CD40LG and Posterior Leukoencephalopathy Syndrome: We compared total cell numbers as well as lymphocytes, granulocytes, and erythrocytes; total protein in CSF; albumin in CSF and serum; IgG level, IgA level, and IgM level in CSF and serum; lactate; and the frequency of BCSFB breakdown between PRES patients and controls (Table 2).