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Case Reports
. 2022 Apr;36(4):e24323.
doi: 10.1002/jcla.24323. Epub 2022 Mar 3.

Hemolytic disease of the fetus and newborn in the sensitizing pregnancy where anti-D was incorrectly identified as RhIG

Mackenzie L Walhof  1 , Judith Leon  1 , Andrea L Greiner  2 , James R Scott  2 , Charles Michael Knudson  1
Affiliations
Case Reports

Hemolytic disease of the fetus and newborn in the sensitizing pregnancy where anti-D was incorrectly identified as RhIG

Mackenzie L Walhof et al. J Clin Lab Anal. 2022 Apr.

Abstract

Background: Hemolytic disease of the fetus and newborn (HDFN) is a potentially fatal complication in Rh-incompatible pregnancies and rarely occurs in the sensitizing pregnancy. Distinguishing RhIG from true anti-D identified is challenging. A case of severe HDFN in which a sample drawn at 28 weeks showed anti-D antibody (3+ strength) attributed to RhIG is described. RBC antibody testing early in pregnancy was negative. At birth, the infant was severely anemic and maternal anti-D titer was 1:256. This case represents a clinically significant anti-D in the sensitizing pregnancy that was missed due to confusion with RhIG.

Methods: To determine if agglutination strength could be helpful, a retrospective chart-review using both electronic and paper medical records was performed on 348 samples identified as RhIG and 52 true anti-D samples. The agglutination strength of antibody was recorded for each sample.

Results: For RhIG, there was an even distribution between the weak to moderate agglutination strength (w+, 1+, and 2+) results (35%, 26%, and 33%, respectively) and just 6% had a 3+ strength. Agglutination strength in patients with high titer (≥1:16) anti-D showed they often (44.4%) have 1+ or 2+ agglutination reactivity.

Conclusions: These results show that agglutination strength alone does not provide reliable evidence to distinguish RhIG from high titer anti-D antibodies. We recommend that in cases where there is any uncertainty about whether the anti-D reactivity is due to RhIG, titers should be performed to rule out clinically significant anti-D antibody.

Keywords: HDFN; RhIG; transfusion.

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Conflict of interest statement

The authors declare that they have no conflicts of interest relevant to this manuscript.

Figures

FIGURE 1
FIGURE 1
Subject timeline. The timeline for the subject in this report is shown. Weeks from the last menstrual period (LMP) are shown on the x‐axis. Appointments prior to 20 weeks were at an outside facility and only limited information from these visits are available
FIGURE 2
FIGURE 2
Agglutination strength from RhIG, low titer anti‐D and high titer anti‐D antibodies. The agglutination strength using PEG enhancement was determined as described in the materials and methods. The proportion of samples with the indicated strength is shown and the number of total samples in each data set is also indicated
See this image and copyright information in PMC

References

    1. Hendrickson JE, Delaney M. Hemolytic disease of the fetus and newborn: modern practice and future investigations. Transfus Med Rev. 2016;30:159‐164. - PubMed
    1. Murray NA, Roberts IA. Haemolytic disease of the newborn. Arch Dis Child Fetal Neonatal Ed. 2007;92:F83‐F88. - PMC - PubMed
    1. Cacciatore A, Rapiti S, Carrara S, et al. Obstetric management in Rh alloimmunizated pregnancy. J Prenat Med. 2009;3:25‐27. - PMC - PubMed
    1. Moise KJ Jr. Management of rhesus alloimmunization in pregnancy. Obstet Gynecol. 2008;112:164‐176. - PubMed
    1. Szkotak AJ, Lunty B, Nahirniak S, Clarke G. Interpretation of pretransfusion testing in obstetrical patients who have received antepartum Rh immunoglobulin prophylaxis. Vox Sang. 2016;110:51‐59. - PubMed

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