Integrative Flashcards
Sites of hemopoiesis:
Fetus 0-2 m (yolk sac) 2-7 m (liver, spleen) 5-9 m (Bone marrow) Infant Bone marrow (all bones) Adult Bone marrow (axial skeleton and proximal end of long bones).
What is the difference between plasma and serum ?
Plasma contain all coagulation proteins while the serum lack most of them mainly the fibrinogen loss in clot formation.
- Plasma obtain from blood collected in tube contain anticoagulant while serum collected from blood in plain tube.
- Plasma mainly use in investigations of coagulation disorders while serum mainly use in biochemical and hormonal investigations.
شنو المسار مال الخلايا حتى تصير RBCs
Basophilic erythroblast
Orthochromatic erythroblast
Reticulocytes
Mature RBCs
Important cells in the BM for this process are precursor cells which including:
Proerythoblast.
- Early normoblasts.
- Intermediate normoblasts.
- Late normoblasts.
- Reticulocytes.
The cell gradually loss their nucleus until formation of reticulocyte as last precursor cell without nucleus.
Reticulocytes
non nucleated red cells with diffusely basophilic cytoplasm due to remaining ribosomal RNA, still able to synthesis the Hb, slightly larger than mature RBC, it remains in BM about 2 days then release to circulation and remains 1-2 days to complete their maturation in the spleen. Normal range in peripheral blood is 0.5-2.5 % from each 100 mature RBC.
Normoblast (precursor of RBC) normally present in the BM and not present in peripheral blood and when appear called
Normoblast (precursor of RBC) normally present in the BM and not present in peripheral blood and when appear called nucleated RBC (NRBC).
Control of erythropoiesis:
Functional feedback: achieved by Erythropoietin (Epo).
- Certain hormones, like growth hormone and androgen enhance erythropoiesis, while estrogen suppresses erythropoiesis.
- Nutritional factors like FA, B12, iron, B6, B2, vitamin C and E.
Erythropoietin (Epo):
It is a glycoprotein produced mainly by the kidney in the adult, stimulates red cell progenitors and precursors cells for RBC formation from the BM. Secretion of Epo is triggered by reduced oxygen carriage of blood:
- Reduced Hb (anemia).
- Hypoxia (cardiac and lung disease).
- Damage to renal circulation.
Epo of great clinical significant in many disorders using recombinant Epo like end stage renal disease and anemia of chronic disease.
Retic count formula
HC / 45* Retic count
Correction for hyperchromasia
The result from above formula /2
Bone marrow examination
Bone marrow aspirate: done from iliac crest or sternum, in which a specimen is aspirated using a wide bore needle from the active marrow, smeared, stained and then examined for any abnormalities.
- Bone marrow biopsy: here a core of bone marrow tissue is taken, processed and stained as in histopathological specimens.
Main indications of BM examination
Marrow infiltration with leukemia, lymphoma, secondary carcinomas and myelofibrosis.
- Cytopenias of unexplained causes: neutropenia, thrombocytopenia, anemia.
Hemoglobin (normal range for male
For female
Packed cell volume (PCV) also called Hematocrit (Male& female )
RBCs count
Hemoglobin (normal range for male 13.0– 17.0 g/dl, female 12.0-
15.0 g/dl).
Packed cell volume (PCV) also called Hematocrit (Male 40-50 %, Female 36-46 %).
• RBC count (Male 5.0 x 1012/L, Female 4.3 x 1012/L).
MCV MCH MCHC RDW ESR
80-100 fl). (27-32 pg).
(32-36 g/dl). (12-15 %).
8 mm/hr
Classification of anemia
BM defect , Retic count low or normal )
( Retic count increase )
Peripheral blood loss
Like:
- Iron deficieny anemia
- Megaloblastic anemia
- Aplastic anemia
- Anemia of chronic dis.
- Anemia associated with BM infilteration.
Retic count increase )
Peripheral blood loss
- Bleeding
- Hemolysis (hemolytic anemia)
Generally iron in the body present in main 3 pools are:
Functional pool: (65-70%)
- Hemoglobin: New RBC formation required 30 mg iron/day mainly derive from breakdown of old RBC. Each unit of blood (450ml) contains 200 mg iron.
- Myoglobin, mitochondria and iron containing enzymes.
(2) Storage pool: (20-25%) present in form of ferritin and hemosiderin that present in RES (BM, liver and spleen) and in the liver parenchymal cells.
(3) Transporting pool: (0.1%) plasma iron carried by iron transporting protein (Transferrin).
Hepcidin
is a small peptide, formed by liver and consider the predominant negative regulator of iron absorption from small intestine (decrease in iron absorption) and iron release from macrophages (decrease in iron release from macrophage).
Causes of iron deficiency:
- Chronic blood loss: (at least 6-8 ml/day). Common cause in adult
and most likely from the gastrointestinal tract and in females
bleeding from genital tract is also quite common.
- Increase in demand: prematurity and infancy (3-6 months), pregnancy, lactation, menstruation and adolescence period.
- Nutritional: rarely to be the sole cause of ID but quite common cause of iron deficiency in developing and underdeveloped countries, especially if inadequate intake is coupled with increased demand.
- Inadequate absorption: from many causes of malabsorption e.g.
Celiac disease.
Clinical features:of IDA
Clinical features related to underlying pathology.
- General signs and symptoms of anemia.
- Mucosal changes in severe IDA as mouth soreness, painless glossitis, angular stomatitis and nails changes as brittle, ridged, and spooning (koilonychias) of nails.
- Pica (craving to eat unusual substances like clay and ice).
- In sever long standing IDA, patient may develop dysphagia (Plummer Vinson syndrome).
- Mental development disturbance and premature labor may associated.
- Plummer Vinson syndrome (Kelly Paterson syndrome) is a triad of dysphagia (pharyngeal web), glossitis and IDA, it has risk of CA, more in women, of unknown etiology.
Anisocytosis
Poikilocytosis
Anisocytosis: change in RBC size as microcytic (decrease in MCV), macrocytic (increase in MCV).
• Poikilocytosis: change in RBC shape as sherocytes, target, tear, sickle, fragmented, oval, rod cells, etc
Stages of iron deficiency anemia:
- Depletion of iron stores: no iron in store (low serum ferritin) and no anemia yet.
- Iron-deficient erythropoiesis: Low serum iron and high TIBC and still no significant anemia yet.
- Iron deficiency anemia: Low Hb, MCV and MCH.
Laboratory findings in IDA:
- Hematological findings:
- Reduce in Hb (6-8 gm/dl) usually moderate degree of anemia.
- Reduce PCV, MCV, MCH, and MCHC.
- Retic count is low.
- WBC usually normal, and platelets counts often increase.
- Blood film: hypochromic microcytic.
LO5
• Decrease or absence in marrow iron store which can detect by Perl’s stain/Prussian blue stain which is diagnostic, but the BM examination is not an indication in suspected case of IDA.
- Biochemical findings:
- Serum iron reduced.
- Total iron binding capacity increased.
- Transferrin saturation reduced <15%.
- Serum Ferritin reduced which reflects storage iron.
- Investigations for suspected underlying causes
Treatment of IDA
Treatment of primary cause.
- Oral iron (most effective) best with ferrous sulphate 200 mg (67 mg elementary iron).
- Dose 100-200mg elementary iron/day, for 3-6 months (to correct the storage state of iron).
Response assessment to IDA
Parental iron
Response assessment by increase Hb (0.5-1gm/wk), retic count increase (peak at 10 days).
• Failure to response may related to wrong diagnosis, failure to take the drug, continuous hemorrhage, mixed anemias, another cause of anemia and malabsorption.
Parenteral iron: Indicated in sever intolerance of oral iron, require rapid restoring, persistent hemorrhage, malabsorption. Iron sorbitol (jectofer) IM, dextran (inferon) IV.
Differential diagnosis of IDA
Differential diagnosis of hypochromic microcytic anemias include four main types of anemia are:
- Iron deficiency anemia.
- Anemia of chronic disease.
- Sideroblastic anemia, result from defect in protoporphyrin ring.
- Thalassemia, result from globin chain defect.
Anemia of chronic disease
Causes
كلها بسبب السايتوكين تروح للبون مارو تقلل تخليق كريات الدم الحمر وتسوي أيضا upregulation of hepcidin
Anemia of chronic disease
Clinical features
Mild to moderate anemia (rarely Hb < 9 gm/dl), start 1-3 months after the underlining disease and the severity related to illness severity.
- Normochromic red cell in most cases or may be hypochromic in peripheral blood.
- Low serum iron despite adequate iron stores (due to defect in iron mobilization from the storage sites by effect of hepcidin and other inflammatory mediators).
- Low serum iron and low TIBC.
- High serum ferritin, high C-reactive protein and high ESR.
- High serum Hepcidin level (important acute phase protein with significant role in regulation of body iron).
Megaloblastic anemia
Clinical
Anemia due to impaired DNA synthesis, result mainly from B12 and Folate deficiency. All haemopoietic cell lines (erythropiesis, granulopoiesis, megakaryopoiesis) are affected result in severe anemia and even pancytopenia.
- The hallmark enlargement of BM erythroid precursors (megaloblast) give rise to abnormal large RBC in blood (macrocytes) in addition to giant granulocytic precursors in BM yielding hypersegmented neutrophils in peripheral blood.
- It important to recognition of MBA because main causes can completely corrected with therapy and it is a serious disease that neurological and psychiatric abnormalities of B12 deficiency may be preventable and reversible with early stage of disease.
Forms of B12
Forms of B12:Methylcobalamin, Adenosylcobalamin, main form in tissue, Cyanocobalamin, form use in investigations, Hydroxycobalamin, form use in treatment.
Absorption of B12 in the ileum pass through some steps:
In stomach: B12 bind to R-factor which produce by saliva and gastric juice.
- In duodenum: Digestion of this complex by pancreatic enzymes, then the B12 bind to Intrinsic factor (IF) which secrete from stomach parietal cells.
- In terminal ileum: IF bind to specific receptor (Cubilin) and B12 appear in portal circulation after 6 hrs bind to transcobalamin-II (TC II).
Folic acid
Human unable to synthesis FA so required intake, main source are vegetable and fruits, but most foods contain FA and it destroyed by cooking.
- Absorption take place in upper half of small intestine mainly jejunum by saturation process.
- It act as a co-enzyme in purine and pyrimidine synthesis.
Biochemical basis of MBA:
MBA; is type of anemia characterized by impaired DNA synthesis.
- DNA synthesis required polymerization of 4 deoxyribonucleoside triphosphates and FA deficiency impaired thymidylate of dUMP to dTMP.
- B12 required to achieve the active form of folate inside the cells.
- So deficiency of any vitamin will lead to impair in DNA synthesis.
- Neurological manifestations occur only with B12 deficiency due to defect in methylation of myelin
Causes of vitamin B12 deficiency:
(1) Malabsorption (main cause) like:
o Gastric causes, as pernicious anemia.
o Intestinal causes, as ileal resection.
o Other causes like severe chronic pancreatitis.
(2) Dietary deficiency: as in vegans, pregnancy, poverty, infancy (dietary cause unlikely related unless malabsorption association).
(3) B12 abnormal metabolism:
Acquired as nitrous oxide inhalation. Inborn error: as TC II and IF deficiency.
Causes of FA deficiency:
(1) Inadequate dietary intake (common cause due to low storage state): old age, poverty, alcoholism, psychiatric disturbance.
(2) Malabsorption like celiac disease.
(3) Increase requirement or loss:
- Physiological as pregnancy.
- Pathological as hemolytic anemia.
(4) Antifolate drugs as anti-convulsants, alcohol and DHFR inhibitors.
Clinical features of MBA (of both B12 & FA deficiencies):
May be asymptomatic, usually insidious onset with signs and symptoms of anemia.
- Mild jaundice (due to intramedullary destruction of red cell precursors).
- Epithelial tissue changes as glossitis and angular stomatitis.
- NTD (neural tube defect ) in FA deficiency and may occur with B12 deficiency of uncleare mechanisms.
- Neurological manifestations only with B12 deficiency due to accumulation of SAH and reduce level of SAM in nervous tissue with defect in methylation of myelin.
- Psychatric abnormality.
Pernicious anemia
- It is MBA due to B12 deficiency, characterized by gastric atrophy, reduce or absent of intrinsic factor with achlorhydria.
- It more in female, mostly a disease of the elderly, more in patients with autoimmune mediated disorders like autoimmune thyroid disease.
- Not common in Iraq, common in north Europe.
- Mostly it is autoimmune in nature with presence of serum antibodies like anti-IF Ab, anti-parietal cells Ab and anti-gasrtin receptor Ab.
Laboratory findings of MBA:
Hematological findings:
- Variable degree of anemia, usually severe anemia < 6 gm/dl.
- MCV increased >100 fl, may be up to 135 fl.
- Increase MCV, MCH, and normal MCHC.
- Increase RDW.
- Low retic count.
- Leucocytes may be reduced, platelets may be moderately reduced (pancytopenia).
- Blood film: oval macrocytes, hypersegmented neutrophils, leukoerythroblastic picture may found.
- BM findings: Hypercellular marrow with megaloblastic changes in all cell lineages.
Management of megaloblastic anemia
- Blood sample and BM examination done before any treatment.
- General measures may require as platelets and RBC concentrate.
- Treatment with specific vitamin if known, otherwise both vitamins should be given.
- B12: lifelong B12 therapy using Hydroxocobalamin by injection. Six injections of 1mg IM for body restore then monthly injection for life.
- Should never give folate on its own in cobalamin deficiency because although response will be seen, aggravation or induction of neurological complications may be induced.
- FA: Folic acid given orally 5-15 mg / day. Duration usually 4 months, but depend on the underlying pathology may be for life in those with untreatable causes.
Response to treatment: of megaloblastic anemia
- Initial correction of patient behavior and appetite within 1-2 days.
- Retic count increase with peak level at 7 days may reach 40-50%.
- Hb level increase 1 gm/dl /wk and corrected in 5-6 wks.
- Peripheral neuropathy may partially improve but spinal cord damage is irreversible.
- Follow up the patient with Hb and retic not by BM examination.
BM failure
BM failure may result from:
- Marrow infiltration or replacement by abnormal or malignant cells.
- Hypoplasia/aplasia (inherited or acquired) either single line or all marrow lineage.
Inherited type:
Pancytopenia like Fanconi anemia.
Single line: Anemia; Diamond Blackfan anemia.
Neutropenia: Kostman’s syndrome. Thrombocytopenia of congenital type.
Acquired type:
Pancytopenia: Acquired aplastic anemia.
Single line: Anemia; acquired pure red cell aplasia.
Neutropenia: induce by drugs and viral infection. TCP: induce by drugs and viral infection.
Pancytopenia
Definition: reduction in all cell line in peripheral blood (anemia, neutropenia, thrombocytopenia).
Etiology of pancytopenia Central (BM) causes:
- Aplastic anemia (congenital or acquired).
- Some cases of acute and chronic leukemias.
- Infiltration with abnormal or malignant cells.
- Megaloblastic anemia (MBA).
- Paroxysmal nocturnal hemoglobinurea (PNH).
Increase peripheral destruction: Hypersplenism, SLE and DIC.
Etiology of pancytopenia Central (BM) causes:
- Aplastic anemia (congenital or acquired).
- Some cases of acute and chronic leukemias.
- Infiltration with abnormal or malignant cells.
- Megaloblastic anemia (MBA).
- Paroxysmal nocturnal hemoglobinurea (PNH).
Hypoplasia/aplasia
Inherited type:
Pancytopenia like Fanconi anemia.
Single line: Anemia; Diamond Blackfan anemia.
Neutropenia: Kostman’s syndrome. Thrombocytopenia of congenital type.
Hypoplasia/aplasia
Acquired type:
Pancytopenia: Acquired aplastic anemia.
Single line: Anemia; acquired pure red cell aplasia.
Neutropenia: induce by drugs and viral infection. TCP: induce by drugs and viral infection.
Aplastic anemia
Definition
Pancytopenia in the peripheral blood due to aplasia or hypocellular marrow in which normal haemopoietic elements are replaced by fat cells. Abnormal cells are not present in the peripheral blood or bone marrow.
Causes of AA: aplastic anemia
Inherited AA like Fanconi anemia. Acquired AA:
- Idiopathic in 50 -75% of cases, most common type and suggested to be autoimmune T-cells mediated immune disorder.
- Ionizing irradiation; Chemicals.
- Drugs as: cytotoxic drugs, chloramphenicol, sulpha and gold.
- Infective agents as hepatitis viruses, HIV, EBV, and other viruses.
Clinical manifestations: of AA
- Any age but peak at 30 yrs.
- Insidious or acute presentation.
- Bleeding tendency.
- Features of anemia.
- Infections.
- No jaundice except post-hepatitis cases.
- No organomegaly.
Laboratory Findings: of AA
- Pancytopenia (anemia, neutropenia, TCP).
- Blood film: normochromic red cell and usually macrocytic.
- Reduced retic count.
- BMA: hypocellular, no abnormal cells. BMA may be dry (diagnosis cannot made with BMA alone).
- BMB (required for diagnosis): hypocellular.
- Cytogenetic analysis for congenital types.
Hemoglobin H disease (Hb-H)
Common in South East Asia, less so in Mediterranean countries and sporadic in Iraq.
The only phenotype of alpha thalassemia of clinical significance.
Clinically: variable degrees of anemia, splenomegaly and jaundice. Unusual to see severe thalassaemic skeletal changes or growth retardation, usually survive to adult life.
Anemia aggravated by infections and oxidant drugs.
Laboratory findings: of alpha thal
Hb is usually 7-10 gm/dl, MCV and MCH reduced.
- Reticulocytosis.
- Blood film shows hypochromic microcytic cells, some target cells.
- On modification of the reticulocyte stain; characteristic Hb-H inclusions will be seen in RBC (Golf ball appearance).
- Hb electrophoresis showing Hb-H and Hb-A.
