blood cell abnormality Flashcards
What is leukaemia
is essentially a bone marrow disease and overspill of the abnormal cells into the blood, producing white blood, is not essential for this diagnosis.
b) How is leukaemia classified?
myeloid or lymphoid
how does it differ from other cancers and why does that make it difficult to treat
cells circulate in the blood stream and migrate into tissues.difficult to apply the concepts of local invasion and metastasis that are used to describe solid tumours to populations of cells that are normally mobile.
why can’t you use the terms malignant and benign when describing luekaemia
malignant and benign that are used to describe solid tumours are not usually applied to leukaemias
what is acute l
if untreated, has profound pathological effects and leads to death in a matter of days, weeks or months
chronic leukaemia
is one that causes less impairment of function of normal tissues and, although it will eventually lead to death, this usually does not occur for a number of years.
why does leukaemia rise
mutations occurring in a primitive cell
growth or survival advantage over normal cells that have not undergone mutation
rise to a clone that steadily replaces normal cell
what are the three forms of mutations in germ cells
beneficial, neutral or harmful; beneficial germline mutations permit the species to evolve.
what can mutations in somatic cells lead to
leukaemia or other cancer
cause of mutation
mutagens or it may be a random, spontaneous process
The abnormal behaviour of the leukaemic clone can include growth that occurs without a dependence on growth factors, continued proliferation without maturation, and a failure to undergo normal cell death (apoptosis).
The abnormal behaviour of the leukaemic clone can include growth that occurs without a dependence on growth factors, continued proliferation without maturation, and a failure to undergo normal cell death (apoptosis).
causes of l
unknown mutagenic drug exposure to irradiation chemical utero
causes of acute
mutations in genes encoding transcription factors with a resultant profound abnormality in the cells ability to mature. However the cells continue to proliferate so that there is an accumulation of primitive cells referred to as blast cells
causes of c
chronic myeloid leukaemia the mutation involves activation of signalling pathways within the cell (in CML this results from the fusion protein BCR-ABL1 encoded by the t(9;22) Philadelphia chromosome). Cells can then proliferate without needing growth factors
however maturation still occurs and, in the case of myeloid cells, mature end cells are still able to function. The impairment of normal physiological processes is therefore much less than in the acute leukaemia
what do the signs and symptoms of leakiuma result from
direct and indirect
what are direct causes
The direct effects of the proliferation of the leukaemic cells, e.g. bone pain, enlarged liver (hepatomegaly), enlarged spleen (splenomegaly) and swollen lymph nodes (lymphadenopathy, mainly in lymphoid leukaemias)
what are indirect causes
The indirect effect of leukaemic cell proliferation, which leads to replacement of normal bone marrow cells by leukaemic cells (causing anaemia, thrombocytopenia, neutropenia).
clinical features
fatigue, lethargy, pallor (anaemia)
fever and infections (neutropenia)
bruising and petechiae (thrombocytopenia)
bone pain (bone marrow expansion)
abdominal enlargement (hepatomegaly, splenomegaly)
lumps and swellings (lymphadenopathy)
what are the essential investigations
full blood count and blood film
profile of the cell surface markers expressed (e.g. to distinguish T and B lymphoid cells); we do this using a technique called flow cytometry.
look for markers such as the Philadelphia chromosome (9;22)
what is a major sign of cll
a ‘smear’ or ‘smudge’ cell: characteristic of CLL
what is aneamia
Anaemia is a reduction in the haemoglobin concentration (Hb) in the circulating blood below what is normal for a healthy person of the same age and gender as the individual.
what is associate with aneamia (lab tests)
with a reduction in the red blood cell count (RBC) and the haematocrit (Hct) (previously referred to as packed cell volume (PCV))
what 4 can result in anaemia
Reduced production of red cells by the bone marrow
Loss of blood from the body
Reduced survival of red cells in the circulation (haemolysis)
Increased pooling of red cells in an enlarged spleen
causes of microcytosis
Iron deficiency anaemia
Anaemia of chronic disease
Thalassaemia
reduced synthesis of haemoglobin. This can be caused by reduced synthesis of haem (iron deficiency or anaemia of chronic disease) or reduced synthesis of globin (thalassaemia).
symptoms of iron defiency
pallor fatihue breathlessness
what is anaemia of chronic disease
reduced synthesis of haemoglobin. This can be caused by reduced synthesis of haem (iron deficiency or anaemia of chronic disease) or reduced synthesis of globin (thalassaemia).
what affect can cytokines and il have
cytokines such as TNF alpha and interleukins in chronic disease lead to a decrease in erythropoietin production and also prevent the normal flow of iron from the duodenum to the red blood cells
Laboratory clues of anaemia of chronic disease
C-reactive protein is high (unlike iron deficiency)
Erythrocyte sedimentation rate (ESR) is high (unlike iron deficiency)
Ferritin is high
Transferrin is low
Acute phase proteins increase
difference between iron defiency or acd
ferritin is low in id but high in acd
transferrin is high in id but low in acd
what does macrocytes result from
abnormal heamopoiesis
red cell precursors sythesis hb but can’t divide so larger
how does magloblastic anaemia cause macrocytosis
delay in maturation of the nuclues
while cytoplasm continues to mature
cell grows
magloblast seen in bone marrow not blood film
what is a magloblast
abnormal bone marrow erythroblast
What is the mechanism of normocytic a
loss of blood
failure of production of rbc
pooling of rbc in spleen
what does an increase in reticlucytes mean
An increased reticulocyte count is seen as a response to haemolytic anaemia and recent blood loss and also as a response to treatment with iron, vitamin B12 or folic acid
what does A reduced reticulocyte mean
count is seen when there is reduced output of red cells from the bone marrow.
how to treat id
Iron replacement therapy such as ferrous sulphate tablets can be given. Although the anaemia will improve with iron replacement, it is very important to ascertain the cause of the anaemia.
