Pathogenesis of dengue: an alternative hypothesis.

This paper presents a novel but entirely hypothetical concept on the pathogenesis of the shock syndrome (DSS) associated with dengue hemorrhagic fever (DHF). Antibody-dependent enhancement (ADE) is widely thought to be central to the development of these clinical entities. Current views on the mechanisms underlying ADE centre on two major lines of thought: 1) Non-neutralizing antibodies to dengue virus (DV) can enhance viral uptake and replication in target cells (monocytes). 2) DHF/DSS are the consequences of enhanced viral replication, paired with immunopathological processes that are evoked by monocyte dysfunction and detrimental reactions caused by activated T-lymphocytes. The present hypothesis proposes, by contrast, a central role for the following processes: 1) Secondary infection of an individual who has sub or non-neutralizing antibody titers against DV leads to a booster antibody response and a steep rise in antibody levels. 2) Antibodies against DV bind to and direct a selective attack of the complement system onto cells expressing viral antigens on their surface. DHF/DSS are the direct and indirect consequences of complement activation on these cells. The advanced hypothesis, which departs from the mainstream of "immune enhancement" concepts, can easily be tested by experimentation.