Related Experiment Video
Updated: Mar 1, 2026
Precision Implementation of Minimal Erythema Dose MED Testing to Assess Individual Variation in Human Inflammatory Response
Published on: October 3, 2019
Need for Different Cutoff Values for Reading Mantoux Test with 2TU and 5TU PPD
Savitha M Ramaraj1, K Nagendra2, Girish Gopal2
1Department of Pediatrics, Mysore Medical College and Research Institute, Cheluvamba Hospital, Irwin Road, Mysore, Karnataka, 570001, India. drsavithamr@yahoo.com.
Insights
The 2 tuberculin unit (TU) and 5TU purified protein derivative (PPD) tests showed no agreement in diagnosing tuberculosis in children. Results indicate that 2TU PPD is not comparable to 5TU PPD for assessing cutaneous hypersensitivity.
Area of Science:
- Pediatrics
- Immunology
- Infectious Diseases
Background:
- Tuberculin skin testing is crucial for tuberculosis diagnosis.
- Standardized purified protein derivative (PPD) dosages are essential for reliable results.
- Comparing different PPD strengths is vital for accurate clinical interpretation.
Purpose of the Study:
- To compare the efficacy of 2 tuberculin unit (TU) versus 5TU purified protein derivative (PPD) in eliciting tuberculin reactions in healthy children.
- To assess the agreement between 2TU PPD and 5TU PPD in identifying latent tuberculosis infection.
Main Methods:
- A cross-sectional study involving 70 healthy children aged 1-12 years.
- Simultaneous Mantoux testing with 2TU and 5TU PPD, with reactions read at 48-72 hours.
- Statistical analysis using McNemar's test, Wilcoxon test, Bland-Altman plots, and kappa statistic to evaluate agreement.
Main Results:
- Only 1 child (10%) tested positive with 2TU PPD, while 7 children (10%) tested positive with 5TU PPD (p=0.031).
- Significant differences in mean induration diameter between 2TU and 5TU PPD (p<0.001).
- No agreement was found between the two PPD strengths based on Bland-Altman plots and kappa statistics.
Conclusions:
- Cutaneous hypersensitivity responses to 2TU PPD and 5TU PPD are not comparable in healthy children.
- The findings suggest potential discrepancies in tuberculosis screening when using different PPD concentrations.
Objective:
To compare the tuberculin reaction of 2 tuberculin unit (TU) with 5TU purified protein derivative (PPD) (both calibrated against RT 23) in healthy children.
Methods:
This was a cross sectional study done in the pediatric outpatient department of a tertiary care teaching hospital. Seventy healthy siblings of the children attending pediatric outpatient department in the age group of 1 to 12 y were enrolled. The exclusion criteria included previously diagnosed tuberculosis patients, malnutrition diagnosed according to the WHO classification, history of drug intake like steroids, recent history of measles, any skin lesions over forearm, history of fever, contact with tuberculosis and previous mantoux testing. The study was conducted wherein each child was subjected to simultaneous testing with 2TU and 5TU by standard technique. The reactions to both the tests was read at 48-72 h. Children with induration ≥10 mm were evaluated for tuberculosis by taking chest x-ray, gastric lavage or sputum smear examination for acid fast bacilli (AFB).
Results:
Considering ≥10 mm induration as positive, subjects positive with 5TU were 7 (10%) and 2TU was 1(p value = 0.031); thus, there is no agreement between the two methods (McNemar's test). Comparing the mean diameter of induration of 2TU and 5TU (p < 0.001, Wilcoxon test), signified no agreement between the two strengths. Bland-Altman plot and kappa statistic showed no agreement between the two strengths.
Conclusions:
Cutaneous hypersensitivity to 2TU PPD is not comparable to that of 5TU PPD.
More Related Videos
Related Concept Videos
01:26Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
01:31Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:
01:25Pulmonary Function Tests
Pulmonary Function Tests are crucial diagnostic tools for assessing respiratory function, particularly in patients with chronic respiratory disorders. They comprehensively evaluate lung volumes, ventilatory function, breathing mechanics, diffusion, and gas exchange. These tests help diagnose pulmonary diseases and play a significant role in monitoring disease progression, evaluating disability, and assessing response to therapy.
PFTs involve using a spirometer, a...
01:14Temperature Measurement Sites
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
01:13Equipments Used to Measure Body Temperature
Glass-bulb Thermometer:
Glass-bulb thermometers are hollow glass tubes with a bulb tip containing liquid such as ethanol or mercury. Historically, glass bulb mercury thermometers were the standard device to measure body temperature. Today, mercury thermometers are prohibited in many countries due to the hazardous effects of mercury and the risk of exposure if the glass bulb breaks. In general,...