Chronic Myeloid Leukemia (CML) Pathogenesis, Symptoms and Treatment
Hey everyone and this is one type of chronic myeloid leukemia
or CML and this is where we're going to talk about how we can distinguish this
type of leukemia from other types of leukemia we're also going to talk about
the pathogenesis of ,CML involving the Philadelphia chromosome. and we're also
going to talk about the signs and symptoms and treatment of CML so chronic
myeloid leukemia is one type of leukemia and its name allows us to distinguish
it from other types of leukemia.
it is a Milo proliferative disorder that presents with
increased granular acidic cell line proliferation granular acidic cells are
neutral folds and that's where the term Milo it actually comes from. And these
cells still have the ability to differentiate so they can be differentiated
mature neutral films that's where the term chronic comes from.
And if we were to take a look at a peripheral blood film we
can see a lot of mature white blood cells a lot of mature neutral films and we
can tell that they're mature because. their nucleus is large in proportion to
,their so that's what chronic myeloid
leukemia is high levels of mature neutrals so a quick approach to determining
the type of leukemia again if we see increased white blood cells often very
high.
And they're mature white blood cells that means it's a
chronic leukemia and it's pmns or neutral cells that mean it's Milo so it's CML
that is a ,quick ,approach to determining. that leukemia is actually a chronic
mile away leukemia. so the epidemiology of CML generally can occur any age but
most commonly occurs in middle age to older adults and generally. ages between
sixteen sixty five years so the path of physiology of CML has to do with what
we call the Philadelphia chromosome.
In the Philadelphia chromosome is the product of chromosome
nine and chromosome twenty two translocation so what happens is that. On
chromosome nine we have a proto oncogene known as c able or just able and this
piece of chromosome nine ,can ,be popped off.
And can be swapped for a piece on chromosome twenty two so a
translocation and what can happen is the piece here ,from chromosome nine can be.
put onto chromosome with the gene able right next to the gene bcr. so after the
chromosome swap pieces with each other can lead to a change chromosome twenty
two what we call a Philadelphia chromosome with the genes bcr and able ,next to
each other.
and this leads to the formation of a fusion gene known as bcr
able which can produce a new protein ,also ,called ,bcr ,able .and. the problem
with this protein is that it is an act of tires and kindness there is no
regulation on this protein and that's not what we want we want to have proper
regulation. and what happens is because this is continuously active this
protein can actually activate.
jack staff pathways and ras raf mek erk pathways both of
which lead to increase in cell survival and proliferation not what we want. so
that's the path of physiology of cml. so CML presents in about three different
clinical phases the first one is what we call chronic phase and chronic phase
is where majority of individuals are diagnosed and it's ,around ,eighty ,eighty
,five percent.
And this is when they present with less than ten percent of
glass cells. they may have slightly increased e. o.c. inoculates and basil
fills at this stage but generally ,the ,stage ,is ,often ,asymptomatic. the
next phase is accelerated phase and this is one. neutrophil differentiation
becomes impaired remember I said that neutrophil still had the ability to
differentiate while in this phase that differentiation ,ability ,starts ,to
,become impaired. and this is when we have about ten to nineteen percent of
circulating blood cells.
And we also see it increase in basic files at this time. the
increase in basic fill count can actually lead to a pure r. ,it is ,so itching.
And we also start to see throne beside opinion at this time because some of the
cells in bone marrow begin to crowd out other cells and generally we start to
see constitutional symptoms in splendor legally in this. phase as well. and the
splendor megalith is caused by an increase in extraordinary humidor policies what
that means is that.
because the bone marrow starts to become crowded out by white
blood cells. other parts of the body have to kind of make up for it in order to
keep producing enough red blood cells so the spleen starts to produce red blood
cells. um as an extraordinary process. the third phase is what we call a blast
crisis. this is when there are greater than twenty percent of blood cells. and
blast sells themselves again failed a different sheet. and oftentimes this is
when CML can convert to another type of leukemia oftentimes it's acute mileage
leukemia so.
um less often a l l. so what are the signs and symptoms of CML
again most individuals ,at ,diagnosis ,are ,asymptomatic. phase but when they
become symptomatic there are a few main symptoms and signs I want you to remember.
splendor r Maggie is one of the biggest ones and splendor Maggie
is the enlargement of spleen this is the most common physical ,finding ,in ,c m
l. and it presents with early society so they get full a little quicker than
they used to so you can imagine if you're having an increased spleen it starts
to push up against your stomach. and you can't eat as much that's why you get
early satiety.
and you also can get left upper quadrant pain simply because
of the enlarging of the tissue another common finding which is actually several
,symptoms are the constitutional symptoms. and in CML they're often mild these can include fatigue Malays
fever weight loss excessive sweating so they just generally don't feel well.
that ,is ,not right. and another sign that's interesting with
CML is tenderness over the lower sternum and this is ,because ,of expanding
bone marrow. symptoms that aren't as specific for CML include anemia simply
because the bone mirrors being crowded out there can be bleeding due to thermal
cylinder there can be pure ,righteous ,due to increased. Uh basal fills. there
can be lugo stasis and there can be pre episode in males for investigations and
diagnosis of cml.
again we look at a c b c we have high white blood cell count
we have high basil cell count and we often can have decrease in red blood cells
or ,the ,anemic ,and ,their thermodynamic. on preferable film like that we
talked before. the preferable film is used to determine if it's mature or
immature white blood cells and in this case its mature white blood cells.
And a bone marrow biopsy is used to determine the percentage
of blast cells so we can categorize what phase they're in. and for diagnosis
the diagnosis is quite simple for c.m.l. it's .just. having evidence of bcr
able fusion product or Philadelphia chromosome they can use mutual fluorescence
and ,other ,tests to determine. this if there is a bcr able fusion product
treatment. is with a madam ib and the madam ib is targeting that tire zine
kindness so it's a tyrosine kinase inhibitor and this is kind of easy for.
remembering because CML is always a magnetic so we always use
a magnetic retreat. there are second generation inhibitors of bcr able or
second generation tkis or tires inhibitors due to drug resistance to.
these include the satin hib and milo to nib so what happens
generally is a patient gets ,treated with a maddening. and what happens is the
cancer can mutate. and can actually mutate resistance to imaginative so that
bcr able protein can actually mutate to .avoid. uh inhibition by a maddening so
this is why we can move on to using some of these other second generation
inhibitors. and just to quickly talk about prognosis.
to determine prognosis for patients with CML we can use a
couple different scores we can use a so-called prognostic score which looks at
spleen size percentage blasts age. platelet count and a kind of a newer score
that's been used to determine the efficacy and prognosis with imaginative
treatment is the Utah score. a bit simpler because it only looks at a couple of
different things again screen size and percentage base of fills ,so ,these both
can.
give you prognostic scores there are online calculators for these to help you with a prognosis for patients with cml. Come and learn to read these valuable things often.