Dlood And Hemolytic Disorder Flashcards
(103 cards)
1
Q
Front
A
Back
2
Q
What are common disorders of the blood and lymphatic system?
A
Red cell disorders lead to anemia (RBC deficiency). White cell disorders lead to leukemia (WBC proliferation). Haemostatic derangements lead to hemorrhagic diathesis. Splenomegaly is a feature of several hematopoietic diseases.
3
Q
What is anemia?
A
Anemia is a reduction in oxygen transport capacity of blood due to reduction in RBC count or hemoglobin concentration.
4
Q
What are the changes in the pathology of anemia?
A
- Bone marrow hyperplasia in red marrow that replaces the yellow marrow. 2. Peripheral blood changes in number size shape of cells and Hb concentration. 3. Extramedullary hematopoiesis in liver spleen and lymph nodes. 4. Tissue changes include pallor and fatty changes in liver and kidney due to hypoxia.
5
Q
What are the causes of anemia?
A
- Excessive bleeding. 2. Increased red cell destruction. 3. Decreased red cell production.
6
Q
How is anemia classified?
A
- Blood loss: Acute trauma and chronic lesions of the gastrointestinal tract gynecologic disturbances. 2. Increased destruction: Hemolytic anemia A. Intrinsic abnormalities of RBC: hereditary disorders of RBC membrane disorders of hemoglobin synthesis enzyme deficiencies. B. Acquired abnormalities: membrane defect such as Paroxysmal Nocturnal Hemoglobinuria. 3. Impaired RBC production: A. Disturbance of proliferation and maturation of erythroblasts: iron folate vit B12 deficiency. B. Disturbance of proliferation and differentiation of stem cells: aplastic anemia.
7
Q
What are the features of hemolytic anemia?
A
- Increased rate of RBC destruction. 2. Increased rate of erythropoiesis. 3. Increased reticulocyte count. 4. Increased retention of body iron. 5. Extramedullary hematopoiesis may develop in the spleen liver and lymph nodes.
8
Q
What is the difference between intravascular and extravascular hemolysis?
A
Intravascular hemolysis occurs within vessels and is caused by trauma toxins or heat resulting in hemoglobinemia hemoglobinuria and hemosiderinuria. Extravascular hemolysis occurs within the cells of the reticuloendothelial (RE) system.
9
Q
What are the causes of hemolytic anemia?
A
- Disorders of RBC membrane cytoskeleton (e.g. spherocytosis). 2. Immune hemolytic anemia. 3. Traumatic hemolytic anemia. 4. Infections (e.g. malaria).
10
Q
What is hereditary spherocytosis (HS)?
A
HS is an inherited defect in the RBC membrane rendering the RBC spheroidal and vulnerable to splenic sequestration and destruction. It is an autosomal dominant trait.
11
Q
What is the pathogenesis of hereditary spherocytosis?
A
The abnormality lies in the protein forming the RBC membrane particularly spectrin which links to membrane proteins like ankyrin band 3 and band 4.1.
12
Q
What are the morphological features of hereditary spherocytosis?
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- Smear shows RBC lacking the central zone of pallor. 2. Reticulocytosis in peripheral blood. 3. Splenomegaly is moderate.
13
Q
What treatment options are available for hereditary spherocytosis?
A
Some patients may need blood transfusions. In HS patients benefit from splenectomy but there is an increased risk of infection especially in children.
14
Q
What characterizes sickle cell anemia?
A
Sickle cell anemia is an autosomal recessive disorder characterized by the presence of abnormal Hb (HbS) due to a mutation in the gene encoding the globin chain.
15
Q
What is the etiology of sickle cell anemia?
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On deoxygenation HbS molecules undergo polymerization causing RBCs to assume an elongated crescent or sickle shape.
16
Q
What are the clinical features of sickle cell anemia?
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- Hemolysis causing anemia. 2. Increased breakdown of Hb with bilirubin formation. 3. Capillary stasis leading to tissue ischemia and infarction.
17
Q
What is thalassemia?
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Thalassemia is a genetic disease characterized by decreased synthesis of alpha or beta globin chains. It is an autosomal codominant disease.
18
Q
What are the types of thalassemia?
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- Alpha thalassemia: globin chain is reduced or absent. 2. Beta thalassemia: globin chain is reduced.
19
Q
What laboratory findings are associated with iron deficiency anemia (IDA)?
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- Microcytic hypochromic anemia. 2. Low serum iron transferrin and ferritin levels. 3. Increased erythropoietin level.
20
Q
What are the causes of vitamin B12 deficiency anemia?
A
- Long-standing malabsorption (e.g. Crohn’s disease tropical sprue). 2. Gastrectomy. 3. Ileum resection. 4. Gastric atrophy (achlorhydria in old age). 5. Pernicious anemia.
21
Q
What are the clinical features of vitamin B12 deficiency anemia?
A
Pallor fatigability mild jaundice dyspnea congestive heart failure and neurological symptoms such as numbness tingling and loss of position sense.
22
Q
What is the diagnosis for pernicious anemia?
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- Low serum vitamin B12. 2. Serum antibody to intrinsic factor. 3. Moderate to severe megaloblastic anemia.
23
Q
What is glucose 6-phosphate dehydrogenase deficiency?
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G6PD is an enzyme in the hexose monophosphate shunt needed to produce reduced glutathione (GSH) which protects RBC from oxidative injury.
24
Q
What is Paroxysmal Nocturnal Hemoglobinuria (PNH)?
A
PNH is an acquired membrane defect secondary to mutation affecting myeloid stem cells resulting in hemolysis at night due to blood becoming acidic during sleep.
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What are the causes of extrinsic hemolytic anemia?
1. Immunohemolytic anemia. 2. Traumatic hemolytic anemia. 3. Infections like malaria.
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What is the morphology of megaloblastic anemias?
Hypercellular bone marrow with increased megaloblasts giant metamyelocytes hypersegmented neutrophils in peripheral blood and large egg-shaped macroovalocytes.
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What are granulocytes?
Granulocytes are a type of white blood cell characterized by the presence of granules in their cytoplasm.
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What is atrophic glossitis?
Atrophic glossitis is a condition characterized by inflammation and atrophy of the tongue.
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What response occurs in the body to Vitamin B12 deficiency within 2-3 days?
A dramatic reticulocytic response occurs in the body.
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What is aplastic anemia?
Aplastic anemia is a condition where multipotent myeloid stem cells are suppressed resulting in marrow failure and pancytopenia.
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What are the causes of aplastic anemia?
1. Idiopathic causes in 12% of cases. 2. Myelotoxic agents such as antineoplastic drugs alkylating agents antimetabolites benzene and chloramphenicol. 3. Community acquired viral hepatitis. 4. Inherited defects in telomerase.
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What role do auto reactive T cells play in aplastic anemia?
Vague auto reactive T cells play an important role as 80% of cases respond to immunosuppressive drugs aimed at T cells.
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What are the morphological features of aplastic anemia?
Hypocellular bone marrow with 90% of intertrabecular space occupied by fat with lymphocytes and plasma cells present.
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What secondary changes occur due to aplastic anemia?
1. Thrombocytopenia results in hemorrhage. 2. Granulocytopenia causes bacterial infection. 3. Anemia can cause fatty liver.
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What is the clinical course of aplastic anemia?
It can occur in all ages and both sexes with a gradual onset symptoms such as weakness pallor dyspnea petechiae and ecchymoses.
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What type of anemia does aplastic anemia resemble?
Normal bone marrow anemia.
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What is the typical reticulocyte count in aplastic anemia?
Reticulocytes are reduced.
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What is the treatment for aplastic anemia?
1. Withdrawal of toxic drugs can cause recovery in some cases. 2. Immunosuppressive drugs. 3. Bone marrow transplant is effective.
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What is myelophthisic anemia?
Myelophthisic anemia is a type of anemia caused by the replacement of marrow by tumors or other lesions.
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What are potential causes of myelophthisic anemia?
1. Metastatic breast prostate or lung cancer. 2. Tuberculosis. 3. Lipid storage disease. 4. Osteosclerosis.
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What is the blood film characteristic of myelophthisic anemia?
Blood film shows misshapen RBCs that resemble teardrops with immature granulocytic and erythrocytic precursors indicating leukoerythroblastosis.
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How is myelophthisic anemia treated?
By treating the underlying condition.
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What is anemia of chronic diseases?
Anemia of chronic diseases is common in hospitalized patients and is characterized by inflammation that induces sequestration of iron within mononuclear phagocytic cells.
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What role does hepcidin play in anemia of chronic diseases?
High hepcidin levels due to inflammatory cytokines inhibit ferroportin preventing iron from entering circulation.
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What blunts the compensatory increase in erythropoietin in anemia of chronic diseases?
Chronic inflammation blunts the compensatory increase in erythropoietin which is not adequate for the degree of anemia.
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What are some causes of anemia of chronic diseases?
1. Chronic microbial infections such as osteomyelitis and bacterial endocarditis. 2. Chronic immune disorders like rheumatoid arthritis. 3. Tumors such as Hodgkin lymphoma and lung carcinoma.
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How is anemia of chronic diseases diagnosed?
It is diagnosed as normocytic normochromic anemia or as iron deficiency anemia with low serum iron levels increased iron in bone marrow and high serum ferritin.
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What is the treatment for anemia of chronic diseases?
1. Erythropoietin and iron administration. 2. Treating the underlying condition is curative.
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What laboratory tests are used in the diagnosis of anemia?
1. Decrease in hemoglobin and hematocrit. 2. Normocytic normochromic. 3. Microcytic hypochromic. 4. Macrocytic. 5. Identification of abnormal Hb such as HbS using gel electrophoresis. 6. Coombs test for immunohemolytic anemia.
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What is polycythemia?
Polycythemia is an increase in red blood cells (RBCs) and hemoglobin (Hb) concentration.
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What are the two types of causes of polycythemia?
1. Relative hemoconcentration caused by a decrease in plasma volume (e.g. dehydration). 2. Absolute increase in RBC mass which can be primary (e.g. polycythemia vera) or secondary to erythropoietin release.
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What are causes of secondary erythropoietin release?
1. Appropriate release in conditions like lung or cyanotic heart disease. 2. Inappropriate release in conditions like renal cell carcinoma hepatocellular carcinoma or cerebellar hemangioblastoma.
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What is leukopenia?
Leukopenia is a decrease in white blood cells (WBCs).
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What is leukocytosis?
Leukocytosis is an increase in white blood cell count commonly due to microbial infection.
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What are the causes of neutrophilic leukocytosis?
Acute bacterial infections myocardial infarction and burns.
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What conditions can cause eosinophilic leukocytosis?
Asthma hay fever allergic skin diseases parasitic infestations or Hodgkin's lymphoma.
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What is lymphocytosis associated with?
Lymphocytosis is often associated with monocytosis hepatitis A cytomegalovirus or Epstein-Barr virus (EBV) infectious mononucleosis.
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What distinguishes Hodgkin lymphoma from Non-Hodgkin lymphoma?
Hodgkin lymphoma is distinguished by the presence of Reed-Sternberg (RS) cells fever and a stereotypical pattern of spread.
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What are the types of Hodgkin lymphoma?
1. Nodular sclerosis 2. Mixed cellularity 3. Lymphocyte depletion 4. Lymphocyte predominance.
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What is the prognosis for nodular sclerosis Hodgkin lymphoma?
Nodular sclerosis has an excellent prognosis.
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What characterizes mixed cellularity Hodgkin lymphoma?
It has an intermediate prognosis and is most common in older adults.
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What is Lymphocyte predominance in Hodgkin lymphoma associated with?
It is associated with an excellent prognosis.
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What are the clinical stages of Hodgkin lymphoma?
Stage I: Affects a single lymph node or a single extralymphatic organ. Stage II: Affects two or more lymph nodes on the same side of the diaphragm. Stage III: Affects lymph nodes on both sides of the diaphragm. Stage IV: Multiple involvement of one or more extralymphatic organs with or without lymphatic involvement.
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What is the clinical course of Hodgkin lymphoma?
Painless enlargement of lymph nodes with symptoms varying by stage. Patients in stage III or IV may complain of fever weight loss or anemia.
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How is Non-Hodgkin lymphoma classified?
Non-Hodgkin lymphoma is classified into three major prognostic groups: Low grade Intermediate grade and High grade.
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What is the most common form of B cell tumors in Non-Hodgkin lymphoma?
Follicular lymphoma.
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What are the key features of Burkitt lymphoma?
Burkitt lymphoma is endemic in Africa sporadic in the US affects children and young adults related to EBV and has a starry sky pattern in its morphology.
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What are the common causes of lymph node enlargement?
1. Acute lymphadenitis (e.g. tonsillitis). 2. Chronic non-specific lymphadenitis (e.g. chronic tonsillitis). 3. Chronic specific lymphadenitis (e.g. tuberculosis). 4. Metastasis from carcinoma.
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What is leukemia?
Leukemia arises from hematopoietic stem cells giving rise to monoclonal proliferation that replaces normal bone marrow cells and invades circulating blood or other organs.
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What are the causes of leukemia?
1. Excessive radiation 2. Viral infections 3. Genetic causes 4. Chemical exposures (e.g. aniline dyes).
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What are the classifications of leukemia?
1. Myeloid neoplasm 2. Lymphoid neoplasm 3. Plasma cell histiocytic leukemia 4. Monocytic leukemia.
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What differentiates acute leukemia from chronic leukemia?
Acute leukemia is characterized by a neoplastic proliferation of blasts while chronic leukemia shows proliferation of mature circulating lymphocytes or leukocytes.
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What is the significance of the Philadelphia chromosome in chronic myeloid leukemia (CML)?
The Philadelphia chromosome BCR-ABL fusion gene is a specific genetic abnormality that is often present in CML.
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What are common clinical features of leukemia?
1. Abrupt onset. 2. Symptoms of depression of bone marrow including fatigue and fever.
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What are the symptoms associated with leukemia in relation to bone and lymphatic system?
Bone pain tenderness from marrow expansion infiltration of subperiosteum. Generalized lymphadenopathy hepatosplenomegaly due to dissemination of leukemic cells more common in ALL.
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What are the CNS manifestations of leukemia?
CNS manifestations as headache vomiting and nerve palsy result from meningeal spread more common in ALL.
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What are the laboratory findings associated with leukemia?
Blast forms in peripheral blood WBC count is variable (more than 100000 cells in 50% of cases or less than 10000 cells) anemia neutropenia and platelet count less than 100000.
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What is Langerhans cell histiocytosis?
A rare tumor primarily affecting children less than 2 years old characterized by hepatosplenomegaly anemia thrombocytopenia and infections. Treated with intensive chemotherapy; approximately 50% of patients survive 5 years.
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What are the characteristics of normal hemostasis?
Normal hemostasis involves blood vessels platelets and the clotting cascade.
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What is the purpose of bleeding time tests?
Bleeding time measures the time taken from skin puncture to stop bleeding which ranges from 2-9 minutes.
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What is the normal range for platelet count?
The normal platelet count is between 150-450 x 10^3 cells/mm^3.
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What does prothrombin time (PT) assess?
PT assesses the adequacy of the extrinsic and common coagulation pathways.
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What does partial prothrombin time (PTT) assess?
PTT assesses the adequacy of the intrinsic and common clotting pathways.
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What are some causes of bleeding disorders?
1. Disseminated intravascular coagulation (DIC) 2. Thrombocytopenia or defect in platelet functions (e.g. aspirin ingestion von Willebrand disease) 3. Deficiency of blood clotting factors (e.g. hemophilias) 4. Increased fragility of vessels associated with vitamin C deficiency scurvy infections chronic glucocorticoid use.
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What is disseminated intravascular coagulation (DIC)?
A condition where sepsis tumors or trauma lead to the consumption of coagulation factors and platelets. In DIC endothelial injury releases tissue factor that exposes subendothelial collagen and von Willebrand factor to promote platelet aggregation and activate the intrinsic coagulation system leading to bleeding thrombosis or both.
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What is thrombocytopenia and its characteristics?
Thrombocytopenia is characterized by spontaneous bleeding prolonged bleeding time normal PT and PTT and a platelet count of 100000 cells/mm3. It results from decreased production or increased destruction and is one of the most common manifestations in AIDS.
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What is immune thrombocytopenic purpura?
A condition where autoantibodies against platelet antigens are triggered by drugs infections lymphoma or are idiopathic. The spleen produces such antibodies leading to destruction of Ig-coated platelets and the spleen is normal in size. Patients may benefit from splenectomy.
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What is heparin-induced thrombocytopenia?
A condition occurring in 5% of patients treated with heparin after 1-2 weeks caused by IgG antibodies that bind to platelets causing their activation which results in venous and arterial thrombosis.
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What is von Willebrand disease (vWD)?
An autosomal dominant disorder caused by mutations in von Willebrand factor (vWF) which acts as a bridging molecule between platelets and subendothelial collagen. vWF stabilizes factor VIII by binding to it leading to mild to moderate bleeding.
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What are the hereditary deficiencies for each coagulation factor?
1. Factor VIII deficiency - hemophilia A 2. Factor IX deficiency - hemophilia B.
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What are the characteristics of hemophilia A?
A X-linked disorder caused by mutation in factor VIII affecting males who experience bleeding in soft tissues and joints with prolonged PTT.
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What are the characteristics of hemophilia B?
A X-linked disorder caused by mutation in factor IX clinically identical to hemophilia A.
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What is splenomegaly?
Enlargement of the spleen secondary to systemic diseases.
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What are the types of splenomegaly based on weight?
1. Massive splenomegaly - more than 1000 gm 2. Moderate splenomegaly - 500-1000 gm 3. Mild splenomegaly - less than 500 gm.
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What conditions can cause massive splenomegaly?
1. Chronic myeloid leukemia 2. Lymphomas 3. Malaria 4. Gaucher disease.
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What conditions can cause moderate splenomegaly?
1. Portal hypertension 2. Hereditary spherocytosis 3. Thalassemia 4. Chronic lymphatic leukemia 5. Amyloidosis 6. Tuberculosis sarcoidosis 7. Metastatic carcinoma or sarcoma.
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What conditions can cause mild splenomegaly?
1. Acute splenitis 2. Acute splenic congestion 3. Infectious mononucleosis 4. Septicemia SLE.
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What is hypersplenism?
A condition where the spleen removes an excessive number of blood elements resulting in anemia leukopenia and thrombocytopenia.
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What are disorders of the thymus gland?
1. Thymic hyperplasia 2. Thymoma.
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What is thymic hyperplasia?
The appearance of lymphoid follicles that contain B cells within the thymus occurring in conditions such as myasthenia gravis SLE and rheumatoid arthritis. Treatment involves thymus removal.
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What is a thymoma?
Tumors of thymic epithelial cells classified into benign and malignant types.
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What are the two types of malignant thymoma?
1. Type I - cytologically benign biologically aggressive with rare distant spread. 2. Type II - cytologically and biologically malignant.
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What are the clinical features of thymoma?
Typically occurs in middle-aged adults and may be asymptomatic in 30% of cases; in 40% symptoms include cough dyspnea and SVC syndrome. Removal is the treatment.
