PURIFIED PROTEIN DERIVATIVE
Indications And Clinical Uses: If there is reason to believe that an individual is infected with a mycobacterium other than M. tuberculosis var. hominis, as an added diagnostic procedure, PPD-B (Mantoux), 0.05 g per test dose may be injected using Tuberculin PPD (Mantoux), 5 TU (bioequivalent) per test dose, as a control. Injections are usually made in the same forearm not less than 5 to 7.5 cm apart, but if necessary may be made on opposite forearms. Since it is well known that cross-reactivity between Tuberculin PPD and PPD-B takes place, it is generally accepted that an individual who shows a larger positive reaction to PPD-B than to Tuberculin PPD is possibly infected with a mycobacterium other than M. tuberculosis var. hominis. Skin testing with PPD-B (Mantoux) can therefore be used as a differential diagnostic test.
Contra-Indications: There are no contraindications.
Warnings: Caution: Reactivity to the test may be depressed or suppressed for as long as 4 to 6 weeks in individuals who have received concurrent or recent immunization with certain virus vaccines (measles, influenza), have had viral infections (rubeola, influenza, mumps and probably others) or who are receiving corticosteroids or immunosuppressive agents.
Dosage And Administration: The test dose for Tuberculin PPD (Mantoux) is 0.1 mL containing 5 TU (0.05 g of PPD), and for PPD-B (Mantoux), the test dose is 0.1 mL containing 0.05 g of Purified Protein Derivative.
Administration: The site of the test is the flexor surface of the forearm about 10 cm below the bend of the elbow.
The skin of the forearm is first cleansed with alcohol and allowed to dry.
The test material is administered intracutaneously with a 1 mL syringe calibrated in tenths and fitted with a short, 3/8″ or 1/2″, 26-or 27-gauge needle.
Disposable sterile syringes and needles may be used. Glass syringes and needles should be sterilized by autoclaving (121°C for 30 minutes), by boiling or by the use of dry heat. Do not sterilize by means of alcohol.
The rubber cap of the vial should be wiped with cotton moistened with alcohol or other suitable antiseptic. The needle is then inserted gently through the cap and a small amount (0.1 mL) of the Tuberculin PPD or PPD-B (Mantoux) is drawn into the syringe, used for rinsing and then completely expelled.
The required amount of antigen is then drawn into the syringe.
The point of the needle is inserted into the most superficial layers of the skin with the needle bevel pointing upward. If the intracutaneous injection is performed properly, a definite white bleb will rise at the needle point, about 1 cm in diameter. This will disappear within minutes. No dressing is required.
If several persons are being tested at one time, it is advisable to use a separate sterilized needle for each individual injection.
Interpretation of the Test: The test is read 48 to 72 hours after administration of the test antigens. The widest diameter of distinctly palpable induration, measured at right angles to the long axis of the arm, should be recorded. Presence of redness, edema or necrosis should also be recorded. Any distinct induration measuring 10 mm or over is considered a positive reaction. Indurations between 5 to 9 mm are considered doubtful.
An individual who does not show a positive reaction to the test dose of PPD-B (Mantoux) may be considered as negative for “atypical” mycobacterial infections.
A positive reaction to PPD-B (Mantoux) larger than to Tuberculin PPD (Mantoux) indicates a sensitivity, which may be the result of a previous infection with atypical mycobacteria. Thus a control test with Tuberculin PPD (Mantoux) should always be performed as indicated above under the heading Indications.
Those individuals giving a positive reaction 10 mm or greater to PPD-B (Mantoux) may or may not show evidence of infection by M. tuberculosis. Chest X-ray examination in these cases is recommended as a means of determining the presence or absence, of pulmonary tuberculosis.
As a result of 2 studies using Tuberculin PPD (Mantoux) and PPD-B (Mantoux), it has been found that in cases of high sensitivity to Tuberculin PPD (indurations greater than 10 mm), the probability of misclassification is of the order of 10%, while in cases of low sensitivity (5 to 9 mm) this probability would increase to about 50%. Therefore, even for those individuals highly sensitized to Tuberculin PPD, a greater response to PPD-B (Mantoux) than to Tuberculin PPD may be due to cross-reactivity and does not necessarily indicate that an individual is infected with “atypical” mycobacteria.
Thus, although testing with PPD-B (Mantoux) can be a valuable aid in detecting those who have been infected with mycobacteria other than M. tuberculosis, additional tests such as bacteriological identification, animal tests, etc. should be carried out before an accurate diagnosis can be reached as to the nature of the mycobacterial strain involved.
Availability And Storage: PPD-B (Mantoux): Purified Protein Derivative (PPD-B), for intracutaneous (Mantoux) testing for “atypical” mycobacterial infections in humans, is prepared from M. avium-intracellulare (Battey bacillus) grown on a protein-free synthetic medium. It is available in the form of a stabilized solution in sterile isotonic phosphate-buffered saline containing Tween 80 0.0005%. Phenol 0.28% has been added as a preservative. The solution is standardized by intracutaneous testing in Battey-sensitized guinea pigs against the Connaught House Standard. Each mL contains: PPD-B (Mantoux) 0.5 g. Vials of 1 mL containing 10 test doses. When stored in the cold, 2 to 8°C, the stabilized PPD-B (Mantoux) solution keeps its potency for at least 1 year after the date of release for distribution. The preparation is ready for immediate use without further dilution.
Tuberculin PPD (Mantoux): Vials of tuberculin PPD (Mantoux) 5 TU (bioequivalent) to be used as the control containing 10 and 50 test doses.
Store in a refrigerator at 2 to 8°C.
PURIFIED PROTEIN DERIVATIVE Connaught PPD-B (Mantoux) Diagnostic Antigen
Posted by RxMed