The Reliability of Candida Skin Test in Investigating Tcell function in Infants

Abstract

Cutaneous delayed-type hypersensitivity (DTH) is the classic in vivo test of cellular immune functions. The aim of this cross sectional study was to investigate the value of the locally prepared candida skin test as a measure of T cell function in comparison to an in-vitro assay. The study included 30 healthy infants 12-24 months old after exclusion of clinical criteria suggestive of immunodeficiency. They were 20 males and 10 females. They were all BCG vaccinated according to the obligatory program of vaccination in Egypt. The enrolled infants were clinically evaluated and subjected to laboratory investigations including, complete blood count with manual differential, in-vivo T cell function test (Candida and tuberculin intradermal skin tests) and in-vitro assessment of T cell function by measurement of IFN-γ in the supernatant of cultured mononuclear cells before and after PHA stimulation. Our results showed that 20 infants (66.7%) had BCG scar. Tuberculin and candida skin test were done in all infants but interpreted in twenty five only while the remaining five infantsdid not show after 48 hours to interpret the results. Seven (28 %) out of the 25 infants, had positive tuberculin skin test while 17 (68 %) of them had positive Candida skin test. The invitro assay was positive in most infants enrolled wheather candida skin test positive or negative.The mean level of IFN-γ in PHA stimulated cells was significantly higher than the mean level of IFN-γ in non stimulated cells.