Primary immunodeficiency disorders are hereditary conditions present at birth that impair the immune system's ability to fight infections and diseases. There are over 150 known types that can affect B cells, T cells, or other immune components. Some common primary immunodeficiencies include severe combined immunodeficiency (SCID), where both cellular and humoral immunity is absent due to a lack of T cells; Bruton's agammaglobulinemia, an X-linked disorder affecting B cell function; and DiGeorge's syndrome, where T cell development is impaired. Secondary immunodeficiencies are acquired later in life from external factors like malnutrition, disease, or medical treatments.

1. IMMUNODEFICIENCY
Dr.Challaraj Emmanuel, E.S.
Associate Professor & Coordinator (PG),
Department of Life Sciences,
Kristu Jayanti College (Autonomous),
K.Narayanapura, Kothanur Post,
Bangalore.

2. INTRODUCTION:
• Immunodeficiency is a state in which the ability of immune system
is compromised or entirely absent to fight against infectious
diseases and cancer.
• Two types of immunodeficiency disorders:
• 1. primary or congenital or inherited
• 2. secondary or acquired
• Immunodeficiency can be specific or non-specific
• 1. specific = abnormalities of B & T cells
• 2. non-specific= abnormalities of non specific components

4. What is primary immunodeficiency disorder?
• To date, over 150 different primary immunodeficiency have been identified.
• All are relatively rare ,usually present at birth and are usually hereditary and
evident during infancy or childhood.
• However, some disorders (such as common variable immunodeficiency) are not
recognized until adulthood.
• A group of disorders characterized by an impaired ability to produce normal
immune response. • Cause: mutations in genes involved in the development
and function of immune organs, cells, and molecules. • Genetically
determined. • Usually diseases of infancy & childhood.

7. Severe Combined Immunodeficiency(SCID):
• Synonyms: Glanzzman-Rinker syndrome, Bubble Boy Disease, Thymic
Alymphoplasia
• Genetic disorder characterised by absence of T-lymphocytes.
• Impairment of both cellular & humoral response
• Specific defects in antigen presentation & functional immune molecules.
• Features of SCID
• Absent tonsils • Small or absent lymph nodes • Absent thymic shadow •
Lymphopenias • Decreased Number of T cells • Severe agammaglobulinemia
(Swiss type of agammaglobulinemia) • No IG’s usually present

8. Bruton’s X-linked Agammaglobuinemia:
• Primarily B-cell defect
• Boys-more affected
• Severe reduction in γ-globulins
• IG’s, circulating and marrow B-cells.
• Probable cause: Molecular defect at Xq22.Mutation of bruton
tyrosine kinase.
• Therapy: IV IG’s.

9. DiGeorge’s syndrome :
• Also called thymic hypoplasia
• Congenital disorder
• Abnormalities in structure derived from 3rd and 4th pharyngeal
pouches
• Predominantly T cell defect
• Charactersitics: Neonatal tetany(absence of parathyroid)
• Therapy: Thymic transplants

10. Wiskott-Aldrich Syndrome:
• X-linked condition
• Incidence: 4:10,00,000
• Severe eczema, recurrent infections, Bloody diarrhea, chronic
otitis
• T cells appear bald :?
• Platelets: Decreased in number, small
• Failure to recognise polysaccharide antigens.
• Defect: Failure in expression of sialophorin.

11. Other Primary ID’s:
• Selective IgA deficiency
• Common variable Immunodeficiency
• X-linked lymphoproliferative disease
• Job’s syndrome

12. Secondary Immunodeficiency:
• Extreme age
• malnutrition
• Metabolic diseases
• uremia
• Surgery and trauma
• Environmental condition