Detection of HHV-8 in Sjögren's syndrome

Kaposi's sarcoma-associated herpesvirus: clinical, diagnostic, and epidemiological aspects

Kaposi's sarcoma-associated herpesvirus (KSHI) is one of the few viruses proven to be associated with tumorigenesis in humans. Its causal association with all clinical and epidemiological variants of Kaposi's sarcoma (KS) is well established. KSHV is also involved in the pathogenesis of primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease (MCD). Possible associations of KSHV with other clinical settings have been extensively examined. The findings from several of these studies are contradictory and are yet to be resolved. Concentrated effort over the last decade, since the initial discovery of KSHV, led to the development of several experimental systems that resulted in a better comprehension of the biological characteristics of KSHV and set the stage for the understanding of mechainisms by which diseases are induced by the virus. The development of molecular, histological, and serological tools for KSHV diagnosis allowed researchers to track the transmission and to study the epidemiology of KSHV. These assays have been applied, in particular in ambiguous cases, in order to confirm clinically and pathologically based diagnoses. Here, we review the advances in the clinical, experimental, diagnostic, and epidemiological research of KSHV.

Prevalences of herpesviruses DNA sequences in salivary gland biopsies from primary and secondary Sjögren's syndrome using degenerated consensus PCR primers

BACKGROUND

Sjögren's syndrome (SS) is an autoimmune exocrinopathy associated with multiple autoantibodies, lymphocyte infiltration of various organs, and functional deficiency of T cells. Several viruses have been implicated by PCR based studies, but their contribution to the pathophysiology of SS is still controversial.

OBJECTIVES

In an attempt to explore the presence of human herpesviruses DNA sequences in salivary glands biopsies from patients suffering of SS, a recently developed strategy based on PCR with consensus degenerated primers that allowed to detect known and eventually unknown herpesviruses was used.

STUDY DESIGN

Salivary glands biopsies from 55 patients suffering of primary and SS syndrome were explored by herpesviruses consensus PCR primers and all the PCR products were sequenced.

RESULTS

Nine out of 55 salivary glands were positive by PCR and sequence analyses allowed to identify Epstein-Barr virus (EBV) in 6 cases and herpes simplex virus (HSV)-1 in 3 cases. We did not detect any sequences that could be related to a new herpesvirus.

CONCLUSION

In view of the good sensitivity of the technique used, our study is not consistent with SS being associated with an unknown herpesvirus. However, our results suggest that EBV and HSV-1 could be implicated in a subset of SS cases and this possibility needs to be explored, to assess the potential benefit of antiviral drugs in some cases.

Detection of HHV-8 sequences and antigens in a MALT lymphoma associated with Sjögren's syndrome

We describe the case of a bilateral parotid mucosa-associated lymphoid tissue (MALT) lymphoma associated with 2 years history of Sjögren's syndrome (SS), which was linked to human herpes virus 8 (HHV-8) infection. Using polymerase chain reaction (PCR) assay HHV-8 sequences were detectable in the lymphoma tissue of both sides. Serologic testing of the patient revealed HHV-8 antibodies in enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA). Immunohistologic staining with two antibodies against open reading frame (ORF) 26 and v-cyclin homologues of HHV-8 revealed positive staining of the salivary acinic cells whereas the lymphoma cells were negative. The potential influence of HHV-8 infection for MALT lymphoma development in this case and possible parallels to gastric MALT lymphoma are discussed.

Kaposi's sarcoma and other manifestations of human herpesvirus 8

Kaposi's sarcoma (KS) was described by Moritz Kaposi in 1872 and was known for an entire century as a rare disorder of older men usually of Eastern European, Mediterranean, and/or Jewish origin. In the early 1980s, the prevalence of KS began to increase dramatically and soon became the most common malignancy in patients with AIDS, especially those who were male homosexuals. In 1994, a new human herpesvirus (HHV) was found to be present in almost 100% of KS lesions. This virus was found to be a gammaherpesvirus, closely related to Epstein-Barr virus, and was designated HHV-8. Subsequently, HHV-8 DNA was found in almost all specimens of classic KS, endemic KS, and iatrogenic KS, as well as epidemic KS (ie, AIDS KS). It is now believed that HHV-8 is necessary, but not sufficient, to cause KS and that other factors such as immunosuppression play a major role. The use of highly active antiretroviral therapy (HAART) since 1996 has markedly reduced the prevalence of AIDS KS in western countries, but because 99% of the 40 million patients with AIDS in the world cannot afford HAART, KS is still a very common problem. Primary effusion lymphoma and multicentric Castleman's disease are also thought to be due to HHV-8. Although HHV-8 DNA has been described in a number of other cutaneous disorders, there is little evidence that HHV-8 is of etiologic significance in these diseases. The mechanism by which HHV-8 causes KS, primary effusion lymphoma, and multicentric Castleman's disease is not well understood but is thought to involve a number of molecular events, the study of which should further our understanding of viral oncology. (J Am Acad Dermatol 2002;47:641-55.)

LEARNING OBJECTIVE

At the completion of this learning activity, participants should be familiar with Kaposi's sarcoma and other manifestations of human herpesvirus 8.

Human Herpesvirus 8 Infections

Human herpesvirus 8 (HHV-8) or Kaposi's sarcoma (KS)-associated herpesvirus is a recently identified virus that is associated with KS, multicentric Castleman's disease, and body cavity-based lymphomas. KS is the most common kind of cancer in AIDS patients and the initial AIDS-defining condition in over 20% of patients. HHV-8 DNA has now been detected in over 95% of KS tissue samples supporting the concept that HHV-8 has a causal role in KS. The discovery has opened new avenues for understanding the epidemiology, pathogenesis, and treatment of KS and related conditions.