Kaposi's sarcoma, oncogenic viruses, and iron

INTRODUCTION: Iron is required for many cellular processes, but it is also toxic in excess quantities. Therefore, iron homeostasis and utilization must be strictly maintained, and defects in iron absorption or transport result in iron depletion or accumulation. Most research has been directed to enteral and placental transfer of iron, but little is known about iron entry through the skin. We present evidence that exposure to wet clay soils in Africa is an important risk factor for Kaposi's sarcoma (KS) and speculate that iron may be responsible for soil toxicity contributing to the pathogenesis of KS. STUDY DESIGN: Evidence gathered from case control studies and related investigations in Uganda between 1995 and 1998 are summarized. RESULTS: A large case control study of KS in HIV-infected adults disclosed affluence and mobility that suggest enhanced sexual exposure to human herpesvirus-8, the putative aetiologic agent of KS. Another study in endemic KS (HIV-negative) also showed affluence and mobility as risk factors. In addition, barefoot exposure to wet soil was an important risk factor for men with endemic KS. Other studies point to diminish delayed hypersensitivity in the lower limbs of KS patients. Geographic similarities of KS to podoconiosis (non-filarial elephantiasis) in Africa implicate soil absorbtion through the skin in the pathogenesis of KS and podoconiosis. CONCLUSION: The hypothesis of soil exposure as a risk for endemic KS has been strengthened by recent investigation. Particulate soil exposure may cause localized microtrauma and inflammation, predisposing to KS on the extremities in HHV-8 infected men. A role for iron toxicity is yet to be determined.     

Human herpesvirus type 8 variants circulating in Europe, Africa and North America in classic, endemic and epidemic Kaposi's sarcoma lesions during pre-AIDS and AIDS era

Human herpesvirus-8 (HHV-8) variants have been found heterogeneously distributed among human populations living in diverse geographic regions, but their differential pathogenicity in Kaposi's sarcoma development remains controversial. In the present study, HHV-8 variant distribution has been analyzed in classic, iatrogenic, endemic as well as epidemic Kaposi's sarcoma (KS) during pre-AIDS and AIDS period (1971-2008) in countries with different KS incidence rate. DNA samples from cutaneous KS lesions of 68 patients living in Africa (n = 23, Cameroon, Kenya and Uganda), Europe (n = 34, Greece and Italy) and North America (n = 11) have been subjected to PCR amplification of HHV-8 ORF 26, T0.7, K1 and K14.1/15, followed by direct nucleotide sequencing and phylogenetic analysis. Among the 23 African samples, the majority of HHV-8 ORF 26 variants clustered with the subtype R (n = 12) and B (n = 5). Conversely, the viral sequences obtained from 45 European and North European tumors belonged mainly to subtype A/C (n = 36). In general, HHV-8 and K1 variant clustering paralleled that of ORF 26 and T0.7. Genotyping of the K14.1/15 loci revealed a large predominance of P subtype in all tumors. In conclusion, comparison of the HHV-8 sequences from classic or endemic versus AIDS-associated KS showed a strong linkage of the HHV-8 variants with specific populations, which has not changed during AIDS epidemic.     

In vitro differentiation of porcine blood CD163- and CD163+ monocytes into functional dendritic cells

Swine monocytes constitute a heterogeneous cell population containing subsets with distinct functional capacities or representing different maturational stages. Based on the expression of CD163, we have recently identified two monocyte subpopulations. In this study, we investigate the ability of both CD163- and CD163+ monocytes to differentiate into dendritic cells (DCs) in the presence of GM-CSF and IL-4. Monocyte differentiation into DC is accompanied by an up-regulation of the expression of swine leukocyte antigen (SLA) I, SLA II and CD80/86 molecules, and a decrease in the expression of CD14, CD16 and CD163. These DC express the pan-myeloid marker SWC3 and display typical dendritic cytoplasmic projections. When monocytes are split into CD163+ and CD163- cells, both subsets give rise to DC. However, compared to CD163- monocyte-derived DC (MoDC), CD163+ MoDC appear to have reached a more advanced stage of maturation, expressing higher levels of SLA II and CD80/86 and inducing more efficiently proliferation of T cells to recall antigens and alloantigens.     

HLA in familial and nonfamilial Mediterranean Kaposi's sarcoma in Greece

Abstract: Fifty-four (54) unrelated patients with Mediterranean Kaposi's sarcoma (MKS) and 8 patients members of 4 unrelated families with familial MKS were serotyped for HLA-A,B and DR antigens. The diagnosis was histologically confirmed and all patients were negative for anti-HIV antibodies. An increased frequency of HLA-B18 (44.4% vs 14.2% in the controls, p<0.001, RR=4.8) and HLA-DR5 (57.6% vs 37.2% in the controls, p<0.025, RR=2.29) was observed in the group of patients with MKS. Seven (7) of the 8 family members with FMKS possessed HLA-DR5, and the affected members in the 3 families shared a common haplotype which included HLA-DR5. These findings support the hypothesis that genetic factors linked to HLA-DR5 antigen may contribute to the pathogenesis of MKS.     

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.     

Classic type of Kaposi's sarcoma and human herpesvirus 8 infection in Xinjiang, China

We report 17 cases of the classic type of Kaposi's sarcoma in Xinjiang, which is located in the north-western area of China surrounded by Mongolia in the east, Russia in the north and Kazakhstan in the west. Fifteen of the patients were of the Uygur people. All patients were male and did not have acquired immunodeficiency syndrome. Most of the lesions were found in the lower and/or upper extremities, with 16 patients showing multiple lesions. Immunohistochemical examination of the lesions revealed that human herpesvirus 8 (HHV-8)-encoded latency-associated nuclear antigen was expressed in the nuclei of spindle-shaped tumor cells. HHV-8 DNA was detected by polymerase chain reaction in all seven cases examined. Phylogenetic tree analysis revealed that DNA sequences of the HHV-8-encoded K1 gene in the seven Kaposi's sarcoma cases were classified as subtype C that was common in the Mediterranean, the Middle East and East Asian countries. In addition, using immunofluorescence we investigated the seroprevalence of HHV-8 in 73 Uygur patients with diseases other than Kaposi's sarcoma. Surprisingly, the serological study revealed that 34 of the patients (46.6%) were positive for antibodies against HHV-8, suggesting that HHV-8 infection is widespread in Xinjiang area. The occurrence of the classic type of Kaposi's sarcoma with a high seropositivity rate implies that Xinjiang is the most endemic area for HHV-8 infection in the world known to date. Considering that Xinjiang is located at the middle point of the Silk Road that used to extend from Rome to China, these data imply that the virus may have been in circulation in this area due to the migration of the people via the Silk Road.     

Human herpesvirus-8: detection of novel herpesvirus-like DNA sequences in Kaposi's sarcoma and other lesions

Kaposi's sarcoma (KS) is a malignancy suspected of having an infectious etiology. Unique viral DNA sequences were recognized in KS lesions, using a novel technique that identifies small differences between two complex genomes. The virus had homology with the herpesvirus family, especially Epstein Barr virus (EBV), yet it was distinct from the known herpesviridae, and was appropriately named human herpesvirus 8 (HHV-8) or Kaposi's sarcoma-associated herpesvirus (KSHV). HHV-8 DNA sequences were present in AIDS-associated KS, classic KS, African endemic KS, Mediterranean KS, iatrogenic KS, and KS in homosexual men without HIV infection. HHV-8 DNA sequences were also present in peripheral blood mononuclear cells (PBMC) of KS+ patients; body-cavity-based lymphomas in HIV positive patients without KS; and in tissue from a number of malignant and non-malignant lesions in patients without HIV infection. The role of HHV-8 in KS and other malignancies is not known. Viruses are notoriously trophic for lesional tissue. Therefore, in order to determine the role of HHV-8 in KS pathogenesis, HHV-8 needs to be isolated and shown to induce immortalization in a suitable system. Regardless of its role in KS, another human herpesvirus has been discovered, and the extent of its pathogenicity needs to be uncovered.Abbreviations KS Kaposi's sarcoma - HHV-8 human herpesvirus-8 - KSHV Kaposi's sarcoma-associated herpesvirus - EBV Epstein-Barr virus RDA representational difference analysis     

Molecular epidemiology of human herpesvirus 8 variants in Kaposi's sarcoma from Iranian patients

Kaposi's sarcoma (KS) is a rare cancer in Iran and there is no epidemiological and molecular information about HHV-8 variants circulating among the Iranian population. In this study HHV-8 sequences have been analyzed in 43 cutaneous KS biopsies from Iranian patients mainly affected by classic KS. DNA samples were subjected to PCR amplification of HHV-8 ORF26, T0.7 and K1 followed by direct nucleotide sequencing and phylogenetic analysis. The analysis of ORF26 showed that 30 (69.8%) and 13 (30.2%) samples belonged to subtypes A/C and K, respectively. In general, the clustering of HHV-8 T0.7 variants paralleled that of ORF26. Genotyping of K1 sequences showed that the majority of samples (39 out of 41) fall into the large C clade with only 2 belonging to the A clade. In conclusion, HHV-8 variants identified among classic Iranian KS are largely related to Eurasian genotypes previously identified in KS from Mediterranean, Middle East, and East Asian regions.     

Kaposi's sarcoma and malignant lymphoma in AIDS

Summary A 48-year-old homosexual with contacts in different countries, including Haiti, presented with multiple pigmented or bluish nodules on both lower legs and upper arms. He had a history of secondary syphilis, hepatitis B and herpes zoster ophthalmicus. Biopsies of the skin tumors revealed a typical Kaposi's sarcoma of low grade malignancy. The endothelial origin of the tumor was indicated by the presence of specific endothelial organelles (Weibel-Palade bodies) in the cytoplasma of the tumor cells. Erythrocytophagocytosis was found in tumor cells within and without the vascular channels. Laboratory tests were compatible with the clinical diagnosis of an acquired immune deficiency syndrome (AIDS) with a helper: suppressor T-lymphocyte ratio of 0.28 and a cutaneous anergy. In the course of the illness tumors of the stomach and duodenum were detected. Histology showed a malignant non-Hodgkin lymphoma of high grade malignancy. Within weeks the patient died in a cachectic state. Autopsy revealed a Kaposi's sarcoma of the skin with metastases in the stomach and a wide-spread malignant lymphoma in the gastrointestinal tract, in several visceral organs and in many lymph nodes.     

Gastrointestinal Kaposi's sarcoma: CD117 expression and the potential for misdiagnosis as gastrointestinal stromal tumour

Aims:  Gastrointestinal Kaposi's sarcoma (KS) may mimic gastrointestinal stromal tumours (GISTs) histologically. Studies have shown that KS outside the gastrointestinal (GI) tract may express CD117, an antibody usually used to support a diagnosis of GIST. The aim was to evaluate the clinicopathological features of GI KS, including the expression of CD117 with and without antigen retrieval.
Methods and results:  Fourteen GI KS were assessed histologically, 12 of which were also subjected to immunohistochemistry for CD34, human herpesvirus (HHV) 8, DOG1 and CD117. CD117 immunohistochemistry was performed with and without antigen retrieval. All cases showed an infiltrative spindle cell tumour. Lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin were typical histological features. In all cases tumour cells were positive for CD34 and HHV8, but negative for DOG1. CD117 was positive in four of 12 cases without antigen retrieval and 10 of 12 cases with antigen retrieval.
Conclusions:  The microscopic distinction of GI KS from GIST can be difficult. Clues that raise the possibility of GI KS include young patient age, a history of immunosuppression, lamina propria infiltration, lymphoplasmacytic inflammation, extravasated red blood cells and haemosiderin deposition. Use of the immunomarkers CD117 (without antigen retrieval), HHV8 and DOG1 may aid in the distinction between GI KS and GIST.     

Distinct expression of Kaposi's sarcoma-associated herpesvirus-encoded proteins in Kaposi's sarcoma and multicentric Castleman's disease

The expression of Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8)-encoded proteins is herein demonstrated in Kaposi's sarcoma (KS) and multicentric Castleman's disease (MCD) in a single lymph node derived from a patient with acquired immunodeficiency syndrome. Immunohistochemistry revealed that both lytic and latent KSHV proteins were expressed in cells of the MCD lesion. KSHV-encoded viral interleukin-6 was also detected in follicular dendritic cells of the germinal center. Cytoplasmic localization of open reading frame 59 protein and latency-associated nuclear antigen suggested KSHV activation in the MCD lesion. Moreover, a high copy number of KSHV was detected in the blood. Clinically, pegylated-liposomal doxorubicin induced regression of not only KS, but also lymphadenopathy of the MCD lesion with a decrease in KSHV load and human interleukin-6 in the blood. To the best of the authors' knowledge this is the first case demonstrating differential expression of virus proteins in two KSHV-associated diseases, KS and MCD, in the same section. The case confirms lytic KSHV infection in MCD, and suggests that clinical symptoms of MCD might be closely linked with KSHV activation.     

Interdigitating dendritic cell sarcoma presenting in the nasal region

Interdigitating dendritic cell sarcoma (IDCS) is an extremely rare neoplasm derived from antigen-presenting cells. IDCS displays aggressive behavior in a third of all cases, and the most common involvement is a solitary lymph node. We report the case of an 87-year-old woman with a right nasal mass. She underwent a wide local excision and right functional lymphadenectomy. Histopathological, immunohistochemical and molecular studies were consistent with the diagnosis of IDCS. Although it is extremely rare, this case suggests that extranodal IDCS should be considered in the differential diagnosis of undifferentiated fusiform neoplasms.     

Spontaneously regressed Kaposi's sarcoma and human herpesvirus 8 infection in a human immunodeficiency virus-negative patient

Kaposi's sarcoma occurring in a 78-year-old woman, with the absence of the human immunodeficiency virus infection, was correctly diagnosed by immunohistochemistry using anti-human herpesvirus 8 (HHV8) antibody (PA1-73N) for the first time. The patient suffered from chronic respiratory failure and was treated with a low dose of steroids for 2.5 years. After her medication dosage was increased for the exacerbation of the respiratory failure, multiple skin tumors in her feet and legs suddenly developed. Histopathologically, skin tumors were suspected as Kaposi's sarcoma at the first biopsy and reactive angiomatosis at the second biopsy. Polymerase chain reaction and immunohistochemistry, however, revealed the presence of HHV8 DNA fragment and positive staining in the majority of spindle cells in the skin tumors. Serological examination confirmed the positivity of anti-HHV8 antibodies. HHV8 infection and steroid-induced immunosuppression, as well as environmental factors played a role in the development of Kaposi's sarcoma in this patient, because she was born in Okinawa, which is a well-known endemic area of Kaposi's sarcoma in Japan. As her general condition improved, the skin lesions regressed without any specific treatment, and disappeared completely 8 months later, in which regression may be associated with evidence of numerous CD8 cell infiltration in the second biopsy tissues. No recurrence was observed during the following 6 month follow up.     

Expression of adhesion molecules in endemic and epidemic Kaposi's sarcoma

Spindle cells and vascular endothelium in nodular lesions of AIDS associated (epidemic) and endemic Kaposi's sarcoma showed similar immunohistochemical patterns of expression for cell adhesion molecules and extracellular matrix proteins. Spindle cells as well as endothelium also expressed both α5 and αV integrin subunits and ICAM-1 suggesting a possible role for inflammatory cytokines in spindle cell formation. The spindle cell compartment was rich in collagen, laminin, fibronectin and tenascin suggesting an important reactive component in the evolution of Kaposi's sarcoma. The lack of thrombospondin expression in the spindle cells favours the contention that they could be transitional, proliferating cells of endothelial origin. Specific expression of tat protein was not seen suggesting minimal if any HIV replication in these lesions. Our findings suggest similar histopathogenetic mechanisms for endemic and epidemic Kaposi's sarcoma. The clinically more malignant features of most AIDS related cases may reflect an important effect of systemic and focal cytokines in HIV patients and possibly other cofactor(s), i. e. tat protein in the induction and growth of the lesions.     

The immunoexpression of bcl-2 and p53 in Kaposi's sarcoma

The aim of this study was to examine the immunohistochemical expression of p53 and bcl-2 in Kaposi's sarcoma and relate this with proliferation index (as measured by MIB-1 staining) and clinicopathological subtypes. Twenty formalin-fixed, paraffin-embedded cases of Kaposi's sarcoma were stained with commercially available antibodies to p53, bcl-2 and MIB-1, after pressure cooking antigen retrieval. All cases were strongly positive for bcl-2 with the majority containing more than 75% positive cells. In comparison, p53 expression was less striking. Eleven cases contained less than 24% (+1) of cells staining positively. Only two cases showed greater than 75% of positive cells, and both of these latter two lesions had metastasized. The MIB-1 staining in all cases of Kaposi's sarcoma was strongly positive, irrespective of clinicopathological type, in keeping with the highly proliferative nature of this lesion. Thus, we have demonstrated uniformly increased expression of bcl-2 protein in Kaposi's sarcoma irrespective of clinicopathological subtype and MIB-1 staining, while p53 expression is relatively less common, except in those cases which have metastasized. This may help identify those cases that will behave in a more aggressive manner. However, more cases need to be evaluated to verify this.     

Kaposi's sarcoma in AIDS patients: Long-term treatment with recombinant interferon alpha-2A and chemotherapy

Summary We evaluated the response to therapy and outcome in patients with HIV-associated KS. Eighteen of 26 patients with newly diagnosed KS were treated continuously with IFN until progression of the disease occurred. In most patients with progressive disease, chemotherapy, usually with vinca alcaloid derivatives was instituted. Results were disappointing: 10 of 26 patients (38.5%) died after a median follow-up period of 4.5 months. Survival was shortest in patients who developed opportunistic infections, malignant lymphoma, or had a low OKT₄/OKT₈ ratio. Only one patient showed a complete remission and one patient had a partial remission under IFN therapy. Five additional patients had stable disease. Chemotherapy was without measurable effect on KS in patients who had progressive disease under IFN. IFN therapy was associated with various, not life-threatening adverse effects and was best tolerated by patients with a low OKT₄/OKT₈ ratio. Our results indicate that only a small portion of AIDS patients with KS seem to benefit from a continuous treatment with IFN.Abbreviations AIDS Acquired immunodeficiency syndrome - CNS Central nervous system - ELISA Enzyme linked immunosorbent assay - ESR Erythrocyte sedimentation rate - HIV Human immunodeficiency virus - IFN Recombinant interferon alpha-2a - KS Kaposi's sarcoma - WHO World Health Organization     

Classic Kaposi's sarcoma presenting first with gastrointestinal tract involvement in a HIV-negative Inuit male--a case report and review of the literature

Kaposi's sarcoma (KS) is a multicentric low-grade vascular malignancy. In North America, it is usually seen in AIDS and solid organ transplant populations. Classic KS is a subtype that traditionally occurs in elderly HIV-negative males of Mediterranean, Eastern European, and Jewish descent. Patients with classic KS characteristically present with skin lesions in the distal extremities. Involvement of the viscera is uncommon in classic KS, but may occur in the late stages of the disease. We report the first case of classic KS presenting in the gastrointestinal tract of an elderly HIV-negative Inuit male from Northern Quebec, Canada.     

Consistent polymerse chain reaction–single-strand conformation polymorphism pattern of human herpesvirus-8 in the course of classical Kaposi's sarcoma assumes its clonal origin

There is emerging evidence that Kaposi's sarcoma–associated herpesvirus (KSHV or HHV-8) has a central role in the pathogenesis of Kaposi's sarcoma (KS). The occurrence of HHV-8 in classical KS biopsies is reported irrespective of its clinical stage (patch, plaque, nodular). HHV-8 was detected in 25 of 28 formalin-fixed paraffin-embedded classical KS samples by nested polymerase chain reaction. In addition, in six patients multiple tumors were available (n = 21). Single-strand conformation polymorphism (SSCP) analysis of the amplicons showed uniform SSCP pattern of samples belonging to the same patient regardless of whether the KS was multiplex or developed again years after the first excision. Most of the SSCP patterns were confirmed by further sequence analysis. The presence of the same sequence variant of HHV-8 in various samples of the same patient supports the clonal origin of classical Kaposi's sarcoma. J. Med. Virol. 54:300–304, 1998. © 1998 Wiley-Liss, Inc.