  Quantum power corrections to the gravitational spin-orbit and spin-spin
interactions, as well as to the Lense-Thirring effect, were found for particles
of spin 1/2. These corrections arise from diagrams of second order in Newton
gravitational constant G with two massless particles in the unitary cut in the
t-channel. The corrections obtained differ from the previous calculation of the
corrections to spin effects for rotating compound bodies with spinless
constituents.
