CD40LG and brucellosis: Among them, 98.36% (60/61) and 37.70% (23/61) of brucellosis patients were positive for IgG and IgM, respectively, with a significant difference between the two antibodies (χ2 = 51.174, p = 0.000), meaning that most of the patients have been infected with Brucella melitensis for at least 3 months.