Comparative Analysis of Hematological Parameters in Indian Sickle Cell Anemia Patients Treated with Low Dose (10mg/kg/day) Versus Standard Dose (20mg/kg/day) Hydroxyurea

Introduction: Sickle cell anemia (SCA) is a hereditary genetic disorder characterized by the production of abnormal hemoglobin (HbS), which leads to altered physiological properties. Hydroxyurea (HU) is an established oral drug that has demonstrated the ability to ameliorate the severity of the disease mainly by increasing the production of fetal hemoglobin (HbF), thereby reducing sickle cell crises. Studies in the Indian population have shown positive clinical outcomes with a low dose (10 mg/kg/day) of hydroxyurea. Low dose is recommended by most of the physicians in India due to fear of adverse events and noncompliance of patients for regular monitoring of blood parameters. However, the effectiveness of low-dose HU compared to the standard dose (20 mg/kg/day) in reducing sickle cell anemia crises remains uncertain due to the diverse clinical severity of SCD in the Indian population. To address this question, the study aimed to conduct a national level randomized control trial involving SCA patients from various ethnic backgrounds to definitively establish the benefits of low-dose HU for Indian patients compared to the standard dose. Materials and Methods: Till date the study enrolled 140 sickle cell anemia patients (2-14 years) after informed consent. Patients were randomly assigned to either low (ARM 1: 10 mg/kg/day) or standard (ARM 2: 20 mg/kg/day) doses of hydroxyurea. 37 patients had been followed up for 6 months' time point of hydroxyurea therapy. Three ml of whole blood samples were collected in K2-EDTA tube, anthropometric details and clinical parameters of patients were studied. Results: 18 participants were allotted ARM 1 with a mean age of 8.9 ± 2.8 years and 19 were allotted ARM 2 with a mean age of 8.6 ± 2.5 years. All patients were followed upto 6 months after hydroxyurea treatment. The clinical severity was classified as class 1 and class II based on the clinical events of patients. It was found that 26 patients are classified under the class I category of severity while 10 patients classified under the class II category of severity. 6(60%) participants with baseline HbF level below 15% had Class II severity whereas 3(11.5%) participants with baseline HbF level of more than 15% had Class II severity. The effect of hydroxyurea dose on haematological indices was also studied which revealed that there was significant decrease in WBC, platelet count by 2.18 ± 2.24 10 3/µl, 24 ± 136.6 10 3/µl in ARM 1 compared to ARM II 4.08 ± 2.6 10 3/µl, 50 ±