Factors associated with alloantibody formation in transfusion dependant Hb E/beta-Thalassemia patients: A hospital-based study in a tertiary care centre of Assam

Abstract

Background

Interaction of Hb E with beta-thalassemia results in red cell phenotypes with weakened alpha -beta interface

causing decreased red cell survival. Severe forms of Hb E/beta-thalassemia on regular blood transfusion are

exposed to multiple red cell antigens causing alloantibody formation. India being a resource poor country, majority

of the blood centers provide only ABO, Rh D matched blood without antibody screening. Hence, limited data is

available on the rate of RBC alloimmunization in the state of Assam, which has highest prevalence of Hb E/Beta

thalassemia patients in India1 . The objective of this study is to analyse the factors associated with RBC

alloimmunisation in transfusion dependent Hb E/Beta thalassemia patients.

Materials and Methods

This is a cross-sectional observational study on transfusion dependent Hb E/beta thalassemia patients visiting the

blood centre Gauhati Medical and Hospital for a duration of one year. Blood grouping was done by conventional

tube technique where as pre transfusion antibody screening and compatibility testing was done by column

agglutination technique.

Results

A total of 188 Hb E/beta-thalassemia patients were included in the study. Alloimmunization was seen in 12 cases

(6.3%). The age of the patients at the time of study ranged from 1 to 28 years with a mean age of 10.2 years

(SD=5.31). Rate of alloimmunisation was lowest (2.36%) in the age group (1-10) years and highest (23%) in the age

group (21-30) years. Those who were transfused ?50 blood units had alloimmunisation rate of 1.71% compared to

20% in those receiving ?150 units. Three cases (2.7%) who received first transfusion at ? 1 years of age developed

alloantibody compared to nine cases (11.5%) who received transfusion after 1 year of age.

Conclusion

Factors like age at first transfusion, number of blood units transfused and mean age showed significant correlation

with the rate of alloimmunization in transfusion dependent Hb E/beta-thalassemia patients.