Human Herpesvirus – 7 Related Fatal Hemophagocytic Syndrome: A Case Report and Review of Literature.
Huimin Guo, Dan Paul Hartmann, Metin Ozedemirli. Georgetown University Hospital, Washington, DC
Background: Hemophagocytic syndrome (hemophagocytic lymphohistiocytosis, HLH) is a rare disease caused by a dysfunction of cytotoxic T cells and natural killer (NK) cells. It can be either primary due to an underlying genetic defect, or secondary associated with malignancies, autoimmune diseases or infections. Infectious triggers are most commonly due to viral infections mainly of the herpesvirus, with Epstein-Barr Virus(EBV) being the most common virus. Other herpesviruses, with exception of Human Herpesvirus-7(HHV-7), have been reported to be assoicated with HLH. HHV-7 is a CD4 T lymphotropic herpesvirus with strong homology to HHV-6. The association of HHV-7 with human disease has not been recognised although some cases of exanthem subitum have been linked to it.
Design: 8 pathology specimens from 5 patients with clinical diagnosis of HLH were analyzed for the presence of HHV-7 DNA. DNAs were isolated from the peripheral blood and formalin-fixed tissues. The sequence of HHV-7 was examined by the nested polymerase chain reaction (PCR) technique. The PCR products from postive cases were purified and sent to capillary electrophoresis analysis for HHV-7 sequence by an ABI sequencer.
Results: HHV-7 was detected in one case. The 2 year-old patient presented with fulminant liver failure, splenomegaly, lymphadenopathy and anemia. A liver transplant was performed and explanted liver revealed fulminant hepatitis with extensive bridging necrosis and numerous lymphocytes and histiocytes infiltrate portal and periportal area. Hemophagocytic cells were observed in bone marrow aspirate. Viral screenings for EBV, CMV, Parvovirus B19, Norovirus, enterovirus, adenovirus and HHV-6 in peripheral blood were negative by RT-PCR. HHV-7 sequence was detected in peripheral blood and in formalin-fixed explanted liver tissue by nested PCR, and confirmed by ABI sequencer. Immunohistochemistry staining for HHV-7 was positive on the formalin-fixed explanted liver tissue.
Conclusions: Although more data are needed, the current result provides first evidence that HHV-7 may also play a pathogenic role in HLH as other Human Herpesviruses. In unexpected fatal hemophagocytic syndrome patient, special viral screening for HHV-7 may be critical for ensuring recovery prior to the occurence of a life threatening complication.
Wednesday, March 2, 2011 1:00 PM
Poster Session VI # 231, Wednesday Afternoon