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Flashcards in Haemoglobinopathies Deck (25):

Thalassaemia indices but normal hba2- need to exclude what

Look at HBF- raised in delta-beta,
Hb E and Lenore
If none of these then it's alpha or gamma delta beta thalassaemia


PCV complicated by Fe def-

Will have inc rdw compared w thal


Zinc protoporphyrin

Raised in alpha and beta so not helpful to distinguish alpha/beta


Reasons for normal HbA2 in beta thal

Fe or folate def
HbH and beta thal hetero
Presence of A2 variant causing split in A2 band

Neonate prior to 6 months


Genetics of hb lepore

Cross over during meiosis of he beta and delta producing fusion gene


Hblepore detection

Hplc- 5-15%
Moves hbs on alk ph, he A on acid


Hb lepore clinical/lab

Imp to dx because of final interaction w hbs and beta thal
Film etc like beta trait
Sometimes inc hbf
If homo- like beta thal major


Inc hba2

Vit b12/folate
Treatment of infection by hiv


Dec hba2

Fe def
Sideroblastic anaemia
Lead poisoning
Juvenile mml
Acquired HBH dx
Aplastic anaemia
Chemo induced hb f inc


Raise hbf neonate

Chronic intrauterine hypoxia
Diabetic mum


Raised hbf adults

Pgy stress erythropoiesis
Aplasti anaemia
Pernicious anemia
Mds, PNh, m6' dm, starvation, thyrotoxic drugs


McHale red in fe def or thalassaemia?

Iron deficiency


Which genes in mum indicate neonatal testing in haemoglobinopathies

Hb S, C, DPunjab, E, OArab, Lepore or β or δβ thalassaemia trait).


Babies dx with what should be retested in 6 weeks

Hbs SS, SC, SDPunjab, SOArab or Sβ thalassaemia
Heel price- use hplc or ief
Can do gel w cord


Detection of an unstable haemoglobin

Heat stability test
Isopropanol test
The unstable haemoglobins are frequently silent using electrophoretic or chromatographic techniques and tests for haemoglobin instability are essential in the detection or exclusion of an unstable haemoglobin.


Sickling syndromes

SS-a/aa, SS-a/-a
SB thal
SDelta beta thal
S Lepore
SD Punjab
SO Arab


What does the strip test detect?

Hb barts- of which there is normally amount of in any alpha thal


Guide to sickle transfusion to prevent Stroke

Regular transfusion to maintain HbS <30% should be offered as initial
treatment to children with SS or S/βo thalassaemia aged 2-16 years judged to
be at high risk for a first stroke on the basis of Transcranial Doppler


Transfusion of sickle in pgy

Women on long-term transfusions for stroke prevention or for amelioration of
severe sickle complications should continue with regular transfusions
throughout pregnancy
Transfusion should be considered in women with worsening anaemia or those
with acute SCD complications
Prophylactic transfusion is not routinely required for sickle pregnancy, but
should be considered for women with:
• previous or current medical, obstetric or fetal problems related to SCD
• women previously on hydroxycarbamide because of severe disease
• multiple pregnancy (


De scribe hplc

 Separates by cation exchange chromatography

§        Identifies variant Hbs by change in electrical charge

§        Change in gradient of buffer means Hb attached to column will elute at different times


Sickle solubility test

Packed red cells reconstitute to a haematocrit of 50%.

§        + PO4 buffer containing reducing and lysis agents

§        Sickle Hb is induced to sickle by the reducing agent and gets trapped in red cells

§        Normal Hb is lysed

§        Centrifuge and read

§        Any sickle Hb results in turbidity


False positive sickle solubiliy test


§        Paraprotein

§        Heinz body haemolytic anaemia

§        Very high white count or nucleated red cell count


Ind for non rhd genotyping

Serological antigen typing/phenotyping cannot be determined due to chronic transfusion requirement (e.g. Thalassemia major, Blackfan Diamond anemia).

- Serologically complex patients - with multiple or unidentified antibodies who require ongoing transfusion support.

- Patients with autoimmune hemolytic anemia and/or with a positive DAT (in spite of chemical treatment), and circulating autoantibody.

- Patients with a suspected alloantibody against an antigen for which no commercial antisera is available (e.g. Possible anti-Doa).

- Select patients with variable or null reactivity using serological methods when a variant allele is suspected (e.g. Sickle cell anemia).


Ind for rhd genotyping

Prenatal patients with discrepant, weak or inconclusive serological RhD testing results where RHD genotyping may modify their blood product or Rh Immune Globulin (RhIG) requirements. For example: prenatal patients with weak or discrepant RhD serology may be Weak D type 1, 2 or 3 and would not require RhIG.

- Patients likely to require chronic transfusion, or with complex transfusion needs, where RHD genotyping may modify their blood product requirements.

- Patients who likely require transfusion with an anti-D who appear serologically D positive.

Genotyping may be useful in a variety of situations where a phenotype cannot be determined


Transfusion indicators thal beta inter

failure to thrive in childhood in the presence of significant anaemia;

emergence of bone deformities;

increasing anaemia not attributable to rectifiable factors;

evidence of a clinically relevant tendency to thrombosis;

presence of leg ulcers;

development of pulmonary hypertension;

delayed or poor pubertal growth spurt and

progressive splenic enlargement.