BACKGROUND: A woman's candidacy for Rh immune globulin depends on whether her blood type is Rh-positive (D antigen-positive) or Rh-negative (D antigen-negative). New molecular blood-typing methods have identified variant D antigens, which may be reported as Rh-positive or Rh-negative depending on the laboratory method. We describe a case illustrating the effect of the new laboratory methods on a woman's candidacy for Rh immune globulin and present recommendations for interpreting the new test results. CASE: A 40-year-old woman presented for management of her third pregnancy. During her first pregnancy, she was typed as Rh-positive ("D") and did not receive Rh immune globulin. During her second pregnancy, she was typed as Rh-negative, in accordance with revised Rh-typing procedures. Anti-D antibody was detected. During her third pregnancy, she was genotyped as a partial D antigen, which was reported as Rh-negative. CONCLUSION: Revisions in laboratory procedures for Rh typing may present as a change in the Rh blood type of pregnant women-and as a change in their eligibility for Rh immune globulin.
BACKGROUND: A woman's candidacy for Rh immune globulin depends on whether her blood type is Rh-positive (D antigen-positive) or Rh-negative (D antigen-negative). New molecular blood-typing methods have identified variant D antigens, which may be reported as Rh-positive or Rh-negative depending on the laboratory method. We describe a case illustrating the effect of the new laboratory methods on a woman's candidacy for Rh immune globulin and present recommendations for interpreting the new test results. CASE: A 40-year-old woman presented for management of her third pregnancy. During her first pregnancy, she was typed as Rh-positive ("D") and did not receive Rh immune globulin. During her second pregnancy, she was typed as Rh-negative, in accordance with revised Rh-typing procedures. Anti-D antibody was detected. During her third pregnancy, she was genotyped as a partial D antigen, which was reported as Rh-negative. CONCLUSION: Revisions in laboratory procedures for Rh typing may present as a change in the Rh blood type of pregnant women-and as a change in their eligibility for Rh immune globulin.
Authors: S Gerald Sandler; Willy A Flegel; Connie M Westhoff; Gregory A Denomme; Meghan Delaney; Margaret A Keller; Susan T Johnson; Louis Katz; John T Queenan; Ralph R Vassallo; Clayton D Simon Journal: Transfusion Date: 2014-12-01 Impact factor: 3.157