Soluble CD163 predicts incident chronic lung, kidney and liver disease in HIV infection

Biological and Clinical Implications of the Vascular Endothelial Growth Factor Coreceptor Neuropilin-1 in Human Immunodeficiency Virus

Plasma vascular endothelial growth factor (VEGF) coreceptor neuropilin-1 (NRP-1) had the largest association with coronary plaque in the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) proteomics analysis. With little known about NRP-1 in people with human immunodeficiency virus (PWH), we explored its relation to other proteins in REPRIEVE and validated our findings through a Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) case-cohort study by assessing its relation to host factors and incident cardiovascular disease and cancer. Within REPRIEVE, NRP-1 was associated with proteins involved in angiogenesis, signal transduction, immunoregulation, and cell migration/adhesion. Within CNICS, NRP-1 was associated with key host factors, including older age and male sex. NRP-1 was associated with an increased hazard of multiple cancers but a decreased prostate cancer risk. Finally, NRP-1 was most strongly associated with mortality and type 2 myocardial infarction. These data suggest that NRP-1 is part of a clinically relevant immunoregulatory pathway related to multiple comorbidities in PWH. Clinical Trials Registration. NCT02344290.

The clinical utility of CD163 in viral diseases

Macrophage activation and hypercytokinemia are notable presentations in certain viral infections leading to severe disease and poor prognosis. Viral infections can cause macrophage polarization into the pro-inflammatory M1 or anti-inflammatory M2 phenotype. Activated M1 macrophages usually restrict viral replication whereas activated M2 macrophages suppress inflammation and promote tissue repair. In response to inflammatory stimuli, macrophages polarize to the M2 phenotype expressing hemoglobin scavenger CD163 surface receptor. The CD163 receptor is shed as the soluble form, sCD163, into plasma or tissue fluids. sCD163 causes detoxification of pro-oxidative hemoglobin which produces anti-inflammatory metabolites that promote the resolution of inflammation. Hence, increased CD163 expression in tissues and elevated circulatory levels of sCD163 have been associated with acute and chronic inflammatory diseases. CD163 and other macrophage activation markers have been commonly included in the investigation of disease pathogenesis and progression. This review provides an overview of the involvement of CD163 in viral diseases. The clinical utility of CD163 in viral disease diagnosis, progression, prognosis and treatment evaluation is discussed.

Dried Blood Specimens as an Alternative Specimen for Immune Response Monitoring During HIV Infection: A Proof of Concept and Simple Method in a Pediatric Cohort

Programs to prevent mother-to-child HIV transmission do not reduce the number of infants exposed during pregnancy and breastfeeding. HIV-exposed but uninfected children (HEU) present higher risk of morbidity and mortality than HIV-unexposed and uninfected children (UU). In this line, the study of immune biomarkers in HIV could improve prediction of disease progression, allowing to diminish comorbidity risk. Dried blood specimens (DBS) are an alternative to serum for collecting and transporting samples in countries with limited infrastructure and especially interesting for groups such as pediatrics, where obtaining a high sample volume is challenging. This study explores the usefulness of DBS for immune profile monitoring in samples from 30 children under clinical follow-up in Kinshasa: 10 HIV-infected (HIV+), 10 HEU, and 10 UU. We have measured the gene expression levels of 12 immune and inflammatory markers (CD14, IL-6, TNFα, HVEM, B7.1, HIF-1α, Siglec-10, IRAK-M, CD163, B7H5, PD-L1, and Galectin-9) in DBS samples by reverse transcription of total RNA and RT-qPCR. Principal component analysis, Kruskal-Wallis test, and Mann-Whitney test were performed in order to study group differences. HIV+ children presented significantly higher levels of seven biomarkers (CD14, IL-6 HVEM, B7.1, Siglec-10, HIF-1α, and CD163) than the UU group. In HEU, we found seven biomarkers significantly elevated (CD14, IL-6, HVEM, B7.1, Siglec-10, HIF-1α, and IRAK-M) vs. UU. Six biomarkers (CD14, IL-6, HVEM, B7.1, Siglec-10, and HIF-1α) showed a significantly higher expression in both HIV+ and HEU vs. UU, with HVEM and CD14 being significantly overexpressed among HIV+ vs. HEU. Our data reveal the utility of DBS for immune response monitoring. Moreover, significant differences in specific biomarker expression across groups strongly suggest the effect of HIV infection and/or HIV exposure on these immune biomarkers' expressions.

Markers of inflammation and immune activation are associated with lung function in a multi-center cohort of persons with HIV

OBJECTIVES

Studies have shown that people with HIV (PWH) may be at increased risk for chronic lung diseases and lung function abnormalities, which may be associated with immune activation. We tested the association of a panel of 12 immune activation and inflammation biomarkers with spirometry and single-breath diffusing capacity for carbon monoxide (DLco).

DESIGN

Cross-sectional, observational study.

METHODS

Participants were enrolled from the Inflammation, Aging, Microbes and Obstructive Lung Disease cohort of PWH at two US sites. Biomarkers were examined and standardized spirometry and DLco testing were performed. We tested associations between each biomarker and lung function, examined individually and in combination, using multi-variable linear and logistic regression.

RESULTS

Among 199 participants, median forced expiratory volume in 1 s (FEV1) was normal (90% predicted) and median DLco was abnormal (69% predicted). The most common lung function abnormality (57%) was a normal FEV1 to forced vital capacity ratio with an abnormal DLco of 80% or less predicted (iso↓DLco). Two markers (IL-6, high-sensitivity C-reactive protein) were associated with FEV1% predicted, whereas eight markers (soluble CD14, soluble CD163, inducible protein-10, soluble CD27, IL-6, soluble tumor necrosis factor receptors 1 and 2, D-dimer) were associated with DLco% predicted. Compared with those participants with normal spirometry and DLco, five markers (soluble CD14, soluble CD163, interferon gamma inducible protein-10, soluble tumor necrosis factor receptors 1 and 2) were associated with iso↓DLco.

CONCLUSION

Among PWH, different markers of immune activation and inflammation are associated with FEV1% predicted than with DLco% predicted and with an iso↓DLco, representing possible unique pathways of chronic lung disease. Identifying plausible drivers of these inflammatory pathways may clarify mechanisms underlying impaired lung function in HIV infection and may identify therapeutic avenues.

Abnormal Levels of Some Biomarkers of Immune Activation Despite Very Early Treatment of Human Immunodeficiency Virus

BACKGROUND

Despite early antiretroviral therapy (ART), ART-suppressed people with human immunodeficiency virus (HIV) (PWH) remain at higher risk for infections and infection-related cancers than the general population. The immunologic pathways that remain abnormal in this setting, potentially contributing to these complications, are unclear.

METHODS

ART-suppressed PWH and HIV-negative controls, all cytomegalovirus seropositive and enriched for HIV risk factors, were sampled from an influenza vaccine responsiveness study. PWH were stratified by timing of ART initiation (within 6 months of infection [early ART] vs later) and nadir CD4+ T-cell count among later initiators. Between-group differences in kynurenine-tryptophan (KT) ratio, interferon-inducible protein 10, soluble CD14 and CD163, soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor were assessed after confounder adjustment.

RESULTS

Most participants (92%) were male, reflecting the demographics of early-ART initiators in San Francisco. Most biomarkers were higher among later-ART initiators. Participants in the early-ART group achieved near-normal soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor levels, but substantially higher KT ratio than those without HIV after confounder adjustment (P = .008). Soluble CD14, soluble CD163, and interferon-inducible protein 10 trended similarly.

CONCLUSIONS

While early-ART initiators restore near-normal levels of many inflammatory markers, the kynurenine pathway of tryptophan catabolism remains abnormally high. Because this pathway confers adaptive immune defects and predicts tuberculosis and cancer progression, this it may contribute to persistent risks of these complications in this setting.

Changes in Immune Activation During Pregnancy and the Postpartum Period in Treated HIV Infection

Background

Pregnant women with HIV (PWWH) have high postpartum morbidity and mortality from infections like tuberculosis. Immunologic changes during pregnancy and postpartum periods may contribute to these risks, particularly the immunoregulatory kynurenine pathway of tryptophan catabolism, which contributes to both HIV and tuberculosis pathogenesis and increases in the early postpartum period.

Methods

Women with HIV initiating antiretroviral therapy (ART) in the Uganda AIDS Rural Treatment Outcomes (UARTO) cohort who were pregnant at enrollment or became pregnant during observation were studied (n = 54). Plasma kynurenine/tryptophan (KT) ratio, soluble CD14 (sCD14), sCD163, sCD27, interferon-inducible protein 10 (IP-10), D-dimer, interleukin-6, and intestinal fatty-acid binding protein levels were assessed through the first year of ART and at 3-month intervals throughout pregnancy and 1 year postpartum. Biomarker changes were assessed with linear mixed models adjusted for ART duration. Hemoglobin concentration changes were used to estimate pregnancy-related changes in plasma volume.

Results

The median pre-ART CD4 count was 134. D-dimer increased through the third trimester before returning to baseline postpartum, while most other biomarkers declined significantly during pregnancy, beyond what would be expected from pregnancy-associated plasma volume expansion. IP-10 and sCD14 remained suppressed for at least 12 months postpartum. KT ratio was the only biomarker that increased above prepregnancy baseline postpartum (mean + 30%; P < .001) and remained higher than baseline for ≥9 months (P ≤ .045 for all time points).

Conclusions

Several immune activation markers decline during pregnancy and remain suppressed postpartum, but the kynurenine pathway of tryptophan catabolism increases above baseline for ≥9 months postpartum. The mechanisms underlying postpartum kynurenine pathway activity are incompletely understood but may contribute to increased tuberculosis risk in this setting.

The Impact of Immunosuppression on Chronic Kidney Disease in People Living With Human Immunodeficiency Virus: The D:A:D Study

BACKGROUND

Relations between different measures of human immunodeficiency virus-related immunosuppression and chronic kidney disease (CKD) remain unknown.

METHODS

Immunosuppression measures included baseline, current, time-lagged and nadir CD4, years and percentage of follow-up (%FU) with CD4 ≤200 cells/μL, and CD4 recovery. CKD was defined as confirmed estimated glomerular filtration rate <60 mL/minute/1.73 m2.

RESULTS

Of 33 791 persons, 2226 developed CKD. Univariably, all immunosuppression measures predicted CKD. Multivariably, the strongest predictor was %FU CD4 ≤200 cells/μL (0 vs >25%; incidence rate ratio [IRR], 0.77 [95% confidence interval [CI], .68-.88]), with highest effect in those at low D:A:D CKD risk (IRR, 0.45 [95% CI, .24-.80]) vs 0.80 [95% CI, .70-.93]).

CONCLUSIONS

Longer immunosuppression duration most strongly predicts CKD and affects persons at low CKD risk more.

NASH in HIV

PURPOSE OF REVIEW

Aging-related comorbidities, including liver disease, represent the main drivers of morbidity and mortality in people with HIV (PWH). Nonalcoholic fatty liver disease (NAFLD) seems a frequent comorbidity in aging PWH nowadays. NAFLD results from a fat deposition into the liver parenchyma that may evolve to nonalcoholic steatohepatitis (NASH), a state of hepatocellular inflammation and injury in response to the accumulated fat leading to liver fibrosis and cirrhosis. We here review the current status of knowledge regarding this emerging comorbidity in PWH.

RECENT FINDINGS

Recent studies suggest that PWH are at higher risk for both NASH and NASH-related liver fibrosis. Several hypothesized pathogenic mechanisms may account for this finding, including increased metabolic comorbidities, hepatotoxic effect of lifelong antiretroviral therapy, and chronic HIV infection. In clinical practice, non-invasive diagnostic tests, such as serum biomarkers and elastography, may help identify patients with NASH-related fibrosis, thus improving risk stratification, and enhancing clinical management decisions, including early initiation of interventions such as lifestyle changes and potential pharmacologic interventions. Clinicians should remain informed of the frequency, significance, and diagnostic and management approach to NASH in PWH.

Endothelial Activation, Innate Immune Activation, and Inflammation Are Associated With Postbronchodilator Airflow Limitation and Obstruction Among Adolescents Living With HIV

BACKGROUND

Chronic inflammation, innate immune activation, T-cell imbalance and endothelial activation have been linked with lung diseases. We sought to determine whether markers of these pathophysiologic pathways were associated with spirometry and chest computed tomography (CT) abnormalities among adolescents living with HIV (ALWH).

SETTING

Coptic Hope Center for Infectious Diseases in Nairobi, Kenya.

METHODS

We performed a cross-sectional study of ALWH (10-19 years old). Participants underwent chest CT, spirometry, and venipuncture for serum biomarkers. We also collected demographic, anthropometric, T-cell subset, antiretroviral therapy, and exposure data. We compared characteristics and biomarkers by airflow obstruction [postbronchodilator FEV1/FVC z-score (zFEV1/FVC) < -1.64]. We used multivariable linear regression to determine associations of log10-transformed biomarkers and chest CT abnormalities with lower postbronchodilator zFEV1/FVC (airflow limitation). We performed exploratory principal components analysis on biomarkers, and determined associations of factors with postbronchodilator zFEV1/FVC and chest CT abnormalities.

RESULTS

Of 47 participants with acceptable quality spirometry, 21 (45%) were female, median age was 13 years and 96% had perinatally-acquired HIV. Median CD4 was 672 cells/µL. Overall, 28% had airflow obstruction and 78% had a chest CT abnormality; airflow obstruction was associated with mosaic attenuation (P = 0.001). Higher endothelial activation (sVCAM-1, sICAM-1), inflammation and innate immune activation (serum amyloid-A, sTREM-1, sCD163), and T-cell imbalance (lower CD4/CD8) markers were associated with airflow limitation. Factors comprising endothelial and innate immune activation were associated with airflow limitation.

CONCLUSIONS

Endothelial activation, innate immune activation, T-cell imbalance, and chronic inflammation are associated with airflow limitation and obstruction, providing insights into chronic lung disease pathophysiology among ALWH.

Toll-Like Receptor 3 Deficiency Leads to Altered Immune Responses to Chlamydia trachomatis Infection in Human Oviduct Epithelial Cells

Reproductive tract pathology caused by Chlamydia trachomatis infection is an important global cause of human infertility. To better understand the mechanisms associated with Chlamydia-induced genital tract pathogenesis in humans, we used CRISPR genome editing to disrupt Toll-like receptor 3 (TLR3) function in the human oviduct epithelial (hOE) cell line OE-E6/E7 in order to investigate the possible role(s) of TLR3 signaling in the immune response to Chlamydia Disruption of TLR3 function in these cells significantly diminished the Chlamydia-induced synthesis of several inflammation biomarkers, including interferon beta (IFN-β), interleukin-6 (IL-6), interleukin-6 receptor alpha (IL-6Rα), soluble interleukin-6 receptor beta (sIL-6Rβ, or gp130), IL-8, IL-20, IL-26, IL-34, soluble tumor necrosis factor receptor 1 (sTNF-R1), tumor necrosis factor ligand superfamily member 13B (TNFSF13B), matrix metalloproteinase 1 (MMP-1), MMP-2, and MMP-3. In contrast, the Chlamydia-induced synthesis of CCL5, IL-29 (IFN-λ1), and IL-28A (IFN-λ2) was significantly increased in TLR3-deficient hOE cells compared to their wild-type counterparts. Our results indicate a role for TLR3 signaling in limiting the genital tract fibrosis, scarring, and chronic inflammation often associated with human chlamydial disease. Interestingly, we saw that Chlamydia infection induced the production of biomarkers associated with persistence, tumor metastasis, and autoimmunity, such as soluble CD163 (sCD163), chitinase-3-like protein 1, osteopontin, and pentraxin-3, in hOE cells; however, their expression levels were significantly dysregulated in TLR3-deficient hOE cells. Finally, we demonstrate using hOE cells that TLR3 deficiency resulted in an increased amount of chlamydial lipopolysaccharide (LPS) within Chlamydia inclusions, which is suggestive that TLR3 deficiency leads to enhanced chlamydial replication and possibly increased genital tract pathogenesis during human infection.

Brief Report: Systemic Inflammation, Immune Activation, and Impaired Lung Function Among People Living With HIV in Rural Uganda

BACKGROUND

Although both chronic lung disease and HIV are inflammatory diseases common in sub-Saharan Africa, the relationship between systemic inflammation and lung function among people living with HIV (PLWH) in sub-Saharan Africa is not well described.

METHODS

We measured lung function (using spirometry) and serum high sensitivity C-reactive protein, interleukin 6 (IL-6), soluble CD14 (sCD14), and soluble CD163 (sCD163) in 125 PLWH on stable antiretroviral therapy (ART) and 109 age- and sex-similar HIV-uninfected control subjects in rural Uganda. We modeled the relationship between lung function and systemic inflammation using linear regression, stratified by HIV serostatus, controlled for age, sex, height, tobacco, and biomass exposure.

RESULTS

Half of subjects [46% (107/234)] were women, and the median age was 52 years (interquartile range: 48-55). Most PLWH [92% (115/125)] were virologically suppressed on first-line ART. Median CD4 count was 472 cells/mm. In multivariable linear regression models stratified by HIV serostatus, an interquartile range increase in IL-6 and sCD163 were each inversely associated with lung function (mL, 95% confidence interval) among PLWH [IL-6: forced expiratory volume in 1 second (FEV1) -18.1 (-29.1 to -7.1), forced vital capacity (FVC) -17.1 (-28.2 to -5.9); sCD163: FVC -14.3 (-26.9 to -1.7)]. High sensitivity C-reactive protein (>3 vs. <1 mg/L) was inversely associated with lung function among both PLWH and HIV-uninfected control subjects [PLWH: FEV1 -39.3 (-61.7 to -16.9), FVC -44.0 (-48.4 to -6.4); HIV-uninfected: FEV1 -37.9 (-63.2 to -12.6), FVC -58.0 (-88.4 to -27.5)]. sCD14 was not associated with lung function, and all interaction terms were insignificant.

CONCLUSIONS

Macrophage activation and systemic inflammation are associated with lower lung function among PLWH on stable ART in rural Uganda. Future work should focus on underlying mechanisms and public health implications.

Age-related M1/M2 phenotype changes in circulating monocytes from healthy/unhealthy individuals

Macrophage polarization is a candidate biomarker of disease-related inflammatory status, but its modulation during aging has not been investigated. To do this, the M1/M2 profile was assessed by CD80/CD163 gating in classical (CD14⁺⁺CD16^-), intermediate (CD14⁺⁺CD16⁺), and non-classical (CD14^lowCD16⁺) monocytes from 31 healthy subjects (CTRs) of different ages. Cytofluorimetric analysis showed a significantly different CD80/CD163 distribution in the three subsets, as more than 80% of classical and intermediate monocytes were CD80⁺CD163⁺, whereas most non-classical monocytes were CD80^-CD163^- and CD163⁺. Non-classical CD163⁺ monocytes were significantly higher whereas classical CD163⁺ and CD80^-CD163^- monocytes significantly lower in older than younger CTRs (cut-off, 65 years), suggesting different age-related trends for M2 subsets. To establish whether an M1/M2 imbalance could be associated with disease, 21 patients with acute myocardial infarction (AMI) were compared with older CTRs. The AMI patients showed a significantly decreased proportion of CD163⁺CD80⁺ and an increased proportion of CD163⁺ and CD163^-CD80^- cells among classical monocytes, opposite trends to those observed in healthy aging. Moreover, a significantly greater proportion of intermediate and non-classical CD80⁺ monocytes suggested a shift to a pro-inflammatory phenotype. Overall, CD163/CD80 cytofluorimetric characterization of circulating monocytes provides additional information about their polarization and could be an innovative tool to monitor aging.

Normalization of Soluble CD163 Levels After Institution of Antiretroviral Therapy During Acute HIV Infection Tracks with Fewer Neurological Abnormalities

Background

Myeloid activation contributes to cognitive impairment in chronic human immunodeficiency virus (HIV) infection. We explored whether combination antiretroviral therapy (cART) initiation during acute HIV infection impacts CD163 shedding, a myeloid activation marker, and in turn, implications on the central nervous system (CNS).

Methods

We measured soluble CD163 (sCD163) levels in plasma and cerebrospinal fluid (CSF) by enzyme-linked immunosorbent assay in Thais who initiated cART during acute HIV infection (Fiebig stages I-IV). Examination of CNS involvement included neuropsychological testing and analysis of brain metabolites by magnetic resonance spectroscopy. Chronic HIV-infected or uninfected Thais served as controls.

Results

We examined 51 adults with acute HIV infection (Fiebig stages I-III; male sex, >90%; age, 31 years). sCD163 levels before and after cART in Fiebig stage I/II were comparable to those in uninfected controls (plasma levels, 97.9 and 93.6 ng/mL, respectively, vs 99.5 ng/mL; CSF levels, 6.7 and 6.4 ng/mL, respectively, vs 7.1 ng/mL). In Fiebig stage III, sCD163 levels were elevated before cART as compared to those in uninfected controls (plasma levels, 135 ng/mL; CSF levels, 10 ng/mL; P < .01 for both comparisons) before normalization after cART (plasma levels, 90.1 ng/mL; CSF levels, 6.5 ng/mL). Before cART, higher sCD163 levels during Fiebig stage III correlated with poor CNS measures (eg, decreased N-acetylaspartate levels), but paradoxically, during Fiebig stage I/II, this association was linked with favorable CNS outcomes (eg, higher neuropsychological test scores). After cART initiation, higher sCD163 levels during Fiebig stage III were associated with negative CNS indices (eg, worse neuropsychological test scores).

Conclusion

Initiation of cART early during acute HIV infection (ie, during Fiebig stage I/II) may decrease inflammation, preventing shedding of CD163, which in turn might lower the risk of brain injury.

Soluble Macrophage Mannose Receptor (sCD206/sMR) as a Biomarker in Human Immunodeficiency Virus Infection

Macrophages play important roles during human immunodeficiency virus (HIV) infection, reflected by changes in macrophage-activation biomarker soluble CD163 (sCD163). Here, we present data on the novel macrophage-activation biomarker soluble mannose receptor/CD206 (sCD206) in HIV infection. We investigated sCD206 blood levels at baseline and follow-up with/without antiretroviral therapy (ART), in 212 patients with HIV type 1 (HIV-1), HIV type 2 (HIV-2), or dual infection. At baseline, there was no difference in sCD206 level between HIV types, and sCD206 was unchanged at follow-up without ART. However, in contrast to sCD163, sCD206 levels decreased significantly for both HIV-1 and HIV-2, but not for HIV-1/2 patients, during ART. Further investigations are needed to establish sCD206 as a biomarker in HIV infection.

Associations between baseline biomarkers and lung function in HIV-positive individuals

OBJECTIVE

The aim of this study was to analyse the association of baseline biomarker data with cross-sectional lung function and subsequent decline in lung function in HIV-positive persons.

DESIGN

Lung function was modelled in all START pulmonary substudy participants who had baseline biomarker data and good-quality spirometry. In longitudinal analyses, we restricted to those participants with at least one good-quality follow-up spirometry test.

METHODS

We performed linear regression of baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC and their longitudinal slopes on log2-transformed baseline biomarkers with adjustment for age, sex, race, region, smoking status, baseline CD4+ T-cell counts and baseline HIV-RNA. Biomarkers included D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-27, serum amyloid A, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1, albumin and total bilirubin.

RESULTS

Among 903 included participants, baseline median age was 36 years, CD4+ cell count was 647 cells/μl, and 28.5% were current smokers. In adjusted analyses, elevated markers of systemic inflammation (hsCRP, IL-6 and serum amyloid A) were associated with lower baseline FEV1 and FVC. Elevated D-dimer and IL-6 were associated with worse airflow obstruction (lower FEV1/FVC). Despite these cross-sectional associations at baseline, no associations were found between baseline biomarkers and subsequent longitudinal lung function decline over a median follow-up time of 3.9 years (3293 spirometry-years of follow-up).

CONCLUSION

Commonly available biomarkers, in particular markers of systemic inflammation, are associated with worse cross-sectional lung function, but do not associate with subsequent lung function decline among HIV-positive persons with early HIV infection and baseline CD4 T-cell counts more than 500 cells/μl.

Upregulation of Chitinase 1 in Alveolar Macrophages of HIV-Infected Smokers

Recent studies suggest that HIV infection is an independent risk factor for the development of chronic obstructive pulmonary disease (COPD). We hypothesized that HIV infection and cigarette smoking synergize to alter the function of alveolar macrophages (AMs). To test this hypothesis, global transcriptome analysis was performed on purified AMs from 20 individuals split evenly between HIV-uninfected nonsmokers and smokers and untreated HIV-infected nonsmokers and smokers. Differential expression analysis identified 143 genes significantly altered by the combination of HIV infection and smoking. Of the differentially expressed genes, chitinase 1 (CHIT1) and cytochrome P450 family 1 subfamily B member 1 (CYP1B1), both previously associated with COPD, were among the most upregulated genes (5- and 26-fold, respectively) in the untreated HIV-infected smoker cohort compared with HIV-uninfected nonsmokers. Expression of CHIT1 and CYP1B1 correlated with the expression of genes involved in extracellular matrix organization, oxidative stress, immune response, and cell death. Using time-of-flight mass cytometry to characterize AMs, a significantly decreased expression of CD163, an M2 marker, was seen in HIV-infected subjects, and CD163 inversely correlated with CYP1B1 expression in AMs. CHIT1 protein levels were significantly upregulated in bronchoalveolar lavage fluid from HIV-infected smokers, and increased CHIT1 levels negatively correlated with lung function measurements. Overall, these findings raise the possibility that elevated CHIT1 and CYP1B1 are early indicators of COPD development in HIV-infected smokers that may serve as biomarkers for determining this risk.

Epigenetic alterations are associated with monocyte immune dysfunctions in HIV-1 infection

Monocytes are key cells in the immune dysregulation observed during human immunodeficiency virus (HIV) infection. The events that take place specifically in monocytes may contribute to the systemic immune dysfunction characterized by excessive immune activation in infected individuals, which directly correlates with pathogenesis and progression of the disease. Here, we investigated the immune dysfunction in monocytes from untreated and treated HIV + patients and associated these findings with epigenetic changes. Monocytes from HIV patients showed dysfunctional ability of phagocytosis and killing, and exhibited dysregulated cytokines and reactive oxygen species production after M. tuberculosis challenge in vitro. In addition, we showed that the expression of enzymes responsible for epigenetic changes was altered during HIV infection and was more prominent in patients that had high levels of soluble CD163 (sCD163), a newly identified plasmatic HIV progression biomarker. Among the enzymes, histone acetyltransferase 1 (HAT1) was the best epigenetic biomarker correlated with HIV - sCD163 high patients. In conclusion, we confirmed that HIV impairs effector functions of monocytes and these alterations are associated with epigenetic changes that once identified could be used as targets in therapies aiming the reduction of the systemic activation state found in HIV patients.

Soluble CD163 and soluble CD14 plasma levels but not cellular HIV-DNA decrease during successful interferon-free anti-HCV therapy in HIV-1-HCV co-infected patients on effective combined anti-HIV treatment

Soluble CD163, soluble CD14 and cellular HIV-1-DNA levels reflect two different aspects of HIV infection: immune activation and the reservoir of infected cells. The aim of this study was to describe their relationships in a cohort of HIV-HCV co-infected patients successfully treated for both HCV and HIV infections. Fifty-five patients were recruited and studied prior to the start of direct-acting antivirals (DAAs) (T0), at week 12 of DAA treatment (T1) and 24 weeks after T0 (T2). The subjects were classified as having undetectable plasma HIV viraemia (UV) or low-level viraemia (LLV) in the 18 months before T2. Plasma levels of sCD163 and of sCD14 were comparable in patients with UV and in subjects with LVL at T0, T1 and T2. The HIV DNA level was positively correlated with LLV but not with sCD163 and sCD14 levels; these two markers of inflammation were positively correlated (p = 0.017). Soluble CD163 and sCD14 decreased over time from T0 to T2 (p = 0.000 and p = 0.034, respectively). In conclusion, the significant decrease in sCD163 and sCD14 levels in patients cured of HCV infection, regardless of the presence of LLV, suggests a main role for HCV in immune activation in HIV-HCV co-infected patients.

Pulmonary disease in HIV-infected adults in the era of antiretroviral therapy

: HIV in the antiretroviral therapy era is characterized by multimorbidity and the frequent occurrence of HIV-associated non-AIDS chronic health conditions. Respiratory symptoms and chronic pulmonary diseases, including chronic obstructive pulmonary disease, asthma, and cardiopulmonary dysfunction, are among the conditions that may present in persons living with HIV. Tobacco smoking, which is disproportionately high among persons living HIV, strongly contributes to the risk of pulmonary disease. Additionally, features associated with and at times unique to HIV, including persistent inflammation, immune cell activation, oxidative stress, and dysbiosis, may also contribute. This review summarizes the available literature regarding epidemiology of and risk factors for respiratory symptoms and chronic pulmonary disease in the current era.

Metabolic syndrome and obesity are the cornerstones of liver fibrosis in HIV-monoinfected patients

BACKGROUND

Metabolic syndrome (MetS) and nonalcoholic fatty liver disease have become a common finding in HIV-infected patients. However, the severity, risk factors and pathogenesis of liver fibrosis in this population have been poorly documented.

OBJECTIVES

To assess the impact of MetS on liver fibrosis and analyze the association between MetS, liver fibrosis and markers of adipose tissue and macrophage activation.

METHODS

In a matched cohort of HIV-1-monoinfected patients with and without MetS, after exclusion of other causes of liver disease, we assessed liver stiffness measurement and measured levels of serum adipokines, homeostasis model assessment index and soluble CD163 (sCD163) and CD14 as markers of fat, insulin resistance and macrophage/monocyte activation, respectively.

RESULTS

A total of 468 HIV-monoinfected individuals were enrolled; 405 (203 with MetS/202 without MetS) were analyzed. Patients with MetS were older and 49% had insulin resistance. The prevalence of significant liver fibrosis (≥F2) was higher in patients with MetS [25.1%, 95% confidence interval (19.3-31.2)] compared with those without MetS [7.9%, (4.6-12.5), P < 0.0001]. In multivariate analysis with adjustment on MetS, obesity [odds ratio: 3.0 (1.1-8.4)] and homeostasis model assessment [1.1 (1.007-1.2)] were independent factors of advanced fibrosis (>= F3).. Serum levels of adipokines and sCD163 were significantly associated with the degree of liver fibrosis. When adjusted on MetS, leptin and sCD163 remained strongly associated with fibrosis/cirrhosis, whereas HIV parameters and antiretroviral therapy were not.

CONCLUSION

In HIV-monoinfected patients, MetS is an important risk factor of liver fibrosis. Adipose tissue and macrophage activation might be key players in the development of liver fibrosis but the exact mechanisms need to be elucidated.