Antibody Screen vs Indirect Coombs

Please help me understand the use of Antibody Screen and Indirect Coombs in LOINC mapping.



The Antibody Screen LOINC options allow for all of the different methods(techniques) for the individual screening cells as well as groupings of the screening cells or just Blood Group Antibody Screen.

The Indirect Coombs LOINC options include all the different AHG reagent specificities or an unspecified reagent choice.



If I have an Antibody Screen that is one Qualitative result observation is the correct LOINC code the Indirect antiglobulin test with the specific reagent used or would it be the methodless Blood group antibody screen?



I would appreciate any clarification regarding this issue.



Thank you,

Jane Burke

Hi Jane,



Wikipedia lists indirect coombs as the method of detecting circulating antibodies and antibody screening as one of the use cases of the method, in addition to cross matches and antenatal screens. Not seeing the entire blood bank section of what you’re mapping can make it tricky to advise, but I’ll try and hopefully others will join in.



There’s a lot of dependencies of how many computer result fields and how granular they were created. As you mention, Antibody screen, for example, has 18 ordinal result LOINC codes, including phases (saline, AHG), warming, cells 1+2+3 conjoined or separated, autologous. There are more for quantitative titers. I found these by placing ‘antibody screen bldbk’ in the RELMA window.



If I place ‘Coombs’ in the RELMA search window, there’s an entirely different set of LOINC codes that comes up. Most with the direct and indirect antihuman globulin test component name. This is all a reiteration of your statement.



One difference comes in as to when to use method. If the site gives granular result fields for saline, AHG , prewarmed, eluted methods, then it seems appropriate to use the Antibody screen AHG phase. If all results are placed in one result field, no matter how much work up was done on the specimen, I personally would leave it at methodless. Another difference would be at the component level, in how many screening cells are they using in separate fields?



I hope that I have understood your question correctly.



Most respectfully,

Pam