CD40LG and infection: The difference could be associated with the time of the sample collection, production of the immunoglobulins or sensitivity that can be attributed to the technique and the antigen in use (i.e., IgM is the first immunoglobulin to be produced in response to an antigen and can be detected during early onset of disease, whereas IgG is maintained in the body after initial exposure for the long-term response and can be detected after the infection has passed).