Viral load in patients infected with dengue is modulated by the presence of anti-dengue IgM antibodies

Abstract

BackgroundThe measurement and detection of viremia and antigenemia in sera have been used as a marker of risk for dengue disease severity and diagnosis. However, evidence exists suggesting that levels of viremia and antigenemia are affected by the presence of specific antibodies. ObjectiveTo compare viral load and circulating NS1 levels in sera from patients positive or negative for dengue specific IgM antibodies. Study designThree hundred and eighty serum samples were analyzed for viral load using qRT-PCR and for levels of circulating NS1 and the presence of specific antibodies using commercial EIAs. Results and conclusionComparison of viremia levels in sera from patients positive or negative for dengue IgM antibodies showed that viral load was significantly higher (p≤0.0001) in patients negative for IgM antibodies. In contrast, levels of circulating NS1 were found unaffected by the presence of IgM (p=0.0038). Thus, dengue virus specific IgM antibodies in sera seem to be a strong negative modulator of viremia levels in patient's sera.