HLA-A∗02, gender and tobacco smoking, but not multiple sclerosis, affects the IgG antibody response against human herpesvirus 6

Increased Serological Response Against Human Herpesvirus 6A Is Associated With Risk for Multiple Sclerosis

Human herpesvirus (HHV)-6A or HHV-6B involvement in multiple sclerosis (MS) etiology has remained controversial mainly due to the lack of serological methods that can distinguish the two viruses. A novel multiplex serological assay measuring IgG reactivity against the immediate-early protein 1 from HHV-6A (IE1A) and HHV-6B (IE1B) was used in a MS cohort (8,742 persons with MS and 7,215 matched controls), and a pre-MS cohort (478 individuals and 476 matched controls) to investigate this further. The IgG response against IE1A was positively associated with MS (OR = 1.55, p = 9 × 10-22), and increased risk of future MS (OR = 2.22, p = 2 × 10-5). An interaction was observed between IE1A and Epstein-Barr virus (EBV) antibody responses for MS risk (attributable proportion = 0.24, p = 6 × 10-6). In contrast, the IgG response against IE1B was negatively associated with MS (OR = 0.74, p = 6 × 10-11). The association did not differ between MS subtypes or vary with severity of disease. The genetic control of HHV-6A/B antibody responses were located to the Human Leukocyte Antigen (HLA) region and the strongest association for IE1A was the DRB1*13:01-DQA1*01:03-DQB1*06:03 haplotype while the main association for IE1B was DRB1*13:02-DQA1*01:02-DQB1*06:04. In conclusion a role for HHV-6A in MS etiology is supported by an increased serological response against HHV-6A IE1 protein, an interaction with EBV, and an association to HLA genes.

Interaction between beta-3 adrenergic receptor genotype and environmental factors on periodontal progression

OBJECTIVES

The purpose of this longitudinal study was to evaluate the relationship between beta-3 adrenergic receptor polymorphism and environmental factors such as smoking on periodontal disease by considering effect modification.

MATERIALS AND METHODS

A total of 294 subjects who participated in all follow-up surveys over the 6-year study period were analysed. After dividing subjects into tertiles according to the number of years exposed to smoking, we conducted Poisson regression analysis to compare the incidence rate ratio (IRR) for periodontal disease events during the 6-year study period with beta-3 adrenergic receptor genotype (1: Arg allele carriers, 2: Arg allele non-carriers) for each tertile adjusted for other four variables.

RESULTS

The number of years exposed to smoking (mean ± standard deviation) for the 1st, 2nd and 3rd tertiles was 0 ± 0, 20.1 ± 9.1 and 45.3 ± 7.7 years, respectively. The IRRs ± SE were 0.89 ± 0.08 (p = 0.218) for the 1st tertile, 1.93 ± 0.36 (p < 0.001) for the 2nd tertile and 2.56 ± 0.23 (p < 0.001) for the 3rd tertile.

CONCLUSION

There was a clear dose-response relationship between beta-3 adrenergic receptor genotype and periodontal disease progression based on the number of years exposed to smoking.

Association between human herpesvirus & human endogenous retrovirus and MS onset & progression

This review discusses the role of Epstein-Barr virus (EBV), human herpesvirus 6 (HHV6) and human endogenous retroviruses (HERVs) in the onset and progression of multiple sclerosis (MS). Although EBV has been established as one of the causal factors in MS onset, its role in MS progression is still uncertain. Moreover, interactions between EBV and other risk factor on MS development still need more investment. With less consistent evidence than EBV, HHV6 has also been implicated in the pathogenesis of MS; moreover, it showed a closer connection with the disease activity. Recent studies found that HERVs were associated with the development and progression of MS. Some antiviral treatments have shown promise for clinical interventions in the future. Future studies are yet needed to fully clarify the role of these agents in MS onset and disease course and the modes by which they realise these effects.

Modulatory effects on dendritic cells by human herpesvirus 6

Human herpesvirus 6A and 6B are β-herpesviruses approaching 100% seroprevalance worldwide. These viruses are involved in several clinical syndromes and have important immunomodulatory effects. Dendritic cells (DC) are key players in innate and adaptive immunity. Accordingly, DC are implicated in the pathogenesis of many human diseases, including infections. In this review the effects of HHV-6 infection on DC will be discussed.