Methods of treating renal transplant rejection using anti-CD40L domain antibodies are provided. The anti-CD40L dAbs are less likely to cause platelet aggregation and thus cause thromboembolism. Appropriate anti-CD40L dAbs doses and administration regimens are also provided. Combination treatments for transplant rejection, particularly renal transplant rejection, using anti-CD40L dAbs, a CTLA4 mutant molecule (e.g., belatacept) and/or anti-CD28 optionally with conventional immunosuppressive renal transplant therapy are provided.