What are the other Names for this Condition? (Also known as/Synonyms)

• Idiopathic CD4 Lymphocytopenia
• Idiopathic CD4 Lymphopenia
• Immunodeficiency 13 (IMD13)

What is Idiopathic CD4 PositIve T-Lymphocytopenia? (Definition/Background Information)

• Idiopathic CD4 Positive T-Lymphocytopenia (ICL) is a rare disorder of the immune system. People with ICL have low levels of a type of white blood cell, called a CD4+ T cell. These low levels can not be explained by other causes of immunodeficiency, including HIV infection
  • T cells have many jobs in our immune system, such as attacking bacteria and viruses
  • CD4 is a protein found on the surface of many different cells within the immune system. It lets the different cells of the immune system work with each other
  • When CD4+ T cells are decreased, the body becomes more prone to infection
• Signs and Symptoms of ICL vary. Some people have no symptoms, however most have illnesses suggestive of a lowered immune system, including infections (varicella-zoster virus, human papilloma virus), autoimmune disorders (autoimmune hemolytic anemia, lupus), and certain types of cancer (non-Hodgkin lymphoma)
• A few people with ICL are found to carry specific gene mutations; however, for most cases of ICL the underlying cause is not known.
• Currently, there is no cure for ICL, but treatments are available to help manage individual symptoms

(Source: Idiopathic CD4 PositIve T-Lymphocytopenia; Genetic and Rare Disease Information Center (GARD) of National Center for Advancing Translational Science (NCATS), USA.)

Who gets Idiopathic CD4 PositIve T-Lymphocytopenia? (Age and Sex Distribution)

• Idiopathic CD4 Positive T-Lymphocytopenia is a rare disorder. Its exact prevalence is not known
• The presentation of symptoms typically occurs in adulthood
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Idiopathic CD4 PositIve T-Lymphocytopenia? (Predisposing Factors)

• Currently, no risk factors have been clearly identified for Idiopathic CD4 Positive T-Lymphocytopenia

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Idiopathic CD4 PositIve T-Lymphocytopenia? (Etiology)

• The exact cause of Idiopathic CD4 Positive T-Lymphocytopenia is not known at the present time
• It is theorized that faulty formation and function of CD4+ T cells, immune deficiencies and genetic factors may contribute to the development of this disorder

What are the Signs and Symptoms of Idiopathic CD4 PositIve T-Lymphocytopenia?

The signs and symptoms of Idiopathic CD4 Positive T-Lymphocytopenia develop due to reduced immunity, and this may give rise to opportunistic infections, autoimmune disorders, malignancies and associated signs and symptoms.

Whereas some individuals may be asymptomatic (other than low CD4+ levels), others may exhibit a range of signs and symptoms, including:

• Bacterial infections: Mycobacterium, Salmonella, Nocardia
• Fungal infections: Candidiasis, Cryptococcus, Histoplasmosis
• Viral infections: Cytomegalovirus, varicella zoster virus, human papillomaviruses
• Parasitic infections: Toxoplasmosis, leishmaniasis
• Autoimmune disorders: 
  • Sjögren syndrome
  • Sarcoidosis
  • Psoriasis
  • Autoimmune hemolytic anemia
  • Lupus
• Cancers (such as squamous cell carcinoma, lymphoma) 
• Bronchiolitis obliterans organizing pneumonia
• Immunodeficiency
• Lymphopenia
• Recurrent otitis media
• Recurrent sinusitis

How is Idiopathic CD4 PositIve T-Lymphocytopenia Diagnosed?

Idiopathic CD4 Positive T-Lymphocytopenia is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests, including blood tests in which CD4+ T cell counts are below 300 cells/mm3  (less than 20 percent of total lymphocytes) in the absence of other immunodeficiencies, including HIV
• Imaging studies
• Biopsy studies, if necessary
• Differential diagnosis to rule-out conditions that may present with low CG4+ counts. Examples include acute or chronic retroviral infections (HIV, human T-lymphotropic virus type 1), sarcoidosis, common variable immunodeficiency, congenital immunodeficiencies, and immunosuppressive states induced by chemotherapy, acute respiratory distress syndrome, or autoimmune disorders

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Idiopathic CD4 PositIve T-Lymphocytopenia?

The complications of Idiopathic CD4 Positive T-Lymphocytopenia may include:

• Severe fatigue owing to recurrent infections
• Scarring of tissues and organs
• Extreme difficulty in breathing
• Reduced quality of life

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Idiopathic CD4 PositIve T-Lymphocytopenia Treated?

The treatment for Idiopathic CD4 Positive T-Lymphocytopenia aims to offer relief from symptoms and improve immune function. Treatment methods may include:

• Prophylactic antibiotics for those who are asymptomatic. Antibiotics may be prescribed following regular monitoring of CD4+ counts
• Interleukin-2 (IL2) therapy, to improve the function of the immune system
• Bone marrow transplantation to replace dysfunctional marrow cells with healthy ones. The bone marrow is the site of generation for all types of blood cells, including CD4+ cells

How can Idiopathic CD4 PositIve T-Lymphocytopenia be Prevented?

• Idiopathic CD4 Positive T-Lymphocytopenia may not be preventable, since the exact cause of this disorder is not known at the present time
• Active research is currently being performed to explore the possibilities for treatment and prevention of disorders such as Idiopathic CD4 Positive T-Lymphocytopenia
• Regular medical screening at periodic intervals with tests and physical examinations are recommended for all affected individuals, irrespective of whether they are symptomatic or not

What is the Prognosis of Idiopathic CD4 PositIve T-Lymphocytopenia? (Outcomes/Resolutions)

• The prognosis of Idiopathic CD4 Positive T-Lymphocytopenia is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• In rare cases, the condition may be transient. The CD4+ cell counts get normalized over time
• In most cases, the CD4+ counts stabilizes over time, and although low, no further decrease in their numbers may occur

Additional and Relevant Useful Information for Idiopathic CD4 PositIve T-Lymphocytopenia:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/