Clearance of human herpesvirus 8 from blood and regression of leukopenia-associated aggressive classic Kaposi's sarcoma during interferon-alpha therapy: a case report.

A human immunodeficiency virus-negative woman with severe classic Kaposi's sarcoma, idiopathic leukopenia, and massive spread of human herpesvirus 8 (HHV-8) in circulating cells showed stable disease remission in response to systemic interferon-alpha treatment that was accompanied by increased CD3(+) and CD4(+) T cell numbers and complete clearance of HHV-8 from the circulation. These results suggest a direct relationship between HHV-8 clearance from blood and regression of Kaposi's sarcoma and are consistent with the in vitro inhibitory effects of interferon-alpha on HHV-8 infection.

Biology of Kaposi's sarcoma.

Kaposi's sarcoma (KS) is an angioproliferative disease occurring in several different clinical-epidemiological forms that, however, share the same histological traits and are all associated with infection by the human herpesvirus 8 (HHV8). KS initiates in a context of immune dysregulation characterised by CD8+ T cell activation and the production of Th1-type cytokines that induce a generalised activation of endothelial cells leading to adhesion and tissue extravasation of lympho-monocytes, spindle cell formation and angiogenesis. These phenomena are triggered or enhanced by infection with HHV8 that, in turn, is reactivated by the same cytokines. Productively-infected circulating cells are recruited into 'activated' tissue sites where HHV8 finds an optimal environment for establishing a persistent, latent infection of KS spindle cells (KSC). HHV8 dissemination is favoured by virus escape mechanisms and immune dysregulation, and leads to immune responses that are not effective against the virus but, paradoxically, exacerbates the reactive process. Although early KS is a reactive process of polyclonal nature that can regress, in time it can progress in to a true sarcoma. The progression of KS appears to be due to the deregulated expression of oncogenes and oncosuppressor genes, to the long-lasting expression of the HHV8 latency genes and, for AIDS-KS, is promoted by the proliferative and angiogenic effects of the HIV-1 Tat protein.

Impaired nutritional status in common variable immunodeficiency patients correlates with reduced levels of serum IgA and of circulating CD4+ T lymphocytes.

BACKGROUND: Common variable immunodeficiency (CVI) is a primary defect of the immune system. Infections, persistent diarrhoea and malabsorption may result in malnutrition, which may in turn contribute to increased morbidity. In this paper, the prevalence of malnutrition in CVI was evaluated. PATIENTS AND METHODS: Forty CVI patients (20 male, 20 female, aged 17-75 years) underwent anthropometric measurements from which body mass index, arm fat and muscle area were calculated. Body mass index values < 18.5 and arm fat and muscle area values < 10th percentile were considered indicative of malnutrition. Patients were divided into four groups according to circulating CD4+ T cells (lower or greater than 300 microL(-1)) and serum immunoglobulin A (IgA) levels (detectable and undetectable). RESULTS: Body mass index < 18.5, arm fat and muscle area < 10th percentile were observed in 23%, 58% and 44%, respectively, of patients. Lower values of body mass index, arm fat and muscle area were more frequent in patients with low CD4+ cells and undetectable IgA. Low arm fat values were more frequent in patients with diarrhoea (P = 0.03). Infectious episodes were more frequent in undetectable IgA than in detectable IgA patients (P = 0.04). CONCLUSIONS: Anthropometric measurements revealed an increased rate of malnutrition in CVI patients, particularly in those with low CD4+ and undetectable IgA, suggesting that selected CVI subjects could be considered for standard or specialized nutritional support.

Correlation between enzyme-linked immunosorbent assay and immunofluorescence assay with lytic antigens for detection of antibodies to human herpesvirus 8.

The purpose of this study was to evaluate, in Kaposi's sarcoma patients, the correlation between antibody titers to the lytic antigens of human herpesvirus 8, as assessed by immunofluorescence assay, and values obtained by an enzyme immunoassay. The methods showed a stringent correlation, r = 0.625 (P<0.001).

Distribution of the natural killer-related receptor for HLA-C during highly active antiretroviral therapy for human immunodeficiency virus infection.

Receptors interacting with Major Histocompatibility Complex class I molecules have been initially found on the surface of human natural killer (NK) cells, where they deliver inhibitory signals to the lysis, being thus defined killer inhibitory receptors (KIR). Subsequently, they were detected also on the surface of T-CD8(+) lymphocytes and are particularly expanded during human immunodeficiency virus (HIV) infection, where they downregulate HIV-specific cytolysis. The expression of KIR recognizing human leukocyte antigen-C alleles was assessed in HIV-infected patients, undergoing highly active antiretroviral therapy (HAART). To this end, the combined expression of CD16/CD56, of CD3 and CD8 as well as of KIR (CD158a and CD158b) surface molecules was analyzed on peripheral blood mononuclear cells by monoclonal antibodies, and flow cytometry. An increase of CD3(+)CD8(+)CD158b(+) cells was found after 6 months of HAART. This finding may have implications for the regulation of T-cell mediated cytolysis during HAART.

Human herpesvirus-8 in lymphomatous and nonlymphomatous body cavity effusions developing in Kaposi's sarcoma and multicentric Castleman's disease.

Human herpesvirus-8 (HHV-8) has been associated with Kaposi's sarcoma, multicentric Castleman's disease and primary effusion lymphoma. Kaposi's sarcoma and multicentric Castleman's disease patients may develop body cavity effusions that, unlike primary effusion lymphoma, are poorly characterized. To better define these effusions, pleural and peritoneal fluids derived from 12 human immunodeficiency virus-seropositive and one seronegative patients affected by Kaposi's sarcoma or multicentric Castleman's disease were analyzed by a combination of morphologic, immunophenotypic, and DNA analyses, including polymerase chain reaction amplification of HHV-8, Epstein-Barr virus, and immunoglobulin heavy-chain (IgH) gene sequences. In addition, HHV-8 serologic status was assessed by using an immunofluorescence assay. All patients were adult men with high antibody titers to HHV-8; 11 of the 13 patients were homosexual/bisexual. Effusions revealed monocyte/macrophage-rich infiltration (10 patients) or large-cell lymphoma with CD45(+)/non-T/non-B phenotype (three of 13 patients); polymerase chain reaction analysis showed the presence of HHV-8 sequences (nine of 13 patients), germline IgH (seven of 12 patients) or clonal IgH rearrangements (four of 12 patients), and rarely Epstein-Barr virus sequences (two of 12 patients). In the setting of HHV-8 infection, two effusion types may occur. One fulfills the criteria for HHV-8-positive PEL (lymphoma-morphology, HHV-8-DNA(+), IgH rearrangement). The other seems more reminiscent of an HHV-8-associated nonneoplastic process (monocyte-macrophage morphology, HHV-8-DNA(+/-), germline IgH). Interestingly, a single case of the latter effusion type harbored a B-cell monoclonal proliferation, which suggests the hypothesis that a prelymphomatous effusion may precede overt body cavity lymphoma.

Immune-derived cytokines in the nervous system: epigenetic instructive signals or neuropathogenic mediators?

The investigation of the effects of inflammatory cytokines (IC) on the growth and differentiation of neural cells has provided new insights on the role of such soluble mediators in nervous system development and/or plastic remodeling as well as in the pathogenesis of inflammatory neurodegenerative disorders, which are characterized by chronic IC dysregulation in the central nervous system (CNS). Thus, the study of the interaction between CNS and immune-derived soluble signals in physiological or pathological conditions is of increasing interest. This review first discusses experimental evidence supporting the instructive/permissive role of immune-derived cytokines on CNS development and plasticity. Next, we focus on human neurological disease states such as multiple sclerosis and the neurodegeneration associated to the acquired immune deficiency syndrome in which different inflammatory cytokines have been proposed as potential neuropathogenic mediators.

Herpes simplex virus vaccine in recurrent herpetic ocular infection.

PURPOSE: To evaluate the efficacy of an antiherpetic vaccine in recurrent herpetic ocular infections. METHODS: Twenty patients with herpes simplex virus 1-related recurrent keratitis/keratouveitis were prospectively enrolled and randomly assigned to receive either a specific vaccination with heat shock-inactivated herpes simplex virus type 1 (10 patients) or to be observed as controls (10 patients). The number, duration, and anatomic localization of relapses were recorded in all the patients for 12 months before inclusion in the study and for a similar period after the assignment of each subject to vaccine or control group. RESULTS: In the vaccine group, we observed a reduction both in the number (p = 0.016) and average duration (p = 0.050) of recurrences, whereas in the control group, no significant change was found comparing a 12-month period before and after inclusion in the study. The comparison between the two groups highlighted a significant reduction in the number (p = 0.013) and average duration (p = 0.051) of relapses in treated subjects, who did not show any significant vaccine-induced side effects. CONCLUSION: The use of a vaccination with heat shock-inactivated herpes simplex virus 1 seems to be able to reduce the number and duration of relapses in herpes simplex virus 1-related keratitis/keratouveitis.

High prevalence of antibodies to human herpesvirus 8 in relatives of patients with classic Kaposi's sarcoma from Sardinia.

A survey for antibodies to a recombinant small viral capsid antigen (sVCA) of human herpesvirus type 8 (HHV-8) was conducted in Sardinia, one of the world's highest incidence areas for classic Kaposi's sarcoma (KS). Prevalence of antibodies to HHV-8 sVCA was greatest in patients with KS (95%), followed by family members (39%) and a Sardinian control population age- and sex-matched to the relatives (11%). Within families, prevalence of antibodies was about equal among spouses, children, and siblings of KS patients, a finding that raises the possibilities of intrafamilial person-to-person or vertical transmission. Antibodies were detected 2-3 times more frequently in males than in females. The data show that prevalence of antibodies to HHV-8 sVCA correlates with the distribution of classic KS in a high- incidence area. Clustering of seroprevalence within some families suggests the presence of familial risk factors for active HHV-8 infection.

Primary effusion lymphoma containing human herpesvirus 8 DNA in two AIDS patients with Kaposi's sarcoma.

BACKGROUND AND OBJECTIVE: Primary effusion lymphomas (PELs) containing Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8/HHV-8) DNA sequences represent a distinct but heterogeneous group of rare non-Hodgkin's lymphomas of null-cell phenotype/B-cell origin. We aimed to describe the clinicopathologic features of two human immunodeficiency virus (HIV)-related PELs occurring in homosexual men with Kaposi's sarcoma (KS). DESIGN AND METHODS: Thoracentesis was followed by morphologic plus immunophenotypic studies and molecular analysis of tumor cell DNA by means of combination of polymerase chain reaction and Southern blot analysis. RESULTS: Patients developed recurrent lymphomatous effusions lacking tissue involvement, in the context of severe immunodepression (CD4 count < 60/microL) and anti-retroviral therapy. The effusions disclosed an immunoblast-like population CD45/CD30+, but B-cell- and T-cell-associated antigen negative, showing clonal immunoglobulin heavy chain gene rearrangements and harbouring HHV-8 DNA sequences. One case contained Epstein-Barr virus genome with no evidence of c-myc, bcl-2 and bcl-6 gene alterations. Both patients had aggressive disease. INTERPRETATIONS AND CONCLUSIONS: These cases represent additional examples of PEL associated with HHV-8 and confirm that the group of HIV-positive homosexual men may be at highest risk for PEL.

gamma-Interferon produced by CD8+ T cells infiltrating Kaposi's sarcoma induces spindle cells with angiogenic phenotype and synergy with human immunodeficiency virus-1 Tat protein: an immune response to human herpesvirus-8 infection?

Kaposi's sarcoma (KS) is an angioproliferative disease associated with infection by the human herpesvirus-8 (HHV-8). HHV-8 possesses genes including homologs of interleukin-8 (IL-8) receptor, Bcl-2, and cyclin D, which can potentially transform the host cell. However, the expression of these genes in KS tissues is very low or undetectable and HHV-8 does not seem to transform human cells in vitro. In addition, KS may not be a true cancer at least in the early stage. This indicated that besides its transforming potential, HHV-8 may act in KS pathogenesis also through indirect mechanisms. Evidence suggests that KS may start as an inflammatory-angiogenic lesion mediated by cytokines. However, little is known on the nature of the inflammatory cell infiltration present in KS, on the type of cytokines produced and on their role in KS, and whether this correlates with the presence of HHV-8. Here we show that both acquired immunodeficiency syndrome (AIDS)-KS and classical KS (C-KS) lesions are infiltrated by CD8+ T cells and CD14+/CD68+ monocytes-macrophages producing high levels of gamma-interferon (gamma IFN) which, in turn, promotes the formation of KS spindle cells with angiogenic phenotype. gamma IFN, in fact, induces endothelial cells to acquire the same features of KS cells, including the spindle morphology and the pattern of cell marker expression. In addition, endothelial cells activated by gamma IFN induce angiogenic lesions in nude mice closely resembling early KS. These KS-like lesions are accompanied by production of basic fibroblast growth factor, an angiogenic factor highly expressed in primary lesions that mediates angiogenesis and spindle cell growth. The formation of KS-like lesions is upregulated by the human immunodeficiency virus Tat protein demonstrating its role as a progression factor in AIDS-KS. Finally, gamma IFN and HLA-DR expression correlate with the presence of HHV-8 in lesional and uninvolved tissues from the same patients. As HHV-8 infects both mononuclear cells infiltrating KS lesions and KS spindle cells, these results suggest that HHV-8 may elicit or participate in a local immune response characterized by infiltration of CD8+ T cells and intense production of gamma IFN which, in turn, plays a key role in KS development.

gamma-Interferon production in peripheral blood mononuclear cells and tumor infiltrating lymphocytes from Kaposi's sarcoma patients: correlation with the presence of human herpesvirus-8 in peripheral blood mononuclear cells and lesional macrophages.

Evidence indicates that, at least in the early stage, Kaposi's sarcoma (KS) is a cytokine-mediated disease and that it is consistently associated with a novel herpesvirus termed human herpesvirus-8 (HHV-8). To gain insights into the mechanisms by which cytokines and HHV-8 may cooperate in disease pathogenesis, we examined the phenotype, the Th1 (gamma-interferon [gamma IFN]) and Th2 (interleukin-4 [IL-4] cytokine profile and the presence of HHV-8 in peripheral blood mononuclear cells (PBMC), tumor-infiltrating lymphocytes (TIL), and spindle cell cultures derived from skin lesions of patients affected by classical KS (C-KS) and acquired immunodeficiency syndrome (AIDS)-associated KS (AIDS-KS). TIL and spindle cell cultures were examined at day 0 or after culture in conditioned media from activated T cells (TCM) that contain the same cytokines increased in KS tissues. No differences were found in the immunophenotype of PBMC from C-KS patients versus controls, except for AIDS-KS patients who showed a T-CD8+ expansion. However, a preferential infiltration of T-CD8+ cells was found in all KS lesions examined, which was maintained after culture of TIL in TCM. gamma IFN production was found in both PBMC and cultures derived from all KS examined; some IL-4 positive supernatants were found only in three AIDS-KS cases. Uninvolved skin did not show appreciable lymphocyte infiltration or cytokine production. The culture conditions of the lesional skin allowed also the appearance of adherent, spindle-like cells bearing markers of tissue macrophages. Finally, most or all of the PBMC, lesions, and macrophagic cell cultures from the skin lesions were found to be positive for HHV-8 infection by nested polymerase chain reaction (PCR). These findings indicate that patients with KS express a Th1 phenotype with a prevalent gamma IFN production, likely accounted for by the local T-CD8+ infiltration. By analogy with other viral infections (i.e., Epstein-Barr virus), this suggests that in loco recruitment of lymphoid cells and the subsequent gamma IFN production may be in response to or elicited by HHV-8 that was found in both PBMC and macrophagic cell cultures from the lesions of the same patients.

Kaposi's sarcoma pathogenesis: a link between immunology and tumor biology.

Kaposi's sarcoma (KS) was a rare disease in Europe and North America until a decade ago, when it became the most common neoplasm complicating the acquired immunodeficiency syndrome (AIDS), where it acquires an aggressive course. Clinical and experimental data suggest that, at least in early stage, KS may not be a true sarcoma, but an hyperplastic-proliferative lesion that may regress. At least three components characterize KS lesions: (1) neoangiogenesis and proliferation of spindle-shaped cells of endothelial and macrophage cell origin, some of which may originate from a circulating precursor; (2) a cellular infiltrate represented by macrophages, lymphoid cells, mast cells, and neutrophils; and (3) the infection of spindle cells and mononuclear cells with a new virus of the Herpesvirinae family defined KS-associated herpesvirus or human herpesvirus-8 (HHV-8). KS lesions are highly responsive, in terms of growth, to inflammatory cytokines (IC) and many lesional cell components are able to secrete cytokines and chemokines, which induce paracrine-autocrine mechanisms of growth, angiogenesis, and promote further cellular recruitment. The association between HHV-8 and KS is close; however, the role of the virus in KS development is yet unknown. Nevertheless, the virus has the potential to encode for homologs of cellular cytokines and some chemokines and its reactivation is sensitive to stimuli provided by IC. This review focuses on these aspects of KS pathogenesis, trying to reconcile many of the clinical and experimental observations. Finally, the role of the HIV-1 Tat protein as a factor of progression in AIDS-KS as well as the role of cellular and HHV-8 encoded proto-oncogenes as factors and markers of progression of KS to a true malignancy is reviewed.

Kaposi's sarcoma cells express the macrophage-associated antigen mannose receptor and develop in peripheral blood cultures of Kaposi's sarcoma patients.

The mannose receptor (MR) is a surface 175-kd C-type lectin expressed by macrophages and dendritic cells. MR is involved in removal of effete cells, phagocytosis of mannose-coated particles, pinocytosis, and antigen presentation. Expression of MR was investigated in 17 biopsies of Kaposi's sarcoma (3 AIDS KS, 13 classical KS, and 1 transplant-associated KS) using three anti-MR monoclonal antibodies (3.29, D547, and PAM1). Immunostaining for MR was detected in 94 +/- 7% KS cells with spindle morphology. In normal tissues, MR was expressed by sinus-lining cells of spleen and lymph nodes, but it was not detected in endothelial cells lining normal hematic and lymphatic vessels, hemangioma, hemangioendothelioma, and lymphangioma. Expression of MR in KS cells prompted us to investigate the possibility that they derive from a circulating precursor cell. Peripheral blood mononuclear cells from 16 patients with KS (10 classical, 1 transplanted, and 5 AIDS) were cultured in PHA-conditioned medium for 10 to 14 days. Confluent monolayers of adherent spindle cells were detected in 8 of 11 classical KS, in 5 of 5 AIDS KS patients, and in 0 of 34 control patients. Peripheral-blood-derived KS-like cells were characterized by co-expression of macrophage and endothelial antigens being positive for CD45 (60%), CD68 (98%), MR (70%), CD14 (25%), VE-cadherin (70%), and von Willebrand factor (10%). When the immunophenotype of peripheral-blood-derived adherent cells was compared with that of KS spindle cells of tissue biopsies, it was found that both cell types are VE-cadherin+/MR+/CD68+, that peripheral-blood-derived spindle cells are CD34- and are less frequently stained for CD31 and von Willebrand factor, and that lesional KS cells do not express the leukocyte markers CD45 and CD18. Our findings are consistent with the possibility that KS lesions derive from tissue accumulation and local proliferation of a special subset of macrophages with endothelial features the normal counterpart of which are the sinus-lining cells of spleen and lymph nodes.