LTOWB forms basis for successful program in San Antonio

Breaking down acronyms with the experts who work with them day in and day out
April 29, 2019

Dr. Samantha Gomez Ngamsuntikul, Associate Medical Director at BioBridge Global, was part of the team that implemented the Brothers in Arms program to bring lifesaving blood transfusions to seriously injured patients in San Antonio and South Texas. She answers the question “What is LTOWB?”

What is LTOWB?

LTOWB stands for low-titer type O-positive whole blood.

The LTWOB donations come from donors who have O-positive blood and low levels of antibodies known as anti-A and anti-B. Donors with blood type O have naturally occurring anti-A and anti-B antibodies. The antibody levels can increase with pregnancy, transfusion or consuming large amounts of probiotics.

What we are trying to avoid is transfusing high titer anti-A and/or anti-B to a patient with type A or B blood. Transfusion of high titer anti-A whole blood could potentially lead to red cell destruction in the recipient.

To prevent that from occurring, we chose an antibody limit. Donors below the cutoff level or titer are considered low titer donors. Above the cutoff makes them high titer donors.

We also use O-positive blood because it can be transfused safely to patients of all blood types.

Based on both military history and research done at Mayo Clinic and UT Health San Antonio, LTOWB has been collected, identified through testing, and then made available for use on medical helicopters, EMS units of the San Antonio Fire Department, and the city’s two Level 1 trauma centers through the Brothers in Arms program.

Using whole blood for trauma care makes sense because patients who bleed, bleed whole blood. Whole blood allows for the rapid transfusion of red cells, platelets and plasma. Whole blood transfusions have been used since World War II. At one point, there was a case of a severe blood transfusion reaction from a high titer O whole blood. So the military started testing donors and transfusing low-titer O whole blood.

In the 70s, component manufacturing became the new fad and there was also research on transfusing saline instead of whole blood. Whole blood usage decreased until there was a resurgence of whole blood usage by the Army in Afghanistan.

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