Not surprisingly, the major risk factor for early SCD fatality is a high
intracellular level of Hb S (and low levels of Hb F)[44]. Hence, the general
protocol for managing SCD in patients is to reduce the Hb S level and treat the
hypoxemia with oxygen therapy[27]. Standard treatments include periodic blood
"exchanges" and transfusions to treat the anemia (low Hb) and
transiently replace Hb S with normal adult Hb[27,125]; transfusions are
supplemented with iron-chelation therapy to prevent the accumulation of body
iron[39].
The more successful treatments of SCD include pharmacological induction of Hb F using butyrate and hydroxyurea[33,46,126]. However, side effects and poor drug efficacy with some of these agents remains as an obstacle for some patients[27].
Currently, allogenic bone marrow transplantation (BMT)[127,128] is the only curative regimen for SCD, but is limited to young patients with
compatible HLA donors who show limited early organ damage. Still, treatment for
SCD is often expensive due to the cost of medication in addition to frequent and
extended hospital stays. This places an enormous social burden on both patients
and their caretakers[129]. Moreover,
notwithstanding BMT, the mean lifespan of treated SCD patients is reduced to
~
40 years of
age[44], and no specific therapy is currently
available to treat (or cure) SCD in all patients.