Natural killer cell degranulation capacity predicts early onset of the immune reconstitution inflammatory syndrome (IRIS) in HIV-infected patients with tuberculosis.

Immune reconstitution inflammatory syndrome (IRIS) is a common and potentially serious complication occurring in HIV-infected patients being treated for tuberculosis (TB) using combined antiretroviral treatment. A role of adaptive immunity has been suggested in the onset of IRIS, whereas the role of natural killer (NK) cells has not yet been explored. The present study sought to examine the involvement of NK cells in the onset of IRIS in HIV-infected patients with TB and to identify predictive markers of IRIS. A total of 128 HIV-infected patients with TB from the Cambodian Early versus Late Introduction of Antiretroviral Drugs (CAMELIA) trial were enrolled in Cambodia. Thirty-seven of the 128 patients developed IRIS. At inclusion, patients had low CD4 cell counts (27 cells/mm(3)) and high plasma viral load (5.76 and 5.50 log/mL in IRIS and non-IRIS patients, respectively). At baseline, NK-cell degranulation capacity was significantly higher in IRIS patients than in non-IRIS patients (9.6% vs 6.38%, P < .005). At IRIS onset, degranulation capacity did not differ between patients, whereas activating receptor expression was lower in IRIS patients. Patients with degranulation levels > 10.84% had a higher risk of IRIS (P = .002 by log-rank test). Degranulation level at baseline was the most important IRIS predictor (hazard ratio = 4.41; 95% confidence interval, 1.60-12.16). We conclude that NK-degranulation levels identify higher IRIS risk in HIV-infected patients with TB.

In-vitro assessment of cutaneous immune responses to aedes mosquito salivary gland extract and dengue virus in Cambodian individuals.

Dengue virus (DENV) poses a global health threat, affecting millions individuals annually with no specific therapy and limited vaccines. Mosquitoes, mainly Aedes aegypti and Aedes albopictus worldwide, transmit DENV through their saliva during blood meals. In this study, we aimed to understand how Aedes mosquito saliva modulate skin immune responses during DENV infection in individuals living in mosquito-endemic regions. To accomplish this, we dissociated skin cells from Cambodian volunteers and incubated them with salivary gland extract (SGE) from three different mosquito strains: Ae. aegypti USDA strain, Ae. aegypti and Ae. albopictus wild type (WT) in the presence/absence of DENV. We observed notable alterations in skin immune cell phenotypes subsequent to exposure to Aedes salivary gland extract (SGE). Specifically, exposure lead to an increase in the frequency of macrophages expressing chemokine receptor CCR2, and neutrophils expressing CD69. Additionally, we noted a substantial increase in the percentage of macrophages that became infected with DENV in the presence of Aedes SGE. Differences in cellular responses were observed when Aedes SGE of three distinct mosquito strains were compared. Our findings deepen the understanding of mosquito saliva's role in DENV infection and skin immune responses in individuals regularly exposed to mosquito bites. This study provides insights into skin immune cell dynamics that could guide strategies to mitigate DENV transmission and other arbovirus diseases.

Rapid decrease in IL-1Ra and IP-10 plasma levels following tuberculosis treatment initiation.

OBJECTIVES: Monitoring tools that could provide quick predictions of tuberculosis (TB) treatment outcomes are urgently needed. Here, we assessed whether the evolution of selected biomarkers of innate immunity may help monitoring TB treatment response within 2 weeks of treatment initiation. METHODS: ANRS12394-LILAC-TB was a proof-of-concept prospective study: adults with a rifampicin-susceptible TB who are HIV-negative and HIV-infected documented by a positive Xpert MTB/RIF test were enrolled in Cambodia and Côte d'Ivoire. Plasma concentrations of interleukin-1 receptor antagonist (IL-1Ra), interferon-γ-induced protein-10 and clusters of differentiation (CD) (scavenging CD163) were measured by commercial enzyme-linked immunosorbent assay kits. A Wilcoxon test for paired data was used for longitudinal comparisons. RESULTS: A total of 55 patients were enrolled (women: 31%, median age: 37 years; median CD4 count in the 10 of 13 participants with HIV: 53 cells/mm3). Overall, 83% were considered in TB treatment success. Compared with baseline, the IL-1Ra plasma levels significantly decreased as soon as week (W) 1, independent of HIV status (-71% in HIV-positive vs -33% in HIV-negative; P <0.001). The IP-10 plasma levels significantly decreased at W1 and W2 compared with baseline (P <0.0001); however, that decrease was less marked in participants with HIV. CONCLUSIONS: Our findings suggest that measuring IL-1Ra plasma levels with a standard enzyme-linked immunosorbent assay technique at baseline and then 1 week after TB treatment onset could help clinicians to quickly assess TB treatment response.

Natural Killer Repertoire Restoration in TB/HIV Co-Infected Individuals Experienced an Immune Reconstitution Syndrome (CAMELIA Trial, ANRS 12153).

IRIS is a common complication in HIV-infected patients treated for tuberculosis (TB) and cART. Our aim was to evaluate NK cell reconstitution in HIV-infected patients with TB-IRIS compared to those without IRIS. 147 HIV-infected patients with TB from the CAMELIA trial were enrolled. HIV+TB+ patients were followed for 32 weeks. The NK cell repertoire was assessed in whole blood at different time points. As CAMELIA has two arms (early and late cART initiation), we analysed them separately. At enrolment, individuals had low CD4 cell counts (27 cells/mm3) and high plasma viral loads (5.76 and 5.50 log/mL for IRIS and non-IRIS individuals, respectively). Thirty-seven people developed IRIS (in the early and late arms). In the early and late arms, we observed similar proportions of total NK and NK cell subsets in TB-IRIS and non-IRIS individuals during follow-up, except for the CD56dimCD16pos (both arms) and CD56dimCD16neg (late arm only) subsets, which were higher in TB-IRIS and non-IRIS individuals, respectively, after cART. Regarding the repertoire and markers of NK cells, significant differences (lower expression of NKp30, NKG2A (CD159a), NKG2D (CD314) were observed in TB-IRIS compared to non-IRIS individuals after the start of cART. In the late arm, some changes (increased expression of CD69, NKG2C, CD158i) were observed in TB-IRIS compared to non-IRIS individuals, but only before cART initiation (during TB treatment). KIR expression by NK cells (CD158a and CD158i) was similar in both groups. CD69 expression by NK cells decreased in all groups. Expression of the NCR repertoire (NKp30, NKp44, NKp46) has similar kinetics in TB-IRIS subjects compared to non-IRIS subjects regardless of the arm analysed. NK cell reconstitution appeared to be better in TB-IRIS subjects. Although NK cell reconstitution is impaired in HIV infection after cART, as previously reported, it does not appear to be affected by the development of IRIS in HIV and TB-infected individuals.

Robust and Functional Immune Memory Up to 9 Months After SARS-CoV-2 Infection: A Southeast Asian Longitudinal Cohort.

The duration of humoral and cellular immune memory following SARS-CoV-2 infection in populations in least developed countries remains understudied but is key to overcome the current SARS-CoV-2 pandemic. Sixty-four Cambodian individuals with laboratory-confirmed infection with asymptomatic or mild/moderate clinical presentation were evaluated for Spike (S)-binding and neutralizing antibodies and antibody effector functions during acute phase of infection and at 6-9 months follow-up. Antigen-specific B cells, CD4+ and CD8+ T cells were characterized, and T cells were interrogated for functionality at late convalescence. Anti-S antibody titers decreased over time, but effector functions mediated by S-specific antibodies remained stable. S- and nucleocapsid (N)-specific B cells could be detected in late convalescence in the activated memory B cell compartment and are mostly IgG+. CD4+ and CD8+ T cell immune memory was maintained to S and membrane (M) protein. Asymptomatic infection resulted in decreased antibody-dependent cellular cytotoxicity (ADCC) and frequency of SARS-CoV-2-specific CD4+ T cells at late convalescence. Whereas anti-S antibodies correlated with S-specific B cells, there was no correlation between T cell response and humoral immune memory. Hence, all aspects of a protective immune response are maintained up to nine months after SARS-CoV-2 infection and in the absence of re-infection.

Virologic and immunologic outcomes in HIV-infected Cambodian children after 18 months of highly active antiretroviral therapy (HAART).

This observational cohort study was conducted among HIV-infected, antiretroviral therapy (ART) naive children in Phnom Penh, Cambodia, to evaluate the feasibility and efficacy of highly active antiretroviral therapy (HAART) delivered using a modified directly observed therapy (MDOT) protocol. From August 2004 to March 2006, 26 children were enrolled and started on a first-line HAART regimen, which was continued for 18 months. The study included a directly observed therapy phase (months 1-3) and a medication self-administration phase (months 4-18). CD4 percentage (CD4%) and HIV-1 RNA plasma viral load (PVL) were measured at baseline and at months 6, 12, and 18. At baseline, the median age was 5.5 years (range: 13 months-12 years), the median CD4% was 4, and the median PVL was 7.5x10(5) copies/ml. At 18 months, 23 (88%) children were alive and participating in the study. Of these children, 20 (87%) had a PVL <400 copies/ml and 12 (52%) had PVL < 50 copies/ml. The median CD4% increased to 23, while the median change in height-for-weight z-score was 0.64. Genotypic resistance typing in 2 children with PVL > 400 copies/ml at 18 months demonstrated mutations associated with resistance to lamivudine (M184V) and non-nucleoside reverse transcriptase inhibitors (Y181C and G190A). The virologic and immunologic outcomes achieved in this study compare favorably with those reported by other pediatric HIV treatment programs worldwide. The study results suggest that MDOT may be effective for HAART administration in limited-resource settings like Cambodia.

High Activation of γδ T Cells and the γδ2pos T-Cell Subset Is Associated With the Onset of Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome, ANRS 12153 CAPRI NK.

Background: Human Immunodeficiency Virus 1 (HIV-1) and Mycobacterium Tuberculosis (Mtb) co-infected patients are commonly at risk of immune reconstitution inflammatory syndrome (IRIS) when initiating antiretroviral treatment (ART). Evidence indicates that innate immunity plays a role in TB-IRIS. Here, we evaluate the phenotype of Gamma-delta (γδ) T cells and invariant Natural Killer (iNK) T cells in tuberculosis-associated IRIS. Methods: Forty-eight HIV+/TB+ patients (21 IRIS) and three control groups: HIV-/TB- (HD, n = 11), HIV+/TB- (n = 26), and HIV-/TB+ (n = 22) were studied. Samples were taken at ART initiation (week 2 of anti-tuberculosis treatment) and at the diagnosis of IRIS for HIV+/TB+; before ART for HIV+/TB-, and at week 2 of anti-tuberculosis treatment for HIV-/TB+ patients. γδ T cells and Invariant natural killer T (iNKT) cells were analyzed by flow cytometry. Results: Before ART, IRIS, and non-IRIS patients showed a similar proportion of γδpos T and iNKT cells. HLA-DR on γδpos T cells and δ2posγδpos T cells was significantly higher in TB-IRIS vs. non-IRIS patients and controls (p < 0.0001). NKG2D expression on γδpos T cells and the δ2posγδpos T cell subset was lower in HIV+/TB+ patients than controls. CD158a expression on γδpos T cells was higher in TB-IRIS than non-IRIS (p = 0.02), HIV+/TB-, and HIV-/TB- patients. Conclusion: The higher activation of γδposT cells and the γδ2posγδpos T cell subset suggests that γδ T cells may play a role in the pathogenesis of TB-IRIS.

A Treatment-Decision Score for HIV-Infected Children With Suspected Tuberculosis.

BACKGROUND: Diagnosis of tuberculosis should be improved in children infected with HIV to reduce mortality. We developed prediction scores to guide antituberculosis treatment decision in HIV-infected children with suspected tuberculosis. METHODS: HIV-infected children with suspected tuberculosis enrolled in Burkina Faso, Cambodia, Cameroon, and Vietnam (ANRS 12229 PAANTHER 01 Study), underwent clinical assessment, chest radiography, Quantiferon Gold In-Tube (QFT), abdominal ultrasonography, and sample collection for microbiology, including Xpert MTB/RIF (Xpert). We developed 4 tuberculosis diagnostic models using logistic regression: (1) all predictors included, (2) QFT excluded, (3) ultrasonography excluded, and (4) QFT and ultrasonography excluded. We internally validated the models using resampling. We built a score on the basis of the model with the best area under the receiver operating characteristic curve and parsimony. RESULTS: A total of 438 children were enrolled in the study; 251 (57.3%) had tuberculosis, including 55 (12.6%) with culture- or Xpert-confirmed tuberculosis. The final 4 models included Xpert, fever lasting >2 weeks, unremitting cough, hemoptysis and weight loss in the past 4 weeks, contact with a patient with smear-positive tuberculosis, tachycardia, miliary tuberculosis, alveolar opacities, and lymph nodes on the chest radiograph, together with abdominal lymph nodes on the ultrasound and QFT results. The areas under the receiver operating characteristic curves were 0.866, 0.861, 0.850, and 0.846, for models 1, 2, 3, and 4, respectively. The score developed on model 2 had a sensitivity of 88.6% and a specificity of 61.2% for a tuberculosis diagnosis. CONCLUSIONS: Our score had a good diagnostic performance. Used in an algorithm, it should enable prompt treatment decision in children with suspected tuberculosis and a high mortality risk, thus contributing to significant public health benefits.

Interleukin-1 receptor antagonist, a biomarker of response to anti-TB treatment in HIV/TB co-infected patients.

OBJECTIVES: Despite the high frequency of tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) in human immunodeficiency virus (HIV)/TB co-infected patients, no diagnostic test is available. Here, we investigated whether monocyte/macrophage activation markers can predict TB-IRIS occurrence and if they are modulated by anti-TB treatment. METHODS: Frozen plasma was obtained from 127 HIV/TB co-infected adults naïve for antiretroviral therapy, enrolled in the CAMELIA trial, 36 of whom developed TB-IRIS. Concentrations of IL-1Ra, sCD14, and sCD163 were measured at anti-TB treatment onset (baseline), after 8 weeks of anti-TB treatment and at TB-IRIS time. RESULTS: At baseline, IL-1Ra and sCD14 concentrations were similar in TB-IRIS and non-IRIS patients. sCD163 concentrations, although significantly higher in TB-IRIS patients, did not remain associated with TB-IRIS occurrence in multivariate analysis. At the time of TB-IRIS, patients displayed higher concentrations of IL-1Ra (p = 0.002) and sCD14 (p < 0.001). The most striking result was the significant decrease in IL-1Ra after 8 weeks of anti-TB treatment (median reduction: -63% (p < 0.0001)). CONCLUSIONS: None of the biomarkers tested was associated with TB-IRIS occurrence. However, repeated measurement of IL-1Ra could help for the diagnosis of TB-IRIS. The substantial reduction of IL-1Ra under treatment suggests that IL-1Ra could be a surrogate biomarker of anti-TB treatment response in HIV-infected patients.

A prospective, comparative study of severe neurological and uncomplicated hand, foot and mouth forms of paediatric enterovirus 71 infections.

OBJECTIVES: In this study, we document the clinical characteristics and investigated risk factors for uncomplicated and severe forms of EV-A71 disease in Cambodian children. METHODS: From March to July 2014 inclusive, all patients with suspicion of EV-A71 infection presenting to Kantha Bopha Hospitals in Phnom Penh and Siem Reap and confirmed by the Virology Unit at the Institut Pasteur du Cambodge were prospectively enrolled in this study. Throat swabs, rectal swabs and serum samples were collected from all consecutive patients with suspected EV-A71 infection. In addition, CSF was also collected from patients with suspected EV-A71 associated encephalitis. A total of 122 patients (29 with uncomplicated disease and 93 with severe disease) with confirmed EV-A71 infection with all available demographic and clinical data for clinical classification and further analysis were included in the study. RESULTS: In this prospective EV-A71 study in Cambodia, we confirmed the previously reported association of male gender and absence of mouth or skin lesions with severe disease. We also highlighted the strong association of neutrophils in blood, but also in CSF in patients with pulmonary oedema. More importantly, we identified new putative nutrition-related risk factors for severe disease. CONCLUSIONS: EV-A71 is an important cause of encephalitis in the Asia-Pacific region. Further studies to determine the risk factors associated with severe EV-A71 disease are needed.

Low frequency of acute hepatitis E virus (HEV) infections but high past HEV exposure in subjects from Cambodia with mild liver enzyme elevations, unexplained fever or immunodeficiency due to HIV-1 infection.

BACKGROUND: In Cambodia, previous studies conducted on hepatitis E virus (HEV) infection are scant, sometimes old, and showed inconsistent results. Moreover, there is no data about HEV infection in Cambodian HIV-1-infected patients. OBJECTIVES: To assess the occurrence of acute HEV infections and the level of past HEV exposure in one Mekong country. STUDY DESIGN: Using anti-HEV IgM and HEV RNA detection, we retrospectively investigated the presence of acute HEV infection in 825 individuals, including 350 subjects with or without fever, 300 subjects with or without liver enzyme elevations (LEE) and 175 antiretroviral treatment (ART)-naïve, severely immunocompromised HIV-1-infected patients. The detection of anti-HEV IgG was also performed to assess ancient HEV exposure. RESULTS: Nine individuals tested positive for anti-HEV IgM yielding an overall rate of 1.1% (95% confidence interval (CI), 0.5-2.0). We did not find significant differences for anti-HEV IgM rates between subjects with unexplained fevers (1.5%) and those with malaria or dengue-associated fever (1.7%) or non-febrile individuals (0%) (P=0.49), and between subjects with (1.5%) and without (2.0%) LEE (P=0.87). No HIV-infected patient tested positive for anti-HEV IgM. HEV RNA was not detected in all tested plasma specimens (n=578). Overall, the anti-HEV IgG prevalence rate was 30.1% (95% CI, 27.0-33.2). CONCLUSIONS: The scarcity of recent HEV infection contrasted with the high level of past HEV exposure. The role of HEV in liver disease is likely minor in Cambodia since no HEV RNA was detected in our studied populations, including HIV-positive patients with severe immunodepression.

Necrotic Tuberculin Skin (Mantoux) Test Reaction: A Case Report and an Estimation of Frequency.

Tuberculin skin testing was performed on a 5-year-old girl in Phnom Penh, Cambodia. She had been immunized by Bacille de Calmette et Guérin. She was tested because of a palpable cervical node and a slightly elevated temperature. Within 48 h, a deep necrotic lesion appeared on the volar aspect of the left arm. The lesion was treated locally, and the child was not treated for suspected TB. To our knowledge, this is the first instance of necrosis in 11,392 people who received Tubersol doses since 1996 to date at our International Vaccination Center, for an estimated incidence of 0.18 per 1,000 (95% Poisson 0.04-0.70 per 1,000 doses used). At a follow-up consultation after 77 days, the lesion had scarred and the child showed no signs suggestive of active TB. Although latent TB infection remains the most likely diagnosis, other types of mycobacterial infection may be considered in the tropical setting and in the absence of signs suggestive of active TB.

TB-IRIS, T-cell activation, and remodeling of the T-cell compartment in highly immunosuppressed HIV-infected patients with TB.

OBJECTIVE: To investigate the impact of tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) upon immunological recovery and the T-cell compartment after initiation of TB and antiretroviral therapy (ART). DESIGN AND METHODS: We prospectively evaluated T-cell immunophenotypes by flow cytometry and cytokines by Luminex assays in a subset (n = 154) of highly immunosuppressed HIV-infected patients with TB from the Cambodian Early versus Late Introduction of Antiretrovirals randomized clinical trial. We compared findings from patients who developed TB-IRIS with findings from patients who did not develop TB-IRIS. Data were evaluated with mixed-effect linear regression, Kaplan-Meier estimates, and Wilcoxon rank-sum tests, and q-values were calculated to control for multiple comparisons. RESULTS: Development of TB-IRIS was associated with significantly greater pre-ART frequencies of HLA-DRCD45ROCD4, CCR5CD4, OX40CD4, and Fas effector memory CD8 T cells, and significantly elevated levels of plasma interleukin (IL)-6, IL-1ß, IL-8, and IL-10, and viral load. Post-ART initiation, effector memory CD4 and Fas effector memory CD4 T-cell frequencies significantly expanded, and central memory CD4 T-cell frequencies significantly contracted in patients who experienced TB-IRIS. By week 34 post-TB treatment initiation, effector memory/central memory CD4 T-cell ratios were markedly higher in TB-IRIS versus non-TB-IRIS patients. CONCLUSIONS: A distinct pattern of pre-ART T-cell and cytokine markers appear to poise the immune response of certain patients to develop TB-IRIS. Experience of TB-IRIS is then associated with long-term remodeling of the CD4 T-cell memory compartment towards an effector memory-dominated phenotype. We speculate that these pre and post-ART TB-IRIS-associated immune parameters may contribute to superior immune control of TB/HIV co-infection and better clinical outcome.

HIV-specific antibodies but not t-cell responses are associated with protection in seronegative partners of HIV-1-infected individuals in Cambodia.

To study biological factors related to protection against HIV-1 infection in Cambodia, we recruited 48 partners of HIV-1-infected patients who remained uninfected (exposed uninfected individuals, EUs) despite unprotected sexual intercourse for more than 1 year and 49 unexposed controls (UCs). HIV-1-specific antibodies (IgA anti-gp41 and IgG anti-CD4-gp120 complex), T-cell responses, and cellular factors that may be involved in protection (peripheral blood mononuclear cell [PBMC] resistance to HIV-1 infection and beta-chemokine production) were evaluated. Anti-HIV-1 antibodies were higher in EUs than those in UCs (P = 0.01 and P = 0.04 for anti-gp41 and anti-CD4-gp120, respectively). We observed a decreased susceptibility to a primary Cambodian isolate, HIV-1KH019, in EU PBMCs as compared with UC PBMCs (P = 0.03). A weak T-cell response to one pool of HIV-1 Gag peptides was found by ELISpot in 1 of 19 EUs. Whereas T-cell specific immunity was not associated to protection, our results suggest that HIV-specific humoral immunity and reduced cell susceptibility to infection may contribute to protection against HIV-1 infection in Cambodian EUs.