Discussion
The level of Hemoglobin F expression is one of the most important modifiers of sickle cell disease .HbF values influence clinical symptomatology both in children and adults. Increase in value of HbF has been associated with fewer number of veno-occlusive crisis ,fewer episodes of acute chest syndrome and reduced early mortality .
Pharmacological intervention using HU induces HbF production. Hydroxyurea is a recommended treatment strategy in sickle cell disease. Multiple clinical trials have proven its efficacy in reducing morbidity and improving quality of life .
Affordable access to hydroxyurea is well established in state of Odisha in India. In the population we surveyed every patient was taking hydroxyurea more or less regularly, as reported by himself. The delivery is at times hampered because, some patients ,find even the small travel distance unmanageable. Regularity is challenge because of social- patient related issues, which need redressal
HU dosing rationalization (fixed dosing ) is standard clinical practice and may defer from recommended dosing guidelines. The criterion of using mild myelosuppression as dosing guide ( has never been utilized. Fixed dose HU had been previously reviewed
HUSTLE (NCT00305175) is a prospective observational study with a primary goal of describing the long-term clinical effects of hydroxyurea escalated to maximal tolerated dose (MTD) in children with SCA. In 230 children, providing 610 patient-years of follow up, the mean attained HbF% at MTD was >20% for up to 4 years of follow-up. When HbF% values were ≤20%, children had twice the odds of hospitalization for any reason (P  < .0001), including vaso-occlusive pain (P  < .01) and acute chest syndrome (ACS) (P  < .01), and more than four times the odds of admission for fever (P  < .001). Therefore, attaining HbF >20% was associated with fewer hospitalizations without significant toxicity. These data support the use of hydroxyurea in children and suggest that the preferred dosing strategy is one that targets a HbF endpoint >20%.  According to a 2014 expert panel report sponsored by the National Heart, Lung, and Blood Institute on the evidence-based management of SCA, HU therapy should be offered to all children as young as 9 months of age, regardless of symptom
In this analysis, HbF levels increased in every individual and were more than desired level of 20 %. The change was seen all across population , irrespective of age and gender. In a short group of higher age group the increase in HbF appeared to be even more striking, This observation needs further study and could be result of longer usage of HU, because of higher age group.
The achievement of desired HbF target levels using “real-world” scenario, compels us to think about HU strategies. The practice of using fixed dose schedules, in real-time clinical practice, with minimal follow up deserves a serious discussion and could be of great use in low resource countries. Probably this cohort of real-world scenario proves effectiveness of this strategy which is feasible, manageable, well tolerated , beneficial and covers for the not well trained health personnel.