Double-Negative T Cell Number and Phenotype Alterations Before and After Effective Antiretroviral Treatment in Persons Living with HIV

Double-negative (DN) T cells represent a small and phenotypically heterogeneous population that display regulatory functions. In HIV infection, DN T cells are decreased in peripheral blood and have been negatively associated with T cell activation. This study was aimed at describing the dynamics and phenotypic characteristics of DN T cells in peripheral blood of people living with HIV (PLHIV) before and after antiretroviral therapy (ART) initiation. We included 41 newly diagnosed, ART-naive individuals with advanced HIV infection, who were followed up for 6 months after ART initiation. The control group included 34 people without HIV (PWHIV), on preexposure prophylaxis for HIV infection. DN T cells in peripheral blood were characterized by flow cytometry. The absolute counts of DN T cells were lower in PLHIV than in PWHIV (p = 0.0223), and were particularly low in individuals with advanced HIV disease (p = 0.0311). Activation of DN T cells before ART initiation was directly associated with viral load (VL) (p = 0.0081, r = 0.4083) and inversely associated with CD4⁺ T cell counts (p = 0.0004, r = -0.4041). Compared with PWHIV, DN T cells of PLHIV expressed higher levels of CD57 (p = 0.0019), Ki67 (p = 0.0065), PD-1 (p = 0.0187), and CD38/HLA-DR (p < 0.0001). After 6 months on ART, expression of Ki67, PD-1, and CD38/HLA-DR on DN T cells returned to similar levels to those observed in PWHIV (p > 0.05 in all cases). However, expression of CD57 decreased only in individuals that start ART with high VL (p = 0.0127). DN T cell counts are decreased in HIV infection. Low DN T cell counts remained despite ART-induced immune reconstitution and viremia control. DN T cell phenotype is altered during chronic untreated infection with a high proportion of proliferating, activated, exhausted, and senescent cells. Most markers return to levels similar to those observed in PWHIV after ART. The impact of altered phenotype of DN T and their regulatory functions warrants further exploration.

Characterization of CD31 expression in CD4+ and CD8+T cell subpopulations in chronic untreated HIV infection

BACKGROUND

The platelet endothelial cell adhesion molecule-1 (PECAM-1) or CD31 has been involved in regulation of T-cell tolerance, activation, survival and homing in mice cells. However, there is limited knowledge about the expression pattern and role of this molecule in human T cells, particularly in conditions of chronic immune activation.

OBJECTIVES

We explored CD31 expression in T cell differentiation subsets of individuals with untreated HIV infection and in non-HIV-infected controls. We also assessed phenotypic differences between CD31+ and CD31- subsets in memory and terminally differentiated (TEMRA) CD4+ and CD8 + T cells.

METHODS

Forty-one individuals with untreated HIV infection and 34 non-HIV-infected controls were included in the study. We compared the expression of CD31 in CD4+ and CD8 + T cells across stages of differentiation in the two study groups by flow cytometry. We also analyzed the expression of CD57 (a marker of senescence), Ki67 (a marker of cycling cells), PD-1 (a marker of exhaustion), and CD38/HLA-DR (a marker of immune activation) on memory and TEMRA CD31+ and CD31- T cells.

RESULTS

CD31 expression was significantly higher in CD8 + T cells than in CD4 + T cells, measured as frequency, absolute numbers and median fluorescence intensity (MFI), in both study groups (p < 0.0001 in all cases). Intermediate differentiation subsets of CD4+ and CD8 + T cells expressed higher levels of CD31 in the context of HIV infection (p < 0.001 in all cases). CD31 expression frequency decreased with cellular differentiation of CD4+ and CD8 + T cells in both groups, but this decrease was steeper in individuals without HIV infection (CD4+: p < 0.001 and CD8+: p < 0.0001). As expected, memory and TEMRA CD4+ and CD8 + T cells expressed significantly higher levels of CD57, PD-1, Ki67 and CD38/HLA-DR in HIV-infected compared to non-HIV-infected individuals (p < 0.01 in all cases). CD31 expression was associated with lower activation of memory (but not TEMRA) CD4 + T cells in non-HIV-infected persons, an effect not observed in the HIV-infected group. CD31 expression on memory CD8 + T cells of HIV-infected individuals was associated higher levels of PD-1 (p = 0.0019) and CD38/HLADR (p = 0.0345), and higher PD-1 expression on CD8 + TEMRA (p = 0.0024), an effect not observed in non-HIV-infected individuals.

CONCLUSION

In the context of HIV-associated chronic immune activation, specifically on memory CD8 + T cells, CD31 expression was associated with higher PD-1 and CD38/HLA-DR co-expression, suggesting that CD31 expression may result from an insufficient attempt to contain T cell exhaustion and activation. CD31-targeted therapies may contribute to modulate these cellular responses.

Prevalence and risk factors for oral human papillomavirus infection in Mexican HIV-infected men

OBJECTIVE

To determine the prevalence and risk factors for oral high-risk human papillomavirus (HR-HPV) infec- tion in human immunodeficiency virus(HIV)-infected men.

MATERIALS AND METHODS

Consecutive male outpatients with HIV-infection were enrolled. Demographic and behav- ioral risk data were obtained. Anal swabs and oral rinses were tested for HR-HPV DNA. Oral, pharyngeal and video laryngoscopy examinations were performed for detection of lesions.

RESULTS

The prevalence of HR-HPV oral infection was 9.3% (subtypes other than HR HPV 16/18 predominated). The prevalence of anal HR-HPV infection was 75.7%. The risk factors for oral infection with HR-HPV were tonsillectomy (OR=13.12) and years from HIV diagnosis (OR=1.17).

CONCLUSIONS

Tonsillectomy and years from HIV diagnosis were associated with oral HPV infection. No association was found between oral and anal HR-HPV infections. This is the first study reporting the prevalence and risk factors for oral HR-HPV infection in Mexican HIV-infected population.

Hepatitis C virus infection and non-Hodgkin's lymphoma: a review and case report of nine patient

The role of hepatitis C virus (HCV) is well established in the development of chronic hepatitis, cirrhosis and hepatic carcinoma, as well as in mixed type II cryoglobulinemia, membranoproliferative glomerulonephritis(MPGN) and porphyria cutanea tarda (PCT). Increasing evidence has been reported of a close association of HCV infection with autoimmune and hematological processes, mainly cytopenias and lymphoproliferative disorders such as B cell non-Hodgkin's lymphoma. We describe the demographic, clinical and histopathological findings of nine patients from the Mexican population with non-Hodgkin's lymphoma and HCV infection.