Kaposi's sarcoma and other manifestations of human herpesvirus 8

First study of the detection of Human Herpes Virus-8 and major blood-borne viruses in iranian patients with SLE: A cross-sectional study

Background

Systemic lupus erythematosus (SLE) is an autoimmune disease caused by genetic and environmental factors such as viral infections. Genomic and serologic tests were applied to detect significant blood-borne viruses in SLE patients to determine whether there was a possible association between viral infections and SLE.

Methods

Antibodies (Abs) against HHV-8, HCMV, EBV, HIV, HBV, and HCV in SLE patients suffering from SLE were assessed by ELISA. In addition, HHV-8 DNA and HIV-1 RNA were quantified by real-time PCR, and the HCV and HBV genomes were detected using nested PCR.

Results

Compared to those in the control group, a high prevalence of anti-HHV-8 (p < 0.0001), anti-HCMV (p = 0.014), and anti-EBV (p = 0.017) Abs was detected in SLE patients. HHV-8, HIV, HCV, and HBV genomic tests were negative in both groups, while only 1.1 %, 2.2 %, and 1.1 % of SLE patients were positive for anti-HIV, anti-HCV Abs, and HBsAg, respectively. The most frequent major complaint in patients was arthralgia (76.7 %).

Conclusions

The increased prevalence of anti-HHV-8 Abs may not be related to the natural history of infection but to molecular mimicry. Increased anti-HCMV and anti-EBV Abs may also be associated with the development of SLE and may play direct or indirect roles in such infections or molecular mimicry. Since arthralgia is the most common symptom in SLE patients, the presence of these symptoms in any patient is a suggestive clue for the diagnosis of SLE. Defining the typical pattern of SLE in divergent nations with distinct environmental and geographical factors can be beneficial for obtaining a prompt diagnosis.

Colonic T-cell-rich, large B-cell lymphoma associated with equid herpesvirus 5 infection and secondary trans-colonic fistula in a horse

A 17-y-old Rocky Mountain gelding was presented to the Virginia-Maryland Veterinary Teaching Hospital because of a 4-wk history of anorexia, weight loss, lethargy, and fever of unknown origin. Abdominal ultrasound revealed lymphadenomegaly of the abdominal and colonic lymph nodes, thickening of the wall of the large colon, and a mass associated with the large colon. The horse was euthanized given a poor prognosis. On autopsy, an ~20-cm diameter mass was found within the mesocolon between the right ventral and right dorsal colon. The mass had invaded through the colonic walls and formed a fistula between the 2 involved lumina. On histologic evaluation, the mass consisted of small numbers of large neoplastic lymphocytes, numerous small lymphocytes, and many foamy macrophages. A diagnosis of T-cell-rich, large B-cell lymphoma was made based on immunohistochemical staining for CD79a, CD3, and Iba1; concurrent infection with equid herpesvirus 5 was confirmed with in-situ hybridization (ISH). To our knowledge, neither a trans-colonic fistula resulting from alimentary lymphoma in a horse nor detection of intralesional equid herpesvirus 5 in equine alimentary lymphoma by ISH has been reported previously.

Kaposi Sarcoma of the Larynx: A Systematic Review

OBJECTIVE

Kaposi sarcoma (KS) of the larynx is a rare disease with few cases reported in the literature. This study aims to provide a comprehensive review of laryngeal KS, including patient characteristics, treatment, and clinical outcomes.

DATA SOURCES

PubMed, CINAHL, SCOPUS, and Cochrane Library.

REVIEW METHODS

A systematic review of the published English literature was conducted. An electronic search and bibliographic examination of articles pertaining to laryngeal KS were performed. Demographic data, tumor site, treatment strategies, follow-up, and outcome were analyzed.

RESULTS

A total 77 cases from 50 articles were included in the review. The mean age was 47.6 years (range, 8-81). There was an 8.6:1 male:female ratio. The most common presenting symptoms were dyspnea (n = 35) and hoarseness (n = 25). Laryngeal KS arose most frequently in the supraglottic region (n = 16). Chemotherapy alone (n = 27) was the most common treatment modality in patients with AIDS-associated KS, and surgical excision alone (n = 7) was most common in patients with other subtypes of KS (eg, classic, transplant associated). Average follow-up was 20.4 months (range, 0.75-120). Most patients with AIDS-associated KS died of other causes (n = 25), but most patients with other subtypes of KS were alive with no evidence of disease at follow-up (n = 13).

CONCLUSION

This review contains the largest pool of laryngeal KS cases to date. Long-term outcomes were generally unfavorable, often due to advanced HIV disease at the time of diagnosis.

Lytic Replication and Reactivation from B Cells Is Not Required for Establishing or Maintaining Gammaherpesvirus Latency In Vivo

Gammaherpesviruses (GHVs) are lymphotropic tumor viruses with a biphasic infectious cycle. Lytic replication at the primary site of infection is necessary for GHVs to spread throughout the host and establish latency in distal sites. Dissemination is mediated by infected B cells that traffic hematogenously from draining lymph nodes to peripheral lymphoid organs, such as the spleen. B cells serve as the major reservoir for viral latency, and it is hypothesized that periodic reactivation from latently infected B cells contributes to maintaining long-term chronic infection. While fundamentally important to an understanding of GHV biology, aspects of B cell infection in latency establishment and maintenance are incompletely defined, especially roles for lytic replication and reactivation in this cell type. To address this knowledge gap and overcome limitations of replication-defective viruses, we generated a recombinant murine gammaherpesvirus 68 (MHV68) in which ORF50, the gene that encodes the essential immediate-early replication and transcription activator protein (RTA), was flanked by loxP sites to enable conditional ablation of lytic replication by ORF50 deletion in cells that express Cre recombinase. Following infection of mice that encode Cre in B cells with this virus, splenomegaly and viral reactivation from splenocytes were significantly reduced; however, the number of latently infected splenocytes was equivalent to WT MHV68. Despite ORF50 deletion, MHV68 latency was maintained over time in spleens of mice at levels approximating WT, reactivation-competent MHV68. Treatment of infected mice with lipopolysaccharide (LPS), which promotes B cell activation and MHV68 reactivation ex vivo, yielded equivalent increases in the number of latently infected cells for both ORF50-deleted and WT MHV68, even when mice were simultaneously treated with the antiviral drug cidofovir to prevent reactivation. Together, these data demonstrate that productive viral replication in B cells is not required for MHV68 latency establishment and support the hypothesis that B cell proliferation facilitates latency maintenance in vivo in the absence of reactivation. IMPORTANCE Gammaherpesviruses establish lifelong chronic infections in cells of the immune system and place infected hosts at risk for developing lymphomas and other diseases. It is hypothesized that gammaherpesviruses must initiate acute infection in these cells to establish and maintain long-term infection, but this has not been directly tested. We report here the use of a viral genetic system that allows for cell-type-specific deletion of a viral gene that is essential for replication and reactivation. We employ this system in an in vivo model to reveal that viral replication is not required to initiate or maintain infection within B cells.

Tissue Pathogens and Cancers: A Review of Commonly Seen Manifestations in Histo- and Cytopathology

Tissue pathogens are commonly encountered in histopathology and cytology practice, where they can present as either benign mimickers of malignancy or true malignancies. The aim of this review is to provide a timely synthesis of our understanding of these tissue pathogens, with an emphasis on pertinent diagnostic conundrums associated with the benign mimickers of malignancy that can be seen with viral infections and those which manifest as granulomas. The oncogenic pathogens, including viruses, bacteria, and parasites, are then discussed with relationship to their associated malignancies. Although not exhaustive, the epidemiology, clinical manifestations, pathogenesis, and histological findings are included, along with a short review of emerging therapies.

Recent advancements in our understanding of equid gammaherpesvirus infections

Equid gammaherpesviruses are ubiquitous and widespread in the equine population. Despite their frequent detection, their contribution to immune system modulation and the pathogenesis of several diseases remains unclear. Genetic variability and the combination of equid gammaherpesvirus strains a horse is infected with might be clinically significant. Initial gammaherpesvirus infection occurs in foals peripartum with latency then established in peripheral blood mononuclear cells. A novel EHV-5 study suggests that following inhalation equid gammaherpesviruses might obtain direct access to T and B lymphocytes via the tonsillar crypts to establish latency. EHV-5 is associated with equine multinodular pulmonary fibrosis, however, unlike with EHV-2 there is currently minimal evidence for its role in milder cases of respiratory disease and poor performance. Transmission is presumed to be via the upper respiratory tract with periodic reactivation of the latent virus in adult horses. Stress of transport has been identified as a risk factor for reactivation and shedding of equine gammaherpesviruses. There is currently a lack of evidence for the effectiveness of antiviral drugs in the treatment of equine gammaherpesvirus infections.

Refractory Thrombotic Thrombocytopenic Purpura in a patient with Kaposi sarcoma

The case is here presented of a 70-year old male patient with rare coexistence of Kaposi Sarcoma and resistant Thrombotic Thrombocytopenic Purpura (TTP). The Kaposi lesions were determined before the diagnosis of TTP and were exacerbated after receiving TTP-associated immunosuppressive therapy, in particular associated with rituximab. TTP in this case was resistant to conventional therapies such as steroid and plasma exchange and current immunosuppressive (rituximab, cyclophosphamide, vincristin) treatments. Novel treatment agents consisting of bortezomib and eculizumab given to the patient were also ineffective. To the best of our knowledge, this case presents the first case of coexistence of TTP and Kaposi sarcoma from Turkey and the challenge of refractory TTP management.

Anaplastic Kaposi's Sarcoma of the Adrenal in an HIV-negative Patient With Literature Review

Kaposi's sarcoma (KS) is a peculiar tumor of viral etiology, with the HHV8 rhadinovirus playing a fundamental role in its development. Several epidemiological categories of KS have been identified, of which the sporadic, endemic, iatrogenic, and the epidemic are the main ones. Several histologic disease morphologies have been described, such as inflammatory, angiomatous, spindle cell, mixed, and the anaplastic (sarcomatous) subtypes. The skin of the limbs is most commonly affected, but any other organ or site may be involved. Microscopically KS may enter the differential diagnosis with several different entities, and for this purpose the immunohistochemical detection of the viral latent nuclear antigen-1 (LNA-1) may be crucial. Sporadic KS is usually benign, but rarely it may be aggressive. Anaplastic histology heralds an ominous course in any clinical context. We report a case of anaplastic retroperitoneal KS, occurring in an HIV-negative adult man. This patient presented with a huge left suprarenal mass, which was totally resected, and initially diagnosed as inflammatory leiomyosarcoma, because of the monomorphic spindle cell tumor morphology. After 12 years the tumor recurred locally as an unresectable mass, which was biopsied and examined. At the time of recurrence, the histologic slides of the primary tumor were reviewed, and the previous diagnosis was changed to that of atypical KS. Histologically the recurrent tumor showed both spindle cell and epithelioid appearances. Strongly diffuse HHV8/LAN-1 immunopositivity was documented in both tumors. The final diagnosis for the entire case was anaplastic KS. Then, the patient died in a few months.

MRI findings of AIDS-related giant facial Kaposi's sarcoma: A case report

RATIONALE

Kaposi's sarcoma (KS) is the most common malignant tumor in HIV-infected people and occurs mainly in the skin, mucous membranes, and lymph nodes. Approximately 33% of the initial skin manifestations of AIDS and approximately 35% to 79% of KS occur during disease progression. Otherwise, AIDS-related facial KS that was simultaneously examined by magnetic resonance imaging (MRI) is rare.

PATIENT CONCERNS

This case was a 30-year-old male homosexual, with left facial nodule for 14 months, and HIV infection was diagnosed 1 month previously. The patient was admitted to hospital because the nodule gradually expanded from 0.2 to 10.0 cm in diameter. Ultrasound examination showed edema of the subcutaneous tissue of the left facial mass, and the boundary was not clear between lesion and normal tissues. Magnetic resonance imaging (MRI) indicated that the left facial mass showed low signal intensity on T1-weighted imaging (T1WI) and T2-weighted imaging (T2WI), and a small amount of high signal intensity was seen in it. Diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) showed low signal intensity. After enhanced scan, the tumor showed uneven enhancement.

DIAGNOSES

The pathological biopsy indicated KS.

INTERVENTIONS

The patient began chemotherapy with the intravenous drip infusion of Doxorubicin Hydrochloride Liposome.

OUTCOMES

The facial KS decreased and the facial swelling was relieved.

LESSONS

MRI could not only provide the diagnostic basis of KS for the therapy, but also could accurately determine the scope of the disease.

Reversible rituximab-induced rectal Kaposi's sarcoma misdiagnosed as ulcerative colitis in a patient with HIV-negative follicular lymphoma

Background

Kaposi’s sarcoma is a low-grade mesenchymal angioproliferative tumor, most commonly observed in immunocompromised individuals, such as HIV-infected patients. Iatrogenic Kaposi’s sarcoma occurs in patients undergoing immunosuppressive therapies. Rituximab is a chimeric monoclonal antibody targeted against the pan B cell marker CD20. Because of its immunosuppressive effects through reduction of mature B-cells, it may exacerbate Kaposi’s sarcoma in HIV-positive patients. Rituximab-related Kaposi’s sarcomas have been previously reported in only two HIV-negative patients and were treated surgically.

Case presentation

Here, we report on a Kaposi’s sarcoma that developed under rituximab treatment in a HIV-negative 55-year-old patient treated for follicular lymphoma. The lesion developed during the maintenance rituximab therapy at the rectal level with an aspect of apparent ulcerative colitis, without any cutaneous lesion. The premature stop of rituximab led to the complete regression of Kaposi’s sarcoma, without any additional specific treatment.

Conclusions

To our knowledge, this is the third case of Kaposi’s sarcoma diagnosed under rituximab in a HIV-negative patient, the first one at the rectal level and the first one that completely regresses after stop of rituximab. This case raises awareness of iatrogenic Kaposi’s sarcoma in HIV-negative patients treated with rituximab, and further highlights the importance of immunosuppression in the pathophysiology of disease.

Pulmonary Kaposi Sarcoma with Osseous Metastases in an Human Immunodeficiency Virus (HIV) Patient: A Remarkable Response to Highly Active Antiretroviral Therapy

BACKGROUND Kaposi sarcoma (KS) is known to involve the mucocutaneous tissues and the aero-digestive tracts. In acquired immune deficiency syndrome (AIDS) patients, KS has an aggressive course and carries poor prognosis. We present a case of pulmonary KS with osseous metastases as the first presentation of human immunodeficiency virus (HIV) infection in a young male. The lesions impressively decreased in size and numbers following initiation of highly active antiretroviral therapy (HAART). CASE REPORT A 34-year-old heterosexual male presented with a one month history of cough and 15-20 pound weight loss within six months. Examination revealed oral thrush, decreased breath sounds and crackles on the right lower lung base. Imaging showed a large right perihilar mass with multiple lytic lesions involving thoracic and lumber vertebrae, ribs, sternum, and clavicles. Blood and sputum cultures, smears for acid fast bacilli, and a QUANTIferon gold test were all negative. He tested positive for HIV and his CD4 count was 7 cells/uL. Bronchoscopy with biopsy was unrevealing. Pathology of the right hilar mass was diagnostic of KS. Following initiation of antiretroviral therapy his condition dramatically improved; repeat chest CT scan showed marked regression of the bony and pulmonary lesions. CONCLUSIONS The dual action of HAART on the recovery of the immune system and against human herpes virus 8 (HHV-8) may essentially cause regression of KS lesions.

Kaposi's Sarcoma-Associated Herpesvirus: Epidemiology and Molecular Biology

Kaposi's sarcoma-associated herpesvirus (KSHV), also known as Human herpesvirus 8 (HHV-8), is a member of the lymphotropic gammaherpesvirus subfamily and a human oncogenic virus. Since its discovery in AIDS-associated KS tissues by Drs. Yuan Chang and Patrick Moore, much progress has been made in the past two decades. There are four types of KS including classic KS, endemic KS, immunosuppressive therapy-related KS, and AIDS-associated KS. In addition to KS, KSHV is also involved in the development of primary effusion lymphoma (PEL) and certain types of multicentric Castleman's disease. KSHV manipulates numerous viral proteins to promote the progression of angiogenesis and tumorigenesis. In this chapter, we review the epidemiology and molecular biology of KSHV and the mechanisms underlying KSHV-induced diseases.

Kaposi sarcoma secondary to endogenous adrenocorticotropic hormone-dependent Cushing syndrome

Kaposi sarcoma (KS) is an angioproliferative tumour that develops as a result of an infection by human herpesvirus 8, which is considered a necessary cause but not sufficient. Other factors - genetic, immunological and environmental - might play a role in the development of the disease. We report a case of KS secondary to endogenous Cushing syndrome (ECS) due to a pituitary adenoma, an association that has been reported only once. We also conducted a search through the Medline and PubMed databases for cases involving KS and ECS, finding only three additional cases that shared common clinical and prognostic features with ours. ECS might favour the development of KS due to immunosuppression. Dermatologists and other clinicians should be aware of this association, as it might be an underdiagnosed condition. It also has an important impact on the management of KS, and based on this review it relies on a good prognosis when ECS is well controlled.

Cavernous hemangioma-like Kaposi sarcoma: a unique histopathologic variant

Kaposi sarcoma (KS) is an angiolymphatic neoplasm with multifactorial etiology. Clinically, KS has been divided into 4 distinct types and 3 well-defined histologic stages. Rare reports in the literature have characterized additional unique histopathologic variants. The authors report a case of KS, confirmed with human herpesvirus type 8 and D2-40 staining, which resembled a cavernous hemangioma on histopathology.

Human herpesviruses 6, 7, and 8 from a dermatologic perspective

Human herpesviruses (HHVs) have frequently been suspected as etiologic agents or cofactors in cutaneous disease. However, clearly established associations are rare. Investigations into an etiologic association between HHVs and cutaneous disease are complicated by the ubiquity and nearly universal prevalence of some herpesviruses. This article summarizes the associations between cutaneous disease and HHV-6, HHV-7, and HHV-8. In addition to a personal library of references, the PubMed database of biomedical literature was searched using the following Medical Subject Heading terms: HHV-6, HHV-7, and HHV-8, each in conjunction with cutaneous manifestations, virology, epidemiology, dermatopathology, and therapeutics, between 1998 and March 2011. Free-text searches with known or suspected disease associations were added for broader coverage. The results have been summarized to provide a practical review for the physician likely to encounter cutaneous diseases.

Evaluation of c-kit expression in classic Kaposi's sarcoma in a cohort of Egyptian patients

BACKGROUND

Kaposi's sarcoma (KS) is an angioproliferative disorder associated with human herpesvirus 8 infection. Classic KS is the most prevalent type of KS in countries of the Mediterranean basin including Egypt. Several in vitro studies have detected c-kit expression in AIDS related-KS however, only a few studies addressed this issue in the classic type with no data on the ethnicity of studied cases. The prospect of installing targeted anti- c-kit treatment to KS patients presents a promising avenue in KS therapeutics.

AIM

To elucidate the expression of c-kit in classic KS cases and study possible relations with expression of HHV8 latency-associated nuclear antigen-1 (LANA-1) and other clinicopathological parameters.

METHODS

Twenty four cases of classic KS of the plaque and nodular stages in the lower limb were studied. Immunohistochemical detection of HHV8-LANA-1 and c-kit was carried out on archival paraffin embedded tissue, possession of the Pathology and Dermatology Departments, Alexandria School Of Medicine, Egypt. Statistical analysis of possible relations between both antigens and clinicopathological parameters (patient's age and gender and histological stage) was performed.

RESULTS

HHV8 expression was detected in 100% of cases while c-kit immunoreactivity was found in 54.2% of cases. There was no correlation between c-kit and HHV8 immunoreactivity or any of the studied clinicopathological parameters.

CONCLUSIONS

This is the first report of c-kit expression in classic KS in an ethnically homogeneous cohort of Arabs of the Mediterranean region. We detected c-kit expression in about half the cases with no relationship to HHV8 LANA expression or clinicopathological parameters.

Prevalence of human herpesvirus 8 infection in systemic lupus erythematosus

Background

For decades, scientists have tried to understand the environmental factors involved in the development of systemic lupus erythematosus (SLE), in which viral infections was included. Previous studies have identified Epstein-Barr virus (EBV) to incite SLE. Human herpesvirus 8 (HHV-8), another member of the gammaherpesvirus family, shares a lot in common with EBV. The characteristics of HHV-8 make it a well-suited candidate to trigger SLE.

Results

In the present study, serum samples from patients (n = 108) with diagnosed SLE and matched controls (n = 122) were collected, and the prevalence of HHV-8 was compared by a virus-specific nested PCR and a whole virus enzyme-linked immunoassay (EIA). There was significant difference in the prevalence of HHV-8 DNA between SLE patients and healthy controls (11 of 107 vs 1 of 122, p = 0.001); significant difference was also found in the detection of HHV-8 antibodies (19 of 107 vs 2 of 122, p < 0.001).

We also detected the antibodies to Epstein-Barr virus viral capsid antigen (EBV-VCA) and Epstein-Barr nuclear antigen-1 (EBNA-1). Both patients and controls showed high seroprevalence with no significant difference (106 of 107 vs 119 of 122, p = 0.625).

Conclusion

Our finding indicated that there might be an association between HHV-8 and the development of SLE.

Disseminated classic Kaposi's sarcoma. Two cases with excellent response to pegylated liposomal doxorubicin

Pegylated liposomal doxorubicin (PLD) is usually used in disseminated HIV-related Kaposi's sarcoma (KS). It is the first-line treatment or second-line therapy in patients who do not tolerate or do not respond to polychemotherapy since 1995, when it was approved by the FDA. We report two cases of disseminated classic KS not associated with immunosuppression in which HHV-8 infection was demonstrated. They showed an excellent response to PLD, with good tolerance and an absence of side effects.

Prevalence of human herpes virus type 1 in epithelial skin cancer

BACKGROUND

Viral DNA may act as an oncogene, especially in skin and lymphoid organs. This group includes some human herpes virus.

OBJECTIVE

To identify human herpes virus type 1 DNA in pre-malignant and malignant skin samples of epithelial tumors comparing to normal skin to determine its role in carcinogenesis. METHODS - Forty-one patients with epithelial tumors were submitted to biopsies from tumor and normal skin. The control group comprised 41 biopsies from patients with other dermatoses than cancer. After DNA extraction, polymerase chain reaction was performed to identify 199-bp band. The results were statistically evaluated by Fisher and McNemar tests.

RESULTS

The virus was identified in 20 subjects without cancer and in 21 with skin cancer. From these, 11 expressed it only in tumor cells. This difference was not significant.

CONCLUSION

There seem to be no direct relation between viral findings in normal skin and skin cancer cells. It may act as a promoter or just coexist at the same site where a neoplastic transformation has already occurred.

CD8+ T cell immunity to Epstein-Barr virus and Kaposi's sarcoma-associated herpes virus

Gammaherpesviruses are agents which have evolved to persist within the lymphoid system and many have oncogenic potential; studying gammaherpesvirus infections therefore has the potential to reveal much about the workings of the immune system and the control over viral oncogenesis. The lymphocryptovirus Epstein-Barr virus (EBV) and the rhadinovirus Kaposi's sarcoma-associated herpesvirus (KSHV, also known as human herpesvirus 8) are the two human gammaherpesviruses. Analysis of the T cell response to EBV has guided understanding of immunity to infection and disease caused by this virus, as well as directed the development of vaccination and therapeutic interventions in EBV-associated disease. Less is known about the T cell response to KSHV and its exact role in controlling virus infection and disease. Here we discuss the CD8+ T cell response to these two gammaherpesviruses.

Spinal Kaposi sarcoma presenting without cutaneous manifestations. Case report

Kaposi sarcoma (KS) is one of the most common tumors in patients with human immunodeficiency virus (HIV), which characteristically presents with cutaneous lesions. The authors report a rare case of spinal KS with no cutaneous manifestation in a 32-year-old man with the acquired immunodeficiency syndrome who presented with abdominal pain. A computed tomography scan revealed incidental lesions in his lumbar spine, and additional imaging studies revealed numerous lesions in the lumbosacral spine and pelvis. An open biopsy was performed, and histopathological examination of the lesion confirmed the diagnosis of KS. At the time of presentation, the patient had no skin lesion or any other manifestation indicative of KS. The authors suggest that in HIV-positive patients who present with spinal lesions, KS should be included in the differential diagnosis.

The non-Hodgkin lymphomas: a review of the epidemiologic literature

The non-Hodgkin lymphomas (NHL) are a heterogeneous group of B-cell and T-cell neoplasms that arise primarily in the lymph nodes. NHL incidence rates in the US doubled between about 1970 and 1990, and stabilized during the 1990s. NHL accounts for approximately 3.4% of cancer deaths in the US. Although some of the observed patterns in NHL have been related to HIV/AIDS, these conditions cannot fully explain the magnitude of the changes; neither do changes in classification systems nor improved diagnostic capabilities. Studies of occupational and environmental exposures (e.g., pesticides, solvents) have produced no consistent pattern of significant positive associations. Inverse associations with ultraviolet radiation exposure and alcohol and fish intake, and positive associations with meat and saturated fat intake have been reported in several studies; additional studies are needed to confirm or refute these associations. Family history of NHL or other hematolympho-proliferative cancers and personal history of several autoimmune disorders are associated with increased risk of NHL, but are not likely to account for a large proportion of cases. HIV and other infectious agents, such as human herpesvirus 8 and Epstein-Barr, appear to be associated with differing types of NHL, such as some B-cell lymphomas. Future epidemiologic studies should evaluate associations by NHL type, enhance exposure information collected, and elucidate factors that may identify susceptible (or resistant) subpopulations because of genetic, immunologic or other characteristics. The extent to which the etiology of NHL types may differ is important to resolve in ongoing and future studies.

Targeting the PI3K and MAPK pathways to treat Kaposi's-sarcoma-associated herpes virus infection and pathogenesis

Cells require the ability to appropriately respond to signals in their extracellular environment. To initiate, inhibit and control these processes, the cell has developed a complex network of signaling cascades. The phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways regulate several responses including mitosis, apoptosis, motility, proliferation, differentiation and many others. It is not surprising, therefore, that many viruses target the PI3K and MAPK pathways as a means to manipulate cellular function. Recently, Kaposi's sarcoma-associated herpes virus (KSHV) has been added to the list. KSHV manipulates the PI3K and MAPK pathways to control such divergent processes as cell survival, cellular migration, immune responses, and to control its own reactivation and lytic replication. Manipulation of the PI3K and MAPK pathways also plays a role in malignant transformation. Here, the authors review the potential to target the PI3K and MAPK signaling pathways to inhibit KSHV infection and pathogenesis.

Posttransplant Kaposi's sarcoma restricted to the site of a previous deep venous thrombosis: abrupt onset after withdrawal of sirolimus

Kaposi's sarcoma (KS) is an angioproliferative neoplasia associated with human herpesvirus 8 (HHV-8) infection. HHV-8 generates KS by means of the secretion of vascular endothelial growth factor (VEGF) andup-regulation of VEGF receptor, KDR, in endothelial cells. We report a case of KS in a 72-year-old male with a renal transplant who had received immunosuppressant drugs including sirolimus, mycophenolate mofetil, tacrolimus and steroids. KS developed 11 months after transplantation, in relation to deep venous thrombosis and withdrawal of sirolimus due to toxicity. Multiple purple papules and nodules were observed exclusively in the limb affected by thrombosis. Diagnosis of KS was confirmed by biopsy. Progressive withdrawal of prednisone was accompanied by full remission of the tumour. The thrombosis and withdrawal of sirolimus may have acted as cofactors in the development of KS, favouring the activation of the VEGF/KDR autocrine loop. Our experience contributes to further evidence that sirolimus may protect against KS.

Seroprevalence of HHV-8 infection in the pediatric population of two university hospitals in Rio de Janeiro, Brazil

BACKGROUND

The authors present a serologic survey of the prevalence of herpesvirus-8 (HHV-8) among 171 children from 0 to 12 years old in Rio de Janeiro, Brazil.

MATERIALS AND METHODS

Sera were tested for latent nuclear and lytic antigens using indirect immunofluorescence and Western blotting.

RESULTS

Serology for HHV-8 was positive in 16 of 171 patients (9.35%). Among 13 HIV-positive patients, four (31%) were also positive for HHV-8. The seropositivity among healthy children was 7.6%, and females were significantly (P<0.002) more associated with HHV-8 seropositivity (16%) than males (1.1%).

CONCLUSIONS

We detected a higher HHV-8 seroprevalence among the pediatric population in Rio de Janeiro, Brazil, when compared with similar studies performed in other countries. Nonsexual routes of transmission are a possible explanation for this pattern. The unusual finding of a higher seroprevalence among female children could be explained by a specific route of exposition or even an epidemiological bias.

Occupational trichloroethylene exposure and non-Hodgkin's lymphoma: a meta-analysis and review

METHODS

Meta-analysis and review of 14 occupational cohort and four case-control studies of workers exposed to trichloroethylene (TCE) to investigate the relation between TCE exposure and the risk of non-Hodgkin's lymphoma (NHL). Studies were selected and categorised based on a priori criteria, and results from random effects meta-analyses are presented.

RESULTS

The summary relative risk estimates (SRRE) for the group of cohort studies that had more detailed information on TCE exposure was 1.29 (95% CI 1.00 to 1.66) for the total cohort and 1.59 (95% CI 1.21 to 2.08) for the seven studies that identified a specific TCE exposed sub-cohort. SRREs for three studies with cumulative exposure information were 1.8 (95% CI 0.62 to 5.26) for the lowest exposure category and 1.41 (95% CI 0.61 to 3.23) for the highest category. Comparison of SRREs by levels of TCE exposure did not indicate exposure-response trends. The remaining cohort studies that identified TCE exposure but lacked detailed exposure information had an SRRE of 0.843 (95% CI 0.72 to 0.98). Case-control studies had an SRRE of 1.39 (95% CI 0.62 to 3.10). Statistically significant findings for the Group 1 studies were driven by the results from the subgroup of multiple industry cohort studies (conducted in Europe) (SRRE = 1.86; 95% CI 1.27 to 2.71). The SRRE for single industry cohort studies was not significantly elevated (SRRE = 1.25; 95% CI 0.87 to 1.79).

CONCLUSIONS

Interpretation of overall findings is hampered by variability in results across the Group 1 studies, limited exposure assessments, lack of evidence of exposure response trends, lack of supportive information from toxicological and mechanistic data, and absence of consistent findings in epidemiologic studies of exposure and NHL. Although a modest positive association was found in the TCE sub-cohort analysis, a finding attributable to studies that included workers from multiple industries, there is insufficient evidence to suggest a causal link between TCE exposure and NHL.

Dos enfermedades relacionadas con el VHH-8 en un paciente VIH-negativo: sarcoma de Kaposi y enfermedad de Castleman multicéntrica. Respuesta a tratamiento con rituximab y CHOP

Human herpes virus 8 (HHV8) was discovered in 1994 in the biopsy of a Kaposi's sarcoma in a patient with AIDS. Since then it has been identified in all variants of Kaposi's sarcoma and in another two rare disorders: multicentric Castleman's disease and primary body-cavity based lymphomas. The case discusses a 68 year old, HIV-negative male patient, presenting Kaposi's sarcoma for one year and being monitored by dermatology, who presented for weakness, anorexia and fever. On examination, he was found to have adenitis of the lymph nodes in his neck, underarm and groin. A biopsy on one of the swellings led to findings characteristic of multicentric plasma cell variant Castleman's disease. Blood tests for HHV8 and HIV were carried out, resulting positive and negative respectively (IgG anti-HHV8 positive, title 1/640, indirect immunofluorescence). PCR amplification showed HHV8 in peripheral blood. Patient received 8 cycles of CHOP and rituximab, leading to complete disappearance of the adenitis and general symptoms, with no worsening of his Kaposi's sarcoma. Patient remained in complete remission for 10 months after treatment. This paper discusses the case of a HIV-, HHV8+ patient, diagnosed with classic Kaposi's sarcoma, who developed multicentric plasma cell variant Castleman's disease. The coincidence of two or more HHV8-related illnesses in a HIV-negative patient has rarely been described in medical literature. Treatment with rituximab combined with CHOP chemotherapy was effective in this case, and no worsening of the patient's KS was observed.

Localized Kaposi's sarcoma in a patient with pemphigus vulgaris

We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.

Epidemiological and clinical characteristics of classic Kaposi's sarcoma in Peru

BACKGROUND

Classic Kaposi sarcoma (KS) occurs predominantly among the elderly, with predominance among Jews, Italians, and Greeks. Classic KS has been seen relatively frequently in Peru.

OBJECTIVE

Our purpose was to outline the epidemiological and clinical profile of classic KS in Peru.

METHODS

Epidemiological and clinical features of all classic KS cases diagnosed between 1969 and 2003 at Hospital Nacional Cayetano Heredia (HNCH) and between 1946 and 2004 at Instituto Nacional de Enfermedades Neoplasicas (INEN) were reviewed and studied retrospectively.

RESULTS

An overall incidence of 2.54 per 10,000 attended patients was obtained at the INEN during the 48-year period (mean, 2.39; standard deviation: 1.99; 95% confidence interval, 2.92-1.86). Twenty-one cases were discovered at HNCH and 106 cases at INEN. A male/female ratio of 2.62:1 was found. Mean age at diagnosis was 68.5 years. Lower limbs were involved in 109 patients (85.8%); the trunk was involved in 11 patients (8.6%). Nodules were the most common type of lesion (85.8%); less commonly found were plaques (27.5%), macules (12.5%), papules (12.5%), and ulcers (8.6%). Sixty-two patients had no symptoms (48.8%). Pain was the most common symptom (26.7%), followed by edema (21.2%), bleeding (14.9%), and pruritus (3.9%). A second primary malignancy was found in 11 patients (8.6%).

LIMITATIONS

These results were obtained from patients with classic KS in Peru and may not be applicable to other populations.

CONCLUSION

Classic KS is quite common in Peru with sporadic cases found throughout the country and some clustering in the coastal region. Classic KS in Peru has a clinical presentation that is very similar, but not identical, to the classic KS described in the Mediterranean region, exhibiting some special clinical and epidemiological characteristics with a nodular, nonsymmetric presentation that usually affects the lower extremities.