Anemia, Pernicious Anemia, Iron Deficiency Anemia

Hematological Disorders

Defined as a hemoglobin concentration in blood below the lower limit of the normal range for the age and sex of the indivisual.

(HbA)Males: 13.0-18.0 g/dl(HbA)Females: 11.5-16.5 g/dlPlasma Hb(quantitative): 0.5-5.0 mg/dlMCV: 77-93 flMCH: 27-32 pgMCHC: 30-35 g/dlNormal RBC Values: 4.5-6.5 million/L(males); 3.8-5.8 million/L(females)Daily Fe requirement:10-15 mg/dayDaily B12 requirement:2-4 mcgms

Normal levels

Pathophysiology

Subnormal level of Hb causes lowered oxygen carrying capacity of the blood. This in turn, initiates compensatory physiologic adaptations such as:

Increased release of oxygen from Hb Increased blood flow volume Maintenance of the blood volume Redistribution of blood flow to maintain the

cerebral blood supply.

Clinical Features

The speed of onset of anemia: rapidly progressive anemia causes more symptoms than anemia of slow-onset as there is less time for physiologic adaptation.

The severity of anemia: mild anemia produces no symptoms or signs but a rapidly developing severe anemia (Hb<6.0 g/dl) may produce significant clinical features.

The age of the patient: the young patient due to good cardiovascular compensation tolerate anemia quite well as compared to the elderly.

The heamoglobin dissociation curve: in anemia, the affinity of heamoglobin for oxygen is depressed as 2,3-BPG in the red cells increase.

Symptoms

The presenting features are: Tiredness Easy fatiguability Generalized muscular weakness Lethargy Headache

In older patients, there may be symptoms of cardiac failure, angina pectoris, intermittent claudication, confusion and visual disturbances.

General Symptoms of Anemia

Investigations A). Haemoglobin Estimation:

Cynmethaemoglobin (HCN) method employing Drabkin’s solution and a spectrophotometer.

If pregnancy, there is haemodilution and, therefore, the lower limit in normal pregnant women is less (10.5 g/dl) than in the non pregnant state.

B).Peripheral Blood Film Examination:

Stain with Romanowsky dyes (Leishman’s stain, May-Grunwal’s stain, Jenner-Giemsa stain, Wright’s stain)

C). Red Cell Indices:

In Fe deficiency and thalassaemia, MCV, MCH and MCHC are reduced.

In anemia due to acute blood loss and haemolytic anemia, MCV, MCH and MCHC are all within normal limits.

In megaloblastic anemia, MCV is raised above the normal range.

D). Leucocyte Count and Platelet Count

E). Reticulocyte Count

F). Erythrocyte Sedimentation Rate

G). Bone Marrow Examination

Classification

A). Pathophysiology I. Anemias due to increased

blood loss a). Acute post-haemorrhagic

blood loss b). Chronic blood loss

II. Anemias due to impaired red cell production

a).Cytoplasmic maturation defects

i. Fe deficiency anaemia ii.Thallassaemia syndromes

b).Nuclear Maturation Syndromes i. Vitamin B12/ Folic acid

deficiency ii. Megaloblastic anemia

c).Defect In Stem cell proliferation

i. Aplastic Anemia pure red cell aplasia

d).Anaemia of chronic disorders e).Bone Marrow Infiltration f). Congenital anaemias

III. Anaemias due to increased red cell destruction(Haemolytic anaemias)

a). Extrinsic red cell abnormalities

b). Intrinsic red cell abnormalities

B).Morphologic

I. Microcytic, hypochromic: MCV, MCH, MCHC are all reduced e.g. after Fe

deficiency anaemia and in certain non-iron deficient anaemias

II. Normocytic, normochromic: MCV, MCH, MCHC are all normal e.g after acute

blood loss, haemolytic anaemias, bone marrow failure, anaemia of chronic disorders

III. Macrocytic, normochromic: MCV is raised e.g in megaloblastic anaemia due to

deficiency of vitamin B12 or folic acid.

ANAEMIA OF BLOOD LOSS

Depending upon the rate of blood loss due to haemorrhage, the effects of post-haemmorhagic anaemia appear.

When the loss of blood occurs suddenly,

i. Immediate threat to life due to hypovolemia which may result in shock and death.

ii. If patient survives, shifting of interstitial fluid to intravascular compartment with consequent haemodilution with low haematocrit.

iii. Hypoxia stimulates production of erythropoeitin resulting in increased marrow erythropoeisis.

When the loss of blood is slow and insidious, the effects of anaemia will become apparent only when the rate of loss is more than the rate of production and the iron stores are depleted.

This results in Fe deficiency anaemia as seen in other clinical conditions.

Acute Blood Loss Chronic Blood Loss

Hypochromic Anaemia

Hypochromic anaemia due to Fe deficiency is the commonest cause of anaemia the world over.

Fe deficiency is the most important cause of microcytic hypochromic anemia which all the three red cell indices (MCV, MCH, MCHC) are reduced and occurs due to defective Hb synthesis.

It is of two types:

a).Hypochromic anaemia due to Fe deficiency

b).hypochromic anaemia other than Fe deficiency

The commonest nutritional deficiency disorder present throughout the world is iron deficiency but its prevalence is higher in developing countries.The factors responsible for iron deficiency in different populations are variable and are best understood in the context of normal iron metabolism.

Iron Deficiency Anemia

Iron Metabolism

Pathophysiology

Iron deficiency anemia develops when the supply of iron is inadequate for the requirement of Hb synthesis.

Initially, negative iron balance is covered by mobilization from the tissue stores so as to maintain Hb synthesis.

It is only after the tissue stores of iron are exhausted that the supply of iron to the marrow becomes insufficient for Hb formation and thus a state of iron deficiency develops.

Sources Of Iron

Etiology

A).Females in reproductive period of life:Highest incidence in women.i. Blood Loss: Most important cause of anemia in women during

child bearing age group. due to persistant and heavy menstrual blood loss. young girls at the start of menstruation may develop mild

anemia due to blood loss.ii. Inadequate Intake: prevalent in women of lower economic

status. besides diet deficient in iron, other factors such as anorexia,

impaired absorption and diminished bioavailability may act as contributory factors.

iii. Increased Requirements: During adolescence and pregnancy the body’s iron demands are increased.

during a normal pregnancy, 750 mg of iron may be siphoned off from the mother - 400 mg to foetus + 150 mg to placenta + 200 mg lost at parturition and lactation

Etiology

B).Post Menopausal Females:i. Post menopausal uterine bleeding:

due to carcinoma of uterus.

ii. Bleeding from alimentary tract: due to carcinoma of stomach and large bowel and hiatus hernia.

C).Adult Males:i. Gastrointestinal Tract: due to peptic

ulcer, haemarrhoids, hook worm infestation, carcinoma of stomach and large bowel, oesophageal varices, hiatus hernia, chronic aspirin ingestion and ulcerative colitis.

ii. Urinary Tract: due to haematuria and haemoglobinurea.

iii. Nose: repeated epistaxis

iv. Lungs: haemoptysis from various causes.

D).Infants and Children: Peak incidence at 1-2 years of age.

Principal cause is increased demand of iron which is not met by inadequate intake of iron in the diet.

Normal full term infants have sufficient iron stores, while premature infants have inadequate reserves because iron stores from the mother are mainly laid down during the last trimester of pregnancy.

Clinical Features

Anemia: onset of iron deficiency anemia is generally slow.

Usual symptoms are weakness, fatigue, dyspnoea on exertion, palpitations and pallor of the skin, mucous membranes and sclerae.

Older patients may develop angina and congestive cardiac failure.

Patients may have dietary cravings such as pica.

Menorrhagia is a common symptom in iron deficient women.

Epithelial Tissue Changes:

Long standing iron deficiency anemia causes epithelial tissue changes in some patients.

Koilonychia (spoon shaped nails)

Atrophic glossitis

Angular stomatitis

Dysphagia (a feature of Plummer Vinson Syndrome)

Koilonychia

Laboratory Findings

Stages: Stage 1: Storage iron depletion

Stage 2: Iron deficient erythropoeisis

Stage 3: Frank iron deficiency anemia where the RBCs become microcytic and hypochromic.

Blood Picture and Red Cell Indices

i. Haemoglobin

ii. Red Cells: Hypochromic and Microcytic and there is Anisocytosis and poikilocytosis.

Target cells, elliptical forms and polychromatic cells are often present. Normoblasts are uncommon. RBC count is below normal level but is proportionate to the fall in Hb

values.

iii. Reticulocyte Count: Normal or reduced but may be slightly raised (2-5%) in cases after haemorrhage.

iv. Absolute Values: MCV, MCH, MCHC are reduced. v. Leucocytes: TLC, DLC are usually normal. vi. Platelets: usually normal but may be slightly to moderately raised in

patients who have had recent bleeding.

Bone Marrow Findings

i. Marrow Cellularity: Increased due to erythroid hyperplasia (M:E decreased)

ii. Erythropoeisis: Normoblastic erythropoeisis with predominance of small polychromatic normoblasts (micronormoblasts). These normoblasts have a thin rim of cytoplasm around the nucleus and ragged and irregular cell border.

iii. Other Cells: Myeloid, Lymphoid and Megakaryocytic cells are normal in number and morphology.

iv. Marrow Iron: Iron staining (Prussian blue reaction) shows deficient reticuloendothelial iron stores and absence of siderotic iron granules from developing normoblasts.

Treatment

1. Correction of the disorder: Appropriate surgical, medical and preventive measures are instituted to correct the cause of blood loss.

2. Correction of iron deficiency: a. Oral therapy: Administration of iron salts such as

ferrous sulfate, ferrous fumerate, ferrous gluconate and polysaccharide iron.

These preparations having varying amounts of elemental iron ranging from 39 to 105 mg.

Optimal absorption is obtained by giving iron fasting, but if side effects occur (nausea, abdominal discomfort, diarrhoea) iron can be given along with food or with a lower iron preparation.

3. Parenteral Therapy:

Indicated in cases who are:- i. Intolerant to oral iron therapy ii. In GIT disorders (Malabsorption) iii. Women with severe anemia a few weeks before expected date

of delivery A common preparation is Iron Dextran which may be given as a

single IM or as IV infusion after dilution with dextrose or saline.

Adverse effects of dextran are anaphylactoid reaction, haemolysis, hypotension, circulatory collapse, vomiting and muscle pain.

Newer iron complexes such as sodium ferric gluconate and iron sucrose can be administered as repeated IV injections with much lower side effects.

Management

Vitamin B12 deficiency; Addisonian anemia; Biermer anemia; Hunter-Addison anemia; Lederer anemia; Biermer-Ehrlich anemia; Addison Biermer Disease

Pernicious Anemia

Was first described by Addison in 1885 as a chronic disorder of middle-aged and elderly indivisual of either sex in which IF secretion ceases owing to atrophy of gastric mucosa.

The average age at presentation is 60 years but rarely can be seen in children under 10 years (Juvenile Pernicious Anemia)

Vitamin B12 is an ‘Erythrocyte Maturing Factor’ or ‘Haemopoeitic Factor’ and present in foods(liver, beef, milk and dairy products).

Pathogenesis

Probably an autoimmune disorder with a genetic predisposition and the disease is associated with HLA types A2, A3 and B7 and blood group A.

Similarly binding and blocking antibodies (Anti Parietal Ab) to IF are found in most patients.

Also associated with other autoimmune disorders like thyroid disorders, type I diabetes mellitus, ulcerative colitis, Addisons disease and acquired agammaglobulinemia.

Relatives of patients have increased incidence.

Corticosteroids have been reported to be beneficial in curing this disease.

Functions of folic acid

Morphologic Features

Most characteristic pathologic finding is gastric atrophy affecting the acid-pepsin secreting portion of stomach, sparing the antrum.

Gastric epithelium may show cellular atypia.

Complications include: peripheral neuropathy, spinal cord damage.

Clinical Features

Onset is insidous and progresses slowly.

Characterized by a triad of symptoms: generalized weakness, a sore, painful tongue.

Anemia, glossitis, neurological(subacute degeneration of spinal cord, retrobulbar neuritis), gastrointestinal manifestations(diarrhoea, anorexia, weight loss, dyspepsia), hepatosplenomegaly, CHF and haemorrhagic manifestations.

Oral Manifestations

Glossitis Pain and burning sensation in lingual

areas ‘Beefy red’ tongue (entirely or in patches) Shallow ulcers resembling apthous ulcers. Glossodynia, glossopyrosis Gradual atrophy of pappilae of tongue

referred to as ‘Bald Tongue’; ‘Hunter’s glossitis’; ’Moeller’s tongue’.

Dysguesia Patients become intolerant to dentures.

Laboratory Findings

A). Blood: RBC count is decreased to 1,000,000 or less per cubic millimeter.

Many cells exhibit Macrocytosis.

Poikilocytosis is also present.

Hb is increased in proportion to the size of the RBCs.

Polychromatophillic cells, stippled cells, nucleated cells, Howell-Jolly bodies and Cabot’s ring puctuate basophilia.

Mild to moderate thrombocytopenia is noticed.

Coexistent iron deficiency is common because achlorhydria prevents solubilisation of dietery ferric iron from foodstuffs.

B). Serum: Indirect bilirubin maybe elevated.

Serum lactate dehydrogenase is markedly increased.

Serum pottasium, cholesterol and skeletal alkaline phosphatase are decreased.

C). Gastric secretions: Total gastric secretions are reduced to about 10%.

Most patients are achlorhydric.

IF is absent or markedly decreased.

D). Bone Marrow: biopsy and aspirate are hypercellular and show trilineage differentiation.

Diagnostic Criteria

Major Criteria

Minor Lab Criteria

Minor Clinical Criteria

Reference Standard Criteria

1. Low serum B12 level in presence of normal renal function.

Macrocytosis in PBF

Neurologic features of paresthesia

Shilling test showing malabsorption of cyanocobalamine

2. Megaloblastic anemia in bone marrow examination.

Anemia of variable degree

Hypothyroidism

3. Positive test for IF Ab

Hypergastrinemia

Vitiligo

4. Positive gastric parietal cell Ab

Family history of PA or hypothyroidism

Treatment

Parenteral vitamin B12 replacement therapy.

Symptomatic and supportive therapy such as physiotherapy for neurologic deficits and occasionally blood transfusion.

Follow up for early detection of cancer of stomach.

Corticosteroid can improve gastric lesion with a return of acid secretion.

Mental and neurologic damage can become irreversible without therapy.

1. Shafer’s textbook of oral pathology2. Navel’s textbook of oral pathology3. Textbook of pathology-Harsh Mohan4. Burket’s oral medicine

References