Temporal Variation of Ljungan Virus Antibody Levels in Relation to Islet Autoantibodies and Possible Correlation to Childhood Type 1 Diabetes

A. L. Nilsson1, *, E. Lagerquist2, K. F. Lynch3, Å. Lernmark2, 3, O. Rolandsson4
1 Department of Pediatrics, Östersund Hospital, Östersund, Sweden
2 Department of Medicine, University of Washington, Seattle, WA, USA
3 Department of Clinical Sciences, Lund University/CRC, University Hospital MAS, Malmö, Sweden
4 Department of Public Health and Clinical Medicine, University of Umeå, Umeå, Sweden

© 2009 Nilsson et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Pediatrics, Östersund Hospital, S-831 83 Östersund, Sweden; Tel: +46 63 15 39 77; Fax: +46 63 15 45 05; E-mail:


Viral infection may trigger islet autoimmunity, type 1diabetes (T1D), or both. Fluctuating population density of bank voles as a putative reservoir of Ljungan virus has been claimed to be associated with variations in T1D incidence rate (IR). We tested the hypothesis that Ljungan virus antibodies reflecting prior exposure(s) to the virus may be associated with islet autoimmunity, childhood diabetes or both. Incident, 0-18y, T1D patients (n = 63) were studied along with age and sample time matched controls (n = 126). The younger children (< 9 years) tended to have a higher incidence rate during winter (IR = 67.6, 95%CI 41.9-103.5) compared to summer (IR = 33.6, 95%CI 15.3-63.9) months. The proportion of children with high level antibodies against Ljungan virus (LVAb) were both younger compared to the rest of the children (p < 0.002) and correlated with half yearly T1D IR (r = 0.78, p = 0.005). High level LVAb fluctuating with season and correlating with T1D IR indicates that past exposure to Ljungan virus may be associated with T1D.