CORE AREA 4CORE AREA 4

HAEMATOLOGYHAEMATOLOGY

GROUP C GROUP C

Full Blood Count-Case CFull Blood Count-Case C

A 25 year old female:A 25 year old female: anaemiaanaemia Never pregnantNever pregnant No change menstrual flow & intermenstrual bleedingNo change menstrual flow & intermenstrual bleeding Normal dietNormal diet No medicationsNo medications No change in bowel habit or symptoms of GI/urinary No change in bowel habit or symptoms of GI/urinary

blood lossblood loss No abnormal physical changeNo abnormal physical change

Lab FindingsLab Findings

HbHb 65 g/L 65 g/L (low)(low) 115-165115-165

MCVMCV 74 fL74 fL 80-10080-100

WCCWCC 4.5 x 104.5 x 1099/L/L 4.0-11.0x104.0-11.0x1099/L/L

WCC WCC differentialdifferential

NormalNormal

PlateletsPlatelets 500 X10500 X1099/L/L ((high)high)

150-400 X10150-400 X1099/L/L

Serum ferritin Serum ferritin 5 ug/L 5 ug/L (low)(low) 10-23010-230

Serum B12Serum B12 220 pmol/L220 pmol/L 120-680120-680

Serum folateSerum folate 2.0 nmol/L2.0 nmol/L (low)(low)

7-457-45

Lab FindingsLab Findings

Red cell Red cell folatefolate

100 nmol/L100 nmol/L (low(low))

360-1400360-1400

Faecal Faecal occult blood occult blood testingtesting

NegativeNegative

QuestionsQuestions

Diagnosis: Iron deficiencyDiagnosis: Iron deficiency

1)1) Is the MCV consistent with the diagnosis? Is the MCV consistent with the diagnosis? Explain.Explain.

2)2) What do the presence of pencil cells, target What do the presence of pencil cells, target cells & Howell-Jolly bodies suggest?cells & Howell-Jolly bodies suggest?

3)3) Is B12 or folate deficiency suspected? Is B12 or folate deficiency suspected? evidence?evidence?

4)4) Are the lab findings typical of iron deficiency Are the lab findings typical of iron deficiency anaemia?anaemia?

Differential diagnosisDifferential diagnosis

Anemia is generally defined as a hematocrit <40% Anemia is generally defined as a hematocrit <40% (hemoglobin <13.5 g/dL) in men or <37% (hemoglobin (hemoglobin <13.5 g/dL) in men or <37% (hemoglobin <12 g/dL) in women <12 g/dL) in women

MCV is a way of classifying anaemias morphologically, MCV is a way of classifying anaemias morphologically, i.e. microcytic, normocytic and macrocytic i.e. microcytic, normocytic and macrocytic

Microcytic anaemia can be caused byMicrocytic anaemia can be caused by Iron deficiencyIron deficiency ThalassaemiaThalassaemia Anaemia of chronic diseaseAnaemia of chronic disease Sideroblastic anaemiaSideroblastic anaemia

MCV and iron deficiencyMCV and iron deficiency

Microcytosis, or a decreased mean cell volume (MCV), is Microcytosis, or a decreased mean cell volume (MCV), is a characteristic feature of iron deficiency anaemia. Why?a characteristic feature of iron deficiency anaemia. Why?

Iron deficiency anaemia manifests in 5 stages:Iron deficiency anaemia manifests in 5 stages: Fe loss exceeds intake, causing progressive depletion of Fe Fe loss exceeds intake, causing progressive depletion of Fe

storage.storage. Exhausted Fe stores cannot meet the needs of the erythroid Exhausted Fe stores cannot meet the needs of the erythroid

marrow. marrow. Anaemia with normal-appearing RBCs and indices occurs Anaemia with normal-appearing RBCs and indices occurs Microcytosis (small size, low MCV) and then hypochromia (pale Microcytosis (small size, low MCV) and then hypochromia (pale

colour, low Hb) is present. colour, low Hb) is present. In advanced iron deficiency, anisocytosis (variable cell size) and In advanced iron deficiency, anisocytosis (variable cell size) and

poikilocytosis (variable cell shape) is seen. poikilocytosis (variable cell shape) is seen.

MCV and iron deficiencyMCV and iron deficiency

Is the MCV result consistent with iron Is the MCV result consistent with iron deficiency?deficiency?

MCV=74fL (80-100fL)MCV=74fL (80-100fL) Analysing result:Analysing result:

MCV (mean cell volume) is a measure of the average MCV (mean cell volume) is a measure of the average volume of a single red blood cell.volume of a single red blood cell.

A value <80fL indicates microcytosis, i.e. the red cells A value <80fL indicates microcytosis, i.e. the red cells are smaller than usual.are smaller than usual.

Microcytosis in the presence of anisocytosis means Microcytosis in the presence of anisocytosis means indicates more advanced iron deficiencyindicates more advanced iron deficiency

MCV and iron deficiencyMCV and iron deficiency So initially it can be said that the MCV value of 74fL So initially it can be said that the MCV value of 74fL

supports the diagnosis of iron deficiency. However it is supports the diagnosis of iron deficiency. However it is not as low as would be expected in iron deficiency.not as low as would be expected in iron deficiency.

Since the MCV is an average value for the red cell Since the MCV is an average value for the red cell volume, it must be considered in the context of the low volume, it must be considered in the context of the low folate level (which causes macrocytosis).folate level (which causes macrocytosis).

The reason postulated for the slightly lowered MCV is The reason postulated for the slightly lowered MCV is that it is a result of a “balancing out” of the microcytosis that it is a result of a “balancing out” of the microcytosis caused by the iron deficiency with the macrocytosis caused by the iron deficiency with the macrocytosis caused by the folate deficiency.caused by the folate deficiency.

Therefore as in this case, patients with concurrent folate Therefore as in this case, patients with concurrent folate and iron deficiency may exhibit a normal or near normal and iron deficiency may exhibit a normal or near normal MCV MCV

PENCIL CELLSPENCIL CELLS

Also known as ovalocytesAlso known as ovalocytes, , cigar cells or cigar cells or elliptocytes.elliptocytes.

Are elongated hypochromic red blood cells.Are elongated hypochromic red blood cells. Consists of a central area of pallor and Consists of a central area of pallor and

haemoglobin at both ends of cell.haemoglobin at both ends of cell.

A characteristic change that occurs in A characteristic change that occurs in

iron deficiencyiron deficiency

PENCIL CELLSPENCIL CELLS

www.sun.ac.za/haema/ dept/rbc.htm

TARGET CELLSTARGET CELLS

Scientific name: CodocytesScientific name: Codocytes RBCs appear like a target with a bullseye.RBCs appear like a target with a bullseye. Erythrocytes are thin and have an Erythrocytes are thin and have an

increased surface membrane area to increased surface membrane area to volume ratio (decrease in haemoglobin volume ratio (decrease in haemoglobin content).content).

Have a central, haemoglobinised area Have a central, haemoglobinised area surrounded by an area of pallor. The surrounded by an area of pallor. The periphery of the cell contains a band of periphery of the cell contains a band of haemoglobin. haemoglobin.

TARGET CELLSTARGET CELLS

http://www.vet.uga.edu/vpp/clerk/Boutureira/

TARGET CELLSTARGET CELLSThe presence of excessive target cells may The presence of excessive target cells may

indicate chronic diseases that cause: indicate chronic diseases that cause: Increases in surface membrane,Increases in surface membrane,

associated with lipid disorders e.g. rare associated with lipid disorders e.g. rare congenital deficiency of lecithin-cholesterol congenital deficiency of lecithin-cholesterol acyl transferase, and liver disease. acyl transferase, and liver disease.

Decreased cytoplasmic volume,Decreased cytoplasmic volume, is is associated with decreased production of associated with decreased production of haemoglobin (iron deficiency), or haemoglobin (iron deficiency), or manufacture of defective haemoglobin manufacture of defective haemoglobin (thalassaemia).(thalassaemia).

POST-SPELENECTOMYPOST-SPELENECTOMY A major function of the spleen is the A major function of the spleen is the

clearance of opsonized, deformed, and clearance of opsonized, deformed, and damaged erythrocytes by splenic damaged erythrocytes by splenic macrophages. macrophages.

If splenic macrophage function is impaired or If splenic macrophage function is impaired or absent because of splenectomy (spleen absent because of splenectomy (spleen removal), altered erythrocytes will not be removal), altered erythrocytes will not be removed from the circulation efficiently. removed from the circulation efficiently.

Therefore, increased numbers of target cells Therefore, increased numbers of target cells may be observed.may be observed.

HOWELL-JOLLY BODIESHOWELL-JOLLY BODIES Are spherical inclusions of nuclear chromatin Are spherical inclusions of nuclear chromatin

remnants in a RBCs (blue black appearance on remnants in a RBCs (blue black appearance on Wright-stained smears).Wright-stained smears).

They are nuclear fragments of condensed They are nuclear fragments of condensed DNA, 1 to 2 µm in diameter, normally removed DNA, 1 to 2 µm in diameter, normally removed by the spleen. by the spleen.

They are seen in severe haemolytic anaemias, They are seen in severe haemolytic anaemias, pernicious anaemia, thalassaemia, and in pernicious anaemia, thalassaemia, and in patients with dysfunctional spleens or after patients with dysfunctional spleens or after splenectomysplenectomy. .

HOWELL-JOLLY BODIESHOWELL-JOLLY BODIES

http://medlib.med.utah.edu/WebPath/HEMEHTML/HEMEIDX.html#2

Vitamin B12 and Folate DeficiencyVitamin B12 and Folate Deficiency

B12 and folate deficiency share the same B12 and folate deficiency share the same haemotological changes including:haemotological changes including: Macrocytosis (MCV > 100fL)Macrocytosis (MCV > 100fL) Anisocytosis (size variation)Anisocytosis (size variation) Megaloblastic bone marrow and anaemia Megaloblastic bone marrow and anaemia Oval red cells (ovalocytosis)Oval red cells (ovalocytosis) Hypersegmented neutrophilsHypersegmented neutrophils

Evidence for Vitamin B12 Evidence for Vitamin B12 DeficiencyDeficiency

Vitamin B12 deficiency occurs when levels Vitamin B12 deficiency occurs when levels < 130 pmol/L< 130 pmol/L This patient has:This patient has:

Serum B12 reading of 220pmol/LSerum B12 reading of 220pmol/L Microcytosis (MCV < 80 fL)Microcytosis (MCV < 80 fL)

These results are inconsistent with vitamin These results are inconsistent with vitamin B12 deficiency.B12 deficiency.

Evidence for Folate DeficiencyEvidence for Folate Deficiency

Folate deficiency occurs whenFolate deficiency occurs when:: Serum folate < 11 nmol/LSerum folate < 11 nmol/L Red cell folate < 510 nmol/LRed cell folate < 510 nmol/L

This patient has:This patient has: Serum folate 2 nmol/LSerum folate 2 nmol/L Red cell folate 100 nmol/L Red cell folate 100 nmol/L

These results are consistent with folate These results are consistent with folate deficiency. deficiency.

Folate and B12 Deficiency ConclusionFolate and B12 Deficiency Conclusion

This patient has serum and red cell folate levels This patient has serum and red cell folate levels consistent with folate deficiency.consistent with folate deficiency.

Deficiency associated with folate and/or B12 Deficiency associated with folate and/or B12 causes megaloblastic anaemia.causes megaloblastic anaemia.

Megaloblastic anaemia causes oval macrocytes, Megaloblastic anaemia causes oval macrocytes, dyspoesis resulting in leukopenia and dyspoesis resulting in leukopenia and thrombocytopenia and hypersegmented thrombocytopenia and hypersegmented neutrophils.neutrophils.

Hypersegmented neutrophils is found in Hypersegmented neutrophils is found in moderate amounts in this patient but may be moderate amounts in this patient but may be due to folate malabsorption.due to folate malabsorption.

Iron Deficiency AnaemiaIron Deficiency Anaemia

Diagnosis will be based on:Diagnosis will be based on: Reduced haemoglobin (man< 12.5- 13.8g/dL, Reduced haemoglobin (man< 12.5- 13.8g/dL,

woman<10-11.5g/dL)woman<10-11.5g/dL) Reduced mean cell volume (<80fL)Reduced mean cell volume (<80fL) Reduced mean cell haemoglobin (<27pg)Reduced mean cell haemoglobin (<27pg) Reduced mean cell haemoglobin concentration Reduced mean cell haemoglobin concentration

(<300g/L)(<300g/L) Blood film- microcytic, hypochromic red cellsBlood film- microcytic, hypochromic red cells Reduced serum ferritin (<10ug/L)Reduced serum ferritin (<10ug/L) Reduced serum iron (man<14umol/L,woman <11umol/L)Reduced serum iron (man<14umol/L,woman <11umol/L) Increased serum iron binding capacity (>75umol/L) Increased serum iron binding capacity (>75umol/L)

The following investigation may be required:The following investigation may be required: Full blood count and blood film Full blood count and blood film

examination examination Haematinic assays (serum ferritin, vitamin Haematinic assays (serum ferritin, vitamin

B12 and folate)B12 and folate) Faecal occult bloodsFaecal occult bloods Mid-stream urine Mid-stream urine Endoscopic or barium studies of GI tract Endoscopic or barium studies of GI tract

Blood FilmBlood Film

Red cells from iron deficient patients contain Red cells from iron deficient patients contain less haemoglobin than normal.less haemoglobin than normal.

The red cells appear pale (hypochromic) and The red cells appear pale (hypochromic) and smaller than normal (microcytic).smaller than normal (microcytic).

Therefore microcytosis, hypochromia and pencil Therefore microcytosis, hypochromia and pencil cells may be present in iron deficiency anaemia.cells may be present in iron deficiency anaemia.

The patient’s blood film presents hypochromic, The patient’s blood film presents hypochromic, microcytic cells, with moderate numbers of microcytic cells, with moderate numbers of pencil cells.pencil cells.

Haemoglobin Haemoglobin The diagnostic criteria for iron deficiency anaemia vary The diagnostic criteria for iron deficiency anaemia vary

(Hb<10-11.5g/dL for women & <12.5- 13.8g/dL for men) (Hb<10-11.5g/dL for women & <12.5- 13.8g/dL for men) between studies.between studies.

The lower limit of the normal range of haemoglobin The lower limit of the normal range of haemoglobin concentration should be used to define anaemia.concentration should be used to define anaemia.

The limitation of using haemoglobin as a measure of iron The limitation of using haemoglobin as a measure of iron status are its lack of specificity and its relative status are its lack of specificity and its relative insensitivity.insensitivity.

To identify iron deficiency anaemia Hb must be To identify iron deficiency anaemia Hb must be measured together with more selective measurement of measured together with more selective measurement of iron status.iron status.

The patient’s Hb concentration is 65g/L.The patient’s Hb concentration is 65g/L.

Mean Cell Volume (MCV)Mean Cell Volume (MCV)

Reduced MCV (microcytosis) occurs when Reduced MCV (microcytosis) occurs when iron deficiency becomes severe, following iron deficiency becomes severe, following the development of anaemiathe development of anaemia

A cut off value of 80fL is accepted as A cut off value of 80fL is accepted as lower limit of normal in adults.lower limit of normal in adults.

The patient’s MCV is 74fLThe patient’s MCV is 74fL

Serum FerritinSerum Ferritin

This is by far the most useful single measure of iron This is by far the most useful single measure of iron statusstatus

It accurately reflects the body stores and it is usually the It accurately reflects the body stores and it is usually the earliest laboratory measure to change in iron deficiencyearliest laboratory measure to change in iron deficiency

It is a sensitive test and is not affected by day to day It is a sensitive test and is not affected by day to day fluctuation in iron intake.fluctuation in iron intake.

A low serum ferritin is a certain proof that patient is iron A low serum ferritin is a certain proof that patient is iron deficient.deficient.

Appropriate lower limit of normal would be 15-16ug/L.Appropriate lower limit of normal would be 15-16ug/L. The patient’s serum ferritin level is 5ug/L/The patient’s serum ferritin level is 5ug/L/ Further tests is usually only required in patient when Further tests is usually only required in patient when

doubt still remains as to the presence of iron deficiency.doubt still remains as to the presence of iron deficiency.

Other ResultsOther Results A raised platelet count is often seen in iron deficiency, A raised platelet count is often seen in iron deficiency,

but a normal or low count certainly doesn’t exclude but a normal or low count certainly doesn’t exclude diagnosis. The patient’s platelet count is raised at diagnosis. The patient’s platelet count is raised at 500*10500*1099/L/L

WCC and WCC differential is normal for this patient, WCC and WCC differential is normal for this patient, which is expected in iron deficiency anaemia.which is expected in iron deficiency anaemia.

Faecal occult blood testing for this patient is negative, Faecal occult blood testing for this patient is negative, which confirms there is no blood in faeces due to which confirms there is no blood in faeces due to GI/Urinary blood loss.GI/Urinary blood loss.

Red serum folate and red cell folate is also reduced Red serum folate and red cell folate is also reduced below the normal range for this patient. Therefore patient below the normal range for this patient. Therefore patient has a folate deficiency.has a folate deficiency.

Does patient have Iron deficient Does patient have Iron deficient anaemia?anaemia?

Supportive results:Supportive results: Serum ferritin levels <5 ug/L Serum ferritin levels <5 ug/L Decreased hemoglobin (suggesting anaemia)Decreased hemoglobin (suggesting anaemia) Blood film: hypochromic (low Hb) and microcytic (low Blood film: hypochromic (low Hb) and microcytic (low

MCV) cellsMCV) cells Presence of pencil cells/target CellsPresence of pencil cells/target Cells High platelet count levelHigh platelet count level

Hence it can be concluded that the patient has Hence it can be concluded that the patient has iron deficiency anaemia. iron deficiency anaemia.