Our main aim in this work is to study the effects of meson-exchange currents (MEC) over asymmetries and recoil polarization observables in A(e,e'p)B reactions. This DWIA+MEC model takes care of relativistic degrees of freedom by using semi-relativistic operators for the one-body current as well as for the two-body MEC. These SR currents are obtained by a direct Pauli reduction of the corresponding relativistic operators by an expansion in terms of missing momentum over the nucleon mass, while the current dependence on the transferred energy and momentum is treated exactly. Also some comparisons with experimental data are made.