What are the I-IV blood type descriptions shown below (commonly used in Eastern Europe), and how do you translate them into the ABO-system?

enter image description here

  • 1
    $\begingroup$ What do you mean by translate? $\endgroup$
    Commented Nov 11, 2014 at 7:09
  • $\begingroup$ @WYSIWYG: Convert it to the system used in the West: redcrossblood.org/learn-about-blood/blood-types $\endgroup$
    – MikeF
    Commented Nov 11, 2014 at 7:14
  • 5
    $\begingroup$ I still don't understand. Isn't it already clear from the image? $\endgroup$
    Commented Nov 11, 2014 at 7:15
  • 1
    $\begingroup$ @WYSIWYG: What's this (I), (II), (III), etc. stuff? I guess that's what I'm asking. $\endgroup$
    – MikeF
    Commented Nov 11, 2014 at 7:17
  • $\begingroup$ I think this description is wrong. Blood type used to be described as AB-I, A-II, B-III and O-IV plus Rh Positive or Negative. $\endgroup$
    – antonio
    Commented Feb 13, 2019 at 23:59

1 Answer 1


It is a direct correlation between the ABO blood groups and the Roman numerals.

 O: I

 A: II



This numeric system was pioneered by Jan Jansky of Czechoslovakia in the early 20th century. Apparently it is still used in some former Soviet states.

Erb IH. 1940. Blood Group Classification (A Plea for Uniformity). Can Med Assoc J 42(5):418-421.

  • 1
    $\begingroup$ I can't upvote it (not enough rep.) But thanks for the info! $\endgroup$
    – MikeF
    Commented Nov 11, 2014 at 7:45
  • 2
    $\begingroup$ @MikeF you should be able to accept it by clicking the check mark. $\endgroup$
    – canadianer
    Commented Nov 11, 2014 at 8:01
  • $\begingroup$ What would O+ in the US be in the UK? $\endgroup$ Commented May 21, 2016 at 7:13

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .