CD40LG and Q fever: Accordingly, all 61 sample sera corresponding to acute Q fever were tested positive by IFA; of these samples, 46 (75.4%) revealed titers against IgG only, while the rest 15 (24.6%) revealed titers against both IgM (titers ranging from 1/200 to 1/1,600) and IgG (titers ranging from 1/480 to 1/7,680).