Purpose: To determine the relative frequency with which Kaposi's sarcoma-associated herpesvirus/HHV-8 (KSHV) DNA is detected in peripheral-blood mononuclear cells (PBMCs) and in plasma of patients with AIDS-KS and AIDS-associated non-Hodgkin's lymphoma (NHL; AIDS-NHL); to determine whether the presence of viral DNA in plasma reflects lysis of tumor cells or reflects the presence of viremia (ie, virion-encapsidated DNA); and to determine the effect of lymphoma therapy on KSHV DNA.
Patients and methods: Samples were obtained from patients enrolled in AIDS Malignancy Consortium clinical trials and from healthy donors. Real time PCR was used to quantify KSHV DNA in peripheral blood mononuclear cells (PBMC) and plasma. DNase digestion and fragment size determination studies were used to characterize the DNA detected.
Results: In patients with AIDS-KS, KSHV DNA was detected in PBMC (54%) and in plasma (62%). In patients with AIDS-NHL, KSHV DNA was detected in PBMC (19%) and in plasma (22%). Median copy numbers also differed. KSHV DNA in plasma appeared to be encapsidated. In six patients with AIDS-NHL who were treated with chemotherapy (with or without rituximab), KSHV copy number declined in PBMC and in plasma.
Conclusion: KSHV DNA is sometimes detected in PBMC or in plasma of patients with AIDS-NHL without KS. Among patients with KSHV DNA detected in PBMC or in plasma, copy number does not distinguish between patients with AIDS-NHL and AIDS-KS. KSHV DNA in plasma likely reflects viremia and not simply lysis of tumor or other KSHV-infected cells. KSHV DNA copy number in PBMC and in plasma declined with lymphoma-directed cytotoxic chemotherapy in each of the six patients studied.