CD4 T-cell activation and reduced regulatory T-cell populations are associated with early development of cataracts among HIV-infected adults in Uganda

Chronic immune activation and accelerated immune aging among HIV-infected adults receiving suppressive antiretroviral therapy for at least 12 years in an African cohort

Background

HIV-associated alterations innate and adaptive immune cell compartments are reminiscent of the process of immune aging.

Objectives

We described immune aging phenotypes among ART-treated HIV-infected adults relative to age-matched HIV-negative counterparts.

Methods

In a cross-sectional comparative study of HIV-infected adults with CD4≥500 cells/μl after at least 12 years of suppressive ART and age-and-gender-matched HIV-negative individuals, immune activation and immune aging phenotypes were measured, using multi-color flowcytometry.

Results

ART-treated HIV-infected individuals had higher body mass index (P = 0.004), waist-hip circumference (P = 0.041), hip circumference (P < 0.001), and diastolic blood pressure (P = 0.012) and immune activation (CD4+CD38+HLADR+; median 4.15,IQR(1.030,14.6)] relative to the HIV-negative age-matched individuals [median 3.14,IQR(1.030, 6.68)]; P=0.0034. Immune aging markers [CD4+CD57+T-cells; median 13.00 IQR (0.45,64.1)] were higher among HIV-infected ART-treated adults<50 years relative to HIV-negative<50 years[median 8.020,IQR(0.004,21.2)]; P=0.0010. Naïve CD4 T-cells, Central memory CD4 T-cells, Terminal Effector Memory T cells (TEMRA: CD27-CD45RA + CCR7-) and immune senescence CD4/CD8+CD28-/CD57+ T-cells were similar among ART-treated HIV-infected individuals<45 years relative to 60 years-and-older HIV-negative counterparts≥; p = 0.0932, p = 0.05357, p = 0.0950 and p = 0.5714 respectively.

Conclusion

ART-treated adults are immunologically two decades older than their HIV-negative counterparts. Accelerated immune aging among individuals aging with HIV underscores the need for an HIV cure to avert the unprecedented complications of accelerated immune senescence and the associated NCD risk in African settings with protracted exposure to endemic co-infections.

Different Immune Control of Gram-Positive and Gram-Negative Mammary Infections in Dairy Cows

In the dairy industry, bovine mastitis represents a major concern due to substantial production losses and costs related to therapies and early culling. The mechanisms of susceptibility and effective response to intra-mammary infections are still poorly understood. Therefore, we investigated innate immunity in acellular bovine skim milk through cytofluorimetric analyses of bacterial killing activity against both Gram-positive and Gram-negative pathogens. Freshly cultured E. coli and S. aureus strains were incubated with colostrum and milk samples at different lactation time points from two groups of cows, purportedly representing mastitis-resistant and mastitis-susceptible breeds; bacterial cells were analyzed for vitality by flow cytometry following incorporation of vital dyes. N-acetyl-β-D-glucosaminidase (NAGase) activity was also investigated in milk and colostrum samples. Our findings revealed that colostrum and milk bacterial killing activity was greater against S. aureus compared to E. coli., with this activity correlated with milk NAGase levels. Furthermore, both killing of S. aureus and NAGase activity were negatively correlated to the elapsed time of lactation. Interestingly, samples from the allegedly mastitis-resistant breed displayed higher bacterial killing and NAGase activities. Our study suggests that diverse control mechanisms are exerted against Gram-positive and Gram-negative pathogens in the mammary glands of cows, probably beyond those already described in the literature.

Increased Levels of Caspase-1 and IL-1β Among Adults With Persistent Immune Activation After 12 Years of Suppressive Antiretroviral Therapy in the Infectious Diseases Institute HIV Treatment Cohort

Background

We sought evidence of activated pyroptosis and the inflammasome pathways among human immunodeficiency virus (HIV)-infected adults after 12 years of suppressive antiretroviral therapy (ART) and persistent immune activation in the Infectious Diseases Institute HIV treatment cohort in Uganda.

Methods

In a cross-sectional study, using peripheral blood mononuclear cells of HIV-infected individuals with high and low immune activation (CD4/CD8+CD38+HLA-DR+ cells) relative to HIV-negative reference group, caspase-1 expression was measured using flow cytometry and plasma interleukin 18 and interleukin 1β (IL-1β) levels using enzyme-linked immunosorbent assay.

Results

There was higher expression of caspase-1 by CD4 T cells of ART-treated individuals with high immune activation relative to those with lower immune activation (P = .04). Similarly, plasma levels of IL-1β were higher among ART-treated individuals with high immune activation levels relative to those with low immune activation levels (P = .009). We observed a low positive correlation between caspase-1 expression by CD4/CD8 T cells and immune activation levels (r= 0.497 and r= 0.329, respectively).

Conclusions

Caspase-1 and IL-1β were high among individuals with high immune activation despite 12 years of suppressive ART. There is a need to further understand the role of persistent abortive infection and the latent HIV reservoir characteristics as drivers of persistent activation and inflammation and to subsequently intervene to prevent the complications of chronic immune activation during long-term ART.

A prospective, randomized, non-blinded, non-inferiority pilot study to assess the effect of low-dose anti-thymocyte globulin with low-dose tacrolimus and early steroid withdrawal on clinical outcomes in non-sensitized living-donor kidney recipients

BACKGROUND

The optimal dose of anti-thymocyte globulin (ATG) as an induction regimen in Asian living-donor kidney recipients is unclear.

METHODS

This is a pilot study in which 36 consecutive patients undergoing living-donor kidney transplantation were randomly assigned to receive either 4.5 mg/kg (n = 19) or 6.0 mg/kg (n = 17) of ATG; all patients had corticosteroid withdrawal within 7 days. The primary end point was a composite of biopsy-proven acute rejection, de novo donor-specific antibody formation, and graft failure.

RESULTS

At 12 months post-transplant, biopsy-proven acute rejection was more common in the ATG4.5 group (21.1%) than in the ATG6.0 group (0%)(P = .048). Importantly, the rate of the composite end point was significantly higher in the ATG4.5 group (36.8% vs 0%)(P = .006). There were significant differences in neither the renal function nor adverse events between the two groups. One case of death-censored graft failure occurred in the ATG4.5 group and no mortality was observed overall. Compared with pre-transplantation, T cells, natural killer (NK) cells, and natural killer T (NKT) cells were significantly decreased in the first week post-transplantation except for B cells. Although T and NKT cells in both groups and NK cells in the ATG4.5 group had recovered to the pre-transplant levels, NK cells in the ATG6.0 group remained suppressed until six months post-transplant.

CONCLUSIONS

Compared with ATG 6.0 mg/kg, ATG 4.5 mg/kg with early corticosteroid withdrawal and low dose maintenance regimen was associated with higher rates of acute rejection in non-sensitized Asian living-donor kidney recipients.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02447822.

B Cell Compartmentalization in Blood and Cerebrospinal Fluid of HIV-Infected Ugandans with Cryptococcal Meningitis

Activated B cells modulate infection by differentiating into pathogen-specific antibody-producing effector plasmablasts/plasma cells, memory cells, and immune regulatory B cells. In this context, the B cell phenotypes that infiltrate the central nervous system during human immunodeficiency virus (HIV) and cryptococcal meningitis coinfection are ill defined. We characterized clinical parameters, mortality, and B cell phenotypes in blood and cerebrospinal fluid (CSF) by flow cytometry in HIV-infected adults with cryptococcal (n = 31) and noncryptococcal (n = 12) meningitis and in heathy control subjects with neither infection (n = 10). Activation of circulating B cells (CD21low) was significantly higher in the blood of subjects with HIV infection than in that of healthy controls and greater yet in matched CSF B cells (P < 0.001). Among B cell subsets, elevated frequencies of memory and plasmablasts/plasma cells most clearly distinguished the CSF from blood compartments. With cryptococcal meningitis, lower frequencies of expression of the regulatory protein programmed death-1 (PD-1) on plasmablasts/plasma cells in blood (median, 7%) at presentation were associated with significantly decreased 28-day survival (29% [4/14 subjects]), whereas higher PD-1 expression (median, 46%) characterized subjects with higher survival (88% [14/16 subjects]). With HIV infection, B cell differentiation and regulatory markers are discrete elements of the circulating and CSF compartments with clinical implications for cryptococcal disease outcome, potentially due to their effects on the fungus and other local immune cells.

Effects of HIV infection and ART on phenotype and function of circulating monocytes, natural killer, and innate lymphoid cells

HIV infection causes upregulation of markers of inflammation, immune activation and apoptosis of host adaptive, and innate immune cells particularly monocytes, natural killer (NK) and innate lymphoid cells (ILCs). Although antiretroviral therapy (ART) restores CD4 T-cell counts, the persistent aberrant activation of monocytes, NK and ILCs observed likely contributes to the incomplete recovery of T-cell effector functions. A better understanding of the effects of HIV infection and ART on the phenotype and function of circulating monocytes, NK, and ILCs is required to guide development of novel therapeutic interventions to optimize immune recovery.

Elevated inflammatory cytokines in aqueous cytokine profile in HIV-1 infected patients with cataracts in Uganda

BACKGROUND

Cataracts occur earlier among HIV-infected adults and this is attributed to various intraocular inflammatory processes that result in early degeneration. In this study we purposed to investigate whether HIV infected individuals with cataracts develop heightened intraocular inflammatory processes compared to their HIV negative counterparts by determining the concentration of 8 cytokines in the aqueous humour of HIV-positive adults with cataracts and their HIV-negative counterparts.

METHODS

A cross-sectional study was conducted among consecutive adults with cataracts that were operated in an ophthalmology surgical camp in western Uganda. We determined levels of Granulocyte macrophage stimulating factor (GM-CSF), interleukin 6 (IL-6), interleukin 8 (IL-8), tumour necrotic factor alpha (TNF-a), interferon gamma (IFN-g), interleukin 4 (IL-4), interleukin 2 (IL-2), and interleukin (IL-10) in the aqueous fluid using a multiplexed cytokine analysis. Data was entered in the SPSS version 10 and analyzed using STATA statistical software version 7.0. Categorical and continuous variables were compared using the χ2 test, Fisher's exact test and the Student's t-test. Bonferroni correction was used to cater for multiple comparison of p values for the various cytokines.

RESULTS

The 50 adults that underwent cataract surgery were outdoor peasants with similar exposure hours to UV radiation. The HIV-positive patients were younger {median age 43 years (SD 11.741)} compared to the HIV -negative patients {median age 66.5 years (SD 21.4)}. The mean CD4+ T cell count of the HIV-positive patients was 161 cells /mm3, and 12(48%) had started anti-retroviral therapy (ART). Pro inflammatory cytokines, GM-CSF, IL-8 and IL-10 were significantly higher among HIV-positive individuals (p = 0.001, 0.030, < 0.001 respectively). HIV-positive individuals on ART also showed significantly higher levels of GM-CSF, IL-8 and IL - 10 (p = 0.002, 0.021, < 0.001 respectively). TNF-a and IL-4 were significantly higher among those with a CD4+ T cell count greater than 200cells/mm3 compared to those with CD4+ T cell count less than 200 cells/mm3 (p = 0.022, 0.032 respectively).

CONCLUSION

Cataracts among HIV-positive adults were associated with higher intraocular inflammation relative to the healthy elderly individuals with cataracts. There is need to explore the potential role of intra-ocular anti-inflammatory agents in the management of cataracts among HIV positive patients.

Acute Spontaneous Coronary Artery Thrombosis as Initial Presentation of HIV Infection in a Young Man

Introduction. The presentation of acute coronary syndrome (ACS) in young HIV patients may be atypical with different pathophysiological and clinical features. Acute coronary thrombosis, as a presentation of acute coronary syndrome in young patients with HIV, raises diagnostic and treatment challenges. Case Presentation. We describe a case of a 33-year-old African man, without traditional atherosclerotic risk factors, who presented with chest pain of acute onset. Emergent coronary angiography revealed extensive thrombus in the left anterior descending coronary artery with no evidence of atherosclerosis in this or other coronary vessels. Plaque and/or thrombus prolapse through the stent was noted following percutaneous coronary intervention (PCI). Resolution of chest pain and improvement in ST-segment elevation was noted after the procedure. A diagnosis of HIV infection was made during the workup for HIV infection. Conclusion. In young patients without traditional risk factors, HIV infection is a possible etiological factor for spontaneous coronary artery thrombosis. Percutaneous coronary intervention in patients with this presentation may be compounded with atherothrombotic complications. The likely pathophysiological pathway is superficial endothelial cell denudation as a result of chronic inflammation and immune activation.