NOBODY has EVER performed either an Indirect Coombs Test (ICT) (or, still worse, an Indirect Coombes Test), or a Direct Coombs Test (DCT) (or, still worse, a Direct Coombes Test). There is most certainly NOT either an Indirect or Direct AHG Test. AHG is a reagent used in both the IAT and the DAT.
The correct terminology for the former test is the Indirect Antiglobulin Test (IAT) and for the latter test is the Direct Antiglobulin Test (DAT). It is true that Coombs was the primary author on three papers describing the test1-3, but Mourant and Race were his co-authors on these papers, and they are often forgotten.
Indeed, Coombs himself did not like the test being referred to as the Indirect Coombs Test and the Direct Coombs Test4, particularly as the principle of the test had been described in two papers published in the early 1900s,5, 6.
1. Coombs RRA, Mourant AE, Race RR. Detection of weak and ‘incomplete’ Rh agglutinins: A New Test. Lancet 1945, 246, 15-16. DOI: 10.1016/S0140-6736(45)90806-3.
2. Coombs RRA, Mourant AE, Race RR. A new test for the detection of weak and “incomplete” Rh agglutinins. British Journal of Experimental Pathology 1945; 26(4): 255-266.
3. Coombs RRA, Mourant AE, Race RR. In vivo isosensitization of red cells in babies with haemolytic disease. Lancet 1946; 247: 264-266. DOI: 10.1016/S0140-6736(46)91925-3.
4. Coombs RRA. Historical note: past, present and future of the antiglobulin test. Vox Sang 1998; 74: 67-73. DOI: 10.1046/j.1423-0410.1998.7420067.x.
5. Moreschi C. Neue tatsachen über die blutkörperchenagglutination. Zbl Bakt 1908; 46: 49-51.
6. Friedemann U. Weitere untersuchungen über den mechanismus der anaphylaxie. Z Immunitätsforsch Exp Ther 1 Originale 1909; 2: 591-641 (cited in reference 4).