CD40LG and infection: In the case of Dengue, there are other factors that could affect sensitivity and specificity: if the sample is taken at an early stage or late stage of the disease, and the possible cross-reactivity with other antibodies Patients with early stage and primary dengue infection should present IgM against Dengue antigens after a few days of infection and the IgM levels should decrease after 90 days [1,2,3,4,11,12,13].