If you do believe that the various blood types all evolved from a more primitive blood type, then blood may be alive, depending upon your definition of self-sustaining. A few days after you get sunburned, you might peel off some dead skin. Reproduction usually figures into a definition of life somehow. When skin grows it must be reproducing itself. But blood doesn t reproduce itself.
Blood is manufactured by bone marrow.
That makes it more like milk, which is manufactured by mammary glands. In this case, we can t measure what we are speaking about. We can t measure life, because our knowledge of life is of a meager and unsatisfactory kind. Science can explain natural phenomenon. Maybe the reason why we can t measure life is because it isn t a natural phenomenon.