  We obtain an exact solution of the self-consistent relativistic
magnetohydrodynamic equations for an anisotropic magnetoactive plasma in the
background of a plane gravitational wave metric (PGW) with an arbitrary
polarization. It is shown that, in the linear approximation in the
gravitational wave amplitude, only the $\mathbf{e_+}$ polarization of the PGW
interacts with a magnetoactive plasma.
