Immunity and Diseases Scientific background to autoimmune diseases

1
Immunity and DiseasesScientific background to
autoimmune diseases
Dr Michael F. Ofori Noguchi Memorial Institute
for Medical Research College of Health
Sciences University of Ghana
2

• 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,

3
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

4
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

5
WHY THIS?

• The results of the failure of the hosts 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.

6
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

7
Examples
8

• Organ specific Autoimmune Diseases
• Hashimotos Thyroiditis
• Frequently seen in middle aged women
• Xterised 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

9
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 101
• Xterised by fever, weakness, arthritis, skin
  rashes and kidney desfunction
• It is more common in African American and
  Hisponic women than Caucasians
• Reasons?

10

• 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

11
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,

12
Why are women more susceptible than men to
Autoimmunity?
13
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

14
Major research Areas

• Causes of Autoimmune Diseases
• The Burden of Autoimmune Diseases
• Diagnosis, Treatment and Prevention
• Training, Education and Information

15
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.
• Its thought that chemical degradation in the
  liver causes a loss of immune tolerance that
  predisposes Individuals to autoimmune diseases.

16
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 25299-302

17
Other studies

• SLE is most prevalent in women of African Origin
  This has been demonstrated in a number of
  studies

• McCarthy et al 1995
• Symmons,1995,
• Houcgberg,1985,
• Siegel et al 1970

18
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

19
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

20
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 Crohns disease
• Treatment of human autoimmune diseases poses
  special challenges

21
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

22
THANK YOU FOR YOUR ATTENTION!!