Development of specific antibody patterns and clinical symptoms following Ockelbo virus infection.

Sixteen patients with symptoms typical for Ockelbo disease (rash, arthralgia, fever) were enrolled in a 2 1/2 year study, during which clinical symptoms were recorded and ELISA was employed to study specific IgM, IgG and IgG subclass development. Initially, all patients presented with rash and arthralgia, and five patients still suffered from joint symptoms at the end of the study period. Ockelbo virus specific IgM was detected during the first week post onset in 6 patients and in 15 patients by day 14. One patient failed to develop specific IgM and was later diagnosed with a human parvovirus B19 infection. All patients were IgM-negative 2 1/2 years post onset. Seroconversions or significant titer rises for specific total IgG were seen in 15 patients. IgG titers generally peaked within one year but in two patients maximum titers were seen 2 1/2 years post onset. Development of IgG1 followed that of total IgG, while IgG3, after an initial increase in all Ockelbo disease patients, remained at peak levels for one year in four patients, three of whom still had detectable IgG3 at the end of the study period. Ockelbo virus specific IgG2 or IgG4 was not detected in any of the patients.