Immunity and DiseasesScientific background to autoimmune

diseases

Immunity and DiseasesScientific background to autoimmune

diseases

Dr Michael F. OforiNoguchi Memorial Institute for Medical Research

College of Health SciencesUniversity of Ghana

Dr Michael F. OforiNoguchi Memorial Institute for Medical Research

College of Health SciencesUniversity 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 AutoimmunityThe 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 includingRheumatoid ArthritisMultiple screlosisLupus ErythematosisCertain types of Diabetes

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

Types Of Autoimmune diseases Types Of Autoimmune diseases

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.

WHY THIS?WHY THIS?

This is referred to the inappropriate response of the immune system against self components .

Autoimmune reactions can cause serious damage to cells and organs

WHAT IS AUTOIMMUNITY?WHAT IS AUTOIMMUNITY?

Examples

Organ specific Autoimmune DiseasesHashimoto’s Thyroiditis

Frequently seen in middle aged womenX’terised by infiltration of thyroid gland by

lymphocytes, macrophages and plasma cellsThe 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 DiseasesHere the response is directed towards a broad

range of targets and antigens and also involve a number of organs and tissuesSystemic Lupus erythematosus (SLE)

Appears in women b/n 20 and 40 years of ageRatio of females to males is 10:1X’terised by fever, weakness, arthritis, skin rashes

and kidney desfunctionIt is more common in African American and Hisponic

women than CaucasiansReasons?

Multiple sclerosisAttacks the CNS and causes neurological disabilitiesIT could be mild such as numbness in limbs or severe

such as paralysis or loss of visionGenetic influence is important hereRisk is higher in women than men 2 - 3X higher

Rhematoid arthritisAttacks the jointsMost often common in women b/n the ages of 40 – 60Main effect being the inflammation of the jointsBut can also cause hemolytic, cardiavascular and

respiratory systems

Economic ImportanceThe 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 malesThey 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 AreasCauses of Autoimmune Diseases

The Burden of Autoimmune Diseases

Diagnosis, Treatment and Prevention

Training, Education and Information

POSSIBLE CAUSES Of Autoimmune diseases

Genetic, Environment, Infections etcRecent 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

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. McCarthy et al 1995 2. Symmons,1995, 3. Houcgberg,1985, 4. Siegel et al 1970

1. McCarthy et al 1995 2. Symmons,1995, 3. Houcgberg,1985, 4. Siegel et al 1970

SLE IN AFRICANSPopulation studies unavailable up to dateMost 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 RAREThis can be explained by the reporting

BIAS

Treatment of Auto-immune Diseases

Current therapies includeTreatment with immunosuppressive drugsThymectomy and plasmapherisis for

diseases involving immune complexesTNF alpha Blockers

For controlling RA and Crohn’s disease

Treatment of human autoimmune diseases poses special challenges

ChallengesUse of Immunosuppressive drugs does not leave

the other immune system IntactImmuno 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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