Fermionic systems differ from their bosonic counterparts, the main difference with regard to symmetry considerations being that T 2 = −1 for fermionic systems. In PT -symmetric quantum mechanics an operator has both PT and CPT adjoints. Fermionic operators η, which are quadratically nilpotent (η 2 = 0), and algebras with PT and CPT adjoints can be constructed. These algebras obey different anticommutation relations: ηη PT + η PT η = −1, where η PT is the PT adjoint of η, and ηη CPT + η CPT η = 1, where η CPT is the CPT adjoint of η. This paper presents matrix representations for the operator η and its PT and CPT adjoints in two and four dimensions. A PT -symmetric second-quantized Hamiltonian modeled on quantum electrodynamics that describes a system of interacting fermions and bosons is constructed within this framework and is solved exactly.