CD40LG and type 1 diabetes mellitus: Additionally, they used RT-PCR to detect Coxsackieviruses B3 and B4 RNA in serum samples of 60 patients with T1DM and 120 healthy subjects; 25%, 23%, and 38% of patients with T1DM tested positive for Coxsackievirus B4 RNA, IgM against Coxsackievirus B4 and GAD65, and IgG against GAD65, respectively, compared with the 1%, 3% and 5% of the control group.