Disorders of the Red Blood Cells

ANEMIA

• Reduction in the oxygen carrying capacity of the blood

• Associated with decreased number of circulating RBCs or an abnormality in the hemoglobin (Hb) contained within the RBCs

ANEMIA

• Often occurs as an underlying condition that requires attention and medical treatment

• Not a disease but a symptom

1. Decreased production of RBCs

2. Blood loss

3. Increased rate of destruction of circulating RBCs (hypersplenism, autoimmune destruction)

4. Chronic disease (e.g., rheumatoid arthritis)

5. Infections

6. Disease of bone marrow

cause of ANEMIA

O2 demand (hypoxia)

serves as the stimulus for erythropoiesis (RBC production)

Kidney

primary sensor for determining the level of oxygenation

erythropoietin

If the level is low, the kidney releases _______, a hormone that stimulates the bone marrow to release RBCs

hemoglobin

the oxygen-carrying molecule of RBCs, consists of two pairs of globin chains (i.e., α plus β, δ, or γ) that form a shell around four oxygen-binding heme groups

33%

Normal RBC is about ____ Hb by volume

IRON DEFICIENCY ANEMIA

A microcytic anemia that can be caused by excessive blood loss, poor iron intake, poor iron absorption, or increased demand for iron

a. Menstruation

b. Pregnancy

c. Bleeding from the gastrointestinal (GI) tract

Depletion of iron commonly occurs with blood loss:

gastrectomy or intestinal disease

Malabsorption of iron can result from ________ that reduces absorption of iron from the duodenum and the jejunum

a. GI bleeding

b. Malignancy

Anemia in men: presence of a serious underlying medical problem

• Impaired immunity

• Resistance to infection

• Diminished exercise tolerance and work performance

Effects of Iron Deficiency Anemia

Ferrous sulfate 2-6 mg/kg/day

Medical management for IDA for children

a. Ferrous sulfate

b. Ferrous fumarate

c. Ferrous gluconate

Patients who have undergone a gastrectomy: iron supplements are provided on a long-term basis (oral administration)

intravenous (IV) or intramuscular (IM) injection

Cases of uncontrolled blood loss: iron cannot be absorbed, or iron is not tolerated, parenteral iron is given by either

Folate

Needed for enzymatic reactions required for the synthesis of purines and pyrimidines of DNA and RNA and thus for the synthesis of proteins

• Poor diet 🥬

• Alcoholism 🍺

• Malabsorption

• Pregnancy (3rd trimester)

Risk Factors for Folate Deficiency

• Folic acid supplements

• Eat leafy greens + citrus

Medical management for Folate Defieciency

PERNICIOUS ANEMIA

Caused by a deficiency of intrinsic factor, a substance secreted by the gastric parietal cells that is necessary for absorption of vitamin B12

PERNICIOUS ANEMIA

Strongly suggests that the disease is of autoimmune origin

• Chronic gastritis

• ↑ risk of gastric cancer ⚠

• Neurologic problems (myelin defect)

• Premature gray hair

• Jaundice

Key Associations: of pernicious anemia

Vitamin B12 (cyanocobalamin) injections given daily for the 1st week and then are tapered eventually to once a month, as needed

Medical Management for pernicious anemia

HEMOLYTIC ANEMIA

RBC destruction problem

1. Immune Attack

2. Extrinsic Factors a. Infection b. Splenomegaly c. Drugs d. Eclampsia

3. Disorders of the RBC membrane a. Spherocytosis

4. Enzymopathies

5. Hemoglobinopathies

Causes of hemolytic anemia

• Sickle Cell Anemia

• Thalassemia

• G6PD Deficiency

types of hemolytic anemia

Sickle Cell Hemoglobin

Result of substitution of a single amino acid valine for glutamic acid-at the 6th residue of the β-chain

Sickle Cell Trait

Heterozygous state in which the affected person carries one gene for sickle cell hemoglobin (HbS)

Sickle Cell Anemia

Homozygous state of sickle cell disorder

SICKLE CELL ANEMIA

more than 80% of hemoglobin is HbS (abnormal)

SICKLE CELL ANEMIA

Distortion of RBC into a sickled shape results from deoxygenation or decreased blood pH

Birth to 20 years of age

Complication of Sickle cell anemia that is Painful events, stroke, acute chest syndrome (fever, chest pain, wheezing, cough, and hypoxia), acute anemia, and infection

From 20 to 40 years of age

Complication of Sickle cell anemia that is Osteonecrosis of hip and shoulder joints, leg ulcers, priapism, liver disease, and gallstones

Older than 40 years of age

Complication of Sickle cell anemia that is Pulmonary hypertension, nephropathy, proliferative retinopathy, and cardiac enlargement, heart murmurs, and sudden death from arrhythmias

1. Jaundice

2. Pallor

3. Dactylitis (hand and foot warmth and tenderness)

4. Leg ulcers

5. Organomegaly

6. Cardiac failure

7. Stroke

8. Attack attacks of abdominal and bone pain (aseptic necrosis)

9. Delays in growth and development

Signs and Symptoms of Sickle cell anemia

routine prophylactic penicillin and early use of antibiotics

medical management of sickle cell anemia in infants

• vaccination againts S. pneumoniae, H. influenzaw, HBV, influnzae

• folic acid dietary supplements

• penicillin prophylaxis for first five years of life

medical management of sickle cell anemia in children

• high dose of folic acid

• analgesic for pain

• hydration blood transfusion

medical management of sickle cell anemia if crisis occur

hydroxyurea

induces production of HbF and thus prevents formation of HbS polymers

stem cell transplantation with bone marrow

source in a majority of cases from sibling donors carries a 10% mortality rate and 90% overall survival rate, with a mean follow up of 54 months

16 years old

patient older than _______ are much less likely to have successful grafts

GLUCOSE-6-PHOSPHATE DEHYDROGENASE

• enzyme that enables the RBC to convert carbohydrates into energy via the hexose monophosphate shunt pathway

• Enzyme deficiency → RBC damage → hemolysis

methemoglobin and denatured Hb

Blockade of this enzymatic pathway in persons with G6PD deficiency allows for production of _______________, which leads to cell membrane alterations and hemolysis of the cell (hemolytic anemia)

APLASTIC ANEMIA

Occurs when the bone marrow is unable to produce adequate numbers of RBCs, white blood cells (WBCs), and platelets because of an inability of the hematopoietic stem cells to proliferate, differentiate, or give rise to mature blood cells

1. Weakness

2. Fatigue

3. Headaches

4. Dyspnea exertion

5. Petexhiae, ecchymoses

6. Epistaxis

7. Gingival bleeding

8. Metorrhagia

Signs and symptoms of aplastic anemia

Metorrhagia

Bleeding between expected menstrual periods

iron deficiency

microcytic anemia

folate deficiency

pernicious anemia

macrocytic anemia

G6PD

sickle cell anemia

aplastic anemia

nomocytic anemia

OM of Patients with nutritional causes of anemia

a. Loss of papillae from the tongue

b. Atrophic changes in the oral mucosa

c. Angular cheilitis

d. Aphthae

e. Burning or sore tongue

Plummer-Vinson Syndrome

sore mouth, dysphagia (resulting from muscular degeneration in the esophagus with esophageal stenosis or ‘webbing’), and an increased frequency of carcinoma of the oral cavity and pharynx

OM of iron deficiency

Plummer-Vinson Syndrome

OM of hemolytic anemia

• Jaundice in oral tissues

• bone marrow spaces appears enlarged

• Radiographic changes:

  • “Stepladder” trabeculae

  • “Hair-on-end” skull

OM of sickle cell anemia

- Delayed eruption of teeth

- Dental hypoplasia

OM of aplastic anemia

• Petechiae, ecchymoses, mucosal pallor, ulceration (infection), gingival bleeding, and gingival hyperplasia

• Necrotizing gingivostomatitis

• history-taking

• Lab tests screening

• Determine the underlying illness

• Hb levels should be above 11g/dL, patient should be free from symptoms

Dental Management in general

G6PD

DENTAL MANAGEMENT:

• Avoid:

  • Aspirin

  • Sulfa drugs

• Infection can worsen hemolysis

Sickle cell anemia

DENTAL MANAGEMENT:

• Treat during non-crisis

• Avoid stress

• Short appointments

• Use antibiotics if needed

Aplastic anemia

DENTAL MANAGEMENT:

High risk of:

• Bleeding

• Infection
  👉 Refer to physician if severe signs present