Immunomodulation and growth factor induction by testosterone treatment in 10 male MS patients. A, Testosterone treatment significantly decreased CD4+ T cell and increased CD16/56+ NK cell percentages. B, Treatment also significantly decreased delayed type hypersensitivity recall responses. C-F, In addition, treatment significantly decreased IL-2 and increased TGFβ1, BDNF and PDGF-BB levels produced by PHA stimulated peripheral blood mononuclear cells (PBMCs) during testosterone treatment (months 3–12) compared to baseline (base). Protein levels are expressed as the mean percent change compared with the mean from two pretreatment baseline time points. Mean month 12 concentrations were 670.5 ± 223.4 pg/ml for IL-2, 1552.0+273.3 pg/ml for TGFβ1, 246.1 ± 40.37 pg/ml for BDNF and 42.6 ± 15.6 pg/ml for PDGF-BB, respectively.