In one aspect, the invention provides methods of inhibiting the effects ofMASP-2-dependent complement activation in a living subject. The methodscomprise thestep of administering, to a subject in need thereof, an amount of a MASP-2inhibitory agenteffective to inhibit MASP-2-dependent complement activation. In someembodiments, theMASP-2 inhibitory agent inhibits cellular injury associated with MASP-2-mediatedalternative complement pathway activation, while leaving the classical (C1q-dependent)pathway component of the immune system intact. In another aspect, theinvention providescompositions for inhibiting the effects of lectin-dependent complementactivation,comprising a therapeutically effective amount of a MASP-2 inhibitory agent andapharmaceutically acceptable carrier.