Global Journal of Transfusion Medicine (May 2024)

Prevalence and Clinical Significance of Immunoglobulin G1 and Immunoglobulin G3 Subclasses of Anti-D Antibody in Rh D Alloimmunized Antenatal Women

  • A. A. Arif Vaheedu,
  • Soonam John,
  • D. Meena,
  • P. S. Shaiji

DOI
https://doi.org/10.4103/gjtm.gjtm_61_23
Journal volume & issue
Vol. 9, no. 1
pp. 28 – 33

Abstract

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Background and Objectives: Hemolytic disease of the fetus and newborn (HDFN) occurs as a result of maternal sensitization to paternal antigens. Studies have shown that the immunoglobulin G (IgG) subclass in maternal serum – particularly the presence of IgG1 and IgG3 either singly or in combination, has an impact on the presence and severity of HDFN. The column agglutination technology is used for the identification of IgG1 and IgG3 subclasses. Therefore, the prevalence of IgG1 and IgG3 subclasses in a cohort of alloimmunized Rh (D) antenatal women at our center was studied and was correlated with severity of HDFN. The aims of this study were as follows: (1) to find out the prevalence of IgG1 and IgG3 subclasses among Rh (D) alloimmunized women and (2) to assess the clinical outcome of newborns born to mothers with respect to IgG subclass. Methodology: This was a descriptive study done on 75 antenatal Rh (D) alloimmunized women who fulfilled the inclusion criteria. Blood samples from study participants were subjected to IgG subtyping using the “DAT IgG1/IgG3 ID card” (Bio-Rad, Switzerland), and the outcome of pregnancy was assessed by categorizing the newborns into mild, moderate, and severe HDFN. The data obtained were analyzed using SPSS version 16. Prevalence was calculated and severity of HDFN was correlated with subclass. Results: Among the study population, 23% of mothers had IgG1 alone. Majority (72%) had both IgG1 + IgG3 subclasses and a few (5%) had IgG2 + IgG4. When the mother had both IgG1 + IgG3 subclasses in their body most newborns had only mild HDFN. Few cases of moderate-to-severe cases of HDFN were seen. Most newborns had only mild HDFN even though there were few moderate-to-severe cases of HDFN. No significant association could be demonstrated between severity of HDFN and type of IgG subclasses. Conclusion: Majority of maternal IgG found in HDFN was a combination of IgG1+IgG3.Such cases exhibited stronger grades of reaction in Indirect Coombs Test. A significant association could not be demonstrated between severity of HDFN and type of IgG subclasses.

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