blood direct renin activity level plasma renin activity level plasma direct renin activity level 2014-06-25T12:39:43Z CMO:0002500 JSmith Measurement of the amount of renin activity in a specified sample of plasma (the fibrinogen-containing fluid portion of the blood in which the particulate components are suspended) via the direct immunologic detection of the renin protein in the sample and subsequent conversion of the protein level to an activity level. VT:0005581 clinical_measurement_ontology