Effect of atorvastatin and clopidogrel on cellular immune function

Lipid lowering therapy by statins and antiaggregation have become the basis of any anti-atherosclerotic prophylaxis either as primary or secondary prophylaxis. As several recent papers indicated immunosuppressive properties of statins we investigated changes in lymphocyte subpopulations, apoptosis markers, and cellular immune response towards mitogens after a short-term therapy with atorvastatin and clopidogrel. Nine healthy volunteers (four male, five female, age ranging from 26 to 43 years) were treated with 20 mg atorvastatin for 4 weeks and for 2 additional weeks with 20 mg atorvastatin and 75 mg clopidogrel after oral consent was given. Lymphocyte subpopulations were counted by flow cytometry. To assess cellular in vitro immune function, lymphocyte transformation tests with four mitogens (PHA, ConA, PWM, and OKT3) were performed. Absolute leucocyte counts remained unchanged as well as the granulocyte, monocyte, lymphocyte, and lymphocyte subpopulation counts. There were no detectable changes in markers of cell activation (HLA-DR, CD25, CD69, and CD86) or apoptosis (CD95, annexin). Cellular in vitro responses towards four mitogens did not show significant changes after atorvastatin nor after atorvastatin plus clopidogrel treatment.In conclusion, our data show that atorvastatin is not an immunosuppressive drug under therapeutical conditions.