Characterization of HIV-related periodontitis in AIDS patients: HIV-infected macrophage exudate in gingival crevicular fluid as a hallmark of distinctive etiology

In an attempt to clarify the immunobiological events featuring periodontitis lesions of AIDS patients in the late stage of the disease, peripheral blood (PB) and gingival crevicular fluid (GCF) leucocytes from periodontitis lesions of 23 late-stage AIDS patients were analysed by three-colour flow cytometry for detection and identification of intracytoplasmic p24(+) cell fractions. The cells were reacted with CD14 and CD68 for mononuclear phagocytes or with CD4 and CD14 for Th cells, then with anti-p24 MoAb. To detect HIV proviral sequences and intracellular p24 RNA sequences, genomic DNA and cellular RNA from leucocytes were extracted for semi-nested polymerase chain reaction (PCR) amplification. CD68(+)/p24(+) and CD14(+)/CD68(+)/p24(+) fractions were larger in GCF than in PB (P < 0.0001; P < 0.003). CD14(+)/p24(+) fraction was lower in GCF than in PB (P < 0.05). The fluorescence intensities (FI) for intracellular p24 in CD68(+) and CD14(+)/CD68(+) cells were higher in GCF than in PB (P < 0.003; P < 0.02), whereas those of CD14(+) macrophages did not differ. The p24 FI of CD68(+) macrophages in GCF correlated with CD4(+) lymphocyte counts in PB (P < 0.005). p24 FI levels of CD14(+) monocytes in GCF and PB significantly correlated (P < 0.02), whereas that of CD68(+) macrophages did not. PCR and reverse transcriptase (RT)-PCR of cellular DNA and RNA yielded positive signals, demonstrating viral integration and production in GCF leucocytes. These results show that periodontitis lesions in AIDS patients can be characterized by a rapid macrophage turnover, and these HIV-infected macrophage exudates in GCF may be considered as a within-mouth source of virus.