Regression of AIDS-related Kaposi's sarcoma following antiretroviral therapy with protease inhibitors: biological correlates of clinical outcome

Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases

Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.

Nitric oxide is induced and required for efficient Kaposi's sarcoma-associated herpesvirus lytic replication

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus associated with several human malignancies. KSHV lytic replication promotes the spread of infection and progression of KSHV-associated malignancies; however, the mechanism regulating KSHV lytic replication remains unclear. In this study, we investigated the role of nitric oxide (NO) in KSHV lytic replication. In the TREx BCBL1-RTA KSHV lytic replication cell system, induction of KSHV lytic replication increased intracellular and extracellular NO. Chemical inhibition of NO production resulted in a lower level of KSHV lytic replication as shown by a reduced level of infectious virions, and decreased levels of viral lytic transcripts and proteins. In a second KSHV lytic replication system of iSLK-RGB-BAC16 cells, we confirmed that KSHV lytic replication increased NO production. Chemical inhibition of NO production resulted in reduced numbers of cells expressing enhanced green fluorescent protein and blue fluorescent protein, two reporters that closely track the expression of KSHV early and late genes, respectively. Consistent with these results, inhibition of NO production resulted in reduced levels of infectious virions, and viral lytic transcripts and proteins. Importantly, exogenous addition of a NO donor was sufficient to enhance the full KSHV lytic replication program. These results demonstrate that NO is required for efficient KSHV lytic replication, and NO plays a crucial role in the KSHV life cycle and KSHV-induced malignancies.

Kaposi's sarcoma-associated herpesvirus seropositivity is associated with parasite infections in Ugandan fishing communities on Lake Victoria islands

We investigated the impact of helminths and malaria infection on Kaposi's sarcoma associated herpesvirus (KSHV) seropositivity, using samples and data collected from a cluster-randomised trial of intensive versus standard anthelminthic treatment. The trial was carried out in 2012 to 2016 among fishing communities on Lake Victoria islands in Uganda. Plasma samples from 2881 participants from two household surveys, the baseline (1310 participants) and the final (1571 participants) surveys were tested for KSHV IgG antibody responses to K8.1 and ORF73 recombinant proteins using ELISA. The baseline survey was carried out before the trial intervention while the final survey was carried out after three years of the trial intervention. Additionally, a subset sample of 372 participants from the final survey was tested for IgE, IgG and IgG4 antibody concentrations to S. mansoni adults worm antigen (SWA) and S. mansoni egg antigen (SEA) using ELISA. Infection by helminths (S. mansoni, N. americanus, T. trichiura and S. stercoralis) was diagnosed using real-time PCR, urine circulating cathodic antigen (CCA) and stool microscopy (Kato-Katz method) while malaria infection was diagnosed using microscopy. We analysed the relationship between helminth and malaria infections and KSHV seropositivity using regression modelling, allowing for survey design. At baseline, 56% of the participants were male while 48% of the participants were male in the final survey. The most prevalent helminth infection was S. mansoni (at baseline 52% and 34% in the final survey by microscopy, 86% by CCA and 50% by PCR in the final survey). KSHV seropositivity was 66% (baseline) and 56% (final survey) among those 1-12 years and >80% in those 13+ years in both surveys; malaria parasitaemia prevalence was 7% (baseline) and 4% (final survey). At baseline, individuals infected with S. mansoni (detected by microscopy) were more likely to be KSHV seropositive (aOR = 1.86 (1.16, 2.99) p = 0.012) and had higher anti-K8.1 antibody levels (acoefficient = 0.03 (0.01, 0.06) p = 0.02). In the final survey, S. mansoni (by microscopy, adjusted Odds Ratio (aOR = 1.43 (1.04-1.95), p = 0.028) and malaria parasitaemia (aOR = 3.49 (1.08-11.28), p = 0.038) were positively associated with KSHV seropositivity. Additionally, KSHV seropositive participants had higher S. mansoni-specific IgE and IgG antibody concentrations in plasma. Furthermore, HIV infected individuals on cART were less likely to be KSHV seropositive compared to HIV negative individuals (aOR = 0.46 (0.30, 0.71) p = 0.002). Schistosoma species skew the immune response towards Th2 and regulatory responses, which could impact on KSHV reactivation if co-infected with both organisms.

Regression of human immunodeficiency virus-associated oral Kaposi sarcoma with combined antiretroviral therapy: A case report and literature review

BACKGROUND

Kaposi's sarcoma (KS) is the most prevalent malignant neoplasia in human immunodeficiency virus positive (HIV+) patients for which the primary mode of management was chemotherapy.

METHODS

We have presented the case of a newly diagnosed HIV+ male patient who was diagnosed with a pedunculated nodule in the anterior region of the hard palate, measuring 3.5 cm in diameter and with 2 months of evolution.

RESULTS

Histopathological examination confirmed the clinical hypothesis of KS. Soon after the diagnosis, the patient started using combined antiretroviral therapy (Biovir and Kaletra), presenting a significant reduction of the lesion after 4 weeks. With 1.5 cm in diameter, the lesion was surgically removed. The patient was followed-up for 10 years without any recurrence.

CONCLUSION

In antiretroviral-naive patients with a well-preserved immune system, the use of cART may be efficient in reducing the progression of the KS lesions, thus avoiding the use of chemotherapeutic agents.

An In Vitro Model for Studying Cellular Transformation by Kaposi Sarcoma Herpesvirus

Kaposi sarcoma (KS) is an unusual tumor composed of proliferating spindle cells that is initiated by infection of endothelial cells (EC) with KSHV, and develops most often in the setting of immunosuppression. Despite decades of research, optimal treatment of KS remains poorly defined and clinical outcomes are especially unfavorable in resource-limited settings. KS lesions are driven by pathological angiogenesis, chronic inflammation, and oncogenesis, and various in vitro cell culture models have been developed to study these processes. KS arises from KSHV-infected cells of endothelial origin, so EC-lineage cells provide the most appropriate in vitro surrogates of the spindle cell precursor. However, because EC have a limited in vitro lifespan, and as the oncogenic mechanisms employed by KSHV are less efficient than those of other tumorigenic viruses, it has been difficult to assess the processes of transformation in primary or telomerase-immortalized EC. Therefore, a novel EC-based culture model was developed that readily supports transformation following infection with KSHV. Ectopic expression of the E6 and E7 genes of human papillomavirus type 16 allows for extended culture of age- and passage-matched mock- and KSHV-infected EC and supports the development of a truly transformed (i.e., tumorigenic) phenotype in infected cell cultures. This tractable and highly reproducible model of KS has facilitated the discovery of several essential signaling pathways with high potential for translation into clinical settings.

Human gammaherpesviruses viraemia in HIV infected patients

BACKGROUND

The Epstein-Barr virus (EBV) and Kaposi's sarcoma associated herpesvirus (KSHV) are consistently associated with lymphoproliferative diseases and cancers in humans, notably in patients with HIV.

AIMS

Our aim was to evaluate whether EBV and/or KSHV viral loads regularly assessed in peripheral blood mononuclear cells (PBMC) correlate with clinical or laboratorial parameters retrieved for patients living with HIV.

METHODS

This was a longitudinal study with a cohort of 157 HIV positive patients attending an academic HIV outpatient clinic in São Paulo State, Brazil. For each patient, up to four blood samples were collected over a 1 year clinical follow-up: on enrolment into the study, and after 4, 8 and 12 months. Total DNA was extracted from PBMC, and EBV and KSHV viral loads were assessed by real time quantitative PCR.

RESULTS

Higher viral loads for EBV were significantly associated with high HIV viraemia, a greater number of circulating T CD8+ cells and lack of virological response to the antiretroviral treatment. KSHV viral load was undetectable in virtually all samples.

CONCLUSIONS

EBV viral load in PBMC correlated with the number of circulating T CD8+ lymphocytes and the response to the antiretroviral therapy in HIV infected patients. In contrast, KSHV was undetectable in PBMC, presumably an effect of the antiretroviral treatment. Therefore, either KSHV infection in the population studied was absent or viral load in PBMC was beyond the analytical limit of the assay.

Prospective stage-stratified approach to AIDS-related Kaposi's sarcoma

PURPOSE

Combination antiretroviral therapy (cART) is standard of care for patients with HIV diagnosed with Kaposi's sarcoma (KS), but the current role of systemic chemotherapy is undefined.

PATIENTS AND METHODS

Since 1998, a prospective stage-stratified approach has been adopted for 469 patients with HIV with KS. Patients with early-stage (T0) KS are treated with cART alone; patients with advanced-stage (T1) KS receive cART plus liposomal anthracycline chemotherapy. Clinical characteristics, overall survival, and KS progression-free survival were analyzed according to stage at presentation and treatment received.

RESULTS

A total of 303 patients presented with T0 stage KS, including 237 who were not receiving cART, and 166 patients had T1 stage KS. Patients with T0 KS had higher CD4 cell counts (P < .001); 90% of patients with T0 KS who were not receiving cART and 84% of those with T1 KS were treated in accordance with the stage-stratified approach. Median follow-up was 4.6 years, and 5-year overall survival was 89%; 54 patients have died, 15 as a result of KS. Overall 5-year survival was 92% for T0 KS and 83% to T1 KS (P = .0024). On-treatment analysis of 213 cART-naive patients with T0 KS treated with cART alone revealed 5-year overall survival of 95% and progression-free survival of 77%. For 140 patients with T1 disease treated with cART and liposomal anthracycline chemotherapy, 5-year overall survival was 85%.

CONCLUSION

This stage-stratified approach to the management of KS achieves high survival in patients with advanced KS and reduces exposure to chemotherapy in patients with early-stage KS.

The impact of human immunodeficiency virus-related diseases on pigmented skin types

Infection with human immunodeficiency virus (HIV) remains a significant problem globally. Early diagnosis and treatment with antiretroviral drugs has considerably improved health outcomes and decreased disease-related morbidity. HIV infection is associated with a wide range of skin disorders enabling dermatologists to diagnose HIV as well as associated opportunistic infections early in the course of disease. Despite concerted efforts by international health organizations to limit disease incidence, the prevalence of HIV infection remains high and is highest in sub-Saharan Africa. The diagnosis of HIV-related skin diseases is challenging as immunosuppression often results in atypical disease presentation. In addition, the clinical presentation will vary in pigmented skin types. The aim of this article is to describe disease variation in pigmented skin types.

Epstein-Barr virus-driven lymphomagenesis in the context of human immunodeficiency virus type 1 infection

Epstein-Barr virus (EBV) is a ubiquitous human γ-herpes virus which establishes a life-long asymptomatic infection in immunocompetent hosts. In human immunodeficiency virus type 1 (HIV-1) infected patients, the impaired immunosurveillance against EBV may favor the development of EBV-related diseases, ranging from lymphoproliferative disorders to B cell non-Hodgkin's lymphomas (NHL). Antiretroviral therapy (ART) has significantly modified the natural course of HIV-1 infection, resulting in decreased HIV-1 plasmaviremia, increased CD4 lymphocytes, and decreased opportunistic infections, indicating a restoration of immune functions. However, the impact of ART appears to be less favorable on EBV-related malignancies than on other AIDS-defining tumors, such as Kaposi's sarcoma, and NHL remains the most common cancer during the ART era. EBV-driven tumors are associated with selective expression of latent oncogenic proteins, but uncontrolled lytic cycle with virus replication and/or reactivation may favor cell transformation, at least in the early phases. Several host's factors may promote EBV reactivation and replication; besides immunodepression, inflammation/chronic immune stimulation may play an important role. Microbial pathogen-associated molecular patterns and endogenous damage-associated molecular patterns, through Toll-like receptors, activate the immune system and may promote EBV reactivation and/or polyclonal expansion of EBV-infected cells. A body of evidence suggests that chronic immune stimulation is a hallmark of HIV-1 pathogenesis and may persist even in ART-treated patients. This review focuses on lymphomagenesis driven by EBV both in the context of the natural history of HIV-1 infection and in ART-treated patients. Understanding the mechanisms involved in the expansion of EBV-infected cells is a premise for the identification of prognostic markers of EBV-associated malignancies.

Successful treatment of an HIV-positive patient with unmasking Kaposi's sarcoma immune reconstitution inflammatory syndrome

BACKGROUND

Kaposi's sarcoma (KS) continues to be the most common human immunodeficiency virus (HIV)-associated neoplasm with considerable morbidity and mortality. While lesions normally resolve upon initiation of antiretroviral therapy (ART), recrudescence or unmasking of KS lesions may occur as part of immune reconstitution inflammatory syndrome (IRIS). Treatment of unmasking KS-IRIS is not yet standardised.

OBJECTIVES

To report the successful treatment of a patient with fulminating mucocutaneous unmasking KS-IRIS by maintaining ART and using pegylated liposomal doxorubicin (PLD).

STUDY DESIGN

The patient, a 39-year-old HIV-positive male with no previous history of KS presented with a 2-week history of cutaneous and oral KS lesions that had disseminated rapidly over the preceding 4 days. The KS lesions appeared 8 weeks after recommencing ART. At the time of this presentation, his CD4+ count was 742 cells/mm(3) with a HIV viral load <400 copies/ml. ART was maintained and treatment with PLD commenced.

RESULTS

Despite the rapid dissemination of KS lesions, virus was undetectable in plasma. In a late-stage vasoformative lesion, immunohistochemistry (IHC) for human herpesvirus 8 (HHV-8) antigen was light and diffuse, with stippled deposits within endothelial cell nuclei. Virus extracted from the lesion was HHV-8 subtype A. The patient responded well to PLD, relapsed a year later, but after further PLD, has remained well for the following 5 years.

CONCLUSION

Despite the absence of HHV-8 viraemia, this is clearly a case of unmasking KS-IRIS. It demonstrates that this entity can be successfully treated by maintaining ART and administering PLD.

CD4+ and CD8+ T-cell skewness in classic Kaposi sarcoma

It is widely accepted that a deranged immune system plays a key role in the onset and evolution of classic Kaposi sarcoma (CKS). Nevertheless, the usage of the T-cell receptor (TCR) β-variable (BV) chain repertoire expressed by peripheral blood lymphocytes in patients with CKS is still unknown. With the aim of providing some further insights into the complex role of the immune system in CKS pathogenesis, we performed an extensive analysis of the TCR BV repertoire in both CD4(+) and CD8(+) T cells in 30 human herpesvirus 8-positive Sardinian patients with CKS and an equal number of age-matched healthy controls. We used a panel of monoclonal antibodies covering approximately 70% of human BV subfamilies and third complementarity determining region (CDR3) spectratyping. Patients with CKS showed an increased frequency of BV expansions in both CD4(+) and CD8(+) lymphocytes, with no prevalent clones. On spectratyping analysis, most of the 720 BV CDR3 profiles obtained from both CD4(+) and CD8(+) T cells in patients with CKS were skewed. In particular, the surprising increase of BV skewing observed in CD4(+) lymphocytes mimics the pattern of progressive TCR BV narrowing described in responses to persistent viral antigen stimulations. Our findings support the hypothesis that CKS evolution is associated with inadequate activation rather than impairment of the immune system.

Epstein-Barr virus load and immune activation in human immunodeficiency virus type 1-infected patients

BACKGROUND

Patients infected with HIV-1 are at high risk of developing Epstein-Barr Virus (EBV)-related diseases. Chronic immune activation is a hallmark of HIV-1 pathogenesis and may play a role in B-cell stimulation and expansion of EBV-infected cells.

OBJECTIVES

The aim of the study was to define the relationship between parameters of immune activation and EBV load in HIV-1-infected subjects.

STUDY DESIGN

A total of 156 HIV-1-infected patients were studied. EBV types 1 and 2 were quantified on peripheral blood mononuclear cells by multiplex real-time PCR. Plasma levels of cytokines and lipopolysaccharide (LPS) were determined by immunoenzymatic assays. B-cell activation was analyzed by flow cytometry.

RESULTS

EBV-DNA was detected in 114 patients, and in all but 3 was EBV type 1. The median [interquartile] EBV-DNA load was 43[1-151] copies/10(5) PBMC. EBV-DNA load was higher in patients with detectable HIV-1 plasma viremia, despite good immunological status (CD4>500 cells/μl), than in patients with undetectable HIV-1 plasma viremia regardless of immunological status (46[5-136] copies/10(5) cells vs 17[1-56] copies/10(5) cells, p=0.008). Patients with high EBV-DNA load (>median value) had higher levels of LPS and proinflammatory cytokines (IL-6, IL-10 and TNF-α) than patients with low EBV load. Furthermore, percentages of activated B-cells correlated with EBV-DNA load (r(s)=0.754; p<0.001).

CONCLUSIONS

Overall, these findings indicate a strong association between HIV-1 viremia, markers of immune activation and EBV load and suggest that persistence of HIV-1 viremia and immune activation, regardless of peripheral CD4 cell depletion/repopulation, may favor expansion of EBV-infected cells and onset of EBV-related malignancies.

Clinical outcomes of HIV-infected patients with Kaposi's sarcoma receiving nonnucleoside reverse transcriptase inhibitor-based antiretroviral therapy in Uganda

BACKGROUND

Clinical outcomes for patients with Kaposi's sarcoma (KS) using nonnucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART) in resource-limited settings have not previously been described.

METHODS

We evaluated HIV-infected patients aged ≥ 18 years, who initiated HAART in the Home-Based AIDS Care (HBAC) project in Tororo, Uganda, between May 2003 and February 2008 and were diagnosed with KS at baseline or during follow-up. We examined independent risk factors for having either prevalent or incident KS and risk factors for death among patients with KS.

RESULTS

Of 1121 study subjects, 17 (1.5%) were diagnosed with prevalent KS and 18 (1.6%) with incident KS over a median of 56.1 months of follow-up. KS was associated with male sex [adjusted odds ratio (AOR) 2.41; 95% confidence interval (CI) 1.20-4.86] and baseline CD4 cell count < 50 cells/μL (AOR 3.25; 95% CI 1.03-10.3). Eleven (65%) of 17 patients with prevalent KS and 13 (72%) of 18 patients with incident KS experienced complete regression (P = 0.137). Eighteen (64%) of 28 patients who remained on NNRTI-based HAART experienced regression of their KS and six (86%) of seven patients who were switched to protease inhibitor-containing HAART regimens had regression of their KS (P = 0.23). Mortality among those with KS was significantly associated with visceral disease (hazard ratio 19.22; 95% CI 2.42-152).

CONCLUSION

Prevalent or incident KS was associated with 30% mortality. The resolution of KS lesions among individuals who initiated HAART with NNRTI-based regimens was similar to that found in studies using only protease inhibitor-based HAART.

Reactive oxygen species hydrogen peroxide mediates Kaposi's sarcoma-associated herpesvirus reactivation from latency

Kaposi's sarcoma-associated herpesvirus (KSHV) establishes a latent infection in the host following an acute infection. Reactivation from latency contributes to the development of KSHV-induced malignancies, which include Kaposi's sarcoma (KS), the most common cancer in untreated AIDS patients, primary effusion lymphoma and multicentric Castleman's disease. However, the physiological cues that trigger KSHV reactivation remain unclear. Here, we show that the reactive oxygen species (ROS) hydrogen peroxide (H₂O₂) induces KSHV reactivation from latency through both autocrine and paracrine signaling. Furthermore, KSHV spontaneous lytic replication, and KSHV reactivation from latency induced by oxidative stress, hypoxia, and proinflammatory and proangiogenic cytokines are mediated by H₂O₂. Mechanistically, H₂O₂ induction of KSHV reactivation depends on the activation of mitogen-activated protein kinase ERK1/2, JNK, and p38 pathways. Significantly, H₂O₂ scavengers N-acetyl-L-cysteine (NAC), catalase and glutathione inhibit KSHV lytic replication in culture. In a mouse model of KSHV-induced lymphoma, NAC effectively inhibits KSHV lytic replication and significantly prolongs the lifespan of the mice. These results directly relate KSHV reactivation to oxidative stress and inflammation, which are physiological hallmarks of KS patients. The discovery of this novel mechanism of KSHV reactivation indicates that antioxidants and anti-inflammation drugs could be promising preventive and therapeutic agents for effectively targeting KSHV replication and KSHV-related malignancies.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of all clinical forms of Kaposi's sarcoma (KS) and several other malignancies. The life cycle of KSHV consists of latent and lytic phases. While establishment of viral latency is essential for KSHV to evade host immune surveillances, viral lytic replication promotes KSHV-induced malignancies. In this study, we show that the reactive oxygen species (ROS) hydrogen peroxide (H₂O₂) induces KSHV reactivation from latency. Furthermore, induction of KSHV reactivation by oxidative stress, hypoxia, and proinflammatory and proangiogenic cytokines, which are physiological hallmarks in all clinical forms of KS patients, is mediated by H₂O₂. Significantly, antioxidants inhibit H₂O₂-induced KSHV lytic replication in culture and in a mouse model of KSHV-induced lymphoma. These results show that ROS is likely an important physiological cue that triggers KSHV replication. The discovery of this novel mechanism of KSHV reactivation indicates that antioxidants and anti-inflammation drugs might be promising preventive and therapeutic agents for effectively targeting KSHV replication and KSHV-related malignancies.

Risk factors influencing antibody responses to Kaposi's sarcoma-associated herpesvirus latent and lytic antigens in patients under antiretroviral therapy

BACKGROUND

Kaposi's sarcoma-associated herpesvirus (KSHV) seropositivity and lytic antibody titer are predictors for Kaposi's sarcoma.

METHODS

We examined demographic, viral, and immunologic factors that influence KSHV latent and lytic antibodies in HIV-infected patients.

RESULTS

Detection rate of KSHV latent but not lytic antibodies was lower in patients with CD4 cells/mm3 less than 200 than greater than 200 (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.11-0.61) and CD8 cells/mm3 less than 400 than greater than 400 (OR, 0.26; 95% CI, 0.07-0.67). Overall seropositivity rate was higher in patients with CD4 cells/mm3 less than 200 than greater than 200 (OR, 2.34; 95% CI, 1.37-4.02) and HIV copies/mL greater than 400 than less than 400 (OR, 1.70; 95% CI, 1.09-2.65). Lytic antibody level was inversely correlated with CD4 count (P < 0.001). Lytic seropositivity (OR, 2.47; 95% CI, 1.35-4.50) and antibody level (adjusted difference mean optical density, 0.324; 95% CI, 0.16-0.46) were higher in patients with HIV infection greater than 15 than less than 15 years. Hispanics had higher lytic seropositivity rate (OR, 1.71; 95% CI, 1.07-2.73) and antibody level (adjusted difference mean optical density, 0.111; 95% CI, 0.03-0.18) than non-Hispanics.

CONCLUSIONS

Lower CD4 and CD8 counts impair antibody response to KSHV latent antigens. Immune deterioration, long-term HIV infection, and Hispanic status are risk factors for Kaposi's sarcoma predictors.

A Retrospective Analysis of AIDS-Associated Kaposi’s Sarcoma in Patients With Undetectable HIV Viral Loads and CD4 Counts Greater Than 300 cells/mm3

Objective: To compare the clinical course of patients with AIDS-related Kaposi’s sarcoma (KS) with CD4 counts >300 cells/mm3 and undetectable HIV viral loads (VLs) to patients with AIDS-KS with lesser CD4 counts and detectable HIV VLs.

Methods: We retrospectively analyzed a cohort of 91 patients with AIDS-KS in a multispeciality clinic. We used χ2 and Student t tests to analyze intragroup differences; survival was determined by Kaplan-Meier analysis.

Results: Twenty (22%) of the 91 patients had newly diagnosed, persistent or progressive KS despite CD4 counts >300 cells/mm3 and undetectable HIV VLs. Age, gender, ethnicity, mode and duration of HIV acquisition, type of antiretroviral therapy (ART), and KS therapy did not differ significantly (P ≤ .005) between this group and the remaining 71 patients. Although tumor stage and response to KS therapy were similar, there was a significantly greater risk of death among the patients with CD4 counts <300 cells/mm3 and detectable HIV VLs (P = .048).

Conclusions: In the highly active antiretroviral (HAART) era, a substantial proportion of patients with KS had undetectable HIV VLs and CD4 counts greater than the level typically associated with opportunistic diseases. They required systemic therapy to control their KS but were significantly less likely to die and demonstrated a trend toward better 15-year survival than patients having KS with lesser CD4 counts and detectable HIV VLs.

The effect of HAART in 254 consecutive patients with AIDS-related Kaposi's sarcoma

OBJECTIVE

A prospective cohort study was performed to evaluate the clinical outcomes of patients with histologically confirmed AIDS-related Kaposi's sarcoma diagnosed since the introduction of HAART.

METHODS

Two hundred and fifty-four consecutive patients (96% men) diagnosed with Kaposi's sarcoma between 1996 and 2008 are included. Clinicopathological and treatment details were prospectively collected. The median follow-up is over 4 years and maximum 12 years.

RESULTS

The mean age at Kaposi's sarcoma diagnosis was 39 years and average duration of known HIV seropositivity was 4 years. At Kaposi's sarcoma diagnosis, only 19% patients were on HAART and only 7% patients had an undetectable plasma HIV viral load. Seventy-nine (31%) patients had AIDS clinical Trial Group stage T1 disease at Kaposi's sarcoma diagnosis and 122 (48%) had AIDS clinical Trial Group stage I1 disease (CD4 cell count < 150 cells/microl). Nodular grade Kaposi's sarcoma represented 28% of the tumours and was significantly associated with black African ethnicity and AIDS clinical Trial Group T1 stage disease. The overall 5-year survival is 89% (95% confidence interval 84-93). One hundred and sixty-three patients were treated with HAART alone for T0 stage Kaposi's sarcoma; only one died of Kaposi's sarcoma and only 37 (22%) required chemotherapy, giving a systemic treatment-free survival at 5 years of 74% (95% confidence interval 67-82) and the overall survival at 5 years is 91% (95% confidence interval 87-95).

CONCLUSION

The high success rate of HAART in a large cohort of AIDS-Kaposi's sarcoma patients over a prolonged period of follow-up will reassure patients and clinicians that this is a well tolerated and effective approach to stage T0 Kaposi's sarcoma.

The CD8 and CD4 T-cell response against Kaposi's sarcoma-associated herpesvirus is skewed towards early and late lytic antigens

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS), the most common malignancy in untreated individuals with HIV/AIDS. The adaptive T-cell immune response against KSHV has not been fully characterized. To achieve a better understanding of the antigenic repertoire of the CD8 and CD4 T-cell responses against KSHV, we constructed a library of lentiviral expression vectors each coding for one of 31 individual KSHV open reading frames (ORFs). We used these to transduce monocyte-derived dendritic cells (moDCs) isolated from 14 KSHV-seropositive (12 HIV-positive) and 7 KSHV-seronegative (4 HIV-positive) individuals. moDCs were transduced with up to 3 KSHV ORFs simultaneously (ORFs grouped according to their expression during the viral life cycle). Transduced moDCs naturally process the KSHV genes and present the resulting antigens in the context of MHC class I and II. Transduced moDCs were cultured with purified autologous T cells and the CD8 and CD4 T-cell proliferative responses to each KSHV ORF (or group) was assessed using a CFSE dye-based assay. Two pools of early lytic KSHV genes ([ORF8/ORF49/ORF61] and [ORF59/ORF65/K4.1]) were frequently-recognized targets of both CD8 and CD4 T cells from KSHV seropositive individuals. One pool of late lytic KSHV genes ([ORF28/ORF36/ORF37]) was a frequently-recognized CD8 target and another pool of late genes ([ORF33/K1/K8.1]) was a frequently-recognized CD4 target. We report that both the CD8 and CD4 T-cell responses against KSHV are skewed towards genes expressed in the early and late phases of the viral lytic cycle, and identify some previously unknown targets of these responses. This knowledge will be important to future immunological investigations into KSHV and may eventually lead to the development of better immunotherapies for KSHV-related diseases.

Do antiretrovirals reduce the risk of non-AIDS-defining malignancies?

PURPOSE OF REVIEW

There is an increasing burden of non-AIDS-defining malignancies (NADMs) in the antiretroviral therapy (ART) era. The recent literature is reviewed with respect to NADM risk, ART use, and immune function.

RECENT FINDINGS

Recent studies have increasingly focused on individual ART use, CD4 T-cell counts, and the risk of NADMs. Certain NADMs have been shown to have a reduced risk with ART use including liver, breast, colorectal, and lung cancers. NADMs associated with immunosuppression included Hodgkin's lymphoma, oral/pharynx, lung, anal, and colorectal cancers. Despite the potential protective effect of ART on some NADMs, recent studies evaluating calendar era trends have noted an increased risk of Hodgkin's lymphoma and anal cancer and no change in risk for lung cancer in the ART era.

SUMMARY

Successful ART use and improvements in immune function for HIV-infected persons may reduce the risk of certain NADMs. However, a continued high risk in the ART era for certain cancers have been observed, including Hodgkin's lymphoma and anal cancers. Future studies should monitor trends in NADMs in HIV-infected persons in the ART era, as well as changes in the prevalence of risk factors, coinfections, and screening practices in this population.

Persistent Kaposi sarcoma in the era of highly active antiretroviral therapy: characterizing the predictors of clinical response

OBJECTIVES

To evaluate the role of highly active antiretroviral therapy and chemotherapy on tumor response among persons with AIDS-related Kaposi sarcoma and identify factors associated with response in a clinic setting.

DESIGN

Retrospective cohort.

METHODS

One hundred and fourteen patients from two HIV clinics with a diagnosis of Kaposi sarcoma were identified via a clinical database. Records were reviewed to confirm Kaposi sarcoma diagnosis and abstract clinical and chemotherapy information. Demographics, laboratory values, and highly active antiretroviral therapy use were abstracted electronically. Cox's proportional hazards models identified predictors of Kaposi sarcoma improvement and resolution.

RESULTS

Thirty-six months following Kaposi sarcoma diagnosis, the rate of improvement among 64 patients with confirmed Kaposi sarcoma was 77% and that of complete resolution was 51%. In univariate analyses, recent chemotherapy was associated with Kaposi sarcoma improvement, and recent HIV viral load and highly active antiretroviral therapy were associated with both improvement and resolution. No measured baseline characteristics (tumor stage, diagnosis year, CD4 T-cell count, HIV viral load, or prior highly active antiretroviral therapy history) or recent CD4 T-cell counts predicted improvement or resolution. In multivariate analyses, recent chemotherapy (hazard ratio 5.5, 95% confidence interval: 2.7-11.2, P < 0.001) and highly active antiretroviral therapy (hazard ratio 4.1, 95% confidence interval: 1.4-12.6, P = 0.01) were predictors of improvement; only recent highly active antiretroviral therapy was associated with resolution (hazard ratio 6.2, 95% confidence interval: 1.5-26.4, P = 0.01). Response was not associated with type of highly active antiretroviral therapy regimen (non nucleoside reverse transcriptase inhibitor based, protease inhibitor based, or ritonavir-boosted protease inhibitor based).

CONCLUSION

Highly active antiretroviral therapy and chemotherapy are important in clinical Kaposi sarcoma response. Despite widespread availability of these therapies, Kaposi sarcoma continues to be a clinical problem; only half the patients achieved complete resolution of disease. New therapeutic approaches are needed.

Insights into pathogenic events of HIV-associated Kaposi sarcoma and immune reconstitution syndrome related Kaposi sarcoma

A decrease in the incidence of human immune deficiency virus-associated Kaposi sarcoma (HIV-KS) and regression of some established HIV-KS lesions is evident after the introduction of highly active anti-retroviral treatment (HAART), and is attributed to generalized immune restoration, to the reconstitution of human herpesvirus (HHV)-8 specific cellular immune responses, and to the decrease in HIV Tat protein and HHV-8 loads following HAART. However, a small subset of HIV-seropositive subjects with a low CD4+ T cell count at the time of introduction of HAART, may develop HIV-KS as immune reconstitution inflammatory syndrome (IRIS) within 8 weeks thereafter.

AIDS-defining and non-AIDS-defining malignancies: cancer occurrence in the antiretroviral therapy era

PURPOSE OF REVIEW

Effective antiretroviral therapy use has resulted in a large number of older individuals living with HIV. Recent literature is reviewed with respect to the incidence and risk factors for cancer in HIV patients.

RECENT FINDINGS

Previous studies have demonstrated substantial declines in AIDS-defining malignancies in the era of antiretroviral therapy, with clear links to better immune function. Increases in non-AIDS-defining malignancies such as Hodgkin's disease, skin, lung, anal, and kidney cancers have been noted by some but not all authors. Certain non-AIDS-defining malignancies may be related to immunodeficiency, although data are conflicting. Recent studies have indicated that confounding by traditional risk factors, including cigarette use, may account for some of the increased risk of lung and other cancers in HIV patients.

SUMMARY

Non-AIDS-defining malignancies account for more morbidity and mortality than AIDS-defining malignancies in the antiretroviral therapy era. Traditional risk factors play a significant role in the increased risk of non-AIDS-defining malignancies for HIV-infected individuals, but do not entirely explain the excess cancer risk. Unanswered questions remain including the relationship of immunodeficiency and the risk of site-specific non-AIDS-defining malignancies, and the effect of antiretroviral therapy duration and drug class on cancer risk.

Interactions and management issues in HSV and HIV coinfection

Significant synergistic interactions have been observed between HIV and herpes simplex virus (HSV). HIV-induced immune compromise can cause frequent and persistent HSV disease, while poorly controlled HSV replication may influence HIV pathogenicity and transmission. HSV-2 seroprevalence is high in HIV-infected cohorts worldwide, with rates of over 80% for HSV-1 and ranging from 33% to more than 80% for HSV-2. As seen in HIV-negative individuals, HSV-2 coinfection is associated with female gender, older age and black ethnicity. HSV infection is commonly under-diagnosed in HIV-infected individuals, although the use of PCR for HSV detection in mucocutaneous swabs and HSV type-specific serology can improve the diagnostic yield. In HIV-1-infected patients with frequent clinical episodes of HSV reactivation, suppressive antiviral therapy may prove beneficial in controlling HSV disease while also reducing HSV-mediated promotion of HIV replication. Antiretroviral therapy leads to a gradual recovery of HSV-specific T-cell responses and a reduction in HSV-related morbidity, indicating that successful management of coinfection should target both HIV and HSV replication. The aim of this review is to address the more speculative issues surrounding the management of HSV/HIV coinfection and to summarize the data that inform them.

Management of AIDS-related Kaposi's sarcoma

The advent of highly active antiretroviral therapy (HAART) has lead to a substantial reduction in the prevalence, morbidity, and mortality associated with AIDS-related Kaposi's sarcoma. Similarly, concomitant advances in chemotherapy and supportive-care protocols have allowed for Kaposi's sarcoma to be managed more effectively in comparison with the pre-HAART era. Furthermore, developments in our understanding of the pathogenesis of Kaposi's sarcoma have identified several molecular targets that can potentially provide new therapeutic strategies. This Review discusses the role of conventional chemotherapeutic and immunomodulatory agents in the treatment of Kaposi's sarcoma and summarises the current status and future prospects of novel molecularly targeted agents in the treatment of this disease.

Dermatologic Manifestations of the Immune Reconstitution Inflammatory Syndrome

The immune reconstitution inflammatory syndrome (IRIS) represents a diverse range of immunopathologic reactions resulting in clinical deterioration that may occur as immune function is partially restored in HIV-infected patients receiving highly active antiretroviral therapy. Approximately half of IRIS events are dermatologic, and dermatologic IRIS is described in relation to a wide range of conditions, the commonest being herpes zoster and herpes simplex. Most cases of IRIS result in mild and moderate symptoms, but non-dermatologic manifestations related to IRIS have resulted in death. This article covers certain general issues related to IRIS and then focuses on the spectrum of dermatologic manifestations.

Systemic treatment of AIDS-related Kaposi sarcoma: current status and perspectives

Kaposi's sarcoma (KS) is the most frequent type of cancer in patients with Acquired Immune Deficiency Syndrome (AIDS). In the western world, its incidence decreased dramatically in the era of highly active anti-retroviral therapy (HAART). In contrast, the incidence of KS has been steadily climbing in parallel with the AIDS epidemic in Africa over the past 10-15 years, being the most common cancer in adult men in countries like Uganda and Zimbabwe. AIDS-KS can be diagnosed at any stage of HIV infection, although it more commonly occurs in the setting of severe immune suppression, especially with an elevated viral load. Up to now, AIDS-KS is still an incurable disease. Its clinical course is variable, ranging from very indolent cases, requiring no or minimal therapy, to a rapidly progressive disease. Various local therapies are available to control small and asymptomatic lesions, while cytotoxic, immunological and biological therapies can be considered for more aggressive disease. The primary goal of therapy in most of the cases is to provide safe and effective palliation, in order to quality of life. Optimal anti-retroviral therapy is a key component of AIDS-KS management. There are still many questions to be answered in the management of patients with AIDS-KS, such as (1) What are the therapeutic agents that should be used in this disease, and in which sequence? and (2) What are the benefits and risks expected with each treatment option? The aim of this review is to discuss the systemic management of AIDS-KS, with special focus on the above mentioned questions.

Remission from Kaposi's sarcoma on HAART is associated with suppression of HIV replication and is independent of protease inhibitor therapy

Highly active antiretroviral therapy (HAART) reduces the incidence and improves the prognosis of Kaposi's sarcoma (KS). This study was designed to identify factors associated with KS clinical responses in HIV-infected patients during HAART. We reviewed the files of 138 HIV-1-infected patients with KS. Epidemiologic and HIV-related clinical and biological parameters were recorded at KS diagnosis (baseline) and every 6 months thereafter. In a subset of 73 antiretroviral-naive patients, we compared the clinical outcome of KS according to the use or nonuse of protease inhibitors (PI). After 6 months of follow-up, KS remission was more frequent in patients who were naive of HAART and who were at ACTG stage S0 at baseline (P=0.03 and 0.02). Undetectable HIV viral load was strongly associated with KS remission (P⩽0.004 at all time points), while CD4 cell count was not. Among the 73 antiretroviral-naive patients at baseline, and who were studied for 24 months, KS outcome did not differ between patients who were prescribed PI-containing and PI-sparing regimens. Intercurrent multicentric Castleman's disease was associated with poor outcome after 60 months of follow-up (P⩽0.0001). Fourteen deaths occurred after a median follow-up of 37.5 months, eight of which were KS related. Suppression of HIV replication appears to be crucial to control KS. Non-PI-based regimens were equivalent to PI-based regimens as regards the clinical and virological outcome of antiretroviral-naive HIV-infected patients with KS.

Evaluation of Antitumoral Properties of the Protease Inhibitor Indinavir in a Murine Model of Hepatocarcinoma

PURPOSE

Accumulating evidences show a higher incidence of hepatic neoplasm in HIV/hepatitis C virus (HCV)-coinfected individuals compared with HCV-monoinfected patients. Treatment with HIV-1 protease inhibitors inhibited cancer-promoted angiogenesis in HIV-infected patients affected by Kaposi sarcoma. We aimed to evaluate the antineoplastic potential activities of the protease inhibitor indinavir (Crixivan) in in vitro and in vivo hepatocarcinoma models.

EXPERIMENTAL DESIGN

We analyzed effects of indinavir on cell growth and invasiveness in Huh7 and SK-HEP-1 hepatocarcinoma cell lines and on in vivo tumor growth of the same cells in nude mice. Morphologic and molecular analyses on explanted tumors were carried out to evaluate vascularization and apoptosis.

RESULTS

We observed a reduced ability to invade an in vitro extracellular matrix for both cell lines treated with indinavir compared with controls (P = 0,001). Moreover, indinavir treatment was able to inhibit matrix metalloproteinase-2 proteolytic activation, whereas there was no effect on cell proliferation. The drug was also able to delay in vivo tumor growth. The inhibition of tumor growth was statistically significant from days 6 to 21 (P = 0.004 and P = 0.003, respectively). Moreover, the drug showed antiangiogenic and proapoptotic actions, as revealed by vessel count and apoptotic index by terminal deoxynucleotide transferase-mediated nick end labeling in explanted tumors. Finally, treatment with indinavir did not block the production of vascular endothelial growth factor in the tumors.

CONCLUSION

Indinavir could be helpful to prevent the development of hepatocarcinomas in HIV/HCV-coinfected individuals. In view of the current trend to substitute protease inhibitors with other antiretroviral agents, this information may have clinical implications.

Evidence of activity of Irinotecan in patients with advanced AIDS-related Kaposi's sarcoma

Fourteen HIV-infected patients with advanced Kaposi's sarcoma (KS) received Irinotecan 150 mg/m intravenously on days 1 and 10. All patients were relapsed/progressed during highly active antiretroviral therapy, administered as primary antineoplastic therapy. An objective response, all partial remissions, occurred in 75% of patients. Irinotecan was well tolerated, severe leukopenia occurred in only 33% of patients. In HIV-infected patients with advanced KS, irinotecan is active and well tolerated.

Current trends of HIV disease of the mouth

HIV infection affects residents of all countries of the world, but the greater majority of affected individuals reside in the developing world. In the past decade there have been substantial changes in the management of HIV disease, particularly the introduction of highly active antiretroviral therapy (HAART). Such agents have reduced significantly the morbidity and mortality associated with HIV disease, however, they are not available for most HIV-infected individuals in the developing world. There is now considerable understanding of the molecular epidemiology, transmission and therapy of the common opportunistic oral infections of HIV disease, and as a consequence of improved anti-HIV strategies, the frequency and severity of oral disease associated with HIV infection have reduced considerably, although HAART may predispose to human papilloma virus infection of the mouth and potentially increase the risk of later oral squamous cell carcinoma. Despite advances in clinical care the majority of individuals with HIV disease worldwide will continue to develop oral disease, as they are resident in the developing world and do not have ready access to even simple therapies.

Ocular association of HIV infection in the era of highly active antiretroviral therapy and the global perspective

Ocular involvement is a common complication of HIV infection. Since the late 1990s, widespread use of highly active antiretroviral therapy (HAART) has altered the spectrum, and reduced the incidence of ocular involvement in developed countries. The incidence of the most common ocular opportunistic infection, cytomegalovirus retinitis, has decreased tremendously. However, immune recovery uveitis secondary to HAART has emerged as a frequent visually threatening condition. Early diagnosis and treatment with periocular steroids is helpful in minimizing visual loss. Clinicians should also be aware that certain antimicrobial agents used to treat opportunistic infections in HIV-positive patients are associated with potentially serious ocular side effects. In developing countries, where most of the world's 40 million HIV-positive patients live, the spectrum and incidence of ocular involvement differ from those in developed countries. The lack of HAART availability is among the many causes of these differences, which may include nutritional factors, basic medical care availability and the levels of exposure to different infectious agents. These factors add to the already challenging task of treating ocular complications and preventing blindness in HIV-positive patients in developing countries.

Treatments of AIDS-related Kaposi's sarcoma

Although Kaposi's sarcoma (KS) has decreased in countries where the highly active antiretroviral therapy (HAART) regimen is available, however it remains, after non-Hodgkin's lymphomas, the most common malignancy in HIV+ patients. Advances in the treatment of AIDS-KS have been achieved, even though a gold standard therapy has not been yet defined. With the availability of HAART, a dramatic KS clinical response has been documented, making HAART essential in all patients. In case of aggressive and/or life threatening KS, more complex therapeutic schedules have to be taken into account, including chemotherapy and/or immunotherapy. Liposomal anthracyclines and paclitaxel have been approved by FDA as first line and second line mono-therapy, respectively. Interferon-alpha (INF-alpha) is the only immunomodulant agent to have shown a therapeutic effect. Among the new drugs, many antiangiogenetic agents have produced encouraging responses. Finally, the identification of the HHV-8 as a causative agent and new metalloproteinase inhibitors may offer promising targets for the KS treatment.

AIDS-related cancer in the era of highly active antiretroviral therapy (HAART): a model of the interplay of the immune system, virus, and cancer. "On the offensive--the Trojan Horse is being destroyed"--Part A: Kaposi's sarcoma

The introduction of highly active antiretroviral therapy (HAART), aimed at controlling human immunodeficiency virus (HIV), has been associated with a dramatic decrease in the incidence of acquired immunodeficiency syndrome-Kaposi's sarcoma (AIDS-KS) and the clinical manifestations of KS appear to be less aggressive. The pathogenesis of AIDS-related KS is related to a system of cytokines (e.g., interleukin-6) driven by autocrine and paracrine loops. More recently, human herpesvirus 8 (HHV-8), was discovered to be the putative etiological agent of this disease. This virus encodes several unique open reading frames that are homologs of human cellular proteins involved in cellular regulations, cell proliferation, apoptosis, and immune regulation. The treatment of this disease depends on whether it is "limited" disease or "extensive" disease. For "limited" disease, local therapy or non-bone marrow suppressive agents should be used. For "extensive" disease, new chemotherapeutic agents, such as liposomal anthracycline, which are active and have little adverse reactions, are indicated. The control of HIV infection continues to be essential. Knowledge of the pathogenesis of the disease has led to the development of novel treatment strategies, aimed at the inflammatory or angiogenesis cytokines necessary for growth or at HHV-8 as the target of therapy.

Therapeutic options for human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus-related disorders

Human herpesvirus-8/Kaposi's sarcoma-associated herpesvirus infection is associated with three proliferative disorders in immunocompromised patients - Kaposi's sarcoma, primary effusion lymphoma and multicentric Castleman's disease. These disorders often develop in patients with advanced AIDS who present a number of therapeutic challenges, underscoring the importance of continuing efforts dedicated to basic and clinical research in this field. In the era of highly active antiretroviral therapy, the incidence of AIDS and Kaposi's sarcoma has considerably decreased, presumably due to enhanced anti-Kaposi's sarcoma-associated herpesvirus immune responses, whereas the situation with primary effusion lymphoma and multicentric Castleman's disease is more complex. Based on advances in the understanding of Kaposi's sarcoma-associated herpesvirus-related disorders and availability of antiretroviral agents, current and future therapeutic approaches will be discussed.

Illness of Immune Reconstitution: Recognition and Management

Some individuals who initiate highly active antiretroviral therapy (HAART) develop new or worsening opportunistic infections or malignancies despite improvements in surrogate markers of HIV-1 infection. These events of paradoxical clinical worsening, also known as immune reconstitution syndromes (IRS), are increased in individuals with prior opportunistic infections or low CD4+ T-cell nadirs. They are thought to result from reconstitution of the immune system's ability to recognize pathogens or tumor antigens that were previously present, but clinically asymptomatic. There is no consensus regarding the diagnostic criteria or pathogenesis of IRS. Knowledge of their presentation and treatment is largely based on case reports. With the introduction of HAART into resource-limited settings, it is likely that significantly more and distinct forms of IRS will be observed. Prospective studies of the incidence and treatment of IRS in multiple settings are critical to better understand their pathogenesis and optimal management.

Immune reconstitution inflammatory syndrome associated with Kaposi sarcoma during potent antiretroviral therapy

Rapidly progressive Kaposi sarcoma (KS) lesions with lymphadenopathy and tissue swelling occurred in a patient during antiretroviral treatment, despite an increased CD4(+) lymphocyte count and decreased HIV-1 level and KS-associated herpesvirus replication, suggesting immune reconstitution inflammatory syndrome. Inflammation resolved coincident with decreases in the CD4(+) lymphocyte count during paclitaxel treatment, whereas KS cleared only after prolonged antiretroviral therapy and chemotherapy.

Pegylated liposomal doxorubicin plus highly active antiretroviral therapy versus highly active antiretroviral therapy alone in HIV patients with Kaposi's sarcoma

Twenty-eight HIV patients either naive or failing highly active antiretroviral therapy (HAART)with moderate-advanced Kaposi's sarcoma (KS)were randomly chosen to initiate a new HAART regimen plus pegylated liposomal doxorubicin(PLD) or the new HAART regimen alone. After 48 weeks, better response rates were observed in the HAART plus PLD group (76% versus 20%). In HIV-infected patients with moderate-advanced KS, HAART alone may not be enough for KS response.

Histological features of kaposi sarcoma in a patient receiving highly active antiviral therapy

The introduction of highly active anti-retroviral therapy (HAART) has changed the clinical presentation of skin diseases in patients with the Acquired Immune Deficiency Syndrome (AIDS). This occurs as a consequence of a newly recognized effect of this therapy known as the "Immune Reconstitution Syndrome," which develops with improvement of immunity. One manifestation of this syndrome is alteration of the natural history of Kaposi sarcoma (KS). While there are multiple reports of KS regression during HAART, there is little documentation of the histologic changes that occur. We present the case of a 55-year-old homosexual male with KS for over 4 years who underwent 6 biopsies over a 3-year period before, during, and after HAART. Kaposi sarcoma lesions prior to HAART were multinodular with ill-defined borders clinically and demonstrated typical features of nodular stage KS histologically. After initiation of HAART in this patient, lesions became uninodular, well circumscribed, and histologically were noted to be less cellular and surrounded by a dense fibrotic stroma. Although the mechanisms for these histologic changes are not clear, it may be due to activity of HAART against human herpesvirus type 8 (HHV-8), the causative agent of KS, to reconstitution of immunity due to diminution in HIV viral load, or both.

Antiretroviral Treatment Regimens and Immune Parameters in the Prevention of Systemic AIDS-Related Non-Hodgkin's Lymphoma

Purpose

Immunosuppression induced by HIV-1 increases the risk of developing non-Hodgkin's lymphoma (NHL). We measured the influence of immunologic factors and highly active antiretroviral therapy (HAART) on this risk. As there are no data demonstrating that specific antiretroviral regimens are effective at protecting from NHL, we compared different HAART regimens.

Patients and Methods

The protective effect of HAART regimens, containing protease inhibitors (PI) and/or non-nucleoside reverse transcriptase inhibitors (NNRTIs) on the development of NHL was examined in a prospectively recorded cohort of 9,621 HIV-infected individuals. Lymphocyte and natural killer subset data were also entered in univariate and multivariate analyses to establish and stratify the risk of NHL.

Results

From this cohort of 9,621 patients, 102 have been diagnosed with systemic AIDS-related NHL since 1996, when HAART became freely available here. By univariate analysis, increased age, higher nadir CD4 and CD8 T-cell counts, CD19 B-cell count, CD16/56 natural killer count and exposure to NNRTI or PI containing HAART conferred significant protection against NHL (P < .05). In a multivariate analysis, age, nadir CD4 and CD8 T-cell counts, and exposure to HAART were independent predictors of risk of NHL (P < .02). NNRTI-based HAART (adjusted rate ratio, 0.4; 95% CI, 0.3 to 0.5) was as protective as PI-based HAART, and these were significantly more protective than nucleoside analogues alone (rate ratio, 0.5; 95% CI, 0.4 to 0.7) or no antiretrovirals (P < .001).

Conclusion

Effective HAART-induced maintenance of CD4 and CD8 counts protects from systemic AIDS-related NHL.

Histological characterization of regression in acquired immunodeficiency syndrome-related Kaposi's sarcoma

BACKGROUND

Kaposi's sarcoma (KS) is an angioproliferative lesion that may regress or progress. Progression is related to spindle cell proliferation and the expression of human herpes virus-8 latency genes, including latent nuclear antigen-1 (LNA-1), cyclin-D1, and bcl-2. KS regression has not been well characterized histologically. Therefore, this study was undertaken to characterize the histopathology of pharmacologically induced regressed cutaneous KS.

METHODS

Skin punch biopsies from eight patients with acquired immunodeficiency syndrome (AIDS)-related KS, that regressed following chemotherapy with paclitaxel or the angiogenesis inhibitor Col-3, were investigated by light microscopy. Comparative immunophenotyping on pre- and post-treatment specimens for CD31, LNA-1, cyclin-D1, bcl-2, and CD117 (c-kit) was performed.

RESULTS

Clinical and histologic features of regression were similar for paclitaxel and Col-3 treatment. On clinical examination, lesions flattened, became smaller, and lost their purple-red appearance, resulting in an orange-brown macule. Histological regression was divided into partial (n = 3) and complete (n = 5) regression. Partially regressed lesions had a significant reduction of spindle cells in the dermal interstitium, with residual spindle cells arranged around superficial and mid-dermal capillaries. Complete regression was characterized by an absence of detectable spindle cells, with a slight increase in capillaries of the superficial plexus. All regressed samples exhibited a prominent, superficial, perivascular, lymphocytic infiltrate and abundant dermal hemosiderin-laden macrophages. This clinicopathologic picture resembled the findings of pigmented purpura. CD31 staining correlated with the reduction of spindle cells. Regression was accompanied by a quantitative and qualitative decrease in LNA-1 and cyclin-D1 immunoreactivity, but no change in bcl-2 or c-kit expression.

CONCLUSIONS

Pharmacologically induced regression of AIDS-related cutaneous KS is characterized by a complete loss or decrease of spindle cells, increased lymphocytes, and prominent dermal siderophage deposition. Without any prior knowledge of the history of KS regression following therapy, regressed KS lesions may be misdiagnosed clinically and histologically as pigmented purpuric dermatitis.

Impact of highly active antiretroviral therapy on the presenting features and outcome of patients with acquired immunodeficiency syndrome-related Kaposi sarcoma

BACKGROUND

The objective of the current study was to evaluate the impact of highly active antiretroviral therapy (HAART) on clinical characteristics of presentation and the natural history of Kaposi sarcoma (KS) in patients already receiving HAART at the time of KS diagnosis.

METHODS

The authors conducted a retrospective cohort study comparing epidemiologic, clinical, and outcome data for 160 patients who were naive to HAART at the time of KS diagnosis (KS-naive) with the corresponding data for 51 patients already receiving HAART at the time of KS diagnosis (KS-HAART). The analysis included all patients with a diagnosis of KS since January 1996 within two Italian cohorts of patients with human immunodeficiency virus.

RESULTS

Immunologic and virologic status at the time of KS diagnosis were significantly more favorable in the KS-HAART group than in the KS-naive group. The frequency of cutaneous involvement was similar in both groups, but cutaneous disease was more indolent among KS-HAART patients, with 1 anatomic site of involvement in 9 patients (21%) and less than 10 lesions in 26 patients (60%), compared with 16 patients (12%; P = 0.06) and 47 patients (34%; P = 0.01), respectively, in the KS-naive group. A smaller proportion of KS-HAART patients presented with visceral disease (24% vs. 39%; P = 0.06); in particular, gastrointestinal tract involvement was significantly less frequent among KS-HAART patients (14%) compared with KS-naive patients (28%; P = 0.05). Median survival was not reached in either group, and the 3-year survival rates of KS-HAART patients (64%) and KS-naive patients (78%) were not significantly different.

CONCLUSIONS

The data from the current study indicate that KS exhibits a less aggressive presentation in patients already receiving HAART compared with patients who are naive to HAART at KS diagnosis. Natural history and outcome do not appear to be influenced by the initiation of HAART before development of KS.

RNA interference: a potential tool against Kaposiʼs sarcoma-associated herpesvirus

PURPOSE OF REVIEW

RNA interference is a conserved cellular function that controls viral infection, the expression of transposable elements, repetitive sequences and genes in embryonic development. Originally described as an antiviral mechanism in plants, known as posttranscriptional gene silencing, it is now appreciated that this phenomenon occurs in all living cells. Double-stranded RNA, when acting as part of RNA interference, reduces expression of genes with sequence similarity, but has no effect on the expression of genes of unrelated sequence. Studies of RNA interference in mammalian cells have demonstrated that exogenous genes delivered by DNA transfection as well as endogenous gene expression can be suppressed by the delivery of RNA interference. We discuss here the potential for exploiting this phenomenon to prevent or treat viral infections, in particular Kaposi's sarcoma-associated herpesvirus.

RECENT FINDINGS

There have been several studies showing that RNA interference can be exploited to target a wide range of human viruses, including HIV-1, human T cell leukaemia virus-1, human papillomavirus, hepatitis B, hepatitis C and the polio virus. RNA interference is effective in mammalian cells and can be delivered by various methods. Double-stranded RNA has been injected into the tail veins of mice to block both virally and chemically induced hepatitis.

SUMMARY

A greater understanding of RNA interference allows us to exploit this phenomenon in order to study the functions of genes in mammalian cells, and also to target the expression of mutated cellular or viral genes. New delivery techniques should be developed to allow the process to be used as a therapeutic tool against viruses and malignancies in humans.

Use of HIV protease inhibitors to block Kaposi's sarcoma and tumour growth

HIV protease inhibitors are antiretroviral drugs that block the enzyme required for production of infectious viral particles. Although these agents have been designed to selectively bind to the catalytic site of HIV protease, evidence indicates that other cellular and microbial enzymes and pathways are also affected. It has been reported that patients treated with highly active anti-retroviral therapy (HAART) containing a protease inhibitor may be at reduced risk of Kaposi's sarcoma (KS) and some types of non-Hodgkin lymphomas; some disease regressions have also been described. Here we review recent data showing that several widely used protease inhibitors, including indinavir, saquinavir, ritonavir, and nelfinavir, can affect important cellular and tissue processes such as angiogenesis, tumour growth and invasion, inflammation, antigen processing and presentation, cell survival, and tissue remodelling. Most of these non-HIV-related effects of protease inhibitors are due to inhibition of cell invasion and matrix metalloprotease activity, or modulation of the cell proteasome and NFkappaB. These elements are required for development of most tumours. Thus, by direct and indirect activities, protease inhibitors can simultaneously block several pathways involved in tumour growth, invasion, and metastasis. These findings indicate that protease inhibitors can be exploited for the therapy of KS and other tumours that occur in both HIV-infected and non-infected individuals. A multicentre phase II clinical trial with indinavir in non-HIV-associated KS is about to start in Italy.