Immunology

1. IMMUNODEFICIENCY
DISEASES (IDD)
Dr.Bile

2. Immunodeficiency Diseases
(IDD)
 These are clinical sequele of impaired function in 1
or more components of the immune system
 Immunodeficiency Diseases (IDD) may be due to
 Embryonic disorder
 Enzymatic defects
 Unknown origin

3. Immunodeficiency Diseases
(IDD)
Signs & symptoms of immunodeficiency
diseases
A.Highly suspicious
1. Increased frequency; relapse; unusual
severe infection
2. Chronic / prolonged duration of infection
3. Infection due to low pathogenicity
microorganisms
4. Poor response to treatment

4. Immunodeficiency Diseases
(IDD)
B. Moderately suspicious
1. Eczema,
2. Cutaneous candidiasis
3. Diarrhea
4. Failure to thrive
5. Hepatosplenomegaly
6. Relapsing abscess

5. Classification of
Immunodeficiency Diseases
1. Primary (congenital) IDD –
 May affect either adaptive or innate
immune functions
 Disorder directly in 1 of the basic
immunological processes (B & T
lymphocytes, complement, or phagocytic
cell)
 Primary immunodeficiency results from a
genetic or developmental defect in the
immune - are inherited

6. Classification of
Immunodeficiency Diseases
2. Secondary IDD –
 Associated with different clinical
conditions
 infections, other illnesses or iatrogenic states
 e.g. Neoplasm,
 autoimmune diseases,
 drugs (anticonvulsants, corticosteroids,
immunosuppresants),
 Aging and starvation

7. Classification of
Immunodeficiency Diseases
Classification of primary immunodeficiencies
1. B-lymphocyte: → 50-75 %
2. T-lymphocyte: → 5-10 %
3. Combined T & B cell deficiencies
4. Phagocytic cell: → 1-2 %
5. Complement: → 1-2 %

8. I. Congenital immunodeficiency
diseases
 Combined B & T deficiencies
 Severe combined immunedeficiency (SCID)
 A rare life threatening congenital deficiency of
humoral & cellular immunities (B & T cells)
 Defect in Lymphoid Progenitor. Lack T, B
and/or NK cells.
 Thymus does not develop. Myeloid &
erythroid cells are normal.

9. Combined B & T deficiencies
 SCID is characterized by 3 main
features:
1. Th-lymphocytes
1. are functioning poorly or are absent
2. Thymus
1. may be small, functioning poorly or absent
3. Stem cells in bone marrow
1. are absent or defective in function:

10.  In all of these situations, little or no Abs are
produced
 Within 3 -12 months after birth, infants with
SCID develop recurrent bacterial, viral, fungal
infections
 It is characterized by rash, lymphopenia,
chronic diarrhea, eosinophilia, wasting,
opportunistic infections, recurrent severe
infections, failure to thrive.

11. Treatment
 Bone Marrow Transplantation

12. Phagocytic cell deficiency
Myeloid Progenitor Cell Differentiation
Defect
 Defect in differentiation from myeloid
progenitor cells into neutrophils results in
Congenital Agranulocytosi.
 Recurrent bacterial infections seen in
patients
 Treated with granulocyte-macrophage
colony stimulating factor (GM-CSF) or G-
CSF.

13. Acquired Immune Deficiency
Disorders
1.Malnutrition
 Inhibits lymphocyte maturation & function
especially when there is a lack of protein in the
diet, also may weaken a person's immune
response.
2. Irradiation
 exposure to X-rays & gamma rays - cause
decreased production of lymphocyte
precursors in the bone marrow.

14. Acquired Immune Deficiency
Disorders
. Medications:
 Immunosuppressive chemotherapy:
ctotoxic drugs used in cancer
chemotherapy- cause decreased
production of lymphocyte precursors in
the bone marrow
 Corticosteroids – used to treat cancer, may
limit the immune system; damages lymphocytes

15. Acquired Immune Deficiency
Disorders
4. Cancers: Leukemia (cancers of the
lymphoid system), metastases - reduces
areas for lymphocyte development
5. Aging
Adaptive immunity, esp CMI, tends to diminish with
age.
6. Chronic conditions
diabetes, cancer, cirrhosis of the liver, make a
person more likely to have infections