T - cell Deficiency

T - cell Deficiency

1. Dr. P. Saranraj
Head
Department of Microbiology
Sacred Heart College (Autonomous)
Tirupattur –635 601
Tamil Nadu, India
Mobile: [phone]; E.mail:
[email protected]
T –CELL DEFICIENCY

2. T –CELL DEFICIENCY
T-celldeficiencyisadeficiencyofT-cells,
causedbydecreasedfunctionofindividualT-
cells,itcausesanimmunodeficiencyofCell-
mediatedimmunity.
IntermsofthenormalmechanismofT-cellwe
findthatitisatypeofWBCsthathasan
importantroleinimmunity,andismade
fromThymocytes.Oneseesinthepartial
disorderofT-cellsthathappenduetoCell
signalingdefects.

3. Microbes causing T –cell deficiency
ThemainpathogensofconcerninT-cell
deficiencies are Herpes simplex
virus,MycobacteriumandListeria.
Also,intracellularfungalinfectionsarealsomore
commonandsevereinTcelldeficiencies.Other
intracellularpathogensofmajorconcerninTcell
deficiencyare:
Bacteria-Mycobacteriumavium,Salmonellasp.,
Rhodococcussp.
Fungi–Pneumocystisjirovecii,Cryptococcus
neoformansandHistoplasmacapsulatum.
Virus–Herpesvirus(Herpessimplexvirus,
CytomegalovirsandVarizellazostervirus).
Protozoa–Toxoplasmagondii,Cryptosporidium

4. Types of T –cell Deficiency
PrimaryorSecondarydeficiency
1)Primary (genetic or hereditary)
immunodeficienciesofTcellsincludesomethat
causecompleteinsufficiencyofTcells,such
asOmennsyndrome,SevereCombined
Immunodeficiency(SCID),andCartilage–
hairhypoplasia.
2)Secondarycausesaremorecommonthan
primaryones.Secondary(oracquired)causes
aremainlybyAIDS,Cancerchemotherapy,
Lymphoma (groupofBloodcancer)and
Glucocarticoid(aclassofSteroidhormone)
therapy.

5. Types of T –cell Deficiency
Completeorpartialdeficiency
1)CompleteinsufficiencyofT-cellfunctioncan
resultfromhereditaryconditions(alsocalled
primaryconditions)suchasOmennsyndrome,
Severecombinedimmunodeficiency(SCID)
andCartilagehairhypoplasia.
2)PartialinsufficienciesofT-cellfunction
includeAIDSandhereditaryconditionssuch
as Chromosomal breakage
syndromes(CBSs).

6. Symptoms of T –cell Deficiency
1)Viralinfections(RespiratorySyncytialVirus
andRotavirus)
2)Diarrhea
3)EczematousorErythrodermatousrashes
(Inflammationofskin)
4)Cachexia(Weightloss)

7. DiagnosisofT–cellDeficiency
1)DelayedHypersensitivitySkinTest.
2)T–cellcount.
3)Microbialdetection
TreatmentT–cellDeficiency
1)Treatmentforinfections(Antimicrobialtherapy).
2)UseofKilledVaccines
3)Immunoglobulinreplacement
4)Supplementalnutrition