Characterization of antibody response in patients with acute and chronic chikungunya virus disease

Background: Chikungunya virus (CHIKV) is a re-emerging arbovirus capable of causing chronic arthralgia, which can last for months to years. Although neutralizing antibodies have been shown to be important for viral clearance, is it not clear whether the quantitative and qualitative nature of antibodies play a role in progression to chronic disease. Objectives: To characterize and compare the antibody responses in acute and chronic patients in a prospective observational CHIKV study in Curaçao during the 2014-2015 outbreak. Study design: We performed virus neutralization tests and ELISA on plasma samples collected from a prospective observational chikungunya study in Curaçao to compare the complement-dependent and –independent neutralization capacity, as well as the antibody avidity index of acute and chronic patients. Results: We found that there was no significant difference in the virus neutralization titers between patients with acute and chronic chikungunya infection. Furthermore, we found that complement increased the neutralization capacity when large amounts of virus was used. Moreover, we found that patients with acute chikungunya disease had a significantly higher antibody avidity index compared to those with chronic disease. Conclusions: This study suggests that virus neutralization titers in late convalescent sera do not play a role in chronic chikungunya. However, the median antibody avidity was lower in these patients and may therefore suggest a role for antibody avidity in the development of chronic disease.