Symptoms: recurrent infections such as sinusitis(more than one documented infection /yr), pneumonia(more than one/yr) , ear infections( more than 8x /yr), deep skin infections, & deep seated infections.
Causes and Treatment: Although there are many different kinds, severe ones are rare.
- Relatively Common ones:
- Specific Antibody Deficiency: This is the most commonly encountered form of immune deficiency in my practice. Typically they are young children with a history of recurrent upper airway infections including otitis, sinusitis, and rhinitis. It is uncommon for them to have serious infections such as pneumonia and meningitis. They have difficulty producing antibodies to common polysaccharides (sugar coated) bacteria such as Pneumococci or Hemophilus Influenza, although they have received vaccinations against these bacteria during the first one year of life. The immunoglobulins(the sum of antibodies) are usually normal since the deficiency is limited to a very small number of antibodies. Probably the immune system of these young children was not ready to respond to the vaccinations or real bacteria during early life. As they get older, the immune system matures and responds better to the same vaccines. If specific antibody defects may persist despite Pneumovax vaccination ( which contains 21 killed serotypes), Prevnar (which contains 7 killed serotypes conjugated to the protein carrier) is given, because the latter is considered to be more immunogenic. In the rare events when patients respond to neither vaccines, prolonged antibiotic treatment ( 6 months, in full therapeutic range) or IVIG (intravenous immunoglobulin G) may be required to control infections. Of note is many of these patients have also allergic symptoms such as asthma and rhinitis.
- Transient Hypogammaglobulinemia of Early Childhood: Some young children (1yr -5yrs of age) may have decreased levels of immunoglobulins (the sum of antibodies). They may have frequent upper airway infections and sometimes lower airway infections (pneumonia). The deficiency is usually transient and a majority of these children will grow out of it. During this period of deficiency, they may need to be on continuous prophylactic antibiotics or even monthly IVIG (intravenous immunoglobulin G) replacement therapy.
- Rare Ones:
- Common Variable Immunodeficiency: Usually starts in late childhood or adulthood with mild recurrent infections, but may progress to more severe infections. They cannot produce enough antibodies and may require IVIG.
- X-linked Immunoglobulin deficiency: Complete absence of antibodies. Most develop frequent upper airway and lower airway infections after infancy ( in some, later in life). They need to be supported with regular IVIG treatments.
- There are many other severe forms such Severe Combined Immune Deficiencies
The goal of our immune system is to protect our body from invading micro-organisms. These organisms are destroyed by the cells with the help of antibodies and other components in the blood and tissues. The following are the most commonly ordered lab tests
- Cells: white cell count, CD4, CD8, NKC
- Quantitative immunoglobulins (IgG, A, M, E)
- Specific antibody: If the antibody level is low, patients are given the vaccination and the blood is drawn after 4 wks to see the response
- Anti-pneumococcal antibody before and after vaccination
- Protective level is ≥1.3 mg/L in greater than 50% of serotypes in 2-5 yr of age, in greater than 70% of serotype after 5 yrs of age
- Good vaccine response is when antibodies rise 4 x or greater
- Anti-Hemophilus antibody
- Protective level is ≥ 1.0 mg/L
- Anti-Tetanus antibody
- Most children have a protective level if they are vaccinated
- Memory B cells: For those patients who do not respond to vaccinations, number of memory B cells (IgD-, CD27+) are checked. When memory B cells are lacking, patients’ immune system does not ‘remember’ if he/she received the vaccinations.
- Complement levels: Complements help antibody and cell to fight infection better
Genetics vs Environment in the Allergic Diseases
It has been the focus of investigation why the incidence of asthma ---
The answer seems to be “probably no”
Epidemiological evidence suggests that viral infections –
Recent epidemiological studies also suggest that Vitamin D deficiency plays a significant role in the genesis of allergic disorders. The incidence rate of asthma is reported higher in the temperate than the warmer zones of the world. A survey showed that 35% of asthmatic children were low in Vitamin D in USA (Brehm, Journal of Allergy and Clinical Immunology, 2010)
A hypothesis is that the vitamin D deficiency leads to a decrease in function and number of regulatory T cells that is important in suppressing allergic potentials
According to the United States Institute of Medicine, the recommended dietary allowances of vitamin D are 600-800 IU/day (15 ugs/day)
The tolerable upper intake levels are;
- 0-6 months of age: 1,000 IU
- 6-12 months: 1,500
- 1-3 yrs of age: 2500 IU
- 4-8 yrs of age: 3000 IU
- 9-71+ years of age: 4000 IU