Human herpesvirus 6A active infection in patients with autoimmune Hashimoto's thyroiditis

ABSTRACT Background: Hypothyroidism due to Hashimoto's thyroiditis (HT) is the commonest autoimmune endocrine illness in which antibodies against thyroid organ result in inflammation. The disease has a complex etiology that involves genetic and environmental influences. Viral infections may be involved in triggering of the disease as their molecular mimicry enhance autoimmune responses. Human herpesvirus-6 (HHV-6) is recognized for its contribution to some autoimmune diseases. Objective: In the current study, the prevalence of HHV-6 active infection in patients with HT and with non-autoimmune thyroid disorders were compared with patients with euthyroidism. In addition, a correlation between presence of HHV-6 infections and HT was investigated. Methods: A total of 151 patients with clinically and laboratory confirmed HT, 59 patients with non-autoimmune thyroid disorders, and 32 patients with normal thyroid function were included in the study. For further confirmation of HT disease, all the precipitants were tested for anti-thyroid peroxidase (TPO), and anti-thyroglobulin (TG) antibodies. For detection of both HHV-6 types A and B, nested PCR and restriction enzyme digestion were used. HHV-6 DNA positive samples were further investigated by DNA sequencing analysis. Results: HHV-6A DNA was found in serum sample of 57 out of 151 patients (38%) with HT, which was significantly more often than in patients with non-autoimmune thyroid disorders (p = 0.001). However, HHV-6 DNA was not detected in serum samples of euthyroid subjects. Conclusions: The results support a possible role for active HHV-6A infection, demonstrated by the presence of HHV-6 DNA in sera, in the development of HT.

Incidence of human herpes virus-6 and human cytomegalovirus infections in donated bone marrow and umbilical cord blood hematopoietic stem cells.

This study examined the incidence of human herpes virus-6 (HHV-6) and human cytomegalovirus (HCMV) infections that are potentially transmitted to haematopoietic stem cells (HSC) transplant recipients via bone marrow (BM) or umbilical cord blood (UCB). Bone marrow progenitor cells were collected from 30 allogenic BM donors. UCB HSC were collected from 34 subjects. The extracted DNA was then processed using nested polymerase chain reaction (nPCR) technique. HCMV and HHV-6 serological status were determined by enzyme immunoassay (EIA). Nested PCR identified HCMV in 22 (73%) of 30 samples of BM progenitor cells but in only eight (23.5%) of 34 samples of UBC HSC ( P = 0.001). HHV-6 DNA was detected in 11 (36.6%) of 30 BM progenitor cells and in only one (2.9%) of 34 UBC cells ( P = 0.002). Both HHV-6 and HCMV infections were determined in nine (26.5%) of 34 bone marrow samples. The results indicate that, the risk of HCMV and HHV-6 via BM progenitor cells is higher than transmission by UCB cells ( P= 0.04).

Prevalence of cytomegalovirus, human herpesvirus-6, and Epstein-Barr virus in periodontitis patients and healthy subjects in the Thai population.

Fifty periodontitis patients and 30 healthy patients with oral cavities were selected from the Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from March 2001 to November 2002. Their ages varied between 15 and 70 years. Among the periodontitis patients, specimens were collected from both disease and healthy sites. All samples were evaluated for the presence of CMV, HHV-6, and EBV-1 by nested PCR. Among the periodontitis patients, CMV was found in 34%, of which 8% were at the disease sites, 10% were at the healthy sites, and 16% were from both sites. EBV was not found in this group of the patients, while HHV-6 was found in 4%, at the disease sites only. CMV was found in one (3.3%) healthy control while HHV-6 and EBV-1 were not found. The depth of sample sites, various demographic and baseline characteristics eg sex, age, occupation and root planning were not associated with the presence of these viruses.

Human herpesvirus infection in children with fever and maculopapular rash.

Fever with maculopapular rash is a common problem in children. Infection with human herpesviruses is one of the common etiologies in fever with rash. The aim of this study has been to examine patients presenting with fever and maculopapular rash without respiratory symptoms for human herpesviruses infection by using multiplex nested-polymerase chain reaction. A descriptive and prospective study was conducted at King Chulalongkorn Memorial Hospital, Bangkok, Thailand from June 2000 to December 2001. One hundred patients, 43 boys and 57 girls, aged between 2 months and 14 years were recruited. Human herpesvirus 6 (HHV6) was the most common (24%) whereas HHV7, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) were present in 9%, 3% and 2% of the patients, respectively. Four percent of the patients simultaneously harbored HHV6 and HHV7. Only one patient had CMV, HHV6 and HHV7. Patients with HHV7 had a mean age of 4.5 years, whereas those with HHV6 had a mean age of 1.6 years. HHV6 and HHV7 were commonly found as causes of fever and maculopapular rash without respiratory symptoms. Co-infection with different herpesviruses can be found in the same patient.

Modulation of nuclear factor kappa b (NF-kB) activity in human herpes virus-6 (HHV-6) infection and its sequellae for cell function: Effects of antisense DNA treatment

Varias poblaciones celulares, susceptibles y no susceptibles, fueron infectadas con el virus herpes humano-6 (HHV-6) y tratadas posteriormente con ácido desoxirribonucleico (ADN) -NF-kB antisentido. Algunos cambios celulares secundarios a la integración del genoma viral pudieron ser corregidos con este tratamiento, mientras que aquellos inducidos por efecto de membrana celular del virus no respondieron de manera uniforme. Es así como el tratamiento con NF-kB puede servir para investigaciones posterioes específicas de los efectos virales en la célula. También puede servir para estudiar las actividades competitivas de las proteínas de NF-kB en los sitios genómicos homólogos

Detection of Epstein-Barr virus DNA and HHV-6 DNA in tissue biopsies from patients with nasopharyngeal carcinoma by polymerase chain reaction.

A total of 34 tissue biopsies were collected from nasopharyngeal carcinoma (NPC) patients and 5 controls with non-NPC. Extracted DNA from tissue biopsies were analyzed for presence of specific gene sequences to EBV type A and type B, and HHV-6 by polymerase chain reaction (PCR). The different sequences of EBV type A and B were parts from the highly divergent forms of the EBV nuclear antigen 2 (EBNA 2). The PCR amplified products for EBNA 2A and EBNA 2B were 115 and 119 base pairs respectively whereas that of HHV-6 DNA was 776 base pairs. The results demonstrated that EBV DNA was detected in 32 of 34 cases (94.1%): 28 (82.3%) with type A, 2 (5.9%) with type B, and 2 (5.9%) with both types. EBV DNA of type A could be detected 1 (20%) of 5 controls. HHV-6 DNA was in 5 of 34 samples (14.7%) whereas HHV-6 DNA was not detectable in biopsy tissues from controls. The results show that in the NPC patient group, A type of EBV is predominant. Detection of HHV-6 DNA in patients group only might be resulted from reactivation of a latent infection or association with EBV-induction of NPC.