Introduction to hematology and normal hemopoiesis Flashcards
Define polycythaemia:
too many red cells
Define leukemia:
excess of white cells in the blood
Define lymphoma:
accumulation of malignant cells in lymph nodes
Define neutropenia:
leads to susceptibility to infection
Define lymphopenia:
immunodeficiency - effect depends on specific type of lymphocyte affected
What are some different clotting disorders?
inherited disorders of poor clotting = hemophilia
acquired disorders of poor clotting = DIC (disseminated intravascular coagulation), aspirin
Increased tendency to clot
- inherited thrombophilia
- acquired disorders - stasis, endothelial damage
What are the normal Hb ranges (g/dl) for cord blood, newborn, children (6m-6 years, 6-14 years), males, females and pregnant females?
cord blood = 13.5-20.5 Newborn = 15 - 23.5 Children (6m-6 years) = 11 -14.5 Children 6-14 years) = 12 -15.5 males = 13-17 females = 12-15.5 pregnant females = 11-14= lower due to consumption of Fe2+ by fetus
What is anaemia and how is it classified?
reduced hemoglobin for age and sex
Classified:
- microcytic = iron deficiency, thalassemia
- normocytic = bone marrow failure, aplastic anaemia, chronic disorders, renal disease
- macrocytic = vitamin B12 or folate deficiency
What is the commonest cause of anaemia worldwide and what are the causes of it?
iron deficiency (hypo chromic, microcytic RBCs (low color)) causes: - chronic blood loss = menstruation, GI blood loss - poor diet = mainly in children (developing world) - malabsorption = a minor cause (often also don't absorb folic acid
What are the treatments for iron deficiency anaemia?
1) treat underlying cause where needed
2) iron tablets (ferrous sulphate 200mg/day)
What are haemoglobinopathies?
inherited disorders of hemoglobin structure
- thalassemia, sickle cell disease
What are the causes of hemolytic anaemia?
inherited: membrane, enzyme or hemoglobin
acquired: immune or non-immune = more common in UK
What is aplastic anaemia?
rare syndrome characterized by loss of haemopoiesis in the marrow
- causes: idiopathic, post-viral, drugs, radiation
- treatment: immunosuppression, bone marrow transplant
Define pancytopenia:
low rbcs, platelets and WBCs in bone marrow
What are the large red blood cells known in macrocytic anaemia?
vitamin B12 deficiency and folate deficiency are associated with very large erythroblasts in the bone marrow = megaloblastic anaemia
What is folate important for and what can a deficiency in it lead to?
important for DNA synthesis = can lead to CNS problems - subacute degeneration of spinal cord
cause spina bifida in newborns
What are neutrophils characteristically like in vitamin b12 deficiency?
neutrophils have too many segments = hypersegmented
What is the blood count and function of neutrophils?
2 x 10^9 L - Protection against bacteria
What is the blood count and function of eosinophils?
0.4 x 10^9L - Protection against parasites
What is the blood count and function of basophils?
0.2 x 10^9 L - Unknown
What is the blood count and function of lymphocytes?
4 x 10^9L - Cellular immunity
What is the blood count and function of monocytes ?
0.2 x 10^9L - Phagocytosis
What are the characteristics of acute leukemia?
due to rapidly dividing primitive (blast) cells
packs the bone marrow and leads to anaemia, infection and bleeding
is fatal within weeks or months if untreated
can often be cured by chemotherapy
What are the characteristics of chronic leukemia?
less rapidly growing - less aggressive than acute
consists of recognizable cells types e.g. neutrophils or lymphocytes
is harder to cure by chemotherapy
Other than acute and chronic how else can leukemia’s been classified?
lymphoid - tumor of B or T lymphocytes
Myeloid - affects cells of all other lineage e.g. neutrophils, red cell, monocytes, or platelets
What are lymphomas and how can they be classified?
tumors of cells that accumulate in lymph nodes
presents as lymphadenopathy
divided into:
- hodgkins lymphoma
-non-hodgkins lymphoma - many different variants
What defines hodgkins lymphoma?
reed-sternberg cells = large with abundant pale cytoplasm and 2 oval lobulated nuclei prominent “owl eye” eosinophilic nucleoli
- only 5-10% of the “owl eyes” are malignant
What is myeloma?
malignancy of plasma cells that produce monoclonal immunoglobin called paraprotein
- presents with renal failure, bone pain and anaemia (commonest characteristic)
- incurable
What are myeloproliferative disorders?
clonal proliferations of stem cells which lead to a hyper cellular bone marrow with increased:
- red cells = polycythaemia
- platelets = essential thrombocythaemia
- white cells = chronic myeloid leukemia
- reactive fibrosis = myelofibrosis
What does effective blood clotting depend on?
interaction between endothelium, platelets and coagulation factors
What are the different patterns of bleeding?
vascular or platelet abnormalities tend to lead to mucosal or skin bleeding
- purpura or bruising
- oral or gastrointestinal bruising
Coagulation disorders tend to lead to bleeding into joints and muscles
What is thrombosis?
tendency to increased thrombosis can be inherited or acquired
- inherited: factor V, antithrombin, protein C or protein S abnormalities
- acquired: vessel damage, stasis, change in blood composition = virchows triad
What are the different types of cells that can be replaced in a blood transfusion and what are the major issues associated with it?
replacement of:
- red cells
- platelets
- coagulation factors
- white cells - difficult
Major issues
- indications
- safety of products
How can bone marrow be examined?
aspirate = involves removal of liquid marrow prior to examination on a slide
- inser needle through the posterior superior iliac crest
trephine = a solid histology section which allows study of marrow cellularity
When is a trephine biopsy particularly used?
in lymphoma
