As has been observed with other, unstandardized, antigens used for DTH skin testing (14), it is possible that some patients may have exquisite immediate hypersensitivity to Candin®. In persons with bleeding tendency, bruising and non-specific induration may occur due to the trauma of the skin test.
There is currently no manufacturer warning information available for this drug.
Candin® is indicated for use as a recall antigen for detecting DTH by intracutaneous (intradermal) testing. The product may be useful in evaluating the cellular immune response in patients suspected of having reduced cellular hypersensitivity. Because some persons with normal cellular immunity are not hypersensitive to Candida, a response rate less than 100% to the antigen is to be expected in normal individuals. Therefore, the concurrent use of other licensed DTH skin test antigens is recommended. The product should not be used to diagnose or treat Type 1 allergy to Candida albicans.
Candida albicans Skin Test Antigen for Cellular Hypersensitivity (Candin®) is a clear, colorless, sterile solution with a pH of 8.0 – 8.5. The antigen should be administered intradermally according to the directions included under Dosage and Administration of this package insert.
Candin® is made from the culture filtrate and cells of two strains of Candida albicans. The fungi are propagated in a chemically defined medium consisting of inorganic salts, biotin and sucrose. Lyophilized source material is extracted with a solution of 0.25% NaCl, 0.125% NaHCO3 and 50% v⁄v glycerol. The concentrated extract is diluted with a solution of 0.5% NaCl, 0.25% NaHCO3, 0.03% Albumin (Human) USP, 8 ppm polysorbate 80 and 0.4% phenol.
The potency of Candin® is measured by DTH skin tests in humans. The procedure involves concurrent (side-by-side) testing of production lots with an Internal Reference (IR), using sensitive adults who have been previously screened and qualified to serve as test subjects. The induration response at 48 hours elicited by 0.1 mL of a production lot is measured and compared to the response elicited by 0.1 mL of the IR. The test is satisfactory if the potency of the production lot does not differ more than ± 20% from the potency of the IR, when analyzed by the paired t-test (two-tailed) at a p value of 0.05.
The potency of the IR is monitored by DTH skin testing. Persons included in the potency assay are qualified as test subjects by receiving four skin tests with the IR from which a mean induration response (mm) is calculated. Current skin tests with the IR must show that the potency of the IR has not changed more than ± 20% from the mean qualifying response in the same test subjects, when analyzed by the paired t-test (two-tailed) at a p value of 0.05. The required induration response at 48 hours to the IR is 15 mm ± 20%.
Skin Test Strength
The skin-test strength of Candin® has been determined from dose-response studies in healthy adults (see Clinical Pharmacology). The product is intended to elicit an induration response ≥5 mm in immunologically competent persons with cellular hypersensitivity to the antigen (see Dosage and Administration).
