Association of T CD4 lymphocyte levels and subgingival microbiota of chronic periodontitis in HIV-infected Brazilians under HAART.

OBJECTIVE

The aim of this study was to determine the subgingival microbiota of HIV-infected patients with chronic periodontitis and different T CD4 lymphocyte levels under HAART.

STUDY DESIGN

64 HIV+ patients (mean age 34.5 +/- 7.3; 75% males) were distributed into Group I: chronic periodontitis (> or = 3 sites with probing pocket depth (PPD) and/or clinical attachment level (CAL) > or = 5 mm); and Group II: periodontal health (no sites with PPD > 3 mm and/or CAL > 4 mm). All subjects received conventional periodontal therapy. Periodontal clinical parameters were evaluated at 6 sites/tooth in all teeth at baseline and 4 months after therapy. The levels of T CD4 were obtained from the patient's medical record. Subgingival plaque samples were taken from the 6 sites with the largest pocket depth in each subject of Group I, and 6 randomly selected sites in subjects of Group II. The presence of 22 subgingival species was determined using the checkerboard DNA-DNA hybridization method. Significant microbiological differences within and among groups were sought using Wilcoxon signed-rank and Mann-Whitney tests, respectively. Relationships between T CD4 levels and microbiological parameters were determined using Kruskal-Wallis test.

RESULTS

Sixty-one percent of the HIV-infected patients represented AIDS cases, although 69% of them were periodontally healthy. The T CD4 lymphocyte mean level was 333 cells/mm3 and viral load was 12,815 +/- 24,607 copies/mm3. Yet, the prevalence of chronic periodontitis was relatively low (36%). Several periodontal pathogens, in particular T. forsythensis (P < .05), were more prevalent in HIV-positive patients with periodontitis than in HIV-positive subjects with periodontal health. Most of the species decreased in frequency after therapy, particularly P. gingivalis (P < .05). E. faecalis and F. nucleatum were significantly more prevalent in the subgingival microbiota of patients with chronic periodontitis and lower levels of T CD4 (P < .05), while beneficial species tended to be more frequently detected in individuals with T CD4 counts over 500 cells/mm3.

CONCLUSION

The subgingival microbiota of HIV-infected patients with chronic periodontitis include a high prevalence of classical periodontal pathogens observed in non-infected individuals. Furthermore, the severe immunosuppression seems to favor the colonization by these species, as well as by species not commonly found in the subgingival microbiota.