Antibodies Against A Beta-Glucan-Protein Complex Of Candida Albicans And Its Potential As Indicator Of Protective Immunity In Candidemic Patients

Sera from candidemic and non-candidemic subjects were examined for antibodies against the cell wall beta 1,3-and beta 1,6-glucans, as well as the beta-glucan-associated protein MP65 of Candida species. Although antibodies against each of the above components were detected in all subjects, candidemic patients had lower antibody titers against beta 1,3-glucan, but higher antibody titers against beta 1,6-glucan and MP65, than non-candidemic subjects. The elevated levels of anti-beta 1,6-glucan and -MP65 antibodies found in candidemic patients were independent on the patient risk category, APACHE II score, presence of co-morbidities, beta 1,3-glucanemia level, Candida isolate, and antifungal treatment. Interestingly, however, the anti-MP65, but not the anti-beta 1,6-glucan antibodies, of candidemic patients had higher titers in survivors than in non-survivors, particularly in those subject categories with the highest mortality (> 65-years old, diabetic, or septic shock patients). Thus, candidemic patients are capable of boosting anti-Candida immune responses upon infection, and some of these responses might be associated to the generation of protective immunity in patients with candidemia.