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Immunity and Diseases
Scientific background to autoimmune
diseases
Dr Michael F. Ofori
Noguchi Memorial Institute for Medical Research
College of Health Sciences
University of Ghana
Autoimmune diseases result when the
immune system attacks the body's own
organs, tissues and cells.
Physicians and scientists have identified a
number of different autoimmune diseases.
Some are well known,
Others are less familiar,
Tolerance and Autoimmunity
The Immune system could go awry and
instead of reacting only against foreign
antigens, could focus its attack on SELF
ANTIGENS
This can result in a number of chronic and
acute diseases including
Rheumatoid Arthritis
Multiple screlosis
Lupus Erythematosis
Certain types of Diabetes
Types Of Autoimmune diseases
Physicians and scientists have identified
more than 80 different autoimmune
diseases.
Some are well known,
rheumatoid arthritis,
multiple sclerosis,
type 1 diabetes
systemic lupus;
others are less familiar,
autoimmune hepatitis,
 Sjögren's syndrome
 pemphigus
WHY THIS?
The results of the failure of the host’s
humoral and cellular immune system to
distinguish SELF from NON-SELF
This will result in the attack of self cells and
organs by Auto-antibodies and self reactive
T-cells.
WHAT IS AUTOIMMUNITY?
This is referred to the inappropriate
response of the immune system against
self components .
Autoimmune reactions can cause
serious damage to cells and organs
Examples
Organ specific Autoimmune Diseases
Hashimoto’s Thyroiditis
Frequently seen in middle aged women
X’terised by infiltration of thyroid gland by
lymphocytes, macrophages and plasma cells
The ensuing inflammatory response causes GOITER
or visible enlargement of thyroid gland – a
physiological response to hypothyroidism (decreased
production of thyroid hormones
Hypothyroidism is caused when Abs are
formed to a number of thyroid proteins
including thyroglobulin and thyroid
peroxidase – both involved in iodine uptake
Autoimmune hemolytic anaemia
Systemic Autoimmune Diseases
Here the response is directed towards a broad
range of targets and antigens and also
involve a number of organs and tissues
Systemic Lupus erythematosus (SLE)
Appears in women b/n 20 and 40 years of age
Ratio of females to males is 10:1
X’terised by fever, weakness, arthritis, skin rashes
and kidney desfunction
It is more common in African American and Hisponic
women than Caucasians
Reasons?
Multiple sclerosis
Attacks the CNS and causes neurological disabilities
IT could be mild such as numbness in limbs or severe
such as paralysis or loss of vision
Genetic influence is important here
Risk is higher in women than men 2 - 3X higher
Rhematoid arthritis
Attacks the joints
Most often common in women b/n the ages of 40 – 60
Main effect being the inflammation of the joints
But can also cause hemolytic, cardiavascular and
respiratory systems
Economic Importance
The social and financial burdens imposed
by these chronic, debilitating diseases
include:
poor quality of life,
high health care costs
substantial loss of productivity
In addition, the majority of autoimmune
diseases disproportionately affect women,
Why are women more
susceptible than men to
Autoimmunity?
Reasons put forward so far includes;
Differences in Antibody production
 Females produces more Ab than males
 They also mount more vigorous immune response
than males
Sex hormones also play important role
 Studies have shown that estrogen can stimulate auto-antibody
production
 Demonstrated in SLE-prone mice
 Testosterone seems to be protective against several types of
autoimmune diseases, eg.SLE, diabetes,MS etc
Ability of pregnant women to modify their
immune system during pregnancy to keep the
fetus
The presence of fetal cell in maternal circulation
for decades – this can also lead to the
development of autoimmune diseases
Major research Areas
Causes of Autoimmune Diseases
The Burden of Autoimmune Diseases
Diagnosis, Treatment and Prevention
Training, Education and Information
POSSIBLE CAUSES Of Autoimmune diseases
Genetic, Environment, Infections etc
Recent reports have shown a marked association
between 2-nonynoic acid, a cosmetic ingredient
and primary biliary cirrhosis (PBC), a disease 9
times more likely to occur in women.
Other suspected triggers of Autoimmune
diseases include
 smoking,
 bacterial & retroviral proteins,
 hormone replacement therapy,
 use of nail polish.
 It’s thought that chemical degradation in the liver
causes a loss of immune tolerance that
predisposes Individuals to autoimmune diseases.
Research In Ghana
 Study Conducted between 1983 and 1989 - 6yrs Period.
 Korle Bu Teaching Hospital
 They recorded 23 cases of Connective tissue disease
during the period out of 4,507 admissions
 Age ranged from 26 – 63 yrs (mean = 44yrs)
 16 (70%) were females
 11 had SLE
 8 had R.A
 SLE 2.4 per thousand
 RA. 1.8 per thousand
 They then concluded that SLE and RA are NOT COMMON
Affram RK and Neequaye AR, (1991). Systemic Lupus
erythematosus and Other Rheumatic Disorders: Clinical
Experience in Accra:, Ghana Medical Journal Vol 25:299-302
Other studies
SLE is most prevalent in women of
African Origin – This has been
demonstrated in a number of
studies
1.
2.
3.
4.
McCarthy et al 1995
Symmons,1995,
Houcgberg,1985,
Siegel et al 1970
SLE IN AFRICANS
Population studies unavailable up to date
Most studies done are on case reports or
series of reports of hospitalized patients.
Some of the countries in which these
studies has taken place include:
South Africa, Zimbabwe, Ghana, Nigeria,
Guinea, Cote D’ voire, Gabon, DR Congo,
Senegal
From all these published reports, SLE
appears to be RARE in Africa
SLE IN AFRICANS Cont’
Recent Studies from South and Central
African suggest SLE to be increased in
these regions whilst that in West African
remain to be RARE
This can be explained by the reporting
BIAS
Treatment of Auto-immune Diseases
Current therapies include
Treatment with immunosuppressive drugs
Thymectomy and plasmapherisis for
diseases involving immune complexes
TNF alpha Blockers
For controlling RA and Crohn’s disease
Treatment of human autoimmune
diseases poses special challenges
Challenges
Use of Immunosuppressive drugs does not leave
the other immune system Intact
Immuno suppressive drugs such as:
Corticosteriods,
Azathioprine
Crclophosphamide
are capable of depressing the immune response
but also puts the patient at a greater risk of
infection and development of cancers
Most current Therapies are not for cure but only
reduces symptoms
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