Predictors and prognostic value of oral hairy leukoplakia and oral candidiasis in South African HIV-infected patients.

BACKGROUND: Oral hairy leukoplakia and oral candidiasis diseases (OHL/OC) are common clinical manifestations of HIV/AIDS. Sparse literature exists from resource-limited countries on their incidence and impact on HIV-infected patients. OBJECTIVE: To determine the predictors and prognosis of OHL/OC in HIV-infected patients. METHODS: Patients were drawn from a cohort established in 1992 and prospectively followed until 1997 in the adult HIV clinics, University of Cape Town. Cox hazards regression models were fitted to determine the predictors of OHL/OC, and the association between OHL/OC and progression to AIDS and death. RESULTS: 218 patients presenting with OHL/OC at their initial clinic visit were excluded. 205/772 patients developed OHL/OC (27.8 cases/100 years). White ethnicity (hazard ratio [HR] = 1.73, 95% CI 1.23-2.33), CD4+ count < 200 cells/(L (HR = 2.55, 95% CI 1.89-3.45), total lymphocyte count < 1250 cells/(L (HR = 1.72, 95% CI 1.28-2.31) and WHO stage 3 or 4 (HR = 2.61, 95% CI = 1.93-3.53) where variables predictive of increased hazard to developing OHL/OC. OHL/OC were independently associated with hazard of AIDS (HR = 3.65, 95% CI 1.89-6.69) and death (HR = 2.12, 95% CI 1.47-4.34). CONCLUSIONS: The presence of OHL/OC in HIV-infected patients provides important prognostic information, and can be used as a cost-effective tool for screening patients in therapeutic interventions in resource-limited settings.

Oral hairy leukoplakia: a manifestation of primary infection with Epstein-Barr virus?

Oral hairy leukoplakia (OHL) is a characteristic lesion presumably secondary to Epstein-Barr virus (EBV) reactivation. It is frequently seen in individuals infected with the human immunodeficiency virus (HIV) and less often in other immunosuppressed individuals. The frequent association of this lesion with HIV infection and its rare occurrence in normal individuals usually motivates the search for immunosuppression, particularly secondary to HIV, when this lesion is found. We describe here a healthy HIV-negative individual with OHL and clinical and laboratory data suggestive of acute EBV infection.

Bromodeoxyuridine incorporation and Ki 67 expression in oral hairy leukoplakia.

OBJECTIVES: Oral hairy leukoplakia (HL) is an acanthotic, hyperparakeratotic lesion characterised by the presence of a replicative Epstein-Barr virus (EBV) infection in the superficial and adjoining layers of the epithelium. EBV or its gene products are capable of modifying epithelial differentiation. The aim of this study was to establish whether the presence of EBV was associated with an alteration in cell turnover by assessing bromodeoxyuridine (BrdU) incorporation and Ki 67 expression in lesional tissue and control mucosa. METHODS: Biopsies of HL together with age, site and sex matched controls (n = 7 and 8 respectively) were incubated in 200 microM BrdU in vitro, fixed in methacarn and processed to paraffin wax. Following acid hydrolysis, incorporated BrdU and Ki 67 were identified in serial 5 microns sections using a three-stage immunoperoxidase technique and cell density expressed as the number of positive cells per mm basement membrane length. RESULTS: Overall, there was no difference in the number of BrdU positive cells per mm basement membrane length between control and HL tissue. However, within HL alone, the presence of focal EBV replication was associated with a significant reduction in the number of basal cells incorporating BrdU compared to adjacent EBV free areas (P < 0.05). There was no significant difference between Ki 67 positive cells in control and HL tissue and no evidence of a reduction of Ki 67 positive cells in areas associated with EBV replication. CONCLUSIONS: These results suggest that there is no evidence of a generalised alteration of the proliferative capacity of basal cells in HL, although the focal reduction in BrdU incorporation may reflect subtle changes on cell turnover by EBV infection.

Apoptosis-associated proteins in oral hairy leukoplakia.

OBJECTIVE: To test the hypothesis that the anti-apoptotic ability of Epstein-Barr virus (EBV) may result in altered expression of apoptosis-associated proteins in oral hairy leukoplakia (HL), we evaluated HL tissue and normal epithelium for these proteins by immunohistochemistry. MATERIALS AND METHODS: Twenty formalin-fixed, paraffin-embedded specimens of HL lesions and six specimens of normal control mucosa were selected from archived tissue specimens. Bcl-2, Bcl-x, Bax and p53 apoptosis-associated proteins were evaluated in immunohistochemically stained tissue sections according to staining intensity and pattern. The percentage of p53-positive basal cells was estimated in sequential fields. RESULTS: Generally, there were only slight differences in the expression of Bcl-2 and Bcl-x proteins in the epithelium of HL and control tissue. The staining for Bcl-2 was weaker in keratinocytes than in putative melanocytes and Langerhans cells. Equivocal diffuse cytoplasmic staining of prickle cells was also noted. Keratinocytes throughout the epithelium stained positively for Bcl-x protein, although upper layers were more weakly stained. The 'balloon' keratinocytes in HL were infrequently positive for Bcl-x. Bax staining in HL differed from that in control tissue in being more heterogeneous. The staining reaction in HL was weak to negative in upper epithelial levels where 'balloon' keratinocytes were located. Weak to moderate nuclear p53 protein staining was detected in a mean of 25.3% of basal keratinocytes in all but one of the HL specimens; weak staining was seen in only two control specimens. CONCLUSIONS: We found only slight immunohistochemical evidence that expression of the apoptosis-associated proteins is altered in HL. p53 appears to over-expressed in HL; we speculate that this may be related to up-regulation or stabilization of wild-type p53 protein related to EBV infection.

Relationship of circulating CD4+ T-lymphocytes and p24 antigenemia to the risk of developing AIDS in HIV-infected subjects with oral hairy leukoplakia.

To investigate the relationship of circulating CD4+ T-lymphocytes and p24 antigenemia to the development of AIDS in HIV-infected subjects with hairy leukoplakia (HL), we have followed over eight years 173 HIV-positive patients, all asymptomatic at the start of the study, and compared those who developed HL (n=55) to those who did not (n=118). Both groups included injection drug users (IDUs), homosexual men, and hemophiliacs. At the time of their first visit, both HL+ and HL- patients had a normal value of CD4+ cells and a low frequency of p24 antigenemia. During the years of follow-up, patients in the HL+ group showed a greater reduction in CD4+ cells, a significant increase in p24 antigenemia, and a higher rate of progression to AIDS. Our study demonstrates that in HIV-positive patients, HL is associated with more compromised immunological parameters and a higher viral replication and that its appearance has a negative prognostic value in relation to AIDS progression.

Effect of Epstein-Barr virus replication on Langerhans cells in pathogenesis of oral hairy leukoplakia.

Epstein-Barr virus (EBV) replicates productively in oral hairy leukoplakia (HLP). One characteristic of human immunodeficiency virus (HIV)-associated HLP is a decreased oral epithelial Langerhans cell count. This prospective study tested the hypothesis that oral epithelial EBV replication decreases oral Langerhans cell counts. EBV replication in HLP was highly correlated with decreased oral Langerhans cell counts. Inhibition of EBV replication restored oral Langerhans cell counts to normal control levels, and the return of EBV replication after treatment resulted in a recurrent decline in oral Langerhans cell counts. Decreased oral Langerhans cell counts occurred independently of HIV infection, as demonstrated in HLP of otherwise healthy HIV-seronegative individuals. These results support the tested hypothesis and suggest that EBV manipulates and evades the mucosal immune response in oral epithelial infection. This novel EBV strategy for eliminating oral Langerhans cells may facilitate the persistence of oral epithelial EBV and may contribute to the pathogenesis of HLP.

Persistent productive Epstein-Barr virus replication in normal epithelial cells in vivo.

Productive Epstein-Barr virus (EBV) replication characterizes hairy leukoplakia, an oral epithelial lesion typically occurring in individuals infected with human immunodeficiency virus (HIV). Serial tongue biopsy specimens were obtained from HIV-infected subjects before, during, and after valacyclovir treatment. EBV replication was detected by Southern hybridization to linear terminal EBV genome fragments, reverse-transcriptase polymerase chain reaction amplification of EBV replicative gene transcripts, immunohistochemical detection of EBV replicative protein, and in situ hybridization to EBV DNA. EBV replication was detected in both hairy leukoplakia and normal tongue tissues. Valacyclovir treatment completely abrogated EBV replication in vivo, resulting in resolution of hairy leukoplakia when it was present. EBV replication returned in normal tongue epithelial cells after valacyclovir treatment. These data suggest that normal oral epithelium supports persistent EBV infection in individuals infected with HIV and that productive EBV replication is necessary but not sufficient for the pathogenesis of oral hairy leukoplakia.