Hi Sheila,
My husband at age 43 had a large DVT in his upper right leg. He had been driving back and forth to his grandmother's house (1 1/2 hour drive each way) for several days because she was dying. The vascular doctor said he tested positive for Protein S deficiency and that it was hereditary (his father had had several blood clots during his lifetime). The doctor said they only recently were able to test for it so his father probably had it too. He told us there was no cure, but taking Coumadin (the only blood thinner available at the time--1994) for the rest of his life would prevent any more blood clots due to the condition. It was somewhat of a pain because of the monthly protime testing. As well, he never had a consistent protime so the doctor was always adjusting his dose of Coumadin. Fortunately, the new blood thinners came out around 2005 and my husband was switched to Xarelto, which required no protime testing. As far as I know, there is no way to increase your protein S. It is a metabolic process that does not work correctly in your body due to a hereditary condition. My husband never had another blood clot until he had covid in 2022, so if you keep taking the Eliquis, you should be okay.