HHV-6B, HHV-7, and B19V Are Frequently Found DNA Viruses in the Human Thymus but Show No Definitive Link with Myasthenia Gravis

Kirsten Nowlan; Leo Hannolainen; Irini M Assimakopoulou; Pia Dürnsteiner; Joona Sarkkinen; Santeri Suokas; Lea Hedman; Pentti J Tienari; Klaus Hedman; Mikael Niku; Leena-Maija Aaltonen; Antti Huuskonen; Jari V Räsänen; Ilkka K Ilonen; Mikko I Mäyränpää; Johannes Dunkel; Sini M Laakso; Maria Söderlund-Venermo; Maria F Perdomo; Eliisa Kekäläinen

doi:10.1093/infdis/jiae600

HHV-6B, HHV-7, and B19V Are Frequently Found DNA Viruses in the Human Thymus but Show No Definitive Link with Myasthenia Gravis

J Infect Dis. 2024 Dec 5:jiae600. doi: 10.1093/infdis/jiae600. Online ahead of print.

Authors

Kirsten Nowlan^{1

2}, Leo Hannolainen³, Irini M Assimakopoulou³, Pia Dürnsteiner^{1

2}, Joona Sarkkinen^{1

2}, Santeri Suokas⁴, Lea Hedman³, Pentti J Tienari^{1

5}, Klaus Hedman^{3

6}, Mikael Niku⁴, Leena-Maija Aaltonen⁷, Antti Huuskonen⁸, Jari V Räsänen⁹, Ilkka K Ilonen⁹, Mikko I Mäyränpää^{10

11}, Johannes Dunkel^{10

11}, Sini M Laakso^{1

5}, Maria Söderlund-Venermo³, Maria F Perdomo³, Eliisa Kekäläinen^{1

2

6}

Affiliations

¹ Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.
² Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland.
³ Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
⁴ Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
⁵ Department of Neurology, Neurocenter, Helsinki University Hospital, Helsinki, Finland.
⁶ HUS Diagnostic Center, HUSLAB, Clinical Microbiology, Helsinki, Finland.
⁷ Department of Otorhinolaryngology, Head and Neck Surgery, Helsinki University Hospital, Helsinki, Finland.
⁸ Pediatric Cardiac and Transplantation Surgery Department, Helsinki Children's Hospital, University of Helsinki, Helsinki, Finland.
⁹ Department of General Thoracic and Esophageal Surgery, Heart and Lung Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
¹⁰ Department of Pathology, University of Helsinki, Helsinki, Finland.
¹¹ HUS Diagnostic Center, Pathology, Helsinki University Hospital, Helsinki, Finland.

PMID: 39657004
DOI: 10.1093/infdis/jiae600

Abstract

Myasthenia gravis (MG) is a rare autoimmune disorder characterised by muscle weakness resulting from autoantibody-mediated disruption of the neuromuscular junction. Notably, it is also frequently associated with thymic pathology. This study explores the relationship between MG and DNA viruses in the thymus, employing targeted NGS and qPCR to analyse thymic tissue samples from both MG patients and healthy controls. We detected HHV-6B, HHV-7, EBV, and B19V across various tissue groups. However, no significant enrichment of these viruses was observed in the thymic tissue of MG patients. Additionally, we confirmed a dormant persistence of B19V within the thymus of seropositive individuals. These findings indicate that DNA viruses are unlikely to serve as primary environmental triggers for MG.

Keywords: DNA viruses; Herpesviruses; Myasthenia gravis; Parvovirus B19; Thymoma; Thymus.