1/4. Fatal acute myocarditis in an infant with human herpesvirus 6 infection.A 5 month old girl had typical clinical features of acute myocarditis just after the febrile period of exanthem subitum and died immediately. She had been healthy, with normal development, and there was no family history of particular note. Myocardial postmortem findings were compatible with acute myocarditis. Although the isolation of human herpesvirus 6 (HHV-6) was not attempted, positive IgM antibody to HHV-6 was detected in the patient's serum. Moreover, HHV-6 variant B dna was detected in several tissues, including myocardium, by the polymerase chain reaction (PCR). In contrast, antibody responses to human herpesvirus 7, another causal agent of exanthem subitum, were not found, and enteroviral rna was not detected in myocardial tissues by reverse transcription PCR. Apoptotic changes were seen in infiltrating cells within the myocardial tissues by means of the TUNEL method. HHV-6 antigen was not detected in several tissues (including myocardium) by immunohistochemical analysis. In conclusion, HHV-6 may have been the causative agent of fatal acute myocarditis in this infant.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/4. Fatal encephalitis/encephalopathy in primary human herpesvirus-6 infection.An encephalitic illness with a fatal outcome occurred in a 9 month old girl with virologically confirmed exanthem subitum. Human herpes-virus-6 (HHV-6) dna was found in the cerebrospinal fluid at the acute stage of the disease by the polymerase chain reaction, but the virus antigen was not detected in her brain tissue. This suggests that HHV-6-induced encephalitis/encephalopathy may be due to a non-infectious process.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/4. Drug-induced hypersensitivity syndrome associated with human herpesvirus 6 and cytomegalovirus reactivation.We describe a patient with drug-induced hypersensitivity syndrome (DIHS) associated with human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) infection induced by sulfasalazine. Two weeks after starting sulfasalazine to treat a rectal ulcer, the patient developed disseminated macular erythema accompanied by fever, liver injury, and lymphadenopathy. Seroconversion of antibodies to HHV-6 was observed. Systemic steroid treatment was not effective against the eruptions. Five months after the onset, he presented with an acute febrile disease. The detection of CMV antigen on peripheral blood leukocytes and positive staining for CMV on cutaneous endothelium indicated active CMV infection. Furthermore, he developed a bacteremia of methicillin resistant staphylococcus aureus. An association the CMV reactivation with DIHS was suggested, although there remains the possibility that the systemic steroid treatment precipitated CMV reactivation. Recently, HHV-6 has been documented to have immunomodulating effects and to be associated with CMV reactivation. Therefore, we should pay attention to the possibility of CMV reactivation in patients with DIHS in whom the immunomodulating virus of HHV-6 has been reactivated.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/4. Distribution of human herpesvirus 6 and varicella-zoster virus in organs of a fatal case with exanthem subitum and varicella.The distribution of human herpesvirus 6 (HHV-6) and varicella-zoster virus (VZV) was examined in autopsy samples from a fatal case with both virus infections. A 9-month-old boy developed convulsive seizures followed by macular skin rashes, rapidly progressed to brain death, and died 15 days after the onset, when signs of varicella were noted. An isolation of HHV-6 from blood and evaluation of antibody activities to various viral agents including HHV-6 were performed before his death. Postmortem examinations included: (i) isolation of HHV-6 and VZV from tissues or organs; (ii) detection of both virus antigens in tissues or organs by an indirect immunofluorescent assay using monoclonal antibodies to both viruses; (iii) amplification of both viruses and human herpesvirus 7 dna sequences by a nested polymerase chain reaction assay; and (iv) endonuclease digestion of amplified products of HHV-6 dna for differentation of variants A and B. Human herpesvirus 6 dna was detected in peripheral blood mononuclear cells (PBMC) and plasma obtained at the eruptive stage but present only in PBMC 15 days after, indicating the primary infection with HHV-6, although the virus was not isolated from the same blood sample and a significant rise in the antibody titers to HHV-6 was not observed. Both virus antigens and dna were detected in various tissues or organs obtained at autopsy, but only VZV was isolated from these samples, suggesting disseminated infection with both viruses in an infant. All the amplified products of HHV-6 dna were variant B. Among the findings for the distribution of virus antigens, it was noteworthy that HHV-6 antigen was demonstrated in the endothelial cells of small vessels in the frontal lobe of the brain. There was no evidence of HHV-7 infection. These data indicate that the primary HHV-6 infection closely followed by the primary VZV infection had the potential hazard of an unexpected and apparently life-threatening event, in which disseminated infections with both viruses were noted in multiple tissues or organs including the brain.- - - - - - - - - - ranking = 4keywords = antigen (Clic here for more details about this article) |