This document discusses how malnutrition affects immunity. It defines malnutrition as a lack of proper nutrients that the body needs to function optimally. There are two types: undernutrition from not enough calories/nutrients and overnutrition from too many calories/fat. Malnutrition increases susceptibility to infection by compromising the immune system, such as reducing complement system functions, phagocyte ability, and hematopoiesis. It also decreases the function of antigen-presenting cells and the production of cytokines that support hematopoietic stem cell growth. In summary, malnutrition weakens the immune system in multiple ways, making the body more vulnerable to infectious diseases.

2. TOPIC: MALNUTRITION AND
IMMUNITY
•SUBJECT: IMMUNOLOGY
•HAFIZ M WASEEM
•UE LAHORE PAKISTAN

3. CONTENTS:-
MALNUTRITION
CAUSES
SIGNS AND SYMPTOMS
MALNUTRITION AFFECTS IMMUNITY
REFERENCES

4. MALNUTRITION :-
Malnutrition refers to when a person’s diet does not provide
enough nutrients or the right balance of nutrients for optimal
health.
A person with malnutrition may lack vitamins, minerals, and
other essential substances that their body needs to function.
Malnutrition affects billions of people worldwide. Some
populations have a high risk of developing certain types of
malnutrition depending on their environment, lifestyle and
resources.

5. MALNUTRITION :-
Undernutrition: This type of malnutrition results from not
getting enough protein, calories or micronutrients. It leads to
low weight-for-height (wasting), height-for-age (stunting) and
weight-for-age (underweight).
Overnutrition: Overconsumption of certain nutrients, such as
protein, calories or fat, can also lead to malnutrition. This
usually results in overweight or obesity.
Causes of malnutrition include inappropriate dietary choices, a
low income, difficulty obtaining food, and various physical
and mental health conditions.

6. CAUSES:-
A low intake of food
Mental health conditions
Social and mobility problems
Digestive disorders and stomach conditions
Alcohol use disorder
In some parts of the world, widespread and long-term
malnutrition can result from a lack of food.

7. SIGN & SYMPTOMS:-
Due to improper diet a person may have deficiency of vitamins
• Vitamin A deficiency leads to vision problems
• Vitamin C deficiency results in scurvy
Lacking all nutrients can lead to kwashiorkor, which is a
“severe form of malnutrition.” One symptom of this condition
is a distended abdomen.
Marasmus is another potential result of severe nutritional
deficiency. A person with marasmus will have very little
muscle or fat on their body.

8. SIGNS & SYMPTOMS:-
Some signs and symptoms of malnutrition include:
• a lack of appetite or interest in food or drink
• tiredness and irritability
• an inability to concentrate
• always feeling cold
• Depression
• loss of fat, muscle mass, and body tissue
• a higher risk of getting sick and taking longer to heal
• longer healing time for wounds
• a higher risk of complications after surgery
• slow behavioral and intellectual development, possibly resulting in
learning difficulties
• Anorexia nervosa is a mental health condition that can lead to
severe malnutrition.

9. MALNUTRITION AFFECTS IMMUNITY
This direct relationship between malnutrition and death is
mainly due to the resulting immunodeficiency and,
consequently, greater susceptibility to infectious agents
The causal relationship of malnutrition with immune
suppression and infection is also aggravated by the profound
effect of many infections on nutrition itself. For example,
gastrointestinal parasites can lead to diarrhea, anemia etc.
Malnutrition can be a consequence of energy deficit (protein-
energy malnutrition - PEM) or a micronutrient deficiency
Kwashiorkor usually manifests as edema, changes in hair and
skin color, anemia, hepatomegaly, lethargy, severe
immunodeficiency and early death.

10. MALNUTRITIONAFFECTSIMMUNITY:-
A condition that results from a genetic or developmental defect in
the immune system is called a primary immunodeficiency.
Secondary or acquired immunodeficiency is the loss of immune
function that results from a variety of extrinsic factors. The most
well known secondary immunodeficiency is caused by the human
immunodeficiency virus (HIV) infection; however, the most
prevalent cause of immunodeficiency worldwide is severe
malnutrition,.
However, for the sake of clarity, we will first refer to some
mechanisms considered innate, i.e., the ones used against any type
of pathogen. For example, availability of complement components
and phagocyte function are compromised during malnutrition,
which will directly affect pathogen elimination. This happens since
the complement system by itself can destroy bacteria or viruses or
because complement receptors present on the phagocyte surface
mediate capture of pathogens. Significantly lower levels of
complement, especially C3 that is the main opsonic component,
were described by Sakamoto et al.

11. MALNUTRITIONAFFECTSIMMUNITY:-
 In addition, phagocyte ability to ingest and kill pathogens was
also reduced .
Antigen-presenting cells (APC) play a cardinal role during the
induction, regulation and maintenance of innate and acquired
immune responses .
 A series of studies demonstrated that the biological function
of different cell types (B lymphocytes, macrophages and
Kupffer cells) is clearly decreased during nutritional
deficiencies.
 Malnutrition clearly affects hematopoiesis, determining
anemia, leucopenia and severe reduction in bone marrow.

12. MALNUTRITIONAFFECTS IMMUNITY:-
• Production of IL-6 and TNF-α by bone marrow cells is also
significantly lower in malnourished animals
• The capacity of malnourished hematopoietic stroma to
support the growth of hematopoietic stem cells (CD34+) in
vitro is also decreased . This is a very relevant finding because
CD34+ cells are able to generate multiple
lymphohematopoietic lineages as myeloid, erythroid and
lymphoid (B and T)

15. THANK YOU

16. REFERENCES:-
https://www.google.com/url?sa=t&source=web&rct=j&url=ht
tps://www.medicalnewstoday.com/articles/179316%23:~:text
%3DMalnutrition%2520refers%2520to%2520when%2520a,ph
ysical%2520and%2520mental%2520health%2520conditions.&
ved=2ahUKEwiMsPaIueLuAhX9QUEAHbu1CBEQFjAHegQIAhAE
&usg=AOvVaw3tF5Q-GvA1gCH31Deci-
JJ&cshid=1613071775701