This document discusses T-cell deficiency, which is caused by decreased function of individual T-cells and results in impaired cell-mediated immunity. It notes that T-cells play an important role in immunity and are made from thymocytes. The main pathogens of concern in T-cell deficiencies are herpes simplex virus, mycobacteria, and listeria, as well as intracellular fungi. T-cell deficiency can be primary/genetic, such as Omenn syndrome or SCID, or secondary due to conditions like AIDS, cancer chemotherapy, or glucocorticoid therapy. Symptoms include viral, bacterial, and fungal infections, diarrhea, skin rashes, and weight loss. Diagnosis involves delayed hypersensitivity skin

1. Dr. P. Saranraj
Head
Department of Microbiology
Sacred Heart College (Autonomous)
Tirupattur – 635 601
Tamil Nadu, India
Mobile: +91-9994146964; E.mail:
microsaranraj@gmail.com
T – CELL DEFICIENCY

2. T – CELL DEFICIENCY
 T - cell deficiency is a deficiency of T - cells,
caused by decreased function of individual T -
cells, it causes an immunodeficiency of Cell -
mediated immunity.
 In terms of the normal mechanism of T - cell we
find that it is a type of WBCs that has an
important role in immunity, and is made
from Thymocytes. One sees in the partial
disorder of T - cells that happen due to Cell
signaling defects.

3. Microbes causing T – cell deficiency
 The main pathogens of concern in T - cell
deficiencies are Herpes simplex
virus, Mycobacterium and Listeria.
 Also, intracellular fungal infections are also more
common and severe in T cell deficiencies. Other
intracellular pathogens of major concern in T cell
deficiency are:
 Bacteria - Mycobacterium avium, Salmonella sp.,
Rhodococcus sp.
 Fungi – Pneumocystis jirovecii, Cryptococcus
neoformans and Histoplasma capsulatum.
 Virus – Herpes virus (Herpes simplex virus,
Cytomegalovirs and Varizella zoster virus).

4. Types of T – cell Deficiency
 Primary or Secondary deficiency
1) Primary (genetic or hereditary)
immunodeficiencies of T cells include some that
cause complete insufficiency of T cells, such
as Omenn syndrome, Severe Combined
Immunodeficiency (SCID), and Cartilage –
hair hypoplasia.
2) Secondary causes are more common than
primary ones. Secondary (or acquired) causes
are mainly by AIDS, Cancer chemotherapy,
Lymphoma (group of Blood cancer) and
Glucocarticoid (a class of Steroid hormone)
therapy.

5. Types of T – cell Deficiency
 Complete or partial deficiency
1) Complete insufficiency of T - cell function can
result from hereditary conditions (also called
primary conditions) such as Omenn syndrome,
Severe combined immunodeficiency (SCID)
and Cartilage hair hypoplasia.
2) Partial insufficiencies of T - cell function
include AIDS and hereditary conditions such
as Chromosomal breakage
syndromes (CBSs).

6. Symptoms of T – cell Deficiency
1) Viral infections (Respiratory Syncytial Virus
and Rotavirus)
2) Diarrhea
3) Eczematous or Erythrodermatous rashes
(Inflammation of skin)
4) Cachexia (Weight loss)

7. Diagnosis of T – cell Deficiency
1) Delayed Hypersensitivity Skin Test.
2) T – cell count.
3) Microbial detection
Treatment T – cell Deficiency
1) Treatment for infections (Antimicrobial therapy).
2) Use of Killed Vaccines
3) Immunoglobulin replacement
4) Supplemental nutrition