This is an extract of our Sickle Cell Anaemia document, which we sell as part of our Haematology Notes collection written by the top tier of University Of Leicester students.
The following is a more accessble plain text extract of the PDF sample above, taken from our Haematology Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:
Sickle Cell Anaemia An inherited disorder of haemoglobin
AetiologyAutosomal recessive - Point mutation (Glutamate to valine) on B haemoglobin chain Causes hydrophobic pocket and sickling of cells Genotypes o Homozygous Sickle Cell Anaemia
? Commonest and most severe o HbSC
? One B chain sickled
? One C chain
? Similar to HbSS but more eye problems o Sickle cell trait
? One normal and one affected B chain
ScreeningDependent on prevalence in region High prevalence o Maternal blood test o If positive - father is tested Low prevalence o Questionnaire Newborn screening as part of the heel prick (Guthrie) test
PathologySickled haemoglobin has low affinity for O2 Polymerises in low O2 tensions Blocks microcirculation causing infarction
Clinical featuresSevere haemolytic anaemia Chronic condition punctuated by 'crises'
Triggers for a crisis
- Change in temp.
Management ChronicProphylactic advice (avoid triggers) Folic acid 5mg OD Prophylactic abx. (splenic autoinfarction = 'asplenic' - Lifelong penicillin V) Vaccinations (against encapsulated bacteria - hyposplenic) Hydroxycarbamide - increases HbF levels (give if >3 crises in 12 months) o Increased fetal Hb in blood = increased O2 carrying capacity Transfusions - beware of Iron overload Stem cell transplant - attempted cure
Buy the full version of these notes or essay plans and more in our Haematology Notes.