Blood for my friend

My brother-in-law came down with a strange unnamed illness, where his bone marrow stopped producing blood. He required a minimun of 2 units of blood per week, for weeks. I had never given blood, as I was iron deficient from youth well into adulthood. I'm 68 and decided to try again. I did not even know my own blood type. The red cross checked my iron and typed me and I donated my 1st pint. A few months later I found out about "double reds" and decided to participate. Now my friend and brother-in-law is doing well. He is A- and it turns out so am I. I plan to continue with double reds. Neil Brown