Prevalence of “unexpected antibodies” in the antenatal women attending the Government Maternity Hospital, Tirupati

Abstract

Background: All antibodies to red cell antigens, other than naturally occurring anti-A and anti-B are considered unexpected. They can be either alloantibodies or auto antibodies. In pregnant women, these antibodies may cross the placenta and cause haemolytic disease of the foetus and newborn (HDFN). Timely detection of such antibodies in antenatal women is essential for early management of HDFN. Methods: A prospective cross-sectional study was carried out on 2060 multiparous pregnant women attending the Government Maternity Hospital, Tirupati to detect prevalence of unexpected antibodies. The women were grouped and typed for ABO and rhesus (Rh) D antigens by tube method and screened for alloantibodies by column agglutination technology. The medical and detailed obstetric history of these women were reviewed. Results: The overall prevalence of alloantibodies was 1.1%. There was a statistically significant difference between alloimmunization rates in the Rh D-antigen negative and D-antigen positive women (12.8% versus 0.3%). The antibodies detected in this study were, anti-D (63.8%), anti-D+C (13.7%), anti-C, anti-E, anti-M, anti-Le a , and anti-Le b (4.5% each). Anti-D contributed to 77.3% of total alloimmunization in this study. Conclusions:In spite of the introduction of prophylactic Rh-immunoglobulin, anti-D (77.3%) is still a common antibody identified in the antenatal women of our region. In developing countries like India, universal antenatal antibody screening, though desirable may not be justified at present as the cost and infrastructure required would be immense. However, it is necessary to impose properly formulated protocols to screen at least the pregnant women with adverse obstetric history.

Red cell alloimmunization in pregnancy: a study from a premier tertiary care centre of Western India

“…Anti-E is reported to be one of the common Rh non-anti-D antibodies causing mild to moderate HDFN [ 3 , 20 ]. In addition, there are reports of anti-e causing HDFN [ 21 ].…”

“…There are approximately 270 antibodies against red blood cell antigens [ 2 ]. The anti-A and anti-B antibodies against red blood cells are part of every adult immune system and thus are natural antibodies [ 3 ]. Any antibodies against red cell antigens other than anti-A and anti-B are considered unexpected, and can be either alloantibodies or autoantibodies.…”

“…In India, according to the guidelines of the Directorate General of Health Sciences Technical Manual, Government of India, alloantibody screening is reserved for Rh-negative women or those with adverse obstetric history [ 1 ]. The studies from New Delhi, Tamil Nadu, Karnataka, and Andhra Pradesh have reported the frequency of these unexpected antibodies as 1.25%, 1.5%, 2.27%, and 1.1%, respectively [ 3 , 6 , 9 , 10 ]. However, no such reports are available for Western India (Rajasthan).…”

Enfermedad hemolítica del feto y del recién nacido por aloanticuerpos contra el antígeno M

“…Típicamente son IgM por lo que no tienen la capacidad de atravesar la barrera placentaria (6), pero existen casos reportados en la literatura de Anti-M causantes de enfermedad hemolítica del feto y el recién nacido (EHFRN). Entre los anticuerpos hacia antígenos no-RH causantes de la EHFRN, los anticuerpos Anti-M representan una frecuencia muy baja, agrupándose con anticuerpos hacia grupos sanguíneos como Lewis, Duffy, e incluso aquellos con reacción inespecífica, de los cuales se reportan prevalencias incluso de <5% en casos de aloinmunización (7). En un reporte realzado en la India por Suresh, et.…”

“…Usualmente son del tipo IgM, por lo que no tienen la capacidad de atravesar la barrera placentaria 6 , pero existen casos reportados de anticuerpos anti-M causantes de la enfermedad hemolítica del feto y el recién nacido. Entre los anticuerpos contra antígenos no-Rh causantes de esta enfermedad hemolítica, la frecuencia de los anti-M es muy baja; estos se agrupan con anticuerpos en grupos sanguíneos como el Lewis o el Duffy, e incluso, aquellos de reacción inespecífica, con prevalencias hasta de menos del 5 % en casos de aloinmunización 7 . En un reporte de Suresh, et al ., en India, en que se hizo el cribado de 2.060 mujeres gestantes, se documentaron 22 casos de aloinmunización materna con RAI positivo, de los cuales solamente uno correspondía a la aloinmunización causada por anti-M, es decir, apenas el 4,5 % de las mujeres con aloinmunización.…”