There are five classes of antibodies (immunoglobulins) that help the body fight infection: IgG, IgA, IgM, IgD, and IgE. Immunoglobulins make up the antibodies that fight infection. Most of the antibodies in the blood and other fluids that surround the body’s tissues and cells are of the IgG class. IgG is divided into four subclasses: IgG1, IgG2, IgG3, and IgG4. People are said to have an IgG subclass deficiency when they lack or have very low levels of one or two IgG subclasses, but have normal levels of other immunoglobulins.
Each IgG subclass plays a slightly different role in protecting the body against infection. Therefore, a person lacking a specific IgG subclass will be vulnerable to certain kinds of infections but not others. For example, the IgG1 and IgG3 subclasses contain antibodies against serious bacterial infections such as diphtheria and tetanus, as well as antibodies against viral proteins. In contrast, the IgG2 subclass contains antibodies against the polysaccharide coating of certain disease-producing bacteria that can cause ear and sinus infections, pneumonia, blood infections and meningitis.
Conditions of IgG Subclass Deficiency:
Recurring ear and sinus infections, sinusitis, bronchitis, and pneumonia are the most frequent illnesses in people with IgG subclass deficiencies. Some people have an increased frequency of infections by an early age; others will not experience infections until later.
Diagnosis of IgG Subclass Deficiency:
A person is considered to have a selective IgG subclass deficiency if blood levels of one or more of the IgG subclasses are below the normal range based on age, and the levels of other immunoglobulins (total IgG, IgA, and IgM) are normal or near normal.
As a person may have no or very low levels of one or more IgG subclasses while maintaining a normal level of total IgG, diagnosis requires measurement of IgG subclasses in addition to serum IgG, IgA, and IgM. IgG4 deficiency often occurs in combination with IgG2 deficiency.
It’s important to remember that the definition of “normal” IgG subclass concentrations varies over time, and from lab to lab. Normal values usually represent a small range below and above the average for a person’s age.
An additional subset of patients have normal levels of immunoglobulin and normal IgG subclasses, yet fail to develop protective antibody levels in response to infections with Streptococcus pneumoniae or vaccines against the bacteria. These people are thought to have a specific antibody deficiency and are usually grouped with patients with IgG subclass deficiency.
Measurement and interpretation of IgG Subclass levels:
IgG subclass deficiency is defined as a reduction in 1 or more subclasses of IgG (IgG1 and IgG2 in particular) by more than 2 SDs below the mean for age-matched controls. Deficiencies in IgG1 or IgG2 are more likely to cause low serum IgG levels because these are the major components. IgG1 levels stabilize by the age of 5 years; however, adult levels of IgG2, IgG3, and IgG4 may not be achieved until adolescence.16 Thus, the interpretation of subclass levels is additionally problematic because levels of each subclass increase at different rates during development. The significance of isolated IgG subclasses is controversial. Laboratories have different age-appropriate reference ranges; aliquots of the same serum may result in different levels from different laboratories.
Reduced levels of 1 or more subclasses may be found in healthy individuals, making precise clinical interpretation challenging. If performed, proper evaluation of IgG subclasses should include measurements on 2 separate occasions at least 1 month apart while the patient is free of infections. Determination of IgG subclasses may be useful in patients with selective IgA deficiency, in which IgG2 deficiency is found in approximately 10% of patients.
However, quantitation of IgG subclasses provides insufficient information about antibody function; therefore, specific functional antibody response to proteins and polysaccharide antigens is important. Without clear deficits of functional antibody, IgG subclass deficiency is not likely to be clinically significant.
Reference:
All Your Lab Results.
One Simple Dashboard.
Import, Track, and Share Your Lab Results Easily
Import, Track, and Share Your Lab Results
Import lab results from multiple providers, track changes over time, customize your reference ranges, and get clear explanations for each result. Everything is stored securely, exportable in one organized file, and shareable with your doctor—or anyone you choose.
Cancel or upgrade anytime
What does it mean if your IgG, Subclass 3 result is too low?
- People with persistently low levels of one or two IgG subclasses and a normal total IgG level have a selective IgG subclass deficiency.
- People with IgG subclass deficiency require more extensive diagnostic evaluation including the demonstration of a poor antibody response to vaccine challenge before one is diagnosed with a clinically significant IgG subclass deficiency necessitating specific treatment that may include Ig replacement therapy.
- IgG subclass deficiencies may be associated with other immunoglobulin abnormalities. One common pattern is IgG2 and IgG4 subclass deficiency associated with IgA deficiency.
- IgG subclass deficiencies are also an integral component of other well-known primary immunodeficiency diseases, such as Wiskott-Aldrich Syndrome and Ataxia-Telangiectasia.
- IgG subclass deficiencies are sometimes associated with poor or partial responses to pneumococcal polysaccharides, specifically IgG2 deficiency with or without IgG4 deficiency.
IgG1 deficiency:
Selective IgG1 deficiency is very rare, as it is usually associated with deficiency of either IgG3, or other immunoglobulin classes, such as in common variable immunodeficiency. Isolated IgG1 deficiency has been reported in chronic fatigue syndrome. As IgG1 is the most abundant IgG subclass, its deficiency often results in hypogammaglobulinemia.
IgG1 and IgG3 deficiency:
People with this combination are commonly present with infections of the lower airways, which can progress to chronic lung disease.
IgG2 and IgG4 deficiency:
Conversely, IgG2 and IgG4 deficiencies manifest in the form of otitis media and sinusitis. IgG2 deficiency is the most common type of IgG subclass deficiency, either as an isolated finding or together with IgG4 deficiency. People with this defect have recurrent infections with encapsulated bacteria such as Streptococcus pneumonia and/or Haemophilus influenza type B. IgG2 deficiency often results in infectious complications, such as bronchiectasis, bronchopneumonia, bronchitis, obstructive lung disease, and asthma. It has also been associated with ataxia telangiectasia and systemic lupus erythematosus (SLE). Children with SLE and IgG2 and IgG4 deficiency may present with cardiac tamponade, instead of the more common nephropathy and arthritis. The impact of decreased concentration of IgG4 cannot be easily assessed, since IgG4 may be present in low concentrations in healthy children. Nevertheless, it was shown that low concentrations of IgG4 are present in a large percentage of patients with recurrent respiratory tract infections.
Possible symptoms:
People with any form of IgG subclass deficiency occasionally suffer from recurrent respiratory infections similar to the ones seen in other antibody deficiency syndromes, chiefly infections with encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenzae. An increased frequency of viral upper respiratory infections may not be an indication of antibody deficiency. Therefore, it is critical to distinguish between infections caused by respiratory viruses from those due to bacterial pathogens.
A few people with IgG subclass deficiency may appear very similar to patients with severe immunoglobulin deficiencies. Rarely, IgG subclass deficient patients may have recurrent episodes of bacterial meningitis or infections of the bloodstream (sepsis).
Diagnosis:
The finding of an IgG subclass deficiency should prompt reevaluation over a period of months before determining that the patient is truly immunodeficient. Subclass deficiencies need to be carefully interpreted taking into account the clinical status of the patient as well as the person’s ability to produce specific antibodies in response to vaccines.
Measurement of IgG subclasses can be recommended in the presence of known associated abnormalities, particularly if recurrent infections are also present.
These circumstances include:
- IgA deficient patients with recurrent infections to determine if there is an associated IgG2 and IgG4 subclass deficiency
- Wiskott-Aldrich and Ataxia-Telangiectasia patients at the onset of recurrent infections
- Specific Antibody Deficiency patients with normal total immunoglobulins
Possible treatment:
- Recurrent or chronic infections of the ears, sinuses and lungs need comprehensive treatment to prevent permanent damage that might result in hearing loss or chronic lung disease. It is also important to encourage patients to continue normal activities of daily living, such as school or work.
- The mainstay of treatment includes appropriate use of antibiotics to treat and prevent infections. The type and severity of infection usually determines the type of antibiotic used and the length of treatment.
- Ig therapy is an option for selected symptomatic patients that have persistent IgG subclass deficiencies, documented poor responses to polysaccharide vaccines and who fail prophylactic antibiotic therapy. The decision to begin Ig replacement therapy needs to be carefully discussed with the healthcare provider
- People with frequent infections and persistent IgG subclass deficiencies with normal anti-polysaccharide antibodies should also be treated using adequate prevention, vaccine and antibiotic therapy, perhaps even considering the use of Ig replacement if other treatment fails.
Laboratories
Bring All Your Lab Results Together — In One Place
We accept reports from any lab, so you can easily collect and organize all your health information in one secure spot.
Pricing Table
Gather Your Lab History — and Finally Make Sense of It
Finally, Your Lab Results Organized and Clear
Personal plans
$79/ year
Advanced Plan
Access your lab reports, explanations, and tracking tools.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 5 reports entered for you
- Cancel or upgrade anytime
$250/ once
Unlimited Account
Pay once, access everything—no monthly fees, no limits.
- Import lab results from any provider
- Track all results with visual tools
- Customize your reference ranges
- Export your full lab history anytime
- Share results securely with anyone
- Receive 10 reports entered for you
- No subscriptions. No extra fees.
$45/ month
Pro Monthly
Designed for professionals managing their clients' lab reports
- Import lab results from any provider
- Track lab results for multiple clients
- Customize reference ranges per client
- Export lab histories and reports
- Begin with first report entered by us
- Cancel or upgrade anytime
About membership
What's included in a Healthmatters membership
Import Lab Results from Any Source
See Your Health Timeline
Understand What Your Results Mean
Visualize Your Results
Data Entry Service for Your Reports
Securely Share With Anyone You Trust
Let Your Lab Results Tell the Full Story
Once your results are in one place, see the bigger picture — track trends over time, compare data side by side, export your full history, and share securely with anyone you trust.
Bring all your results together to compare, track progress, export your history, and share securely.
What Healthmatters Members Are Saying
Frequently asked questions
Healthmatters is a personal health dashboard that helps you organize and understand your lab results. It collects and displays your medical test data from any lab in one secure, easy-to-use platform.
- Individuals who want to track and understand their health over time.
- Health professionals, such as doctors, nutritionists, and wellness coaches, need to manage and interpret lab data for their clients.
With a Healthmatters account, you can:
- Upload lab reports from any lab
- View your data in interactive graphs, tables, and timelines
- Track trends and monitor changes over time
- Customize your reference ranges
- Export and share your full lab history
- Access your results anytime, from any device
Professionals can also analyze client data more efficiently and save time managing lab reports.
Healthmatters.io personal account provides in-depth research on 10000+ biomarkers, including information and suggestions for test panels such as, but not limited to:
- The GI Effects® Comprehensive Stool Profile,
- GI-MAP,
- The NutrEval FMV®,
- The ION Profile,
- Amino Acids Profile,
- Dried Urine Test for Comprehensive Hormones (DUTCH),
- Organic Acids Test,
- Organix Comprehensive Profile,
- Toxic Metals,
- Complete Blood Count (CBC),
- Metabolic panel,
- Thyroid panel,
- Lipid Panel,
- Urinalysis,
- And many, many more.
You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.
If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.
We implement proven measures to keep your data safe.
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.