IgG, Subclass 3

Optimal Result: 15 - 102 mg/dL.

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:

 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3099256/

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.

Frequently asked questions

Unlock Your Health Journey with Healthmatters.io! Ever wished for a one-stop digital health haven for all your lab tests? Look no further! Healthmatters.io is your personalized health dashboard, bringing together test reports from any lab. Say goodbye to scattered results—organize and centralize your lab data effortlessly. Dive into the details of each biomarker and gain insights into the meaning behind your medical test data.

Join the community of thousands who've transformed the way they understand their lab results. Experience the joy of having all your lab data neatly organized, regardless of where or when the tests were done.

For our professional users, Healthmatters.io is a game-changer. Revel in the intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history. It's not just a dashboard; it's your gateway to a smarter, more informed health journey!

Healthmatters.io personal account provides in-depth research on 4000+ 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.

While we do talk about popular labs, we welcome reports from lots of other places too. It's as simple as this: if you can get a test done, you can upload it to Healthmatters. We can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.

Still on the hunt for a specific biomarker? Just tell us, and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account!

There are two ways to add your test reports to your healthmatters.io account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."

Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.

For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you. We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.

Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.

Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.

For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.

Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.

Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.

The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.

For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.

Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.

You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.

Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.

Unlocking the insights from your lab tests has never been this intuitive! We've crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into a treasure trove of testing data.

1. Graph View:

Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.

2. All Tests View

Get a quick grasp of your test reports in minutes! Explore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.

3. Table View:

For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.

Experience the power of clear, organized data visualization with Healthmatters.io — your key to understanding and taking charge of your health journey!

Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.

Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.

A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.

The professional or business account is designed for health professionals who wish to track and organize their clients' laboratory results.

Use promo code to save 10% off any plan.


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.