Obesity is associated with higher levels of circulating cytokines involved in the development of cardiovascular disease in people living with HIV.

BACKGROUND: Obesity is increasingly described in people living with HIV (PLWH), but its impact on immune activation and inflammation in HIV is still poorly characterised. We aimed to analyse the difference in circulating cytokines involved in pathways associated with co-morbidities in PLWH according to the presence or absence of obesity. METHODS: Age and sex matched PLWH with and without obesity (BMI ≥30 kg/m2) from a multicentre, prospective cohort were recruited with a 1:2 ratio. Twenty-three biomarkers covering pathways associated with systemic inflammation (hsCRP, IL-2, IL-6, TNFR1, TNFR2, TNF-α, IFN-γ, IL-18), coagulation (vWF, D-dimer, sCD40L), endothelial function (E-selectin, P-selectin, sICAM-1, sVCAM-1), atherosclerosis (MPO, Lp-PLA2), immune regulation (IL-1RA), innate immune activation (MIP-1, MCP-1, sCD163, sCD14) and microbial translocation (LBP) were measured in the two groups. Between-group difference in biomarkers were assessed using Mann-Whitney test. Associations between obesity and biomarkers were assessed using logistic regression adjusted for age, gender, ethnicity, smoking status, and antiretroviral therapy (ART). RESULTS: Ninety-nine ART-treated PLWH were included in the analysis (33 with obesity, 66 without obesity). PLWH with obesity had higher levels of hsCRP, IL-6, vWF, D-dimer, E-selectin, MPO, IL-1RA, and LBP. Six markers (hsCRP, IL-6, vWF, E-selectin, MPO, IL-1RA), reflecting systemic inflammation, coagulation and atherosclerosis pathways were associated with increased odds of obesity in the adjusted logistic regression model: hsCRP (aOR 2.7, 95% CI [1.7, 4.29]), IL-6 (3.77 [1.43, 9.93]), vWF (5.33 [1.51, 18.75]), E-selectin (6.28 [1.36, 29.04]), MPO (6.85 [1.87, 25.04]), IL-1RA (6.45 [2.28, 18.2]). No association was observed between obesity and markers of innate immune activation and gut microbial translocation. CONCLUSIONS: Obesity in PLWH was associated with activation of systemic inflammatory, endothelial, atherosclerosis and coagulation pathways, rather than those associated with innate immune activation and gut microbial translocation. These pathways point towards an unfavourable cardiovascular profile in PLWH with obesity, which will have to be further explored in future studies on long-term outcomes.

A comparison of transient elastography with acoustic radiation force impulse elastography for the assessment of liver health in patients with chronic hepatitis C: Baseline results from the TRACER study.

Background: Liver stiffness measurements can be used to assess liver fibrosis and can be acquired by transient elastography using FibroScan® and with Acoustic Radiation Force Impulse imaging. The study aimed to establish liver stiffness measurement scores using FibroScan® and Acoustic Radiation Force Impulse in a chronic hepatitis C cohort and to explore the correlation and agreement between the scores and the factors influencing agreement. Methods: Patients had liver stiffness measurements acquired with FibroScan® (right lobe of liver) and Acoustic Radiation Force Impulse (right and left lobe of liver). We used Spearman's correlation to explore the relationship between FibroScan® and Acoustic Radiation Force Impulse scores. A Bland-Altman plot was used to evaluate bias between the mean percentage differences of FibroScan® and Acoustic Radiation Force Impulse scores. Univariable and multivariable analyses were used to assess how factors such as body mass index, age and gender influenced the agreement between liver stiffness measurements. Results: Bland-Altman showed the average (95% CI) percentage difference between FibroScan® and Acoustic Radiation Force Impulse scores was 27.5% (17.8, 37.2), p < 0.001. There was a negative correlation between the average and percentage difference of the FibroScan® and Acoustic Radiation Force Impulse scores ( r (95% CI) = -0.41 (-0.57, -0.21), p < 0.001), thus showing that percentage difference gets smaller for greater FibroScan® and Acoustic Radiation Force Impulse scores. Body mass index was the biggest influencing factor on differences between FibroScan® and Acoustic Radiation Force Impulse (r = 0.12 (0.01, 0.23), p = 0.05). Acoustic Radiation Force Impulse scores at segment 5/8 and the left lobe showed good correlation (r (95% CI) = 0.83 (0.75, 0.89), p < 0.001). Conclusion: FibroScan® and Acoustic Radiation Force Impulse had similar predictive values for the assessment of liver stiffness in patients with chronic hepatitis C infection; however, the level of agreement varied across lower and higher scores.

Dysregulated early transcriptional signatures linked to mast cell and interferon responses are implicated in COVID-19 severity.

Background: Dysregulated immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are thought to underlie the progression of coronavirus disease 2019 (COVID-19) to severe disease. We sought to determine whether early host immune-related gene expression could predict clinical progression to severe disease. Methods: We analysed the expression of 579 immunological genes in peripheral blood mononuclear cells taken early after symptom onset using the NanoString nCounter and compared SARS-CoV-2 negative controls with SARS-CoV-2 positive subjects with mild (SARS+ Mild) and Moderate/Severe disease to evaluate disease outcomes. Biobanked plasma samples were also assessed for type I (IFN-α2a and IFN-ß), type II (IFN-γ) and type III (IFN-λ1) interferons (IFNs) as well as 10 additional cytokines using multiplex immunoassays. Results: We identified 19 significantly deregulated genes in 62 SARS-CoV-2 positive subject samples within 5 days of symptom onset and 58 SARS-CoV-2 negative controls and found that type I interferon (IFN) signalling (MX1, IRF7, IFITM1, IFI35, STAT2, IRF4, PML, BST2, STAT1) and genes encoding proinflammatory cytokines (TNF, TNFSF4, PTGS2 and IL1B) were upregulated in both SARS+ groups. Moreover, we found that FCER1, involved in mast cell activation, was upregulated in the SARS+ Mild group but significantly downregulated in the SARS+ Moderate/Severe group. In both SARS+ groups we discovered elevated interferon type I IFN-α2a, type II IFN and type III IFN λ1 plasma levels together with higher IL-10 and IL-6. These results indicate that those with moderate or severe disease are characterised by deficiencies in a mast cell response together with IFN hyper-responsiveness, suggesting that early host antiviral immune responses could be a cause and not a consequence of severe COVID-19. Conclusions: This study suggests that early host immune responses linking defects in mast cell activation with host interferon responses correlates with more severe outcomes in COVID-19. Further characterisation of this pathway could help inform better treatment for vulnerable individuals.

Development of a coordinated acute diabetic foot pathway for management of acute diabetic foot infection and ulceration.

BACKGROUND: Diabetic foot ulceration (DFU) has become an increasingly common emergency presentation. These patients are presenting at a younger age and with increasingly complex co-morbidities. They require frequent hospitalisation for management of DFU which has significant consequences for management of health resources but also for quality of life in the diabetic patient population. AIM: The aim of this study was to evaluate the impact of the development of a coordinated, streamlined acute diabetic foot pathway for management of in-patients presenting as emergencies with DFU on length of stay, re-admission to hospital and minor and major amputations. METHODS: A dedicated acute diabetic foot pathway was introduced to St. Vincent's University Hospital (SVUH) in April 2016. Management of patients admitted urgently to the emergency department or out-patient clinics of St. Vincent's University Hospital during the 3-year period before April 2016 was compared to that of patients admitted in the 3 years after April 2016 following introduction of the acute diabetic foot pathway. Demographic data hospital length of stay, need for re-admission, major and minor amputations performed and cost of hospital stay were compared before and after introduction of the pathway. RESULTS: There were 931 admissions with acute diabetic foot ulceration or infection between January 2012 and December 2019; 419 were admitted between January 2012 and March 2016 and 512 between April 2016 and December 2019. There was no difference in demographic data between the two time periods. Length of stay decreased from 13 +/- 4.24 to 3 +/- 1.41 days between the two time periods (p < 0.001). Re-admission rates within 30 days decreased from 21.7 to 10.1% (p < 0.05). The number of major lower limb amputations decreased over the two time periods from 8.8 to 7.2% with a concomitant increase in minor amputations from 16.7 to 25.3%. Risk of major lower limb amputation was significantly higher in those patients living more than 20 km from the hospital. Costs associated with in-patient stay for management of DFU decreased from €9,247,700 to €8,988,100 despite an 18% increase in the number of patients treated and a 9.9% increase in hospital admissions. CONCLUSION: Introduction of a dedicated, streamlined pathway involving multi-disciplinary input resulted in a significant improvement in patient management as assessed by length of hospital stay and need for re-admission. While the number of major lower limb amputations has decreased there has been a significant increase in the number of minor amputations.

Macrophage Activation Marker Soluble CD163 Is a Dynamic Marker of Liver Fibrogenesis in Human Immunodeficiency Virus/Hepatitis C Virus Coinfection.

Background: Coinfection with human immunodeficiency virus (HIV) accelerates hepatitis C virus (HCV)-related liver fibrosis. Macrophages are triggered during both viral infections and are critical in liver inflammation/fibrogenesis. Liver fibrosis strongly associates with serum soluble CD163 (sCD163, a macrophage activation marker); comprehensive evaluation in HIV/HCV coinfection is lacking. Methods: We retrospectively analyzed sCD163 (enzyme-linked immunosorbent assay) and hepatic CD163 (immunofluorescent CD163/CD68 costaining) in patients infected with HIV/HCV, HCV, or HIV, pre- and post-antiviral therapy. Results: sCD163 was significantly higher in HIV/HCV compared to either monoinfection, and decreased following successful antiviral therapy, although did not fully normalize. In HIV/HCV, sCD163 was associated with necroinflammation, Ishak fibrosis scores, and noninvasive fibrosis scores. We observed a novel trend whereby sCD163 levels progressively increase with increasing Ishak fibrosis score, peaking at stage 4, above which levels plateaued. Periportal CD163+ macrophage frequency was also higher with increasing fibrosis score. When stratified by fibrosis stage, sCD163 levels were higher in HIV/HCV than HCV but only in individuals with mild to moderate fibrosis. Conclusions: In HIV/HCV, increasing sCD163 levels accompanied periportal CD163+ macrophage enrichment in mild to moderate fibrosis, but not in established cirrhosis, suggesting that sCD163 is a dynamic biomarker of fibrogenesis rather than accumulated fibrosis. Our findings implicate HIV-related macrophage activation in accelerated fibrosis progression in HIV/HCV coinfection.

Getting to the heart of hypopituitarism.

A 53-year-old woman was diagnosed with hypopituitarism following an acute presentation with cardiac tamponade and hyponatraemia, having recently been investigated for a pericardial effusion. Secondary hypothyroidism is a rare cause of pericardial effusion and tamponade, but an important differential to consider. Management requires appropriate hormone replacement and, critically, a low threshold for commencing stress dose steroids. Clinical signs classically associated with cardiac tamponade are frequently absent in cases of tamponade due to primary and secondary hypothyroidism, and the relatively volume deplete state of secondary hypoadrenalism in hypopituitarism may further mask an evolving tamponade, as the rise in right atrial pressure is less marked even in the presence of large effusion. Our case demonstrates the importance of a high index of suspicion for cardiac tamponade in this patient cohort, even in the absence of clinical signs, and for measuring both thyroid-stimulating hormone and thyroxine levels when evaluating a pericardial effusion.

Mycobacterium marinum infection contracted from seaweed wrap in a psoriasis patient undergoing treatment with adalimumab.

We report a patient with psoriasis who developed Mycobacterium marinum (M. marinum) infection after seven years of treatment with adalimumab, a human anti-TNF (tumor necrosis factor) monoclonal antibody. TNF is a pro-inflammatory cytokine that plays a central role in the pathogenesis of psoriasis and a number of other immune-mediated inflammatory diseases. TNF plays an important role in granuloma formation and host defense against mycobacterial infections. Several cases of atypical mycobacterial infections in patients on TNF inhibitors have been reported. To our knowledge, this is the second reported case of M. marinum infection in a patient on adalimumab for the treatment of psoriasis.

Chronic hepatitis C infection-induced liver fibrogenesis is associated with M2 macrophage activation.

The immuno-pathogenic mechanisms of chronic hepatitis C virus (HCV) infection remain to be elucidated and pose a major hurdle in treating or preventing chronic HCV-induced advanced liver diseases such as cirrhosis. Macrophages are a major component of the inflammatory milieu in chronic HCV-induced liver disease, and are generally derived from circulating inflammatory monocytes; however very little is known about their role in liver diseases. To investigate the activation and role of macrophages in chronic HCV-induced liver fibrosis, we utilized a recently developed humanized mouse model with autologous human immune and liver cells, human liver and blood samples and cell culture models of monocyte/macrophage and/or hepatic stellate cell activation. We showed that M2 macrophage activation was associated with liver fibrosis during chronic HCV infection in the livers of both humanized mice and patients, and direct-acting antiviral therapy attenuated M2 macrophage activation and associated liver fibrosis. We demonstrated that supernatant from HCV-infected liver cells activated human monocytes/macrophages with M2-like phenotypes. Importantly, HCV-activated monocytes/macrophages promoted hepatic stellate cell activation. These results suggest a critical role for M2 macrophage induction in chronic HCV-associated immune dysregulation and liver fibrosis.

Improved adipose tissue function with initiation of protease inhibitor-only ART.

OBJECTIVES: Use of ART containing HIV PIs has previously been associated with toxicity in subcutaneous adipose tissue (SAT), potentially contributing to the development of lipodystrophy and insulin resistance. However, the effect of PIs on SAT function in ART-naive patients independent of other ART classes is unknown. This study aimed to elucidate the effect of initiating PI-only ART on SAT function in ART-naive subjects. METHODS: In the HIVNAT-019 study, 48 HIV-infected, ART-naive Thai adults commencing PI-only ART comprising lopinavir/ritonavir/saquinavir for 24 weeks underwent assessments of fasting metabolic parameters and body composition. In a molecular substudy, 20 subjects underwent SAT biopsies at weeks 0, 2 and 24 for transcriptional, protein, mitochondrial DNA (mtDNA) and histological analyses. ClinicalTrials.gov registration number: NCT00400738. RESULTS: Over 24 weeks, limb fat increased (+416.4 g, P = 0.023), coinciding with larger adipocytes as indicated by decreased adipocyte density in biopsies (-32.3 cells/mm2, P = 0.047) and increased mRNA expression of adipogenesis regulator PPARG at week 2 (+58.1%, P = 0.003). Increases in mtDNA over 24 weeks (+600 copies/cell, P = 0.041), decreased NRF1 mRNA expression at week 2 (-33.7%, P < 0.001) and increased COX2/COX4 protein ratio at week 24 (+288%, P = 0.038) indicated improved mitochondrial function. Despite decreased AKT2 mRNA at week 2 (-28.6%, P = 0.002) and increased PTPN1 mRNA at week 24 (+50.3%, P = 0.016) suggesting insulin resistance, clinical insulin sensitivity [by homeostasis model assessment (HOMA-IR)] was unchanged. CONCLUSIONS: Initiation of PI-only ART showed little evidence of SAT toxicity, the changes observed being consistent with a return to health rather than contributing to lipodystrophy.

Circulating Soluble CD163 is Associated with Steatohepatitis and Advanced Fibrosis in Nonalcoholic Fatty Liver Disease.

OBJECTIVES: Soluble CD163 (sCD163), a marker of Kupffer cell activation detectable in serum, correlates with inflammation and fibrosis in chronic viral hepatitis, but its role in nonalcoholic fatty liver disease is unknown. We hypothesized that sCD163 would correlate with nonalcoholic fatty liver disease activity and fibrosis. METHODS: Liver biopsies and serum were obtained from 145 obese subjects undergoing gastric bypass surgery. Subjects were divided into four groups based on fibrosis stage and nonalcoholic fatty liver disease activity score (NAS); Group 1: F0, NAS=0; Group 2: F<2, 0

B-cell depletion attenuates serological biomarkers of fibrosis and myofibroblast activation in IgG4-related disease.

OBJECTIVES: Fibrosis is a predominant feature of IgG4-related disease (IgG4-RD). B-cell depletion induces a prompt clinical and immunological response in patients with IgG4-RD, but the effects of this intervention on fibrosis in IgG4-RD are unknown. We used the enhanced liver fibrosis (ELF) score to address the impact of rituximab on fibroblast activation. The ELF score is an algorithm based on serum concentrations of procollagen-III aminoterminal propeptide, tissue inhibitor of matrix metalloproteinase-1 and hyaluronic acid. METHODS: Ten patients with active, untreated IgG4-RD were enrolled. ELF scores were measured and correlated with the IgG4-RD Responder Index, serum IgG4, circulating plasmablasts and imaging studies. Through immunohistochemical stains for CD3, CD20, IgG4 and α-smooth muscle actin, we assessed the extent of the lymphoplasmacytic infiltration and the degree of fibroblast activation in one patient with tissue biopsies before and after rituximab. RESULTS: The ELF score was increased in patients with IgG4-RD compared with healthy controls (8.3±1.4 vs 6.2±0.9; p=0.002) and correlated with the number of organs involved (R(2)=0.41; p=0.04). Rituximab induced significant reductions in the ELF score, the number of circulating plasmablasts and the IgG4-RD Responder Index (p<0.05 for all three parameters). Rituximab reduced both the lymphoplasmacytic infiltrate and myofibroblast activation. IgG4-RD relapse coincided with recurrent increases in the ELF score, indicating reactivation of collagen deposition. CONCLUSIONS: The ELF score may be a clinically useful indicator of active fibrosis and the extent of disease in IgG4-RD. B-cell depletion has the potential to halt continued collagen deposition by attenuating the secretory phenotype of myofibroblasts in IgG4-RD lesions.

Antiviral treatment of hepatitis C.

Hepatitis C virus (HCV) infection is a substantial health problem worldwide. Most patients infected with HCV remain chronically infected, with an increased risk of cirrhosis and hepatocellular carcinoma. Although they are associated with toxicities and low sustained viral response rates, interferon alfa and ribavirin have been the mainstay of treatment until recently. New direct acting antivirals, specifically designed to inhibit three viral proteins (the NS3/4A protease, the NS5A protein, and the NS5B RNA dependent RNA polymerase) are now becoming available. The NS3/4A inhibitor simeprevir and NS5B inhibitor sofosbuvir have recently been licensed and can reduce the length of antiviral treatment, improve response rates, and allow for interferon-free regimens for some HCV genotypes. Several other newer direct acting antivirals have shown promise in clinical studies and are likely to be licensed soon. These agents seem to facilitate the use of shortened courses of combination interferon-free therapy, which are associated with high (>95%) sustained response rates and relatively few toxicities. These regimens have also been successful in patients who were previously difficult to treat, including those with cirrhosis, HIV coinfection, and those who have undergone liver transplantation. The high cost of these agents may be the biggest challenge to their implementation worldwide.

Increased platelet reactivity in HIV-1-infected patients receiving abacavir-containing antiretroviral therapy.

BACKGROUND: Current or recent use of abacavir for treating human immunodeficiency virus type 1 (HIV-1) infection has been associated with increased rates of myocardial infarction (MI). Given the role of platelet aggregation in thrombus formation in MI and the reversible nature of the abacavir association, we hypothesized that patients treated with abacavir would have increased platelet reactivity. METHODS: In a prospective study in adult HIV-infected patients, we determined associations between antiretrovirals (ARVs), and in particular the nucleoside reverse transcriptase inhibitor abacavir, and platelet reactivity by measuring time-dependent platelet aggregation in response to agonists: adenosine diphosphate (ADP), thrombin receptor-activating peptide (TRAP), collagen, and epinephrine. RESULTS: Of 120 subjects, 40 were ARV-naive and 80 ARV-treated, 40 of whom were receiving abacavir. No consistent differences in platelet reactivity were observed between the ARV-naive and ARV-treated groups. In contrast, within the ARV-treated group, abacavir-treated subjects had consistently higher percentages of platelet aggregation upon exposure to ADP, collagen, and epinephrine (P = .037, P = .022, and P = .032, respectively) and had platelets that were more sensitive to aggregation upon exposure to TRAP (P = .025). CONCLUSIONS: The consistent increases in platelet reactivity observed in response to a range of agonists provides a plausible underlying mechanism to explain the reversible increased rates of MI observed in abacavir-treated patients.

High-density lipoprotein levels and 10-year cardiovascular risk in HIV-1-infected patients.

We aimed to determine the contribution of high-density lipoprotein cholesterol (HDL-c) to cardiovascular disease (CVD) risk in a cohort of HIV-infected patients. The contribution of CVD risk factors to the predicted CVD risk was assessed. We estimated the degree of reclassification of CVD risk if HDL-c concentration was increased in all patients by 20 and 40%, respectively. After age, HDL-c contributed most to the overall cardiovascular risk. Increasing HDL-c by 20% and 40% reclassified six and 12 patients to lower CVD risk groups, respectively. In this cohort, HDL-c contributed more to cardiovascular risk than smoking, total cholesterol, systolic blood pressure (SBP) and sex.