Mean serum zinc and copper levels were measured in pediatric patients with idiopathic aplastic anemia. Zinc levels were significantly lower in patients compared to controls and correlated with severity of disease. Serum copper levels were significantly higher in patients. There was no correlation with severity of disease. Cu/Zn ratio also correlated with severity of disease.

Key words: Aplastic anemia, Copper, Trace elements, Zinc.

Role of zinc and copper has been studied extensively in health and disease. Zinc is necessary for optimum performance of immune function and deficiency results in increased morbidity due to infections especially gastrointestinal and respiratory [1, 2]. Alterations in serum levels of zinc and copper have also been studied in several malignant and lymphoproliferative disorders [3, 4]. There are no studies in patients with aplastic anemia. Aim of this study was to evaluate the serum levels of zinc and copper in pediatric patients with idiopathic aplastic anemia at the time of diagnosis and to correlate the levels with severity of disease.

45 patients with newly diagnosed idiopathic aplastic anemia in the age group of 4 to 15 years admitted in pediatric ward over 18 months were included in the study. Inclusion criteria were: at least two of the following (i) hemoglobin <10 g/L (ii) platelet count <50 ×10⁹/l (iii) neutrophil count <1.5× 10⁹/l with a hypocellular bone marrow (cellularity <25%) [5]. Inherited bone marrow failure syndromes were excluded from study based on cytogenetics and chromosomal fragility test. Severity of disease was graded according to published criteria [6]. 40 age and sex matched healthy children served as controls. 5 mL venous blood was collected in deionized plastic tubes for estimation of zinc and copper by atomic absorption spectrophotometer. Statistical analysis was done using SPSS software version 16.0.

Median age of the study group was 8.9 years (range 4-15 years). 48.5% of patients and 44.4% controls had weight for age below 3^rd centile. Study and control groups were comparable in their nutritional status. 7 patients had very severe, 27 had severe and 11 had non severe aplastic anemia. Mean serum zinc level was 33.87 ± 16.29 µg/dL in study group and 140.26 ± 55.37µg/dL in control group (Table I). Difference was statistically significant (P value <0.001). Serum zinc levels had significant correlation with disease severity. Patients with very severe aplastic anemia had lowest levels of zinc (P <0.001). Serum copper levels were 122.65 ± 49.02 µg/dL in patients and 77.25 ± 18.58 µg/dL in control group (P <0.001). There was no correlation with disease severity. Copper-zinc ratio was higher in the study group and correlated with disease severity (P < 0.001).

TABLE I	Mean Serum Copper and Zinc Levels, and Copper-zinc Ratio 

in Children With Aplastic Anemia and Controls

Our results demonstrated significantly low levels of serum zinc in patients with aplastic anemia which correlated with disease severity. Zinc deficiency may further compromise the low immunity seen in these patients as zinc plays a vital role in immune function. Similar trend was seen for copper zinc ratio. We also observed increased serum levels of copper in the patients although the levels did not correlate with severity of disease. Similar alterations and an inverse relationship between zinc and copper levels have been previously observed in childhood leukaemia and lymphoma where they have been used to monitor the disease severity and relapse [7]. Increased uptake of zinc from serum because of increased metabolism has been suggested as a possible mechanism for low zinc levels [8]. Similar mechanisms may be operative in patients with aplastic anemia but needs more investigation. This is a new area of research and there are no other studies to make a comparative analysis of our results. Correlation with treatment outcome would be an interesting application of this study.

8. Delves HT, Clayton BE, Bicknell J. Concentration of trace metals in the blood of children. Br J Prev Soc Med. 1973;27:100-7.