate for stains, culture, and biopsy in all HIV patients with DKS, as this will permit the early diagnosis of co-infections and prevent further complications in those who receive chemotherapy.

HIV-1 Vpr Inhibits Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication by Inducing MicroRNA miR-942-5p and Activating NF-κB Signaling

Kaposi's sarcoma-associated herpesvirus (KSHV) infection is required for the development of several AIDS-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). The high incidence of AIDS-KS has been ascribed to the interaction of KSHV and HIV-1. We have previously shown that HIV-1-secreted proteins Tat and Nef regulate the KSHV life cycle and synergize with KSHV oncogenes to promote angiogenesis and tumorigenesis. Here, we examined the regulation of KSHV latency by HIV-1 viral protein R (Vpr). We found that soluble Vpr inhibits the expression of KSHV lytic transcripts and proteins, as well as viral particle production by activating NF-κB signaling following internalization into PEL cells. By analyzing the expression profiles of microRNAs combined with target search by bioinformatics and luciferase reporter analyses, we identified a Vpr-upregulated cellular microRNA (miRNA), miR-942-5p, that directly targeted IκBα. Suppression of miR-942-5p relieved the expression of IκBα and reduced Vpr inhibition of KSHV lytic replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV lytic replication. Our findings collectively illustrate that, by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized HIV-1 Vpr inhibits KSHV lytic replication. These results have demonstrated an essential role of Vpr in the life cycle of KSHV.

IMPORTANCE

Coinfection by HIV-1 promotes the aggressive growth of Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). In this study, we have shown that soluble HIV-1 Vpr inhibits KSHV lytic replication by activating NF-κB signaling following internalization into PEL cells. Mechanistic studies revealed that a cellular microRNA upregulated by Vpr, miR-942-5p, directly targeted IκBα. Suppression of miR-942-5p relieved IκBα expression and reduced Vpr inhibition of KSHV replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV replication. These results indicate that by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized Vpr inhibits KSHV lytic replication. This work illustrates a molecular mechanism by which HIV-1-secreted regulatory protein Vpr regulates KSHV latency and the pathogenesis of AIDS-related malignancies.

MiRNA-891a-5p mediates HIV-1 Tat and KSHV Orf-K1 synergistic induction of angiogenesis by activating NF-κB signaling

Co-infection with HIV-1 and Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of aggressive AIDS-related Kaposi's sarcoma (AIDS-KS) characterized by abnormal angiogenesis. The impact of HIV-1 and KSHV interaction on the pathogenesis and extensive angiogenesis of AIDS-KS remains unclear. Here, we explored the synergistic effect of HIV-1 Tat and KSHV oncogene Orf-K1 on angiogenesis. Our results showed that soluble Tat or ectopic expression of Tat enhanced K1-induced cell proliferation, microtubule formation and angiogenesis in chorioallantoic membrane and nude mice models. Mechanistic studies revealed that Tat promoted K1-induced angiogenesis by enhancing NF-κB signaling. Mechanistically, we showed that Tat synergized with K1 to induce the expression of miR-891a-5p, which directly targeted IκBα 3′ untranslated region, leading to NF-κB activation. Consequently, inhibition of miR-891a-5p increased IκBα level, prevented nuclear translocation of NF-κB p65 and ultimately suppressed the synergistic effect of Tat- and K1-induced angiogenesis. Our results illustrate that, by targeting IκBα to activate the NF-κB pathway, miR-891a-5p mediates Tat and K1 synergistic induction of angiogenesis. Therefore, the miR-891a-5p/NF-κB pathway is important in the pathogenesis of AIDS-KS, which could be an attractive therapeutic target for AIDS-KS.

Acetylsalicylic acid (aspirin) and salicylic acid interaction with the human erythrocyte membrane bilayer induce in vitro changes in the morphology of erythrocytes

Despite the well-documented information, there are insufficient reports concerning the effects of salicylate compounds on the structure and functions of cell membranes, particularly those of human erythrocytes. With the aim to better understand the molecular mechanisms of the interaction of acetylsalicylic acid (ASA) and salicylic acid (SA) with cell membranes, human erythrocyte membranes and molecular models were utilized. These consisted of bilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. The capacity of ASA and SA to perturb the multibilayer structures of DMPC and DMPE was evaluated by X-ray diffraction while DMPC unilamellar vesicles (LUV) were studied by fluorescence spectroscopy. Moreover, we took advantage of the capability of differential scanning calorimetry (DSC) to detect the changes in the thermotropic phase behavior of lipid bilayers resulting from ASA and SA interaction with PC and PE molecules. In an attempt to further elucidate their effects on cell membranes, the present work also examined their influence on the morphology of intact human erythrocytes by means of defocusing and scanning electron microscopy, while isolated unsealed human erythrocyte membranes (IUM) were studied by fluorescence spectroscopy. Results indicated that both salicylates interact with human erythrocytes and their molecular models in a concentration-dependent manner perturbing their bilayer structures.

Trends in Kaposi's sarcoma survival disparities in the United States: 1980 through 2004

BACKGROUND

Kaposi's sarcoma (KS) is the most common cancer diagnosed among people with HIV in the United States. Highly active antiretroviral therapy (HAART) is an essential treatment for KS, and recent reports document the emergence of racial disparities in KS incidence and HIV-related mortality in the post-HAART era (1996 to present). The aim of this study was to examine trends in KS survival by race from the beginning of the HIV epidemic through the introduction of HAART.

METHODS

Median cause-specific survival and adjusted hazard ratios for KS from 1980 to 2004 were calculated by race using Surveillance, Epidemiology, and End Results nine-area data.

RESULTS

Median survival among both black and white patients was relatively constant until 1995 (average median survival, 14 and 18 months, respectively). In 1996, white patients experienced an increase in median survival to 103 months. In subsequent years, the increase in median survival was so great that white patients did not reach 50% mortality (follow-up ending December 31, 2007). Survival among black patients increased gradually until its peak in 2001 when median survival had not been reached after 83 months of follow-up. However, subsequent relative decreases to 35 months occurred in 2002 and 2004.

CONCLUSIONS

The current analysis provides evidence that there have been substantial increases in KS survival among white patients in the HAART era. Black patients have also experienced some improvements but to an attenuated extent.

IMPACT

Careful attention should be paid to the continuing evolution of trends in KS survival and survival disparities.

Kaposi sarcoma: a continuing conundrum

Kaposi sarcoma (KS) remains a challenge. Its classic or Mediterranean form tends to be benign. In transplant recipients it may be less so. As part of the AIDS pandemic, of which it was an original defining component, it may be life-threatening. It is due to human herpesvirus-8, which is necessary but not sufficient to produce the disease. KS has a low prevalence in the general population of the United States and United Kingdom, with an intermediate rate in Italy and Greece, and a high one in parts of Africa. In Italy, hot spots include its southern regions, the Po River Valley, and Sardinia, possibly related to a high density of blood-sucking insects. An important challenge is to treat KS patients without immunocompromising them. The potential of effective anti-herpes virus therapy and the use of sirolimus in transplantation recipients have added new opportunities for KS prevention.

LEARNING OBJECTIVES

At the conclusion of this learning activity, participants should be able to provide the most recent information about Kaposi sarcoma in the context in which it occurs. Its classic or Mediterranean form, its pattern in transplant recipients and others iatrogenically immunosuppressed, and its occurrence as a potentially life-threatening part of the AIDS pandemic will be stressed. Its etiology and transmission will be discussed in detail to facilitate understanding of Kaposi sarcoma and of human herpesvirus-8 infection in the general population of the United States and United Kingdom, in Italy and Greece, and in certain parts of Africa. Its therapy, including the concept of doing it without immunocompromising the patient, will be stressed. New opportunities for Kaposi sarcoma prevention will also be discussed.

Kaposi's sarcoma - still an enigma

Kaposi's sarcoma (KS) is an unusual neoplasm that has proved to be an enigma in many ways since its original description in 1872. KS, a vascular tumour that is otherwise rare, is at present the most common neoplasm in patients with AIDS. The lesions contain spindle cells that share features with endothelial cells and smooth muscle cells and are in all likelihood primitive mesenchymal cells that can form vascular channels. These cells are monoclonal in origin indicating therefore that KS is a neoplasm. The presence of a novel type of human herpes virus, KS herpesvirus (KSHV) also called human herpesvirus type 8 (HHV8) in KS lesions support a viral ethiology. KS may be mistaken in the skin for an inflammatory or other lesion, thus skin biopsy is important for correct diagnosis, with the use of immunohistochemistry or molecular biology if needed. Radiation or interferon alpha dominate in the therapeutic approaches.

Viral diseases of the oral mucosa

A wide variety of both DNA and RNA viruses affect the oral cavity. When considered in conjunction with cutaneous features, careful examination of the oral mucosa and oropharynx aids the clinician in making a diagnosis. Examination of the oral cavity should be incorporated as a regular component of the dermatologic examination because diagnostic clues are readily available to assist in the evaluation of infectious processes.

Antiviral agents: Nonantiviral drugs

The current arsenal of antiviral agents available to the practitioner is expanding rapidly, such that by the time this article goes to press, new drugs may have already been added. Although the majority of approved drugs have been developed for use in only a few viral infections (eg, HIV, herpesviruses, and papillomavirus), discoveries made in the development of these drugs may lead to antiviral agents effective against other viruses. In addition, new uses for the currently available drugs are under evaluation. This review of antiviral agents discusses the treatments available for viral infections such as herpes simplex virus, varicella zoster virus, cytomegalovirus, human papillomavirus, chronic viral hepatitis, and others.

Intralesional vinblastine vs. 3% sodium tetradecyl sulfate for the treatment of oral Kaposi's sarcoma. A double blind, randomized clinical trial

In this double-blind, randomized trial, we compared the clinical efficacy of intralesional vinblastine (VNB) and 3% sodium tetradecyl sulfate (STS) in the treatment of oral Kaposi's sarcoma (OKS). Subjects with OKS were randomly assigned to receive a single intralesional injection of either VNB or STS, at a standard dose (0.2 mg/cm(2)). Differences were evaluated by the Mann-Whitney U and Fisher's exact tests. Sixteen HIV-infected patients were included, eight received VNB and eight received STS; clinical response was evaluated at days 7, 14, and 28 following treatment. Tumor size reduction was 0.68 and 0.61 cm in the VNB and STS groups, respectively (P=0.80). Two VNB patients had complete or partial response whereas four STS subjects had partial responses (P=0.61). Patients in both groups experienced minimal toxicity. We conclude that intralesional vinblastine or STS are adequate for the management of OKS. The benefits of STS are its low cost and ease of use.

A case series of acquired immunodeficiency syndrome patients with initial neoplastic diagnoses of intraoral Kaposi's sarcoma

BACKGROUND

Oral Kaposi's sarcoma (KS) may represent the initial clinical manifestation of immunosuppression in human immunodeficiency virus disease. This article reviews the treatment provided to these patients and the outcome of the disease and provides the opportunity to assess the impact of improvements in the medical therapy of acquired immunodeficiency syndrome on disease outcome.

METHODS

A tumor registry was examined to identify patients in whom oral KS was the first neoplastic diagnosis.

RESULTS AND CONCLUSIONS

Thirty-seven cases of oral KS representing 1.9% of all cases of KS were identified as the first malignant diagnosis in patients with acquired immunodeficiency syndrome. Patients with oral KS have limited survival; the cause of death is either infection or malignancy. In our study, the palate was the most common site of primary involvement in the oral cavity. Recently diagnosed patients remained alive longer than those diagnosed earlier, and the patients with the most recently diagnosed cases were alive at the completion of the study, suggesting that medical management of human immunodeficiency virus has improved with new therapies.

Characterization of a novel human herpesvirus 8-encoded protein, vIRF-3, that shows homology to viral and cellular interferon regulatory factors

The genome of the human herpesvirus 8 (HHV-8) contains a cluster of open reading frames (ORFs) encoding proteins with homology to the cellular transcription factors of the interferon regulatory factor (IRF) family. Two of these homologues, vIRF-1 and vIRF-2, were previously identified and functionally analyzed. In this study, we have characterized a novel gene, designated vIRF-3, encoded within the previously predicted ORF K10.5 and our newly identified ORF K10. 6. Northern blotting of RNA extracted from BCBL-1 cells with a vIRF-3-specific probe and reverse transcription-PCR analyses revealed a single transcript of 2.2 kb with a splice present in the coding region. The vIRF-3 mRNA levels in BCBL-1 cells were increased upon 12-O-tetradecanoylphorbol-13-acetate treatment, with kinetics of expression similar to those of the early immediate genes. The vIRF-3 ORF encodes a 73-kDa protein with homology to cellular IRF-4 and HHV-8-encoded vIRF-2 and K11. In transient transfection assays with the IFNACAT reporter, vIRF-3 functioned as a dominant-negative mutant of both IRF-3 and IRF-7 and inhibited virus-mediated transcriptional activity of the IFNA promoter. Similarly, the overexpression of vIRF-3 in mouse L929 cells resulted in inhibition of virus-mediated synthesis of biologically active interferons. These results suggest that by targeting IRF-3 and IRF-7, which play a critical role in the activation of alpha/beta interferon (IFN) genes, HHV-8 has evolved a mechanism by which it directly subverts the functions of IRFs and down-regulates the induction of the IFN genes that are important components of the innate immunity.

Antiangiogenic strategies and agents in clinical trials

The understanding that the growth of tumors depends on the acquisition of a blood supply has led to the development of new therapies for cancer and other angiogenic diseases based on inhibition of neovascularization. This review examines the role of angiogenesis in cancer progression and describes various strategies for interfering with this process. The developmental status of angiogenesis inhibitors in human clinical trials is presented, including their proposed mechanisms of action. Standard chemotherapeutic agents and angiogenesis inhibitors are compared, noting that different end points might need to be considered in clinical trials and that drug resistance may be less of a problem with antiangiogenic therapy than with conventional chemotherapy regimens. The suggestion is made that cytotoxic chemotherapy and angiogenesis inhibitors used in combination may produce complementary therapeutic benefits in the treatment of cancer.

Alpha interferon inhibits human herpesvirus 8 (HHV-8) reactivation in primary effusion lymphoma cells and reduces HHV-8 load in cultured peripheral blood mononuclear cells

Infection by human herpesvirus 8 (HHV-8) is associated with the development of Kaposi's sarcoma (KS). Since regression of KS can be achieved by treatment of the patients with alpha interferon (IFN-alpha), we analyzed the effects of IFN-alpha or anti-IFN-alpha antibodies (Ab) on HHV-8 latently infected primary effusion lymphoma-derived cell lines (BCBL-1 and BC-1) and on peripheral blood mononuclear cells (PBMC) from patients with all forms of KS and from at-risk subjects. IFN-alpha inhibited in a dose-dependent manner the amplification of HHV-8 DNA in BCBL-1 cells induced to lytic infection with tetradecanoyl phorbol acetate (TPA). This effect was associated with the inhibition of the expression of HHV-8 nut-1 and kaposin genes that are induced early and several hours, respectively, after TPA treatment. In addition, IFN-alpha inhibited virus production and/or release from BCBL-1 cells. Inhibition of nut-1 and kaposin genes by IFN-alpha was also observed in BC-1 cells induced with n-butyrate. Conversely, the addition of anti-IFN-alpha Ab to TPA-induced BCBL-1 cells resulted in a larger number of mature enveloped particles and in a more extensive cytopathic effect due to the neutralization of the endogenous IFN produced by these cells. IFN was also produced by cultured PBMC from HHV-8-infected individuals, and this was associated with a loss of viral DNA during culture. However, the addition of anti-IFN-alpha Ab or anti-type I IFN receptor Ab promoted the maintenance of HHV-8 DNA in these cells that was associated with the detection of the latency-associated kaposin RNA. Finally, the addition of IFN-alpha reduced the HHV-8 load in PBMC. Thus, IFN-alpha appears to have inhibitory effects on HHV-8 persistent infection of PBMC. These results suggest that, in addition to inhibiting the expression of angiogenic factors that are key to KS development, IFN-alpha may induce KS regression by reducing the HHV-8 load and/or inhibiting virus reactivation.

Preclinical evaluation of chimeric L6 antibody for the treatment of Kaposi's sarcoma with radioimmunotherapy

L6 is a murine IgG2a monoclonal antibody with panadenocarcinoma reactivity. Chimeric L6 (ChL6), the variable region of murine L6 combined with a human IgG1 constant region, has been used in clinical trials for the delivery of radioimmunotherapy to patients with breast cancer. AIDS-associated Kaposi's sarcoma (KS), a malignancy of vascular endothelium, may be an excellent candidate for systemic radioimmunotherapy because KS is well vascularized and radioresponsive. Because ChL6 has been noted to bind vascular endothelium, our hypothesis was that ChL6 will recognize and bind KS tumors making this a potentially useful antibody for the treatment of KS with radioimmunotherapy. To test this hypothesis, 4 human KS spindle cell cultures established from cutaneous punch biopsy specimens (KS-MR, KS-NO, KS-JD and KS 6-3E) and one well-characterized human KS cell line (KS Y-1) were assessed for L6 immunoreactivity. All 5 cell cultures were L6 positive by immunohistochemistry. KS Y-1 cells grown as nude mouse xenografts were also L6 positive by immunohistochemistry. Competitive binding assays performed on the KS Y-1 and KS 6-3E cell cultures showed high density and high affinity cell binding. Biodistribution experiments performed on nude mice with KS Y-1 xenografts demonstrate tumor targeting by ChL6. These findings indicate that ChL6 may be a useful antibody for the radioimmunotherapy of KS. Future experiments will assess the therapeutic efficacy of radiolabeled ChL6 with and without concurrent systemic radiosensitizing chemotherapy.

Kaposi's sarcoma and human herpesvirus-8

KS is a major cause of morbidity and mortality among AIDS patients and a treatment problem in the sporadic cases that are not associated with HIV. All four forms of the disease are linked to a newly described herpesvirus, HHV-8 or KSHV, via strong epidemiologic associations and biologic plausibility as a causal agent. HHV-8 is also epidemiologically associated with body cavity-based lymphomas, which are almost unique to AIDS, and Castleman's disease. Existing radiation and chemotherapeutic treatments of KS are only partially effective and cause significant adverse effects. New preventive approaches and therapies aimed at inhibiting HHV-8 may be effective. New treatments that interfere with the molecular mechanisms that drive KS may, in the future, provide the best opportunities to control the disease.