Haemoglobinopathies And Thalassaemia

Question 1

HbSS epidemiology: common ethnicities, median survival and incidence

Answer 1

Commonly affects: Africans, central/south Americans of African ethnicity, Greek, Turkish, Arabic and Indian

Median survival 65

Affects 1:2500 live births

Question 2

Who has antenatal screening for HbSS

Answer 2

Those who fall into the high risk category in the family origin questionnaire

Question 3

Postnatal screening for hbss

Answer 3

-All babies arriving in UK who are <1
-presurgical if high prevalence area
-unexplained anaemia if from high prevalence area

Question 4

Generic treatment for all sickle cells

Answer 4

-pen V/erythromycin
-folic acid
-vaccinations: flu, covid, pneumovax 5 yearly and men ACWY, B and C
-ECHO 3 yearly (TRV >2.5)
-slit lamp exam
-urine PCR
-transcranial doppler from age 2-16

Question 5

Work up at diagnosis

Answer 5

Family history
Siblings who are affected/unaffected
Red cell phenotypes
Screen for hbv/hcv/hiv
S%
G6PD

Question 6

Tests at regular clinic appointments

Answer 6

Ferritin- if >1000 organise ferritin and t2 cardiac mri
Urine pcr - <50mg/ml
ECHO for TRV <2.5
Lung function tests for pulmonary htn is symptomatic
Vitamin D
TCD annually

Question 7

Tests at regular clinic appointments

Answer 7

Ferritin- if >1000 organise ferritin and t2 cardiac mri
Urine pcr - <50mg/ml
ECHO for TRV <2.5
Lung function tests for pulmonary htn is symptomatic
Vitamin D
TCD annually

Question 8

When to consider iron chelation

Answer 8

Ferritin >1000
Liver iron >7mg/gDW

Question 9

Indications for urgent red cell exchange

Answer 9

Acute neurological event
ACS
Multi organ failure
Severe sepsis
Systemic fat embolism
Progressive hepatopathy
Resistant priapism
Surgery
Girdle syndrome (abdominal mesenteric infarcts)

Question 10

Indications for elective ebt

Answer 10

Primary stroke prevention in those transitioning from paediatrics
Secondary stroke prevention (s% target 20 rather than 30)
Pregnancy
Refractory leg ulcers

Hct target 0.32-0.34

Question 11

When to offer HU

Answer 11

-for hbss or hbs/b0 aged 9-42 months regardless of severity
-those with 3 or more acute complications in a year
- all with severe phenotype
- had ACS
- primary prevention in children who have had 1 year of regular transfusions without image associated cerebral vasculopathy

Question 12

Pregnancy advice/actions in hbss

Answer 12

-risk of increased for following
Mum: pre-eclampsia, preterm delivery, spontaneous abortion, vte, uti
Baby: iugr

Counselling pre and stop: HU, ACE-I and iron chelation 3 mknths prior to conception

Meds: Start vit D, folic acid and pen V.
Low dose aspirin 12-36/40
Thromboprophylaxis from 28/40 or earlier if additional risk factors and continue 6 weeks post partum

Monitor regularly in specialist combined obs haem clinic. Serial growth scans with doppler every 4 weeks from 24/40

Question 13

Hbss confirmatory tests

Answer 13

Hb electrophoresis/highperformance liquid chromatography

HPLC first line
Isometric focusing (IEF)
capillary electrophoresis (CE)
Cellulose acetate electrophoresis (CAE)

Question 14

Hbss prenatal diagnosis

Answer 14

Must be performed if both parents cariers

1st trimester CVS from 10 weeks
2nd trimester fetal blood sampling