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Early Clues. Stronger Futures.

Screening Children for Immune Deficiencies, Simply and Early

The IgG Total Test helps detect low antibody levels in children—supporting early diagnosis of immunodeficiency and strengthening global health efforts.

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Identify Low IgG Levels to Support Early Immune Care

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Low levels of antibodies can affect an individual’s ability to fight infection and mount an effective immune response to either natural infections or to vaccines. Low levels of antibodies may be caused by many factors including diseases, conditions, or treatments. Primary antibody disorders can affect an individual’s ability to produce antibodies. Such disorders are part of a larger family of immune disorders known as primary immunodeficiency, or inborn errors of immunity. IgG antibodies are the most common antibody types which can protect from infection. It is important to know if a person’s antibody levels are too low to produce healthy responses to infection so that follow-up testing can be conducted to determine the cause of the low antibody level and for recommended treatment and precautions.

The IgG Total Rapid Test is an innovative lateral flow assay designed to screen for low levels of IgG antibody in children, helping identify those who may have Primary Immunodeficiency Diseases (PID). Early detection enables timely intervention, treatment, and vaccination follow-up, particularly for polio eradication efforts.

Currently, the test is undergoing validation in Tunisia and Pakistan as part of a global initiative to enhance PID surveillance and public health outcomes.

Why It Matters:

  • Helps identify children with low IgG levels at risk of persistent infections.

  • Supports poliovirus surveillance by detecting individuals that may be shedding the virus.

  • Provides a simple, rapid, and cost-effective solution for low-resource settings.

  • Supports early diagnosis and referral for further immunological evaluation.

Clarity Where It Counts Most

Understanding How the IgG Total Rapid Test Supports PID Screening

A graphic representation of the polio virus

About the Test (Intended Use & Background)

Understanding Primary Immunodeficiency Disease (PID)

Primary Immunodeficiency Diseases (PIDs) are a group of genetic disorders where the immune system fails to function properly. Children with PIDs are highly susceptible to infections, including prolonged shedding of vaccine-derived poliovirus (VDPV), making them a key population for targeted polio eradication efforts.

Early diagnosis and intervention are critical to managing these conditions, improving quality of life, and preventing life-threatening complications. Increasing awareness of PID also supports global health initiatives by identifying hidden reservoirs of infection and enabling more effective surveillance and response strategies.

How the IgG Total Rapid Test Works

Intended Use

The IgG Total test is intended to screen for low levels of IgG antibodies in serum and plasma that could indicate a deficiency in IgG. IgG deficiency may be an indicator of problems with the immune system such as primary antibody deficiency or an inborn error of immunity. The IgG Total Test is a screening test and not intended for diagnosis. Follow up testing is recommended for test results or for clinical signs of concern.

Principle

The IgG Total Test contains a membrane test strip which is precoated with immunoglobulin G (IgG) and with recombinant proteins which are reactive with IgG and a sample pad which is precoated with detector colloidal gold conjugate of protein which binds IgG. Test and control lines in the result window are not visible before applying the diluted sample. The sample diluted in assay buffer interacts with the detector conjugate and then moves chromatographically through the membrane. The detector will bind IgG in the sample to saturation in the presence of normal levels of IgG antibodies and will not bind to the test lines.

When IgG levels are low in the sample, the detector conjugate is available to bind the test lines and one or more test lines may appear. The Control line is used for procedural control, indicating that dilute specimen has been added and the test reagents are reactive and may vary in intensity. The absence of a control line indicates that the test has not run correctly and the results are invalid.

Fast. Clear. Actionable.

Step-by-Step Guide to Performing the IgG Total Rapid Test

Follow simple, guided steps to run the IgG Total Rapid Test and interpret results—delivering clear insights into antibody levels within 15 minutes.

  • Bring all kit components to temperature between 15°C and 30°C prior to testing.

  • Ensure that there is a clean surface on which to conduct testing. 

  • Prepare a testing cup by placing it in a rack and adding 175 µL of assay diluent to the test well. Place cap back on sample diluent vial after use. 

  • Collect sample (see Specimen collection and handling section) and mix with sample diluent to dilute the sample.

  • Collect 2.5 µL serum or plasma using a calibrated pipette.

  • Add the serum or plasma sample to the sample diluent and pipette up and down at least 20 times with a stirring motion to help mix the sample into the diluent.

  • The end of the lateral flow test strip is added to the diluted sample.

Results are ready in 15 minutes, with clear cutoff thresholds.

Result Interpretation:

Helps identify very low IgG levels (<300 mg/dL), moderately low IgG levels (<500 mg/dL), and normal IgG levels (>500mg/dL).

  • Two test lines → Very low IgG (<300 mg/dL)
  • One test line → Moderately Low IgG (<500 mg/dL)
  • Control line only → Normal IgG (>500 mg/dL)
  • No control line → Invalid test, repeat with new test strip

Refer to the Test Instructions for Full Details

Note: The IgG Total Rapid Test has been successfully transferred from PATH to LifeSADX for manufacturing, commercialization, and global access.

Trusted Data. Global Impact.

Clinical Validation Supporting Early PID Detection

The IgG Total Test underwent rigorous clinical validation to ensure accuracy, usability, and effectiveness.

Clinical Studies:

Tunisia

Institute Pasteur Study

  • Study includes 40-60 PID patients tested before their IV-Ig treatment.

Pakistan

Pakistan – Aga Khan University Study

  • Assessing sensitivity, specificity, and usability in pediatric patients.
  • Study involves 130 children suspected of PID and 100 healthy controls.

These studies support the global use of the IgG Total Test for early detection of PID and polio surveillance.

Let’s Advance Global Health Together

Get in Touch with LifeSADX

For any purchasing enquiries or to partner with us for Global Access, for more information, product inquiries, and distribution opportunities, please contact us using the form below. Alternatively, you may send us an email at info@lifesadx.com