Study finds that PI-containing regimens have a beneficial effect on oral candidiasis independent of any immune reconstitution

Highly active antiretroviral therapy containing protease inhibitors (PIs) have an early beneficial effect on Candida virulence in the oral cavities, independent of any immune reconstitution, report Italian researchers.

Dr Antonio Cassone and colleagues at the department of Bacteriology and Medical Mycology of the Instituto Superiore di Sanita in Rome, say that PIs have this beneficial effect within weeks of starting treatment.

Previously Dr Cassone and colleagues had reported that some patients treated with PIs showed resolution of oral candidiasis long before any rise in the CD4+ T cell counts. The researchers hypothesised that PIs inhibited the activity of secretory aspartyl proteinase (Sap), a virulence trait for mucosal candidiasis. In the January 15 issue of the Journal of Infectious Diseases they report confirmation of this effect in a cross-sectional study of 30 therapy-naïve patients with HIV.

One group of 15 patients was treated with PI containing HAART regimens, and another group of 15 patients was treated with NNRTI HAART. The researchers tested saliva samples from all subjects on days 0, 14, 30, 90 and 180.

Of those treated with PI HAART, Sap was detected in the saliva of 11 patients at baseline and then in 6, 3, 0 and 0 at subsequent points. Of those treated with NNRTI HAART, Sap was detected in 7 patients at baseline and then in 7, 9, 6, and 5 patients at subsequent points.

In another 30 patients Sap was detected in 0 of 15 after one year on PI HAART, and it was detected in 7 of 15 subjects after a year of treatment on NNRTI HAART.

Dr Cassone and colleagues write: “The anti-Sap effect of PI HAART was associated with clinical resolution of oral candidiasis but not with late and inconstant recovery of anticandidal cellular immunity.

“In all subjects the two therapeutic regimens compared well in increasing CD4+ T cell counts and abating viraemia. Thus, PIs exert an early, immune reconstitution-independent effect on candida virulence in the oral cavities of HIV-positive subjects.”