CD40LG and Q fever: Of these 8 positive results by LAMP, 6 confirmed and 18 probable cases of Q fever were diagnosed by the immunofluorescence assay, IFA (6 patients had 4-fold increase in the IgG titer of the antibody against I phase antigen of C. Burnetii while 12 patients had single serum IgM and IgG positive and 6 patients has single serum IgG positive).