Challenges in Thalassemia Carrier Detection in a Low Resource Setting Area of Eastern Indonesia: the Use of Erythrocyte Indices.

Abstract

Thalassemia major becomes the fifth catastrophic disease in Indonesia, however, national wide screening program is not mandatory. This study aimed to re-assess the validity of the various erythrocyte indices in determining ?-thalalssemia carrier among pregnant women in a low resource setting area. An analytic study was performed, comparing conventional cut-off various erythrocyte indices with new modified cut-offs by Kumar et al. The concordance analysis was calculated with Mentzer Index (MI) as reference. The validity of erythrocyte indices against hemoglobin (Hb) A2 were analysed, confirmed by molecular examination for ?- and common ?-Globin South East Asia population. Of 102 pregnant women, 34% was still anemic after completion of 90 iron pills. The concordance of conventional cut-off Shine & Lal index (<1530) was none to slight in agreement (kappa 0.097) to conventional cut-off MI (<13). The concordance of SLI increased significantly to substantial agreement when both used modified cut-offs (kappa 0.729). However, both SLI and MI had missed most of HbE carriers and ?-thalassemia carriers which seemed to be prevalent in this population as shown by DNA examination. In contrary, simple MCV<80fl and MCH<27pg had covered those carriers. This is the first study from Nusa Tenggara Timur, a low resource area in Indonesia in attempt to mass screen thalassemia carriers in this area where a simple MCV<80 fL and MCH<27pg have been used for preliminary screening rather than other indices. Since the population in eastern part of Indonesia has different genetic background compared to the west, DNA analysis is of great interest to map the spectrum of globin mutations.