Immunodefisiency & Autoimmune

Introduction

• Immunodeficiency disorders occur when the body's immune response is reduced or absent

• T or B cell lymphocytes (or both) do not work as well as they should, or when your body doesn't produce enough antibodies.

Classification

Primary secundary

Primary immunodeficiency (PID)

• Many of these disorders are hereditary and are autosomal recessive or X-linked.

• Gx: recurrent or persistent infectionOther signs include:– Poor response to treatment– Delayed or incomplete recovery from illness– Certain types of cancers (such as Kaposi's sarcoma or

non-Hodgkin's lymphoma)– Certain infections (including some forms of

pneumonia or recurrent fungal yeast infections)

Diagnosis

• full blood count (including accurate lymphocyte and granulocyte counts)

• immunoglobulin levels (the three most important types of antibodies: IgG, IgA and IgM).

• Complement levels

The International Union of Immunological Societies recognises eight classes of primary

immunodeficiencies

• Combined T- and B-cell immunodeficiencies• Antibody deficiencies• Well-defined syndromes• Immune dysregulation diseases• Phagocyte disorders• Innate immunity deficiencies• Autoinflammatory disorders• Complement deficiencies

Treatment of primary immunodeficiencies

• intravenous immunoglobulin (IVIG) or subcutaneous immunoglobulin (SCIG) in antibody deficiencies

• hematopoietic stem cell transplantation (for SCID and other severe immunodeficiences)

• Reduction of exposure to pathogens, and in many situations prophylactic antibiotics may be advised.

Acquired immunodeficiency "secondary" or "acquired" immunodeficiency

• Common causes for secondary immunodeficiency are malnutrition, aging and particular medications (e.g. chemotherapy, disease-modifying antirheumatic drugs, immunosuppressive drugs, after organ transplants, glucocorticoids).

• cancer, particularly those of the bone marrow and blood cells (leukemia, lymphoma, multiple myeloma), and certain chronic infections. Immunodeficiency is also the hallmark of acquired immunodeficiency syndrome (AIDS)

Autoimmune

Autoimmune DiseasesAutoimmune Diseases

• Loss of self-tolerance leads to production of antibodies or T cells that react against one’s own antigens.

• Immune system response to self antigens causes damage to organs.

• The major factors that contribute to the development of autoimmunity are genetic susceptibility and environmental triggers

Loss of Tolerance in Autoimmune Disease

Susceptibility genes (usually multiple)

Triggering factors (probably environmental)

Loss of tolerance

Auto reactive T cells Auto reactive B cells Inadequate regulatory mechanism

Persistent pathogenic auto antibodies

Persistent pathogenic immune complexes Persistent damaging auto reactive T cell

Classification

• Autoimmune diseases may be either systemic or organ specific

• Three types of autoimmune disorders:–Cytotoxic (Type II reactions)– Immune complex (Type III reactions)–Cell-mediated (Type IV reactions)

Type II antibody against cell-surface or matrix antigens ( syndrome, autoantigen

and consequence )

Type III immune complex disease ( syndrome, autoantigen and consequence)

Type IV cell-mediated disease (syndrome, autoantigen and

consequence)

Autoantibodies against cell-surface receptors