Potential role of Candida albicans germ tube antibody in the diagnosis of deep-seated candidemia

Patients with candidemia may have transient or catheter-related infections without involvement of deep tissues or deep-seated candidiasis. Clinical differentiation of these entities may not be evident with conventional microbiological and imaging methods. Our aim was to determine if the detection of Candida albicans germ tube-specific antibody (CAGTA) in patients with candidemia was related to the extent of the disease. This study was conducted from 2003 to 2012 with 50 patients diagnosed as having candidemia, that is, 29 with deep-seated candidiasis and 21 with non-deep-seated candidiasis. The most common species recovered from samples obtained from these patients were C. albicans, 40%; C. tropicalis, 20%; C. parapsilosis, 18%; and C. glabrata, 12%. Serum samples were processed according to the manufacturer's recommendations (Vircell Microbiologist S. L., Granada, Spain). The CAGTA tests were positive in 1/21 non-deep-seated candidemias (DSCs; 4.76%) and 20/29 DSCs (68.96%; P < 0.01). Accordingly, the values for specificity and positive predictive values of CAGTA for identifying DSC were 95%. We concluded that the presence of a positive CAGTA test in a sample from a patient with candidemia suggests deep-seated candidiasis. Extension screening studies should be considered and origins other than catheters should be searched. Prospective studies are needed to determine the clinical implications of this finding and its potential use in defining the optimal duration of therapy.