Study of parathyroid dysfunction among children and adolescent with alpha-thalassemia major

ABSTRACT

Background: Parathyroid hypofunction is one the endocrinopathies affecting patients with ?-thalassemia major [TM], while parathyroid hyperfunction is not well assessed. In this study, we aimed to evaluate the prevalence of parathyroid dysfunction in children with thalassemia major and to study its relation to age, gender, splenic status, serum calcium and ferritin. Study Sesign In 70 children with TM /[41 [58.6%] males and 29 [41.4%] females with mean age 14.8+/-2.9 years; range 6-18 years/]; serum levels of intact pa rathormone [iPTH], calcium, phosphorus and alkaline phosphatase were measured. liver iron content was assessed in 42 cases with magnetic resonance imaging by means of T2*. Average serum ferritin was calculated for 1 year prior to the study. Results: Mean iPTH and serum phosphorus were within normal range. Mean calcium was below the lower limit of normal range. Seventy-three percent had normal parathyroid function with 3 [4.3%] had borderline iPTH. The prevalence of parathyroid dysfunction was evident in 27% cases. Thirteen [18.5%] had low iPTH and 6 [8.6%] cases had elevated iPTH levels. Forty-three [61.4%] cases had hypocalcemiaand5 cases [7.1%] had hyperphosphatemia. Age above 12 years, sex, splenectomy, hypocalecemia, serum ferritin above 1500 ng/ml and being not chelated were not proved to be risk factors of parathyroid dysfunction. There is a good correlation between serum ferritin and liver iron concentation [LIC] [r=0.5, p=0.001]. No correlations were found between PTH and age, frequency of blood transfusion, serum ferritin, serum calcium, phosphorus or alkaline phosphatase. Conclusion: Parathyroid dysfunction is common in patients with ?-thalassemia major and worth screening in early childhood even in the absence of hypocalcemia or iron overload. This might be the first step towards decreasing its prevalence among TM population. In addition, the onset and dose of calcium and vitamin D supplementation in pediatric patients with ß-thalassemia major should be re-evaluated