Red cell antigens will be named in accordance with the American Association of Blood Banking (AABB) naming standards[^24]. In addition to the antigen or antibody, a modifier would be included in the super-system (the second subfield of the System field), to indicate whether testing was performed on the patient, donor, or blood product. Unless explicitly stated, testing is assumed to have been on a material collected from a patient. Additional information about the person identified in the System, such as the donor’s name or relationship to patient, should be placed in other OBX or comment segments of the message.
Blood bank reporting illustrates the need for a method of reporting by panel and by multiple-answer mechanism. The LOINC database provides observation names for both kinds of reporting.
3.2.1 Panel reporting
Each reportable antigen must have its own test, so that each element in a full set of binary tests could be reported as (negative, positive) or (0, 1).
The fully specified names of A, AB, B, and O blood types (as observations) would be as follows:
Measure of serum antibody against type A blood of donor:
A Ab:PrThr:Pt:Ser/Plas^donor:Ord:Presence of A antigen on donor’s red blood cells:
A Ag:PrThr:Pt:RBC^donor:Ord:Presence of A antigen on the blood cells in a pack of blood given to the patient:
A Ag:PrThr:Pt:RBC^BPU:Ord:3.2.2 Multiple answer reporting
All blood antibodies found (or not found) can also be reported in one result term:
Antigens absent:Prid:Pt:BBL^BPU:Nom:
Antibodies identified:Prid:Pt:Ser/Plas:Nom:The LOINC database provides other “observations” for reporting: the status of each blood pack (e.g., held, given, discarded), and for reporting that information when HIS and medical records systems want it; how much of each type of blood product was given at a moment in time; the type of each pack; any adverse reaction to that pack; and the pack number to accommodate laboratories that send this information as discrete observations.
Blood product disposition:Type:Pt:^BPU:Nom:Blood product type:Type:Pt:^BPU:Nom:[^24]: Walker RH. American Association of Blood Banks Technical Manual. 11th ed. Bethesda, MD: American Association of Blood Banks, 1993.