Iron deficiency anaemia in sickle cell disorders in India

BACKGROUND & OBJECTIVE

Iron deficiency anaemia (IDA) is uncommon in individuals with sickle cell disease (SCD) because of availability of an adequate iron source potentially from increased red cell turnover and from blood transfusions. Also, iron deficiency anaemia can often go unnoticed because the sickle cell disease patients are already anaemic. Iron deficiency in sickle cell patients may result in lowering the intracellular haemoglobin concentration and this may ameliorate sickling. The present study was undertaken to determine the prevalence of iron deficiency anaemia and the response of iron supplementation in sickle cell disorders in tribal population of the four States viz. Maharashtra, Gujarat, Orissa and Tamil Nadu.

METHODS

A total of 8434 individuals (7105 AA, 1267 AS and 62 SS) were tested for zinc protoporphyrin/haem (ZPP/H) ratio and haemoglobin levels. Twenty two sickle cell anaemia (SS), 47 sickle cell trait (AS) and 150 normal control (AA) individuals who were iron deficient, were given iron therapy for a period of 12 wk and the laboratory investigations were repeated at the 13th wk.

RESULTS

Sixty seven per cent of subjects with sickle cell anaemia and 26 per cent with sickle cell trait had elevated ZPP/H ratios (>80 micromol/mol) as against 22.8 per cent of normal individuals. The elevated ZPP/H ratios is an indicator of microcytic anaemia of iron deficiency. Following iron therapy, an improvement in the Hb levels and ZPP/H ratios was observed in both sickle cell disorders and normal individual cases.

INTERPRETATION & CONCLUSION

This study suggests that iron deficiency anaemia is an important problem in Indian sickle cell anaemia patients and iron supplementation should be given only in proven cases of iron deficiency anaemia.

Red cell genetic abnormalities, beta-globin gene haplotypes, and APOB polymorphism in the Great Andamanese, a primitive Negrito tribe of Andaman and Nicobar Islands, India

The Great Andamanese are a primitive Negrito tribe of the Andaman and Nicobar Islands, India, with a total population of 37. We studied 29 individuals from eight families from this population for abnormal hemoglobins, G6PD deficiency, DNA haplotypes, and apolipoprotein B (APOB, gene) polymorphism. Hb E was detected in five individuals, the prevalence of Hb E heterozygotes being 14.3%. One individual had beta-thalassemia trait. One female was G6PD deficient and showed the G6PD Orissa mutation. Haplotype analysis of the beta-globin gene cluster showed that the betaE chromosomes were linked to two haplotypes (- - - - - + + and + + - + + + +) representing the framework 1 gene, whereas the betaA chromosomes showed eight different haplotypic patterns corresponding to framework 1 and 3 genes. APOB polymorphism analysis showed that the 631-base-pair (bp) allele was the predominant one with a high homozygosity rate, which could be due to the higher rate of inbreeding in this isolated group. The presence of Hb E and our findings on haplotype analysis supports the hypothesis that the Great Andamanese are reasonably believed to be the surviving representatives of the Negrito race that once flourished in the entire Southeast Asian region in ancient times.

Detection of the beta s gene: an evaluation of the solubility test against automated chromatography and haemoglobin electrophoresis

The solubility test is evaluated against automated high-performance liquid chromatography (HPLC) and haemoglobin (Hb) electrophoresis for its efficacy in screening for the beta s gene in population groups in remote areas. Blood samples taken from 3246 individuals from the tribal populations of the Dhule and Gadchiroli districts of Maharashtra state were analysed by all three methods. The solubility test detected 871 out of 932 individuals positive for the beta s gene by HPLC and Hb electrophoresis, and showed an overall sensitivity of 93.8% and specificity of 100%, with a positive predictive value of 100% and negative predictive value of 97.4%. Both HPLC and Hb electrophoresis are relatively expensive and not available in most laboratories in remote tribal areas, where the frequency of the beta s gene is very high. We conclude that the solubility test could be used for preliminary screening to determine the prevalence of the beta s gene in different population groups, particularly in remote areas where other facilities are not available. Individuals who test positive for the beta s gene by the solubility test require further investigation by either HPLC or Hb electrophoresis.