European Journal of Cardiovascular Medicine

Beta thalassemia is an autosomal recessive genetic disease. The cause is partial or complete lack of ability to synthesise beta chains of the haemoglobin. ^[1] This process of beta globin chain synthesis is controlled by a gene located on chromosome. There can be more than 200 mutations of this gene, leading to varying degrees of inability to synthesise beta chains of haemoglobin. In thalassemia major, there is complete lack of ability to synthesise beta chains of haemoglobin.

This leads to chronic haemolysis and severe anaemia. ^[2] Patients present with varying degrees of anaemia from early childhood and are transfusion dependent. According to an epidemiological study, beta thalassemia is the most common genetically transmitted haematological disorder in Indian children. ^[3]

Iron metabolism in thalassemia- Normally, the amount of iron (20-30 mg/day) needed for daily production of 300 million new RBCs is provided mostly by the iron which is recycled by macrophages. ^[4] The iron stored in macrophages is safe, and it does not lead to oxidative stress. ^[5] Duodenal absorption in normal persons is approximately 1-2 mg/day, which is balanced with iron excretion of 1-2 mg/day. In thalassemic patients, there is increased iron absorption (3-9 mg/day). ^[6] This causes increase in body’s iron burden. Additionally in thalassemia major patients, regular blood transfusions lead to double iron accumulation (420 ml of transfused blood is equivalent to 200 mg of iron).

In these patients, the excess iron saturates the plasma transferrin, which then transfers the iron to a storage protein called apoferritin. Thus the storage protein ferritin is formed. Ferritin is a 450 kDa protein consisting of 24 subunits which is present in every cell type. ^[7] The ferritin levels measured have a direct correlation with the total amount of iron stored in the body. This fact applies in all types of anaemia of chronic disease due to any cause. ^[8] In iron overload disorders such as haemochromatosis, serum ferritin levels have been found to be abnormally increased. ^[9]

Role of vitamin B12 and Folic acid- Vitamin B12 and folic acid are essential nutrients for erythropoiesis. Deficiency of either of these vitamins leads to megaloblastic anaemia. ^[10] Vitamin B12 defficiency may also cause severe neurological deficit. Low serum folate has well been described in homozygous beta thalassemia. ^[11] Reports on vitamin B12 status in thalassemic patients are at variance. ^[12] In homozygous beta thalassemia, erythropoiesis is depressed. The cause can be iron overload or deficiency of these vitamins.

The + signs indicate enhancement, and the - signs indicate inhibition. Demethylation of methyl-tetrahydrofolate (CH3THF) to THF is a critical step in DNA synthesis because THF is the substrate for the enzyme that converts (THF)-1 to the polyglutamated form (THF)n. Only polyglutamated (THF)n participates in purine synthesis.

Ninety children of Thalassemia included in study group while Ninety normal children in control group. Estimation of levels of folic acid, vitaminB12 and serum ferritin were made in autoanalyzer.

Inclusion criteria were including normal liver and kidney functions test.

Exclusion criteria include use of medication which induce iron chelation such as iron chelating agent therapy, phenytoin, carbamazepine, antifolates, theophylline and diabetes mellitus, carcinoma, anemia excluded from research.

In our study, Thalassemic patients had much higher ferritin levels in comparison with healthy controls. Study group showed a decrease in serum folic acid and vitamin B12 levels with mean value of 5.75±1.18 ng/mL and 165.8±33.37 pg/mL respectively as compared to control group was 13.05±5.88 ng/mL and 441.34±129.65 pg/mL (P<0.001) whereas increased concentration of ferritin with mean value of 2154.8±333.790 ng/mL in study group as compared to control group was 200.7±68.99 and was statistically highly significant (p<0.001).

Table 1: Mean ±SD of Serum Ferritin in cases and control group subjects

Table 2 :Mean ±SD of Vit-B12 in cases and control group subjects

Table 3: Mean ± SD of Serum Folic Acid in cases and control group subjects

Table 4:

Our studies showed that serum ferritin level of thalassemia patients was much higher than normal healthy controls. Also, a highly significant decreased folic acid levels was observed in the paediatric age group as compared to the control group.

Our study indicates that deficiency of folic acid in thalassemia subjects. Vitamin B12 deficiency also seen in our study group as compared with controls. Mean concentrations of vitamin B12 decline and was highly significant in thalassemic group. Our observations are also supported by some previous studies.

The management of thalassemia major (TM) involves consistent and frequent erythrocyte suspension (ES) support. ^[13] According to the Beta-Thalassemia Diagnosis and Treatment Guide of the Turkish Society of Hematology, it is recommended to maintain hemoglobin (Hb) levels at or above 9 g/dL through blood transfusions (Beta Thalassemia Diagnosis and Treatment Guide, Turkish Society of Hematology, 2011). However, in this particular TM patient cohort, only 45 individuals (40.2%) achieved this Hb threshold. This deviation could be attributed to the low socioeconomic and educational backgrounds of the patients included in the study. Additionally, challenges in securing compatible blood, often sourced from family members for cross-matched supply, may have contributed to this variance. Despite potential fluctuations in Hb levels due to hemolysis resulting from immune reactions, the mean frequency of transfusions in this cohort, occurring once every 2.66 weeks, aligns with the recommended TM treatment guidelines.

Persistent ES transfusions in TM patients lead to iron accumulation and subsequently elevated blood ferritin levels. Iron chelator therapy is employed to mitigate iron buildup. Notably, studies have linked cardiac failure to ferritin levels exceeding 1000 ml/ng. ^[14] Within our study, over 90% of patients exhibited ferritin levels surpassing this threshold. We posit that inconsistent or incorrect use of iron chelating agents might have contributed to this observation.

In a study involving healthy children, vitamin B12 and folate deficiencies were reported in 14.2% and 1.1% of cases, respectively. ^[15] However, within the TM patient population, folate deficiency emerges as a more frequent occurrence. In our study, nearly one third of patients displayed folate deficiency. Despite this, the mean serum levels of Hb, ferritin, vitamin B12, copper, and zinc in the subgroup of patients with folate deficiency mirrored those observed throughout the entire cohort. Another interesting finding was the relatively low prevalence of vitamin B12 deficiency, present in only 6.25% of patients.

The prevalence of copper deficiency has been reported at 1.5% in healthy children, and in TM patients, normal blood copper levels were found in 81.4%-90.2% of cases. ^[16] In our study, copper deficiency was detected in 10% of patients, consistent with previous findings. Similarly, zinc deficiency, which was observed in 64.6% of the pediatric TM cohort studied by Hasan, affected around a quarter of our patient population (24%). Zinc deficiency is not uncommon in healthy children, and its supplementation has demonstrated potential benefits in increasing bone mineral density, a crucial consideration given the risk of osteoporosis in pediatric TM patients. ^[17] Consequently, the provision of zinc supplements to children with TM could hold clinical significance.

This study sheds light on the prevalence of folic acid and zinc deficiencies among pediatric patients with thalassemia major (TM). The observed deficiencies in this cohort underscore the significance of addressing micronutrient status in these patients. Given the limited sample size and potential socio-economic factors, further investigations in larger and diverse populations are warranted to validate these findings. Should our results be corroborated by future research, the incorporation of folic acid and zinc supplementation could emerge as a valuable intervention strategy for children afflicted by TM. This study thus contributes to a deeper understanding of nutritional considerations in TM management and opens avenues for improved clinical care

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