Human Herpesvirus-8 Negative Multicentric Castleman Disease in a Patient with Human Immunodeficiency Virus Treated with Highly Active Antiretroviral Therapy and Chemotherapy

Multicentric Castleman disease (MCD) is a rare lymphoproliferative disorder with a high mortality rate in undiagnosed patients. Traditionally, human immunodeficiency virus (HIV) positive MCD occurs due to infection with human herpes virus-8 (HHV), which is thought to play a role in the pathogenesis of MCD. We present the case of a 49-year-old woman who was referred to our oncology clinic for generalized lymphadenopathy in a waxing and waning pattern for the last four years. She was found to be HIV positive. Here we report a rare case of HIV-positive, HHV-negative MCD that responded to prompt treatment with highly active antiretroviral therapy (HAART) followed by chemotherapy as evidenced by improved CD4+ T cell numbers and reduction in lymphadenopathy. The findings in this HHV seronegative patient may indicate an alteration in the virulence and tropism between HHV and HIV, and further demonstrate the need for continued investigation into the pathogenesis of Castleman disease.

Update on HHV-8-Associated Malignancies

The human herpesvirus 8 (HHV-8) is the oncogenic virus associated with Kaposi's sarcoma (KS) and lymphoproliferative disorders, namely, primary effusion lymphoma and multicentric Castleman's disease. KS is among the most common malignancies seen in HIV-infected patients despite the decreased incidence of KS in the era of highly active antiretroviral therapy. Advances in molecular pathology reveal HHV-8 tumorigenesis is mediated through molecular mimicry wherein viral-encoded proteins can activate several cellular signaling cascades while evading immune surveillance. This knowledge has led to the evolution of multiple therapeutic strategies against specific molecular targets. Many such therapeutic modalities have shown activity, but none have proven to be curative. Identifying possible prognostic factors is another active area of research. This review summarizes the recent developments in the fields of virus transmission, molecular biology, and treatment of HHV-8-related neoplasms.

Heat shock-enhanced T cell apoptosis with heat shock protein 70 on T cell surface in multicentric Castleman's disease

We report here that T cells from patients with multicentric Castleman's disease (MCD) are sensitive to hyperthermia. T cells from two of three patients with MCD revealed DNA ladder formation and chromatin condensation following heat shock (30 min at 41.5 degrees C). Peripheral blood mononuclear cells (PBMC) from the same MCD patients exhibited high levels of spontaneous apoptosis after 72 h in culture and elevated apoptosis after heat shock, as evaluated by a quantitative flow cytometric assay. Heat shock protein 70 (hsp70) was detected on the cell surface of T cells in all three patients after heat shock. Furthermore, hsp70 was detected on T cells in the two MCD patients with apoptosis even in the absence of heat shock. T cells from normal samples did not show either heat-shock-induced expression of cell-surface hsp70 or apoptosis. Thus, heat shock treatment augmented hsp70 expression on the cell surface of T cells and enhanced apoptosis. Our studies suggest that hyperthermia may influence the clinical course of MCD.