Is human herpesvirus 6 linked to Kikuchi-Fujimoto disease? The importance of consistent molecular and serologic analysis

Background: Kikuchi-Fujimoto disease, also called histiocytic necrotizing lymphadenitis, is a self-limiting lymphadenopathy of unknown cause. The patient often presents with fever, malaise, and lymphadenopathy primarily involving the cervical lymph nodes. Laboratory findings are nonspecific, and the diagnosis is established by identifying characteristic pathologic features from lymph node biopsy. The etiologic agent has been proposed to be of viral origin; specifically, human herpesvirus 6 (HHV-6) has been implicated. Methods: The clinical, histologic, serologic, and molecular data from 471 cases of Kikuchi-Fujimoto disease reported between 1982 and 2001 and their relationship to HHV-6 were reviewed. Results: Thirty-two of the 471 patients in this review were tested for HHV-6 serology; all 32 had elevated titers for HHV-6. One hundred twelve patients with lymphadenopathics, including hi tiocytic necrotizing lymphadenitis, tested positive for HHV-6 by polymerase chain reaction. In situ hybridization results were positive in 41 cases. Conclusion: This review illustrates the necessity for consistent molecular and serologic analysis.