39 - Development of immune system in childhood. Immunopathological reactions. Oral immunity

Question 1

Intrauterine development

Answer 1

Passive immunity from mother

Develop of own immuno-reactivity ⇢ Protection of foetus from congenital infection

Question 2

Newborn

Answer 2

At birth there is phagocytic activity of:

• Complement interferons other factors of NS immunity

Congenital + acquired infection occur w/undifferentiated clinics + generalisation

Question 3

Maternal antibodies

Answer 3

Begin to decline from 2 month of infant

Within 6 months they disappear (except when breastfeeding)

Question 4

Oral mucosa

Answer 4

Adapts as a barrier

Supported by immuno-regulatory networks

Depends on microbial colonisation

Question 5

Breast feeding

Answer 5

Helps shape immune phenotype

Breast milk contains:

• immune cells cytokines growth factors IgA
• Provides early post natal development of secretory immunity

Question 6

3-6 months of age

Answer 6

Immune reactions are more subdued

More difficult to recover from infections

⇣ productivity of lymphoid tissues

Homeostasis is easily broken by malnutrition + antibiotics

Question 7

6-12 months

Answer 7

Child begins to walk + so has contact w/environment

1st viral infections ⇢ respiratory, retrovirus, bowel, herpes, measles, chickenpox, rubella

At this period diseases is more severe

Question 8

1-3 years

Answer 8

Close contact w/adults

child is exposed to a variety of infections

they have better immunological reactivity

immune organs + system starts to develop

Serum reactions are weak

Antibody conc is low in re-encounter w/antigen-antibody titre ⇡

Question 9

After 3 years

Answer 9

Viral infections occur more easily

Often subclinical + asymptomatic

Question 10

School + adolescence

Answer 10

Incidences close to that in adults

Immunopathological reactions are protective + adaptive of the body

Question 11

Immunopathological reactions

Answer 11

Allergies

Autoimmune

Immunodeficiencies

Question 12

Allergic

Answer 12

Antigen that causes allergic response = allergen

4 types of allergic response

1. Allergic-immediate reactions ⇢ humoral hypersensitivity ⇢ anaphylactic
2. Cytotoxic ⇢ humoral ⇢ immediate ⇢ toxic effect on cells
3. Immediate reactions ⇢ toxic effect on antigen-antibody reaction
4. Cell-mediated delayed reaction ⇢ similar to cellular immune reactions

Question 13

Autoimmune reactions

Answer 13

Immune system is self-tolerant of its own tissue + antigens

When this tolerance is lost ⇢ body produces antibodies against its own cells + antigens

Question 14

Oral immunity

Answer 14

Adaptive immunity in mouth may be impaired

Commensal MOs have similar antigens ⇢ bind to molecules of MO

Microorganism does not perceive them as foreign/or develop a cross-immune response

The body recognises its cells as foreign