Clinical Background
Cell-mediated immunity is mediated by T-lymphocytes (T-cells) and their effector response and interactions with other immune cells. Several inherited T-cell disorders have been identified.
T-cell immunodeficiency diseases include:
- Severe combined immunodeficiency (SCID)
- DiGeorge syndrome
- Wiskott-Aldrich syndrome (WAS)
- Ataxia telangiectasia
- Chronic mucocutaneous candidiasis
Epidemiology
- Incidence - all are rare disorders
- Age - onset from neonatal to infancy to adulthood in rare instance
- Gender - equal distribution except for male predominance in sex-linked SCIDs and sex-linked WAS
Pathophysiology
- In T-cell immunodeficiency diseases, defective lymphocyte responses may occur to stimulants such as:
- Nonspecific mitogens (PHA, Con A and PWM)
- Specific antigens, such as Candida or tetanus
Clinical Presentation
- Severe combined immunodeficiency
- Early onset of severe infections (intracellular bacterial, viral, fungal, pneumocystis)
- Growth failure
- Persistent diarrhea
- Earliest onset in X-linked SCIDs, adenosine deaminase deficiency (ADA) deficiency, purine nucleoside phosphorylase deficiency (PNP), ZAP-70 defects and others
- Occurrence of graft-versus-host disease upon exposure to maternal lymphocytes or blood transfusions
- DiGeorge syndrome
- Congenital heart disease
- Hypocalcemic tetany
- Palatal abnormalities
- Thymic hypoplasia with T-cell deficiency infections (fungal, viral, bacterial, pneumocystis)
- Wiskott-Aldrich syndrome
- Profound thrombocytopenia with small, nonfunctioning platelets
- Recurrent infections, viral, pneumococcal
- Eczema
- Ataxia telangiectasia
- Progressive cerebellar dysfunction
- Recurrent infections, sinopulmonary
- Oculocutaneous telangiectasia
Treatment
- Patients with severe T-cell defects, such as severe combined immunodeficiency, may be appropriate candidates for bone marrow, stem cell transplants or even gene therapy
- Early evaluation and treatment may decrease morbidity and mortality
See Also
