Transcript What is CD4 counts?

Ms FBC
50 year old
Diabetes mellitus
HIV – treated with Zidovudine many years
Chronic renal failure (due to HIV)
Haemodialysis 3 times a week
Full blood count
Test
Result
Reference range
WCC
4 x 109
4.8 – 10.9 x 109 /L
RCC
3.10 x 1012
4.2 – 5.4 x 1012 /L
Hb
92
120 – 160 g/L
Hct
27.6
37 – 47 %
MCV
91.7
82 – 98 fL
MCH
30.6
27 – 33 pg/cell
MCHC
33.3
31 – 35 g/dL
RDW
15.4
11 – 16 %
Platelets
199 x 109
140 – 440 x 109 /L
Segs (poly morphonuclear neutrophils)
53
45 – 73 %
Bands (immature neutrophils)
9
3–5%
Monocytes
8
2–8%
Atypical lymphocytes
2
0–6
Lymphocytes
15
20 – 40 %
Eosinophils
13
0–4%
CD4 lymphocytes
550
440 – 1600 cells/mm3
Creatinine
0.24
0.04 – 0.11 mmol/L
Urea
3.0
3 – 10 mmol/L
Explain the haematological parameters
which are consistent with the patient’s HIV.
Progressive cytopenias (anemia,
thrombocytopenia, leukopenia) commonly
occur in HIV-infected patients
The pathophysiologic mechanisms are
multifactorial and include direct effects of
HIV on haemapoetic precursor cells,
alterations in the microenvironment of the
bone marrow, and immulogic destruction
of peripheral blood cells.
Explain the haematological parameters
which are consistent with the patient’s HIV.
Anaemia is common in HIV
Intrinsic factor production is inadequate
leading to  absorbance of vitamin B12 &
folic acid
Chronic infection with human parvovirus
B19 reduces RBC precursors in the
presence of already impaired
erythropoiesis secondary to HIV infection
Results in  Hb and low red blood cell
Explain the haematological parameters
which are consistent with the patient’s HIV.
Patients with HIV infection may have
severe neutropenia and pancytopenia.
Direct damage on haemopoietic precursor
cells, which is consistent with the patients
low neutrophil count.
Also anti-HIV drugs have additive effect on
neutropenia as they cause bone marrow
suppression (known as “additive toxicity”).
Explain the haematological parameters
which are consistent with the patient’s HIV.
Other parameters includes
# Reduced platelet count.
# Prolonged prothrombin time.
*Due to stimulated macrophages releasing
large amounts of plasminogen activator.
In this patient platelets count were within range.
this may be due to the use of Ziduvodine
Zidovudine known as AZT _ prevent HIV
fragments and antibodies from binding to
platelets and marking them for destruction.
Explain the haematological parameters
which are consistent with the patient’s HIV.
Drugs used for HIV (e.g. acyclovir, AZT,
ganciclovir) also cause myelosupression
to a greater extent.
Opportunistic infections and malignancies
in HIV potentiates myelosupression
Lymphocytopenia and Reactive
lymphocytosis seen in this patient is
caused by HIV specifically.
Explain the haematological parameters
which are consistent with the patient’s HIV.
HIV infects CD4 T-cells, causes  CD4 T-cells
numbers
not seen in this patient as the count are within
the normal range), dramatic decreases only
occur in untreated HIV cases. When the count
fall below 200cells/mm3 they are said to have
AIDS.
Patients infected with HIV have increased
eosinophil and basophil levels (will be explained
later by Tuan).
Haematological Parameters Which Are Consistent
With Chronic Renal Failure in Ms FBC
RCC
3,01 x 1012
4.2 – 5.4 x 1012/L
Hb
Hct or PCV
MCV
MCH
92
27.6
91.7
30.6
120 – 160 g/L
37 – 47%
82 – 98 fL
27 – 33 pg/cell
MCHC
RDW
Creatinine
33.3
15.4
0.24
31 – 35 g/dL
11 – 16%
0.04 – 0.11mmol/L
Urea
3,0
3 – 10 mmol/L
Chronic Renal Failure
Firstly, there is a defining parameter of renal
failure which is an elevation of serum creatinine
levels. This reflects the decrease in kidney
function and thus GFR.
Secondly, the patient is displaying anaemia with
a reduction in red cell counts, haemoglobin and
haematocrit.
Finally, the red blood cell indices which indicate
what type of anaemia are within range (MCV,
MCH, MCHC and RDW). This indicates that this
patient is experiencing normocytic,
normochromic anaemia.
Allow me to explain…
Normocytic, normochromic anaemia has a
few possible causes:
acute blood loss
excessive haemolysis
anaemia of a chronic disease
What’s happening in this patient?
In this patient the anaemia could have been caused by
acute blood loss or excessive haemolysis. However, it is
more likely that the anaemia is due to the chronic renal
failure due to a history of diabetes mellitus. The hormone
required to produce red blood cells erythropoietin (EPO)
is mainly produced by the kidney. With a reduction in
functional kidney mass, the amount of EPO produced
each day is reduced leading to normocytic,
normochromic anaemia. Another possibility is that the
patient is deficient of iron, folate and vitamin B12 to the
extent where the RBC indices balance up to appear
normocytic and normochromic.
The patient has mild eosinohilia – what
could this parameter reflect?
Eosinophil
Granular leukocyte (type of white blood cell)
Phagocytic but less effective than neutrophils
The primary stimuli for eosinophil production are
interleukin IL-5, IL-3, and the granulocytemacrophage colony-stimulating factor (GM-CSF)
Manufactured in the bone marrow
transferred into the bloodstream and the gut lining
Produced by immune system to combat parasitic
organisms
once the parasite has been removed, the level of
eosinophils in the bloodstream is allowed to return to
normal
Eosinophilia
Condition that cause abnormally high
levels of eosinophils to develop in either
the blood or body tissues
Body keep producing eosinophils at a high
rate
 Accumulate in the blood and tissues
 Build-up of eosinophils ultimately leads to body
damage.
Mild
Moderate
Severe
0.7 – 1.5 x 109 cells/L
1.5 – 5 x 109 cells/L
> 5 x 109 cells/L
Causes of eosinophilia
There are many causes of increased eosinophil
production by the body
Connective tissue diseases
Helminthic infections
Parasitic worm
Idiopathic hypereosinophilic syndrome
Neoplasia
Tumor – new and abnormal growth
Lymphocytic leukemia
Allergies
Asthma
Allergic rhinitis
Food
Medications (drug reaction)
Dialysis and recent blood transfusion
Eosinophilia and Ms FBC’s
condition
High eosinophils level
HIV
Cutaneous manifestations
 Frequently occur in patients who are infected with
HIV
 Due to the alterations in the immune system
 Initial signs of virus-related immunosuppression
Eosinophilia and Ms FBC’s
condition
High eosinophils level
Zidovudine
Develop opportunistic infections and other
complications of HIV infection
Anaemia
In severe cases require blood transfusion
Myalgia
 Eosinophilia-Myalgia Syndrome
Eosinophilia and Ms FBC’s
condition
High eosinophils level
Dialysis
Allergic symptoms occur immediately after
initiation of dialysis
Possibly due to inadequate rinsing of the
dialyser
Eosinophilia and Ms FBC’s
condition
High eosinophils level
Diabetes mellitus
Uncontrolled blood glucose level
 Increase risk of skin ulceration and infection
Treatment of eosinophilia
There are no direct treatment for
eosinophilia
Treat the underlying caused of
eosinophylia
Once the caused have been removed, the
level of eosinophils in the bloodstream is
allowed to return to normal
HIV pharmacotherapy is likely to be based
on which parameter?
HIV pharmacotherapy is mainly based on CD4
count.
However Viral Load also plays an important
role in HIV pharmacotherapy. It helps to
decide whether to start anti-HIV treatment.
These two tests are crucial in helping to decide
when to start treatment, and to monitor the
effects of the treatment.
What is CD4 counts?
CD4 cells, or T-helper cells, are white blood cells which
organise the immune system’s response to some
imcroorganisms, including bacteria, fungal infections and
viruses.
The CD4 count is the measurement of the number of CD4
cells, in a cubic millimeter of blood. Ie CD4 cells/mm3.
The CD4 count of a person who is not infected with HIV
may lie anywhere between 500 and 1200.
However The Human Immunodeficiency Virus (HIV) can
infect and replicate within cells of CD4 and use them to
produce more HIV copies, resulting in destruction of CD4
cells.
What CD4 counts predict
A CD4 count between 500 and 200 indicates that some
damage to the immune system has occurred.
If CD4 count drops below 350, or start falling rapidly, antiHIV treatment should be discussed whether or not to start.
If CD4 count falls below 250-200 anti-HIV drugs treatment
are recommended to start. This is because it is the level at
which the risk of AIDS-related illness is greatly increased.
It is recommended that people start treatment before their CD4
count falls below 200, as people who start treatment with a
CD4 count below 200 face a greater risk of death, in the shortterm than those who start before their CD4 count drops below
this level.
Factors that can alter in the CD4 count
CD4 count can go up and down in response to
infections, stress, smoking, exercise, the menstrual
cycle, the contraceptive pill, the time of day and even
the seasons of the year.
Different types of CD4 counting-machine also give
different readings.
What is the viral load test?
Viral load is the term used to describe the amount of HIV in
blood. The more HIV in blood, the faster CD4 cells are likely
to disappear, and the greater risk of developing symptoms or
further illness within the next few years.
Viral load tests estimate the number of HIV particles in the
liquid, or plasma part of the blood. The result of a viral load
test is described as the number of copies of HIV RNA/mm.
Viral load should ideally only be measured when the person is
well. If there is an infection or have recently had a vaccination,
the viral load could temporarily increase.
What information can Viral Load provide in
relation to HIV pharmacotherapy?
In combination with CD4 count, Viral Load can
provide information on the likely course of HIV
infection and may help to predict risk of developing
symptoms in the future.
Among people with the same CD4 count, those with
higher Viral Load tend to develop symptoms more
quickly than those with lower viral load.
Among people with the same Viral Load, those with
lower CD4 counts tend to develop symptoms more
quickly.
Relationship between CD4 and Viral Load
% of people who develop AIDS
within 3 years (assuming no
treatment)
A high viral load, regardless of
CD4 cell count, increases risk of
AIDS-related illness.
** indicates lack of data
Viral CD4
Load
CD4 CD4 CD4 CD4
Below
200
201350
351500
501750
Above
750
Below
1,500
**
**
**
3.7
0
1,5007,000
**
**
2.0
2.0
2.0
7,00020,000
**
8.1
8.1
8.1
3.2
20,000
55,000
40.1
40.1
16.1
16.1
9.5
Above
55,000
85.5
64.4
42.9
32.6
32.6