Some jws when calling WTS headquarters regarding transfusion policies have found there are invisible policies that are more allowing but not in print....wow! One elder was stunned and realized that jws had died not knowing this invisible policy. No I will not give the details, I am sure they have changed. BTW, look up info on the use of hemoglobin-based products in the Watchtower Online Library if it won't trigger you. (The WTS makes this a long "medical" discussion but I put the comments that directly quote their reason for changing this to a conscientious matter rather df'ing)
August 2006 Awake p.10-12
What Are Hemoglobin-Based Oxygen Carriers?
Note that this is made from human or bovine red blood cells. Then the WTS says it is processed changing into some other than the original hemoglobin. But is that true, can blood be modified and acceptable. The WTS considers it another type of blood fraction. But says using it is a conscience matter (but in reality saying the WTS would not choose to take it which would cause many jws to reject it)
Some manufacturers now process hemoglobin, releasing it from human or bovine red blood cells. The extracted hemoglobin is then filtered to remove impurities, chemically modified and purified, mixed with a solution, and packaged. The end product—not yet approved for use in most lands—is called a hemoglobin-based oxygen carrier, or HBOC. Since the heme is responsible for the rich red color of blood, a unit of HBOC looks just like a unit of red blood cells, the primary component from which it is taken...
As long as the HBOC is derived from blood, there are two objections that may be raised. One, the HBOC carries out the key function of a primary component of blood, the red cells. Two, hemoglobin, from which the HBOC is derived, makes up a significant portion of that component...Unlike red blood cells, which must be refrigerated and discarded after a few weeks, the HBOC can be stored at room temperature and used months later. And since the cell membrane with its unique antigens is gone, severe reactions due to mismatched blood types pose no threat.
However, compared with other blood fractions, the HBOC presents more challenges to conscientious Christians, who seek to obey God’s law on blood. Why? As long as the HBOC is derived from blood, there are two objections that may be raised. One, the HBOC carries out the key function of a primary component of blood, the red cells. Two, hemoglobin, from which the HBOC is derived, makes up a significant portion of that component. Regarding this and similar products, then, Christians face a very serious decision. They must carefully and prayerfully meditate on Bible principles concerning the sacredness of blood. With a keen desire to maintain a good relationship with Jehovah, each must be guided by his Bible-trained conscience.—Galatians 6:5.