This presentation is focused on diagnostic utility of Red blood cell indices which will be very useful for undergraduate and postgraduate of medical field.

1. CASE 1
 25 yr old Patient with history of fatigue,
 RBC: 3.7 x 106/µl
 Hb: 8.0 g/dl
 MCV: 62 fl
 MCH: 19.0 pg
 MCHC: 27 g/dl
 WBC: 5.3 x 109/l
 Platelets: 400 x 109/l
 Impression?
 MICROCYTIC HYPOCHOMIC ANEMIA

2. CASE 2
 30 yr old, Male patient with fatigue
 RBC: 4.5 x 106/µl
 Hb: 11.0 g/dl
 MCV: 115 fl
 MCH: 25.0 pg
 MCHC: 30 g/dl
 WBC: 7 x 109/L
 Platelets: 350 x 109/L
 Impression?
 MACROCYTIC ANEMIA

3. CASE 3
 23 yr old, Male patient
 RBC: 4.5 x 106/µl
 Hb: 11.0 g/dl
 MCV: 87 fl
 MCH: 30.0 pg
 MCHC: 33 g/dl
 WBC: 6.5 x 109/L
 Platelets: 350 x 109/L
 Impression?
 NORMOCYTIC NORMOCHROMIC ANEMIA

4. DR. MANAN SHAH
P O S T G R A D U A T E
M D P A T H O L O G Y
DIAGNOSTIC UTILITY OF
RBC INDICES

5. OBJECTIVES
 To define & calculate the RBC Indices
 To describe the application of RBC indices in
diagnosing various disorders.
 To interpret RBC Histograms.

6. RBC INDEX
 It is a quantitative measurement of red blood cell,
the amount and concentration of hemoglobin in
them.
 They were first introduced by Wintrobe in 1929 to
define the size (MCV) and hemoglobin content
(MCH & MCHC) of red blood cells

7. DEFINITIONS:
 Mean cell volume (MCV)
 It is the measure of average volume of RBCs
 Mean cell Hemoglobin (MCH)
 It is a measurement of the average weight of hemoglobin in
individual erythrocytes.
 Mean Cell Hemoglobin Concentration (MCHC)
 It is the average concentration of hemoglobin in erythrocytes
 Red cell distribution width (RDW)
 It is a measure of variability of erythrocyte size

8. WHY RBC INDICES REQUIRED?
 To classify the erythrocytes by their volume and
Hemoglobin content
 This indices suggest how the RBC’s appear
microscopically and provide significant information
(most commonly for Anemia diagnosis)
 Laboratory professionals correlate the indices with
Hct, Hb and RBC count to ensure that technical
problems are identified when they occur

9. MEAN CELL VOLUME
 MCV = Hct(L/L) x 1000
RBC count ( x 1012/L)
 Normocytic: 80-100 fL
 Microcytic: Red cells with reduced volume(<80fL)
 Macrocytic: Red cells with an increased
volume(>100 fL)
 Remember MCV is a measurement of volume
whereas estimation of size of flattened cells is a
measurement of cell diameter. Cell diameter and
cell volume are not same

10. MCV Increased
MCV Decreased
Causes?
Causes?
Fig. 2
Fig. 1

11. MEAN CELL HEMOGLOBIN CONCENTRATION
 It is the average concentration of hemoglobin in a
deciliter of erythrocytes and expressed in g/dl
 It is the ratio of hemoglobin mass to volume in which
it is contained
 MCHC = Hb (g/dl) x 100
Hct (L/L)
 Normochromic: 32-36g/dl
 Hypochromic: <32g/dl
 Hyperchromic: >36g/dl

12. MEAN CELL HEMOGLOBIN CONCENTRATION
 Hypochromic: If the area of central pallor is >1/3rd
of the cell size
 Hyperchromic: The only erythrocyte that is
hyperchromic with an MCHC of > 36g/dl is the
spherocyte
Apparent hyperchromasia ( high MCHC) is usually
due to an artifactual increase in the haemoglobin
result, due to haemolysis, lipaemia, or large numbers
of Heinz bodies

13. MCHC Decrease
Causes?
MCHC Increase..??
Causes?
Fig. 3
Fig. 4

14. MEAN CELL HEMOGLOBIN
 It is a measurement of the average weight (in
picograms 10 -12 g)of hemoglobin in individual
erythrocytes. It is calculated by:
 MCH = Hb (g/dl) x 10
 RBC( x 10 12/L)
 MCH varies in direct linear relationship with the
MCV. Cells with less volume contain less Hb and
vice versa
 Normal value for the MCH : 28 to 34 pg

15. MCH Increase MCH Decrease
 B12 deficiency
 Folic acid deficiency
 Reticulocyte
 Hemolytic anemia
 alcoholism
 Iron deficiency anemia
 Thalassemia
 Anemia of chronic
disorder
MEAN CELL HEMOGLOBIN

16. • Comment on size of RBC..?
Anisocytosis
Fig. 5

17. CASE 4
 25 yr old Patient with history of fatigue
 RBC: 3.0 x 106 /µl
 Hb: 8.0 g/dl
 MCV: 62 fl
 MCH: 19.0 pg
 MCHC: 30 g/dl
 WBC: 5.3 x 109/l
 Platelets: 400 x 109/l
 Impression:
 MICROCYTIC HYPOCHOMIC ANEMIA
 Differential diagnosis?

18. CASE 4
 25 yr old Patient with history of fatigue
 RBC: 3.0 x 106 /µl
 Hb: 8.0 g/dl
 MCV: 62 fl
 MCH: 19.0 pg
 MCHC: 30 g/dl
 WBC: 5.3 x 109/l
 Platelets: 400 x 109/l
 RDW: 18%
 Impression:
 MICROCYTIC HYPOCHOMIC ANEMIA
 Importance of RDW here?

19. RED CELL DISTRIBUTION WIDTH
 RDW is used because MCV is less reliable in describing
the erythrocyte population when considerable variation
in erythrocyte size occurs.
 RDW is a coefficient of variation in size distribution of
RBCs
 Measured as : RDW = Standard deviation of MCV × 100
MCV
 Normal value:11.5-14.5%
 Increased value indicates ANISOCYTOSIS.

20. RDW and MCV

21. RDW
 RDW is increased in Iron deficiency anemia.
 While RDW is normal in Thalassaemia minor.
 Combination of low MCV and high RDW is one of the
best screening test for the Iron deficiency anemia.
 Mentzer index..?
 Sideroblastic anemia..?
 Further evaluation..?

22. FURTHER EVALUATION
 For IDA
 S. ferritin level (low)
 TIBC (Increased)
 Transferrin saturation (Decreased)
 PBS: pencil cells, anisocytosis
 RBC count: Decrease
 For Thalassaemia
 PBS: target cells, polychromatic cells, basophilic stipling
 Rbc count: Normal / Raised.
 HbA2: Raised(>3.5)
 For Sideroblastic anemia
 S. iron increased
 S. ferritin level increased
 Dimorphic anemia and pappenheimer bodies seen

27. Elliptocytes/ pencil
cells
Causes..?
Codocytes/Target cells
Causes..?
Fig. 6
Fig. 7

28. Echinocytes/ Burr
cells
Causes..?
Acanthocytes/ spur cells
Causes..?
Fig. 8
Fig. 9

29. Stomatocytes/
mouth cells or cup
cells
Causes..?
Drapanocytes/
sickle cell
Causes..?
Fig. 10
Fig. 11

30. Dacryocytes/
Teardrop cells
Causes..?
Spherocytes
Causes..??
Fig. 12
Fig. 13

32. CASE 5
 26 yr, Patient of low socio economic status comes with history
of weakness since 6 months, history of chronic abuse of PPI.
 RBC: 3.0 x 106 /µl
 Hb: 11.0 g/dl
 MCV: 75 fl
 MCH: 24.0 pg
 MCHC: 29 g/dl
 WBC: 5.3 x 109/l
 Platelets: 400 x 109/l
 RDW: 17%
 Interpretation?
 Microcytic hypochromic anemia
 Is Vit B12 def possible in this patient?
 A case of dimorphic anemia or combine anemia.
If yes - explain MCV?

35. CAUSES?
 Folate/ Vit B12 and Iron deficiency
 Malnutrition
 Malabsorption
 Pregnancy
 Alcoholism
 Atrophic gastritis (Vit B12)
 Thalassaemia and Vit B12 / Folate deficiency
 Iron deficiency with hemolysis. (prosthetic valve)
 Peripheral blood smear examination is very critical.

36. CASE 6
 32 yr old patient with GI Bleed/hemorrhoid, no history
of drugs or hematological disorder
 RBC: 3.0 x 106 /µl
 Hb: 11.0 g/dl
 MCV: 102 fl
 MCH: 26.0 pg
 MCHC: 32 g/dl
 WBC: 5.3 x 109/l
 Platelets: 400 x 109/l
 RDW: 12%
 Impression?
 Macrocytic Normochromic anemia

37. RETCULOCYTES
 Premature RBC
 They contain remnants of Ribosomal RNA
 Number of reticulocytes in PBS is a fairly accurate
reflaction of erythropoietic activity
 It is most useful and cost effective test in monitoring and
response to iron therapy

38. RETCULOCYTES COUNT
 It can be done by two methods,
 Manual method
 Automated method
 Manual method.
 Romanowsky stain can not stain reticulocytes effectively.
 Suspect reticulocyte when Polychromatophilic cells on
PBS with Romanowsky stain seen (erythocyte with
bluish tinge)
 A supravital stain such as NEW METHYLENE BLUE,
BRILLIANT CRESYL BLUE must be used to identify
reticulocytes.

39. RETCULOCYTES COUNT
 Automated methods
 By Fluorescent flow cytometry
 Or by scattered light with methylene blue staining
 In automated method >30,000 RBCs are assessed
 So the method is more precise and has high degree of accuracy than
the manual method. (where only 1000 RBCs are assessed)
 It is also more accurate when reticulocyte count is low

40. RETCULOCYTES COUNT
 Corrected reticulocyte count
 Used to adjust the reticulocyte count in proportion to the
severity of anemia
 Corrected retic count= patient hematocrit
Normal hematocrit x % reticulocyte
 Its practical importance is to assess the degree of
erythropoiesis in anemic patient.
 In anemic patient <2% of corrected retic count associated with
hypo cellular bone marrow

41.  Reticulocyte production index
 This index is used to correct the time of prolongation of
maturation of reticulocyte due to sever anemia
 Calculated by = patient hematocrit x retic count (%)
normal hematocrit x retic maturation time(days)
 Also known as SHIFT CORRECTION INDEX
PCV% MATURATION DAY(S)
45% 1
35% 1.5
25% 2
15% 2.5

42. REICULOCYTE SUPRAVITAL STAIN

43. Fig. 14
Fig. 15
Heinz bodies
Howell-jolly bodies

44. RETICULOCYTES
 A higher reticulocytes count may indicate:
 Anemia due to RBC being destroyed earlier than normal
(hemolytic anemia)
 Bleeding (GI Bleeding)
 Blood disorder in a fetus or newborn (erythroblastosis fetalis)
 Kidney disease, with increased production of erythropoietin
 Reticulocyte count may be higher during pregnancy.
 A lower reticulocytes count may indicate:
 Bone marrow failure (eg. drug, tumor, radiation Rx or infection)
 Cirrhosis of the liver
 Untreated patient of pernicious / megaloblastic anemia
 Chronic kidney disease

45. STRESS RETICULOCYTE OR STRESS ERYTHROPOIESIS
 In sever anemia when human body is in need of
reticulocyte or when there is a overproduction of
RBC, these is increase in reticulocyte in blood.
 This is called as Shift reticulocyte or stress
reticulocyte.
 This is similar to shift to left in WBC.

47. CASE 7
 65 yr, Male, chronic cigarette smoker. H/o chronic cough
and confusion since few weeks.
 Complete blood count of the patient done…
 RBC: 7.0 x 106/µl
 Hb: 20 g/dl
 MCV: 70.o fl
 Hct: 60%
 WBC: 16 x 109/l
 Platelets: 625 x 109/l
 Reticulocyte: 3.5%
 Differential diagnosis..?

48. CASE 7
 Detail history…
 Presented with no change in voice
 No h/o haemoptysis, weight loss.
 No change in pattern of cough, and not affecting his sleep.
 Enlarged spleen, slightly purple-red discoloration of
facial skin
 Chest X-ray: hyperinflation, no evidence of lung cancer
 Differential Diagnosis..?
 Diagnosis: Polycythemia vera

49. RBC COUNT
 It is total number of RBC per µL or a liter of blood.
 The test can help to diagnose anemia with low
number of RBCs and other conditions affecting red
blood cells.
 Conditions require RBC count are,
 Kidney diseases
 Anemia
 Bonemarrow disorder like mylofibrosis

50. RBC COUNT
 Mature RBC is a biconcave disc about 7-8 µ in
diameter.
 Normal volume is 80-100 fl, normal hemoglobin
content is 28-34 pg/dl.
 Normal RBC count
 Male: 4.3 – 5.9 (x 1012/l or 106/µl)
 Female: 3.5 – 5.0 (x1012/l or 106/µl)

51. RBC COUNT
 Higher numbers of RBCs may be due to:
 Cigarette smoking
 Failure of the right side of the heart (cor pulmonale)
 Dehydration (for example, from severe diarrhea)
 Kidney tumor (renal cell carcinoma)
 Low blood oxygen level (hypoxia)
 Bone marrow disease that causes abnormal increase in RBCs
(polycythemia vera)
 Drugs like gentamycin / methyldopa

52. RBC COUNT
 Low number of RBC may be due to:
 Anemia
 Bleeding
 Bone marrow failure (for example, from radiation, toxins, or tumor)
 Deficiency of a hormone called erythropoietin (due to kidney disease)
 RBC destruction (hemolysis) due to transfusion, blood vessel injury,
or other cause
 Malnutrition
 Multiple myeloma
 Deficiency of iron, copper, folic acid, vit B6, or vit B12 in the diet
 Over hydration
 Pregnancy

53. POLYCYTHEMIA
 Polycythemia is a general term used to describe
erythrocytosis resulting in an increase in both hemoglobin
concentration and hematocrit ie increase in number of RBC
 It can be due to,
 Relative polycythemia
 Due to decrease plasma volume
 There is normal or even decrease red cell mass
 It is generally mild polycythemia
 Due to dehydration, hemoconcentration
 Secondary polycythemia
 Physiologic stimulus is present hense the name secondary
 Elevated plasma EPO levels (unlike polycythemia vera)
 Polycythemia vera

54. POLYCYTHEMIA VERA
 Increased in Red Cell Mass
 Acquired myloproliferative disorder
 Over production of all 3 cell line, mostly RBC
 Increased HB
 > 18.5 g/dl in Male
 > 16.5 g/dl in Female
 Increased Hematocrit
 > 52% in Male
 >48% in Female
 Also known as 1° polycythemia, Polycythemia rubra vera
and Osler Syndrome.
 Result from the mutation in JAk2, a signaling
molecule in 95% of cases.

55. FURTHER EVALUATION OF PV
 EPO level are normal or low in PV
 On PBS
 RBC overcrowding and with feathered edge seen
 Leukocyte aggregate in PBS of PV patient.
 Increased WBC count and platelet number
 BONE MARROW BIOPSY
 Shows red cell hyperplasia

57. CASE 8
 A 20 yr old male, with history of weakness since few
month
 RBC: 1.0 x 106/µl
 Hb: 6 g/dl
 MCV: 110.o fl
 Reticulocyte count: <1%
 WBC: 0.4x 109/l
 Platelets: 10 x 109/l
 Impression..?
 PANCYTOPENIA
 Causes of Pancytopenia?

58. APLASTIC ANEMIA
 It is condition of pancytopenia with hypocellular
bonemarrow
 Diagnostic criteria:
 Bone marrow cellularity: <25% (hypocellularity)
 Plus two of following
 Granulocyte count: <0.5x109/L
 Platelet count: <20x 109/L
 Anemia with corrected reic count: <1%

59. HEMATOCRIT
 Hematocrit measures the volume that the RBC occupy
within whole blood.
 It is expressed in percentage or L/L.
 In automated analyzer, the hematocrit is usually
calculated by the measured MCV and RBC count by
using formula
 Hematocrit = MCV (fl) x RBC count (x1012/l)
1000

60. HEMATOCRIT
 Elevated hematocrit
 Dengue fever (sign of an
increased risk of DSS)
 Polycythemia vera
 COPD
 Hemolytic anemias
 False high hematocrit
 Dehydration
 Burns patient
 Sever vomiting
 If Sample is not mixed
properly
 Low hematocrit
 Iron deficiency anemia
 Leukemia
 False low hematocrit
 Hemodilution
 Volume overload
 pregnancy

61. HEMATOCRIT
 One should interprets accuracy of RBC count,
hematocrit and hemoglobin value using quick formula
called the “RULE OF THREE”.
 RBC Count x 3 = hemoglobin x 3 = hematocrit(%)
 If error > 3% of the measured value, a measurement error
or instrument malfunction suspected.
 DIURNAL VARIATION
 RBC Count, hematocrit and hemoglobin concentration shows
diurnal variation
 These values are higher in the morning

63. MICRO HEMATOCRIT
 Definition:
 A procedure for determining the ratio of the volume of packed
red blood cells to the volume of whole blood by centrifuging a
minute quantity of blood in a capillary tube coated with
heparin. (RED color marked capillary tube).
 Uses:
 Sample is very less
 Pediatric age group

64. LIMITATIONS OF RBC INDICES
 Though the test for RBC INDICES is cost effective
and simple, it has its own limitations. Such as,
 It is a screening test not a diagnostic test
 MCV is not reliable when Anisocytosis is present
 In combine or dimorphic anemia again MCV is not reliable
 MCV does not reflect the diameter of the RBC, It is a volume of
RBC
 False high or false low value, which should be evaluated
further
 Automated Reticulocyte count is not standardized yet. And
manual method has inter-observer bias.

65. RBC HISTOGRAM
PRICE – JONES CURVES

66. X axis: RBC volume Y axis: RBC Number

67. Salient Features
 RBC Histogram is a bell shaped curve
 The instrument counts cell as erythrocyte with volume
sizes between 25 fl to 250 fl
 Area of the peak is used to calculate the MCV and the
RDW. This area represents 60-125 fl.
 Shift to right- RBC are larger (Macrocytes)
 Shift to left- RBC are smaller (Microcytes)

77. SUMMERY
 RBC index (MCV, MCH, MCHC) and RBC count
helps in diagnosis of anemia
 Combination of various RBC indices (MCV, MCH,
MCHC) especially with RDW is useful in differential
diagnosis of anemia
 Reticulocyte count is a important indicator of bone
marrow activity and it can also be useful in
monitoring and response to iron therapy

78. REFERENCES
 McKenzie SB, Williams JL. Clinical laboratory
hematology. 3rd edition. New jersey: Pearson
education inc; 2015
 Bain BJ, Bates I, Laffan MA, Lewis SM. Practical
hematology. 11th edition. Netherlands: Elsevier; 2012
 Lokwani DP. Interpretation of complete blood count
and histograms
 McCann S, Foa R, Smith O, Conneally E. Clinical
cases uncovered: Hematology. New jersey: Wiley-
Blackwell; 2009