Detection of Kaposi sarcoma‐associated herpesvirus in bone marrow biopsy samples from patients with multiple myeloma

BACKGROUND Kaposi sarcoma‐associated herpesvirus (KSHV) recently has been identified in the bone marrow (BM) dendritic cell of multiple myeloma (MM) patients. However, whether or not KSHV is associated with MM remains controversial because many studies have failed to detect the presence of KSHV DNA sequences in the BM of their MM patients. METHODS We have assayed for KSHV DNA sequences in the BM biopsy samples from 49 patients with MM and from 8 patients with normal BM, using nested polymerase chain reaction and dot blot analysis. The polymerase chain reaction product of KSHV was further determined by single‐strand conformation polymorphism and sequence analyses. RESULTS KSHV DNA was detectable in 22 of 49 patients (44.9%) with MM but was not detectable in normal BM cells. Single‐strand conformation polymorphism and sequence analyses showed that there were interpatient specific mutations. Sixteen out of 22 KSHV DNA sequences belonged to a previously defined subgroup, and the other 6 remain unclassified and may represent distinct strains of KSHV in Taiwan. CONCLUSIONS Data strongly supported that KSHV infection did exist in the BM of the current study patients with MM. However, the role of KSHV in the pathogenesis of multiple myeloma remains to be determined. Cancer 2001;91:1409–13. © 2001 American Cancer Society. Kaposi sarcoma‐associated herpesvirus (KSHV) has been implicated in the pathogenesis of multiple myeloma, where it has been identified in bone marrow dendritic cells but not in the neoplastic myeloma plasma cell population. However, the latter finding remains controversial. In this study, KSHV infection was found in the bone marrow of patients with multiple myeloma.