Hospitalization for pneumonia among individuals with and without HIV infection, 1995-2007: a Danish population-based, nationwide cohort study

Incidence of bacterial respiratory infection and pneumonia in people with HIV with and without airflow limitation

OBJECTIVES

We aimed to determine the incidence rate, pathogen composition, and risk factors, particularly airflow limitation, associated with bacterial respiratory infection and pneumonia in a prospective cohort of well-treated people with HIV (PWH) between 2015-2021.

METHODS

We included 1007 PWH from the Copenhagen Comorbidity in HIV infection (COCOMO) study. Spirometry was performed at inclusion. Microbiology samples were collected prospectively. Cumulative incidence was determined by the Aalen-Johansen estimator. Cox proportional hazard models were used to calculate risk factors, adjusted for traditional and HIV-specific variables.

RESULTS

The incidence rates of first bacterial respiratory infection and pneumonia were 12.4 (95% CI 9.7-15.5) and 5.5 (95% CI: 3.8-7.7) per 1000 person-years, respectively. The cumulative incidence of pneumonia was four times higher in PWH with airflow limitation (11.8% vs 3.2%, P <0.001). Risk factors for bacterial respiratory infection were airflow limitation (hazard ratio [HR] 2.9, [95% CI: 1.7-5.1], P <0.001), smoking (HR 2.3, [95% CI: 1.4-3.8], P <0.001), and previous AIDS-defining event (HR 2.0, [95% CI: 1.2-3.3], P = 0.009). For pneumonia, airflow limitation (HR 2.7, [95% CI: 1.2-6.3], P = 0.016), smoking (HR 2.5, [95% CI: 1.2-5.4], P = 0.016), and older age (HR 1.5, [95% CI: 1.1-2.1], P = 0.015) were identified as risk factors.

CONCLUSIONS

Increased emphasis on airflow limitation prevention, including smoking cessation, may reduce the burden of bacterial respiratory infection and pneumonia in PWH.

COPD in People with HIV: Epidemiology, Pathogenesis, Management, and Prevention Strategies

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disorder characterized by airflow limitation and persistent respiratory symptoms. People with HIV (PWH) are particularly vulnerable to COPD development; PWH have demonstrated both higher rates of COPD and an earlier and more rapid decline in lung function than their seronegative counterparts, even after accounting for differences in cigarette smoking. Factors contributing to this HIV-associated difference include chronic immune activation and inflammation, accelerated aging, a predilection for pulmonary infections, alterations in the lung microbiome, and the interplay between HIV and inhalational toxins. In this review, we discuss what is known about the epidemiology and pathobiology of COPD among PWH and outline screening, diagnostic, prevention, and treatment strategies.

Improved induced innate immune response after cART initiation in people with HIV

Introduction

Impairment of the innate immune function may contribute to the increased risk of bacterial and viral infections in people with HIV (PWH). In this study we aimed to investigate the induced innate immune responses in PWH prior to and after initiation of combinational antiretroviral therapy (cART). Furthermore, we aimed to investigate if the induced innate immune responses before initiation of cART were associated with CD4+ T-cell recovery one year after initiating cART.

Material and method

The induced innate immune response was assessed by the TruCulture^® whole blood technique in 32 PWH before cART initiation and after 1, 6 and 12 months. To mimic bacterial and viral infections we used a panel of three stimuli (lipopolysaccharide (LPS), resiquimod (R848), and polyinosinic:polycytidylic acid (Poly I:C)) to stimulate the extracellular Toll-like receptor (TLR) 4 and the intracellular TLR7/8 and TLR3, respectively. The following cytokine responses were analyzed by Luminex 200: Tumor Necrosis Factor (TNF)-α, Interleukin (IL)-1b, IL-6, IL-8, IL-10, IL-12p40, IL17A, Interferon (IFN)-α, and IFN-γ.

Results

At baseline PWH with nadir CD4+ T-cell count <350 cell/µL had lower levels of LPS-, R848-, and Poly I:C-induced IL-6 and IFN-γ, LPS- and R848-induced TNF-α and IL-12, LPS induced IL-1b, and R848-induced IL-10 than PWH with nadir CD4+ T-cell count >350 cells/µL. The majority (>50%) had induced cytokine concentrations below the reference intervals at baseline which was most pronounced for the LPS- and Poly I:C-induced responses. The induced responses in the whole population improved after 12 months of cART, and more PWH had induced cytokine concentrations within the reference intervals after 12 months. However, the majority of PWH still had LPS-induced INF-α, INF-γ and Poly I:C-induced TNF-α and IL-6 below the reference interval. The induced innate immune responses before cART initiation were not associated with the CD4+ T-cell recovery after 12 months of cART.

Conclusion

The innate immune response was impaired in PWH, with a more pronounced impairment in PWH with low nadir CD4+ T-cell count. Initiation of cART improved the innate immune response, but compared to the reference intervals, some impairment remained in PWH without viral replication.

Antibiotic Prescribing for Acute Respiratory Illnesses in Persons with HIV compared to Persons without HIV

Background

Antibiotic overuse increases healthcare cost and promotes antimicrobial resistance. People with HIV (PWH) who develop acute respiratory infections (ARI) may be assumed “higher risk,” compared with non-PWH, but comparative antibiotic use evaluations have not been performed.

Methods

This observational, single-center study compared antibiotic prescribing in independent clinical encounters for PWH and non-PWH diagnosed with ARI in outpatient clinical practices using ICD 10 codes between January 1, 2014 and April 30, 2018. Fisher’s exact test compared categorical variables with antibiotic prescribing patterns.

Results

There were 209 patients in the PWH cohort vs. 398 patients in the non-PWH cohort. PWH had median CD4+ count of 610 cells/mm3 with 91% on antiretroviral therapy and 78% were virally suppressed. Thirty-seven percent of all visits resulted in an antibiotic prescription, 89% were inappropriate. Antibiotics were prescribed more frequently in non-PWH (35% PWH vs. 40% non-PWH; p 0.172) and managed according to guidelines more often in PWH (37% PWH vs. 30% non-PWH; p 0.039). Antibiotics were prescribed appropriately most frequently in PWH managed by HIV clinicians (29% PWH managed by HIV clinician vs. 12% PWH managed by non-HIV clinician vs. 8% non-PWH p 0.010). HIV clinicians prescribed antibiotics for a mean duration of 5.9 days vs. PWH managed by a non-HIV clinician for 9.1 days vs. non-PWH for 7.6 days (p &lt;0.0001).

Conclusion

Outpatient antibiotic overuse remains prevalent among patients evaluated for ARI. We found less frequent inappropriate antibiotic use in PWH. Prescriber specialty, rather than HIV diagnosis, was related to appropriateness of antimicrobial prescribing.

Dysregulation of the Immune Environment in the Airways During HIV Infection

HIV-1 increases susceptibility to pulmonary infection and disease, suggesting pathogenesis in the lung. However, the lung immune environment during HIV infection remains poorly characterized. This study examined T cell activation and the cytokine milieu in paired bronchoalveolar lavage (BAL) and blood from 36 HIV-uninfected and 32 HIV-infected participants. Concentrations of 27 cytokines were measured by Luminex, and T cells were phenotyped by flow cytometry. Blood and BAL had distinct cytokine profiles (p=0.001). In plasma, concentrations of inflammatory cytokines like IFN-γ (p=0.004) and TNF-α (p=0.004) were elevated during HIV infection, as expected. Conversely, BAL cytokine concentrations were similar in HIV-infected and uninfected individuals, despite high BAL viral loads (VL; median 48,000 copies/ml epithelial lining fluid). HIV-infected individuals had greater numbers of T cells in BAL compared to uninfected individuals (p=0.007); and BAL VL positively associated with CD4+ and CD8+ T cell numbers (p=0.006 and p=0.0002, respectively) and CXCL10 concentrations (p=0.02). BAL T cells were highly activated in HIV-infected individuals, with nearly 2-3 fold greater frequencies of CD4+CD38+ (1.8-fold; p=0.007), CD4+CD38+HLA-DR+ (1.9-fold; p=0.0006), CD8+CD38+ (2.8-fold; p=0.0006), CD8+HLA-DR+ (2-fold; p=0.022) and CD8+CD38+HLA-DR+ (3.6-fold; p<0.0001) cells compared to HIV-uninfected individuals. Overall, this study demonstrates a clear disruption of the pulmonary immune environment during HIV infection, with readily detectable virus and activated T lymphocytes, which may be driven to accumulate by local chemokines.

The association between antimicrobial resistance and HIV infection: a systematic review and meta-analysis

OBJECTIVES

People living with HIV (PLWH) are at increased risk of infections with resistant organisms due to more frequent healthcare utilization. Our objective was to investigate the association between HIV and antimicrobial resistance (AMR).

METHODS

We searched MEDLINE, EMBASE, Web of Science, LILACS and African Journals Online. Studies were eligible if they reported on AMR for colonization or infection with bacterial pathogens (excluding mycobacteria and bacteria causing sexually transmitted infections) and were stratified by HIV status, species and antimicrobials tested. Pooled odds ratios were used to evaluate the association between HIV and resistance.

RESULTS

In total, 92 studies published between 1995 and 2020 were identified. The studies included the following organisms: Staphylococcusaureus (n = 47), Streptococcus pneumoniae (n = 28), Escherichia coli (n = 6) and other Gram-negative bacteria. PLWH had a 2.12 (95%CI 1.36-3.30) higher odds for colonization and 1.90 (95%CI 1.45-2.48) higher odds for infection with methicillin-resistant S. aureus, a 2.28 (95%CI 1.75-2.97) higher odds of infection with S. pneumoniae with decreased penicillin susceptibility, and a 1.59 (95%CI 0.83-3.05) higher odds of resistance to third-generation cephalosporins in E. coli and Klebsiella pneumoniae.

CONCLUSION

This review shows an increased risk of AMR in PLWH across a range of bacterial pathogens and multiple drug classes. The lack of laboratory capacity for identifying AMR, and limited access to alternative treatment options in countries with the highest burden of HIV, highlight the need for more research on AMR in PLWH. Overall, the quality of studies was moderate or low, which may impact the findings of this review.

Prevalence of ESBL-producing Escherichia coli in adults with and without HIV presenting with urinary tract infections to primary care clinics in Zimbabwe

BACKGROUND

People living with HIV may be at increased risk for infections with resistant organisms. Infections with ESBL-producing organisms are of particular concern because they limit treatment options for severe Gram-negative infections in low-resource settings.

OBJECTIVES

To investigate the association between HIV status and urinary tract infections (UTIs) with ESBL-producing Escherichia coli.

PATIENTS AND METHODS

Cross-sectional study enrolling adults presenting with UTI symptoms to primary care clinics in Harare, Zimbabwe. Demographic and clinical data were collected during interviews and a urine sample was collected for culture from each participant. Antimicrobial susceptibility testing was performed according to EUCAST recommendations.

RESULTS

Of the 1164 who were enrolled into the study, 783 (64%) were female and 387 (33%) were HIV infected. The median age was 35.8 years. Urine cultures were positive in 338 (29.0%) participants, and the majority of bacterial isolates were E. coli (n = 254, 75.2%). The presence of ESBL was confirmed in 49/254 (19.3%) E. coli. Participants with HIV had a 2.13 (95% CI 1.05-4.32) higher odds of infection with ESBL-producing E. coli than individuals without HIV. Also, the prevalence of resistance to most antimicrobials was higher among participants with HIV.

CONCLUSIONS

This study found an association between HIV and ESBL-producing E. coli in patients presenting with symptoms suggestive of UTI to primary care in Harare. HIV status should be considered when prescribing empirical antimicrobial treatment.

Care of Critically Ill Patients with Human Immunodeficiency Virus

Care of patients with human immunodeficiency virus (HIV) infection in the intensive care unit (ICU) has changed dramatically since the infection was first recognized in the United States in 1981. The purpose of this review is to describe the current important aspects of care of patients with HIV infection in the ICU, with a primary focus on the United States and developed countries. The epidemiology and initial approach to diagnosis and treatment of HIV (including the newest antiretroviral guidelines), common syndromes and their management in the ICU, and typical comorbidities and opportunistic infections of patients with HIV infection are discussed.

Statin use and risk of severe bacterial infection in a population living with HIV: prospective cohort study of the ANRS CO3 Aquitaine Cohort 2000-2018

OBJECTIVES

Bacterial infections remain one of the main causes of morbidity and death in people living with HIV (PLHIV) in the most recent years. Several studies have demonstrated a protective effect of statins in the primary prevention of bacterial infections in other immunocompromised populations, but this effect remains controversial. The objective of this study was to evaluate the effect of statin use on the occurrence of a first episode of severe bacterial infection (SBI) in PLHIV in the ANRS CO3 Aquitaine cohort between 2000 and 2018.

METHODS

All individuals included in the prospective ANRS CO3 Aquitaine cohort who had at least two follow-up visits between 2000 and 2018 were included. The primary endpoint was the occurrence of a first episode of bacterial infection leading to hospitalization of ≥48 hours or death. Statin exposure was updated during follow-up. Marginal Cox structural models were developed to consider the potential indication bias and time-dependent confusion. Numerous sensitivity analyses were carried out.

RESULTS

In this study 51 658 person-years were followed. The overall incidence of a first episode of SBI was 12.4/1000 person-years. No effect of statins on the occurrence of SBI was demonstrated when subjects were considered on statins throughout their follow-up after treatment initiation (HR = 0.97; 95%CI: 0.75-1.25). The results were similar for the effect of statins on the risk of pneumonia and for all sensitivity analyses.

CONCLUSION

In this large cohort of PLHIV with 18 years of follow-up and a high risk of severe infections, we found no effect of statins on the risk of occurrence of SBI or pneumonia.

Validation for using electronic health records to identify community acquired pneumonia hospitalization among people with and without HIV

Background

Cohort studies identifying the incidence, complications and co-morbidities associated with community acquired pneumonia (CAP) are largely based on administrative datasets and rely on International Classification of Diseases (ICD) codes; however, the reliability of ICD codes for hospital admissions for CAP in people with HIV (PWH) has not been systematically assessed.

Methods

We used data from the Veterans Aging Cohort Study survey sample (N = 6824; 3410 PWH and 3414 uninfected) to validate the use of electronic health records (EHR) data to identify CAP hospitalizations when compared to chart review and to compare the performance in PWH vs. uninfected patients. We used different EHR algorithms that included a broad set of CAP ICD-9 codes, a set restricted to bacterial and viral CAP codes, and algorithms that included pharmacy data and/or other ICD-9 diagnoses frequently associated with CAP. We also compared microbiologic workup and etiologic diagnosis by HIV status among those with CAP.

Results

Five hundred forty-nine patients were identified as having an ICD-9 code compatible with a CAP diagnosis (13% of PWH and 4% of the uninfected, p < 0.01). The EHR algorithm with the best overall positive predictive value (82%) was obtained by using the restricted set of ICD-9 codes (480-487) in primary position or secondary only to selected codes as primary (HIV disease, respiratory failure, sepsis or bacteremia) with the addition of EHR pharmacy data; this algorithm yielded PPVs of 83% in PWH and 73% in uninfected (P = 0.1) groups. Adding aspiration pneumonia (ICD-9 code 507) to any of the ICD-9 code/pharmacy combinations increased the number of cases but decreased the overall PPV. Allowing COPD exacerbation in the primary position improved the PPV among the uninfected group only (to 76%). More PWH than uninfected patients underwent microbiologic evaluation or had respiratory samples submitted.

Conclusions

ICD-9 code-based algorithms perform similarly to identify CAP in PLWH and uninfected individuals. Adding antimicrobial use data and allowing as primary diagnoses ICD-9 codes frequently used in patients with CAP improved the performance of the algorithms in both groups of patients. The algorithms consistently performed better among PWH.

Prevalence and Etiology of Community-acquired Pneumonia in Immunocompromised Patients

Background

The correct management of immunocompromised patients with pneumonia is debated. We evaluated the prevalence, risk factors, and characteristics of immunocompromised patients coming from the community with pneumonia.

Methods

We conducted a secondary analysis of an international, multicenter study enrolling adult patients coming from the community with pneumonia and hospitalized in 222 hospitals in 54 countries worldwide. Risk factors for immunocompromise included AIDS, aplastic anemia, asplenia, hematological cancer, chemotherapy, neutropenia, biological drug use, lung transplantation, chronic steroid use, and solid tumor.

Results

At least 1 risk factor for immunocompromise was recorded in 18% of the 3702 patients enrolled. The prevalences of risk factors significantly differed across continents and countries, with chronic steroid use (45%), hematological cancer (25%), and chemotherapy (22%) the most common. Among immunocompromised patients, community-acquired pneumonia (CAP) pathogens were the most frequently identified, and prevalences did not differ from those in immunocompetent patients. Risk factors for immunocompromise were independently associated with neither Pseudomonas aeruginosa nor non–community-acquired bacteria. Specific risk factors were independently associated with fungal infections (odds ratio for AIDS and hematological cancer, 15.10 and 4.65, respectively; both P = .001), mycobacterial infections (AIDS; P = .006), and viral infections other than influenza (hematological cancer, 5.49; P < .001).

Conclusions

Our findings could be considered by clinicians in prescribing empiric antibiotic therapy for CAP in immunocompromised patients. Patients with AIDS and hematological cancer admitted with CAP may have higher prevalences of fungi, mycobacteria, and noninfluenza viruses.

Enrichment of the airway microbiome in people living with HIV with potential pathogenic bacteria despite antiretroviral therapy

BACKGROUND

Long-term antiretroviral therapy (ART) enables people living with HIV (PLW-HIV) to be healthier and live longer; though they remain at greater risk of pneumonia and chronic lung disease than the general population. Lung microbial dysbiosis has been shown to contribute to respiratory disease.

METHODS

16S-rRNA gene sequencing on the Miseq-platform and qPCR for typical respiratory pathogens were performed on sputum samples collected from 64 PLW-HIV (median blood CD4 count 676 cells/μL) and 38 HIV-negative participants.

FINDING

Richness and α-diversity as well as the relative-abundance (RA) of the major taxa (RA>1%) were similar between both groups. In unweighted-Unifrac ß-diversity, the samples from PLW-HIV showed greater diversity, in contrast to the HIV negative samples which clustered together. Gut bacterial taxa such as Bilophila and members of Enterobacteriaceae as well as pathogenic respiratory taxa (Staphylococcus, Pseudomonas and Klebsiella) were significantly more frequent in PLW-HIV and almost absent in the HIV-negative group. Carriage of these taxa was correlated with the length of time between HIV diagnosis and initiation of ART (Spearman-rho=0·279, p=0·028).

INTERPRETATION

Although the core airway microbiome was indistinguishable between PLW-HIV on effective ART and HIV-negative participants, PLW-HIV's respiratory microbiome was enriched with potential respiratory pathogens and gut bacteria. The observed differences in PLW-HIV may be due to HIV infection altering the local lung microenvironment to be more permissive to harbour pathogenic bacteria that could contribute to respiratory comorbidities. Prompt start of ART for PLW-HIV may reduce this risk.

The effect of HIV status on the frequency and severity of acute respiratory illness

Introduction

Antiretroviral therapy has improved the health of people living with HIV (PLW-HIV), though less is known about how this impacts on acute respiratory illness. These illnesses are a common cause of ill health in the general population and any increase in their frequency or severity in PLW-HIV might have significant implications for health-related quality of life and the development of chronic respiratory disease.

Methods

In a prospective observational cohort study following PLW-HIV and HIV negative participants for 12 months with weekly documentation of any acute respiratory illness, we compared the frequency, severity and healthcare use associated with acute respiratory illnesses to determine whether PLW-HIV continue to have a greater frequency or severity of such illnesses despite antiretroviral therapy.

Results

We followed-up 136 HIV positive and 73 HIV negative participants for 12 months with weekly documentation of any new respiratory symptoms. We found that HIV status did not affect the frequency of acute respiratory illness: unadjusted incidence rates per person year of follow-up were 2.08 illnesses (95% CI 1.81–2.38) and 2.30 illnesses (1.94–2.70) in HIV positive and negative participants respectively, IRR 0.87 (0.70–1.07) p = 0.18. However, when acute respiratory illnesses occurred, PLW-HIV reported more severe symptoms (relative fold-change in symptom score 1.61 (1.28–2.02), p <0.001) and were more likely to seek healthcare advice (42% vs 18% of illnesses, odds ratio 3.32 (1.48–7.39), p = 0.003). After adjustment for differences in baseline characteristics, PLW-HIV still had higher symptom scores when unwell.

Conclusions

HIV suppression with antiretroviral therapy reduces the frequency of acute respiratory illness to background levels, however when these occur, they are associated with more severe self-reported symptoms and greater healthcare utilisation. Exploration of the reasons for this greater severity of acute respiratory illness may allow targeted interventions to improve the health of people living with HIV.

Trial registration

ISRCTN registry (ISRCTN38386321).

'Looking after the survivors': the health of a cohort of long-term human immunodeficiency virus patients 25 years on

BACKGROUND

Patients with human immunodeficiency virus (HIV) infection have higher rates of cardiovascular disease, metabolic disorders and malignancy than their uninfected peers.

AIM

To survey the health of a South Australian cohort of long-term HIV patients, who had been diagnosed with HIV prior to the availability of combination antiretroviral therapy.

METHODS

Data from 88 patients were collected retrospectively across four domains: demographics, HIV history, antiretroviral medication and medical comorbidity.

RESULTS

There were high rates of cardiovascular risk factors, in particular active smoking, dyslipidaemia and diabetes mellitus, which translated into a high rate of ischaemic heart disease and cerebrovascular accidents. A large proportion of the patients suffered depression and cognitive impairment. Approximately one-fifth of the cohort had been diagnosed with a malignancy, with anal cancer being the most prevalent. Many patients had experienced permanent toxicity from antiretroviral therapy.

CONCLUSION

The present study showed high rates of 'non-HIV morbidity' in a group of long-term HIV patients in South Australia. Clinicians should aggressively modify cardiovascular risk factors, ensure appropriate immunisations, monitor mental health and consider targeted malignancy screening in these patients. A robust clinical infrastructure and multidisciplinary team is required to facilitate the complex care needs of long-term HIV patients.

Etiology, clinical, and epidemiological characteristics of severe respiratory infection in people living with HIV

People living with HIV (PLWH) are more prone to severe respiratory infections. We used the severe acute respiratory infection (SARI) definition to describe the etiology, clinical, and epidemiological characteristics in this population. This was a prospective observational study including PLWH hospitalized with fever and cough. Those with symptom onset up to 10 days were classified as severe acute respiratory infection and 11–30 days as non-severe acute respiratory infection. Blood, urine samples and nasopharyngeal swabs were collected. Data were extracted from patient charts during their hospital stay. Forty-nine patients were included, median CD4 cell count: 80 cells/mm³, median time since HIV diagnosis and hospital admission: 84 months and 80% were antiretroviral therapy exposed. Twenty-seven patients were classified as SARI. Etiology was identified in 69%, 47% were polymicrobial. Respiratory virus (9 SARI vs. 13 non-SARI), bacteria (5 SARI vs. 4 non-SARI), Mycobacterium tuberculosis (6 SARI group vs. 7 non-SARI group), Pneumocystis jirovecii (4 SARI vs. 1 non-SARI), Cryptococcus neoformans (1 SARI vs. 3 non-SARI), and influenza A (1 SARI vs. 2 non-SARI). Dyspnea was statistically more prevalent in SARI (78% vs. 36%, p = 0.011) but the risk of death was higher in the non-SARI (4% vs. 36%, p = 0.0067). In the severely immunocompromised PLWH, severe acute respiratory infection can be caused by multiple pathogens and codetection is a common feature.

Opportunistic Respiratory Infections in HIV Patients Attending Sukraraj Tropical and Infectious Diseases Hospital in Kathmandu, Nepal

Introduction

Opportunistic bacterial and fungal infections are the major cause of morbidity and mortality among immune suppressed HIV-positive patients. The main objective of this study was to determine bacterial and fungal organisms causing respiratory infections and their susceptibility to commonly prescribed antimicrobials among HIV patients attending a tertiary infectious disease hospital in Kathmandu.

Methods

Sputum samples were collected from the HIV-positive patients attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) from August 2017 to March 2018. A total of 100 sputum samples were cultured on conventional bacterial and fungal culture media. Bacterial and fungal isolates were identified based on their colony characteristics, microscopic morphology and various biochemical tests. Antibiotic susceptibility test (AST) of bacterial isolates was performed by modified Kirby Bauer disc diffusion method.

Results

Out of 100 sputum samples cultured, 24% (n=24) showed bacterial growth, 42% (n=42) showed fungal growth and 10% (n=10) had both bacterial and fungal growth. Among bacteria, 91.6% (n=22) were monomicrobial and 8.4% (n=2) were polymicrobial in growth, of which, Klebsiella pneumoniae (37.5%) were predominant isolates, followed by Pseudomonas aeruginosa (29.2%), and Escherichia coli (16.7%). The antibiotic susceptibility test (AST) showed 68% (17/25) of bacterial isolates were multi-drug resistant (MDR) and among them 41.2% (7/17) were found to be extended spectrum β lactamase (ESBL) producers. Fungal growth was observed in 42% of samples (42/100). A total of six different species of Candida and four different genera of molds were identified. On species differentiation, Candida albicans (20%) were followed by Candida parapsilosis (4%), and Candida dubliniensis (3%); and various molds were Aspergillus fumigatus (4%), Aspergillus flavus (2%), and Penicillium species (5%). CD4 count was inversely associated with bacterial and fungal infections. Fifty percent of the patients with the fungal infections had a CD4 count below 200. No fungal organisms were isolated from HIV-positive patients under antifungal drug treatment.

Conclusion

HIV-positive patients with a CD4 count less than 200 cells/µL are more vulnerable to opportunistic infections of bacterial and fungal origin. Early isolation, identification and appropriate treatment can reduce mortality due to co-infections. Routine screening of opportunistic pathogens is critical to contain the disease progression.

Pneumococcal vaccination in adult people living with HIV on suppressive antiretroviral therapy: a case-control study

There is little information on the effectiveness of the pneumococcal vaccines (PVs), especially for the pneumococcal conjugate vaccines (PCVs), in HIV-infected patients in the modern antiretroviral era. This is a case–control study where cases were people living with HIV (PLWH) with confirmed pneumococcal infection (CPI) and controls were PLWH without CPI matched with cases by gender and year of HIV diagnosis. The selection process was blinded to the study factor (vaccination). Sample size estimation yielded 61 cases and 183 controls. We analyzed the effect of PV on CPI using Cox proportional-hazards regression model with time-dependent covariates. We included 256 subjects: 64 cases, and 192 controls. PVs had been administered to 115 (45%) patients. Only the modified Charlson Comorbidity Index (HR 1.16, 95%CI 1.06–1.27, P = 0.001) and the CD4 nadir (HR 0.99, 95% CI 0.98–0.99, P = 0.001) were independently associated with CPI. Receipt of PV was not associated with CPI after adjusting in the multivariate model with time protection as a dependent covariate (HR 0.65, 95% CI 0.35–1.32 P = 0.250). We also investigated the influence of different immunization schedules. In an adjusted model, we found no evidence of protection against CPI, including double immunization schedules (HR 0.42 95%CI 0.15–1.19 P = 0.102). In this case–control study, we could not show an association between pneumococcal vaccination and confirmed pneumococcal infection, although a protective effect of particular schedules of immunization cannot be ruled out.

Pathogenesis of HIV-Related Lung Disease: Immunity, Infection, and Inflammation

Despite anti-retroviral therapy (ART), human immunodeficiency virus-1 (HIV)-related pulmonary disease continues to be a major cause of morbidity and mortality for people living with HIV (PLWH). The spectrum of lung diseases has changed from acute opportunistic infections resulting in death to chronic lung diseases for those with access to ART. Chronic immune activation and suppression can result in impairment of innate immunity and progressive loss of T cell and B cell functionality with aberrant cytokine and chemokine responses systemically as well as in the lung. HIV can be detected in the lungs of PLWH and has profound effects on cellular immune functions. In addition, HIV-related lung injury and disease can occur secondary to a number of mechanisms including altered pulmonary and systemic inflammatory pathways, viral persistence in the lung, oxidative stress with additive effects of smoke exposure, microbial translocation, and alterations in the lung and gut microbiome. Although ART has had profound effects on systemic viral suppression in HIV, the impact of ART on lung immunology still needs to be fully elucidated. Understanding of the mechanisms by which HIV-related lung diseases continue to occur is critical to the development of new preventive and therapeutic strategies to improve lung health in PLWH.

HIV gp120 in the Lungs of Antiretroviral Therapy-treated Individuals Impairs Alveolar Macrophage Responses to Pneumococci

RATIONALE

People living with HIV are at significantly increased risk of invasive pneumococcal disease, despite long-term antiretroviral therapy (ART). The mechanism explaining this observation remains undefined.

OBJECTIVES

To determine if apoptosis-associated microbicidal mechanisms, required to clear intracellular pneumococci that survive initial phagolysosomal killing, are perturbed.

METHODS

Alveolar macrophages (AM) were obtained by BAL from healthy donors or HIV-1-seropositive donors on long-term ART with undetectable plasma viral load. Monocyte-derived macrophages (MDM) were obtained from healthy donors and infected with HIV-1_BaL or treated with gp120. Macrophages were challenged with opsonized serotype 2 Streptococcus pneumoniae and assessed for apoptosis, bactericidal activity, protein expression, and mitochondrial reactive oxygen species (mROS). AM phenotyping, ultrasensitive HIV-1 RNA quantification, and gp120 measurement were also performed in BAL.

MEASUREMENTS AND MAIN RESULTS

HIV-1_BaL infection impaired apoptosis, induction of mROS, and pneumococcal killing by MDM. Apoptosis-associated pneumococcal killing was also reduced in AM from ART-treated HIV-1-seropositive donors. BAL fluid from these individuals demonstrated persistent lung CD8⁺ T lymphocytosis, and gp120 or HIV-1 RNA was also detected. Despite this, transcriptional activity in AM freshly isolated from people living with HIV was broadly similar to healthy volunteers. Instead, gp120 phenocopied the defect in pneumococcal killing in healthy MDM through post-translational modification of Mcl-1, preventing apoptosis induction, caspase activation, and increased mROS generation. Moreover, gp120 also inhibited mROS-dependent pneumococcal killing in MDM.

CONCLUSIONS

Despite ART, HIV-1, via gp120, drives persisting innate immune defects in AM microbicidal mechanisms, enhancing susceptibility to pneumococcal disease.

Treating bacterial pneumonia in people living with HIV

Introduction: Bacterial pneumonia remains an important cause of morbidity and mortality in people living with HIV (PLWH) in the antiretroviral therapy (ART) era. In addition to being immunocompromised, as reflected by low CD4 cell counts and elevated HIV viral loads, PLWH often have other behaviors associated with an increased risk of pneumonia including smoking and injected drug use. As PLWH are aging, comorbid conditions such as chronic obstructive pulmonary disease (COPD), cancers, and cardiovascular, renal and liver diseases are emerging as additional risk factors for pneumonia. Pathogens are often similar to those in HIV-uninfected individuals; however, PLWH are at risk for unusual and/or multi-drug resistant organisms causing bacterial pneumonia based, in part, on their CD4 cell counts and other exposures. Areas covered: In this review, we focus on the recognition and management of bacterial community-acquired pneumonia (CAP) in PLWH. Along with antimicrobial treatment, we discuss prevention strategies such as vaccination and smoking cessation. Expert opinion: Early initiation of ART after HIV infection can decrease the risk of pneumonia. Improved efforts at vaccination, smoking cessation, and reduction of other substance use are urgently needed in PLWH to decrease the risk for bacterial pneumonia. As PLWH are aging, comorbidities are additional risk factors for bacterial CAP.

HIV infection is associated with elevated biomarkers of immune activation in Ugandan adults with pneumonia

INTRODUCTION

Pneumonia is an important cause of morbidity and mortality in persons living with human immunodeficiency virus (HIV) infection. How immune activation differs among HIV-infected and HIV-uninfected adults with pneumonia is unknown.

METHODS

The Inflammation, Aging, Microbes, and Obstructive Lung Disease (I AM OLD) Cohort is a prospective cohort of adults with pneumonia in Uganda. In this cross-sectional analysis, plasma was collected at pneumonia presentation to measure the following 12 biomarkers: interleukin 6 (IL-6), soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1 and sTNFR-2), high sensitivity C-reactive protein (hsCRP), fibrinogen, D-dimer, soluble CD27 (sCD27), interferon gamma-inducible protein 10 (IP-10), soluble CD14 (sCD14), soluble CD163 (sCD163), hyaluronan, and intestinal fatty acid binding protein. We asked whether biomarker levels differed between HIV-infected and HIV-uninfected participants, and whether higher levels of these biomarkers were associated with mortality.

RESULTS

One hundred seventy-three participants were enrolled. Fifty-three percent were HIV-infected. Eight plasma biomarkers-sTNFR-1, sTNFR-2, hsCRP, D-dimer, sCD27, IP-10, sCD14, and hyaluronan-were higher among participants with HIV infection, after adjustment for pneumonia severity. Higher levels of 8 biomarkers-IL-6, sTNFR-1, sTNFR-2, hsCRP, IP-10, sCD14, sCD163, and hyaluronan-were associated with increased 2-month mortality.

CONCLUSIONS

As in other clinical contexts, HIV infection is associated with a greater degree of immune activation among Ugandan adults with pneumonia. Some of these are also associated with short-term mortality. Further study is needed to explore whether these biomarkers might predict poor long-term outcomes-such as the development of obstructive lung disease-in patients with HIV who have recovered from pneumonia.

Characteristics and Outcomes of Acinetobacter baumannii Infections in Patients with HIV: A Matched Case-Control Study

Acinetobacter baumannii (AB) infection is an increasing global threaten to hospitalized patients, especially those with impaired immune function. Still, few studies addressed the disease burdens and outcomes of AB infection in HIV patients. We aimed to describe characteristics and outcomes of AB infections in patients with HIV, measure the impact of AB infection on 28-day mortality in HIV patients, as well as assess the predictors of 28-day survival among HIV patients with AB pneumonia. A retrospective study with HIV/AB co-infected patients was conducted at Shanghai Public Health Clinical Center (SPHCC), China. Patients with AB pneumonia were further analyzed for predictors of mortality, as well as an additional 1:1 case-control study to determine the fatality of AB pneumonia compared with pneumonia of other pathogens. We found the incidence of AB infection was 17.4 cases per 100 person-years among all hospitalized HIV patients. Hospital mortality rate was 37.5% (21/56). There was a higher 28-day mortality rate in HIV patients with pneumonia due to AB than other pathogens (34% vs 16%, P = 0.03). APACHE II score was independently associated with 28-day survival by multivariate logistic regression (P = 0.031). Our findings indicate that AB infection is incident and can be fatal in HIV seropositive population. AB infection is an independent risk factor of mortality in patients with HIV and pneumonia. A lower APACHE II score on admission predicts a higher 28-day survival rate among HIV/AB co-infected patients.

Pulmonary Infections in Immunocompromised Hosts: Clinical

Pulmonary infections in immunocompromised patients remain a significant contributor to mortality, morbidity, and health care-associated costs in such a vulnerable patient population. Their epidemiology is changing, set forth by new trends in immunosuppressive regimens and also prophylaxis. The host characteristics, presenting clinical symptomatology, along with radiographic patterns, have also evolved. The microbiology diagnostics are now enriched with nonculture methods for better identification of the causative pathogens. Chest imaging remains the cornerstone of the initial workup. Our article will examine the new trends in epidemiology, clinical findings, and diagnostics for immunocompromised patients with pulmonary infections (transplant recipients, neutropenic hosts, HIV-infected patients, and patients with autoimmune conditions). We will also review the differential diagnosis that most of the times includes malignancies and drug or radiation-related toxicities.

Community-acquired bacterial pneumonia in adult HIV-infected patients

INTRODUCTION

Despite active antiretroviral therapy (ART), community-acquired pneumonia (CAP) remains a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected patients and incurs high health costs. Areas covered: This article reviews the most recent publications on bacterial CAP in the HIV-infected population, focusing on epidemiology, prognostic factors, microbial etiology, therapy, and prevention. The data discussed here were mainly obtained from a non-systematic review using Medline, and references from relevant articles. Expert commentary: HIV-infected patients are more susceptible to bacterial CAP. Although ART improves their immune response and has reduced CAP incidence, these patients continue to present increased risk of pneumonia in part because they show altered immunity and because immune activation persists. The risk of CAP in HIV-infected patients and the probability of polymicrobial or atypical infections are inversely associated with the CD4 cell count. Mortality in HIV-infected patients with CAP ranges from 6% to 15% but in well-controlled HIV-infected patients on ART the mortality is low and similar to that seen in HIV-negative individuals. Vaccination and smoking cessation are the two most important preventive strategies for bacterial CAP in well-controlled HIV-infected patients on ART.

Role of the lung microbiome in HIV pathogenesis

PURPOSE OF REVIEW

The purpose of this review is to summarize recent findings on the lung microbiome in HIV-infected patients and associated pulmonary diseases, and the relationship of airway microbial communities to metabolic and immune signatures within this patient population.

RECENT FINDINGS

The lung microbiome in HIV infection is a relatively new and rapidly developing field; early studies in the field produced inconclusive evidence as to whether HIV-infection changes the lower airway microbiome. More recent microbiome investigations have addressed these inconsistencies by incorporating systems biology approaches and laboratory models. Several investigations have now identified enrichment of Prevotella, Veillonella, and Streptococcus in the lower airways as consistent correlates of advanced HIV-infection and HIV-associated pulmonary diseases. These bacteria are associated with specific metabolic and immune profiles within the lung and circulation, providing the first indication that the lung microbiome may play a functional role in the pathogenesis of HIV-infection and HIV-associated pulmonary disease.

SUMMARY

This review summarizes knowledge to date on the lung microbiome in HIV infection, as well as challenges and accomplishments in the field within the last 2 years. Although the lung microbiome in HIV infection is still an emerging field, recent studies have formed a framework for future functional analysis of microbes in HIV pathogenesis.

Long-term risk and outcome of infection-related hospitalization in granulomatosis with polyangiitis: a nationwide population-based cohort study

OBJECTIVE

To assess the long-term risk and outcome of infection-related hospitalization (IH) among patients with granulomatosis with polyangiitis (GPA).

METHOD

We used administrative databases to establish a GPA cohort (n = 398), construct a comparison cohort of population controls (n = 3980), and collect clinical data. Cox regression analyses were used to determine hazard ratios (HRs) as a measure of relative risk. Follow-up began at date of GPA diagnosis and continued for up to 10 years.

RESULTS

GPA patients had a markedly increased long-term risk of IH compared to controls [HR (95% confidence interval) year 1: 9.5 (7.0-12.8); years 2-5: 3.2 (2.4-4.3); years 6-10: 2.6 (1.8-3.9)]. Increased long-term risks were found for hospital-treated pneumonia, urinary tract infection, sepsis, and skin infection. We did not observe a lower risk of IH for people diagnosed with GPA during 2005-2014 than for those diagnosed during 1995-2004. Mortality at 3 and 6 months after IH did not differ significantly between patients diagnosed with vasculitis during 2005-2014 and those diagnosed during 1995-2004. Charlson Comorbidity Index score ≥1 was identified as a predictor of pneumonia and urinary tract infection in the GPA cohort, but not of sepsis or skin infection.

CONCLUSION

Patients with GPA have a high risk of IH, even after prolonged follow-up. The long-term risk of IH and mortality after IH did not decline across recent calendar periods among Danish GPA patients. These observations underscore the need for clinical strategies to reduce the burden of infectious complications in GPA.

HIV is associated with airway obstruction: a matched controlled study

OBJECTIVE

To explore whether airway obstruction is associated with HIV in a cohort of HIV-infected and uninfected smokers.

METHODS

People living with HIV (PLWHIV) participated in the ANRS EP48 HIV CHEST study, an early lung cancer diagnosis study with low-dose chest tomography. HIV-uninfected study participants were from the CONSTANCES cohort. Inclusion criteria were an age greater than 40 years, a smoking history of at least 20 pack-years, and for PLWHIV, a CD4 T-lymphocyte nadir less than 350/μl and last CD4 cell count more than 100 cells/μl. Two randomly selected HIV-uninfected study participants were matched by age and sex with one PLWHIV. Prebronchodilatator forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio was the primary outcome, and association of FEV1/FVC ratio less than 0.70 and FEV1 less than 80% of the theoretical value, as a proxy of chronic obstructive pulmonary disease, the secondary outcome.

RESULTS

In total, 351 PLWHIV and 702 HIV-uninfected study participants were included. Median age was 50 years, and 17% of study participants were women. Plasma HIV RNA was less than 50 copies/ml in 89% of PLWHIV, with a median CD4 cell count of 573 cells/μl. HIV (β -2.19), age (per 10 years increase; β -2.81), tobacco use (per 5 pack-years increase; β -0.34), and hepatitis C virus serology (β-2.50) were negatively associated with FEV1/FVC. HIV [odds ratio (OR: 1.72)], age (per 10 years increase; OR 1.77), and tobacco use (per 5 pack-years increase; OR 1.11) were significantly associated with the secondary outcome.

CONCLUSION

Our study found a significant association of airway obstruction with HIV status in smokers aged more than 40 years with previous immunodeficiency.

Community-acquired lower respiratory tract infections in HIV-infected patients on antiretroviral therapy: predictors in a contemporary cohort study

Community-acquired pneumonia represents the most frequent bacterial infection in patients with HIV/AIDS.

PURPOSE

We aimed to assess variables associated with lower respiratory tract infection (LRTI) among HIV-infected adults using ART.

METHODS

A cohort study of HIV-infected patients aged ≥18 years, enrolled from 2000 to 2015, on ART for at least 60 days, with primary outcome as the 1st episode of LRTI during follow-up. The independent variables included were sex at birth, age, race/skin color, educational level, tobacco smoking, alcohol use, cocaine use, diabetes mellitus, CD4 count, HIV viral load, influenza and pneumococcal vaccination. Extended Cox proportional hazards models accounting for time-updated variables were fitted to assess LRTI predictors.

RESULTS

2669 patients were included; median follow-up was 3.9 years per patient. LRTI was diagnosed in 384 patients; incidence rate was 30.7/1000 PY. In the unadjusted Cox extended models, non-white race [crude hazard ratio (cHR) 1.28, p = 0.020], cocaine use (cHR 2.01, p < 0.001), tobacco smoking (cHR 1.34, p value 0.007), and HIV viral load ≥400 copies/mL (cHR 3.40, p < 0.001) increased the risk of LRTI. Lower risk of LRTI was seen with higher educational level (cHR 0.61, p < 0.001), rise in CD4 counts (cHR 0.81, p < 0.001, per 100 cells/mm3 increase), influenza (cHR 0.60, p = 0.002) and pneumococcal vaccination (cHR 0.57, p < 0.001). In the adjusted model, aHR for CD4 count was 0.86, for cocaine use 1.47 and for viral load ≥400 copies 2.20.

CONCLUSIONS

LRTI has a high incidence in HIV-infected adults using ART. Higher CD4 counts and undetectable viral loads were protective, as were pneumococcal and influenza vaccines.

Bloodstream infections in HIV-infected patients

In the combined antiretroviral therapy era, HIV-infected patients remain a vulnerable population for the onset of bloodstream infections (BSI). Worldwide, nontyphoid salmonellae, Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus and coagulase negative staphylococci are the most important pathogens. Intravenous catheter associated infection, skin-soft tissue infection and endocarditis are associated with Gram-positive bacteremia. Among the Gram-negative, nontyphoidal Salmonella have been previously correlated to sepsis. Other causes of BSI in HIV-infected patients are mycobacteria and fungi. Mycobacteria constitute a major cause of BSI in limited resource countries. Fungal BSI are not frequent and among them Cryptococcus neoformans is the most common life-threatening infection. The degree of immunosuppression remains the key prognostic factor leading to the development of BSI.

Antiretroviral Therapy as Prevention of … Pneumococcal Infections?

BACKGROUND

Despite antiretroviral therapy, it is generally believed that the risk for pneumococcal infections (PnIs) is high among patients infected with human immunodeficiency virus (HIV). However, most studies in this field have been conducted before 2010, and the proportion of virologically suppressed patients has drastically increased in these latter years thanks to larger indications and more effective antiretroviral regimens. This study aimed to re-evaluate the current risk of PnI among adult patients infected with HIV.

METHODS

The incidence of PnI was evaluated between 1996 and 2014 in 2 French regional hospitals. The 80 most recent cases of PnI (2000-2014) were retrospectively compared with 160 controls (HIV patients without PnI) to analyze the residual risk factors of PnI.

RESULTS

Among a mean annual follow-up cohort of 1616 patients, 116 PnIs were observed over 18 years. The risk factors of PnI among patients infected with HIV were an uncontrolled HIV infection or "classic" risk factors of PnI shared by the general population such as addiction, renal or respiratory insufficiency, or hepatitis B or C coinfection. Pneumococcal vaccination coverage was low and poorly targeted, because only 5% of the cases had been previously vaccinated. The incidence of invasive PnIs among HIV patients with a nonvirologically suppressed infection or comorbidities was 12 times higher than that reported in the general population at the country level (107 vs 9/100000 patients), whereas the incidence among virologically suppressed HIV patients without comorbidities was lower (7.6/100000 patients).

CONCLUSIONS

Human immunodeficiency virus infection no longer per se seems to be a significant risk factor for PnI, suggesting a step-down from a systematic to an "at-risk patient" targeted pneumococcal vaccination strategy.

Convergence in the Epidemiology and Pathogenesis of COPD and Pneumonia

Chronic obstructive pulmonary disease (COPD) is one of the main causes of human mortalities globally after heart disease and stroke. There is increasing evidence of an aetiological association between COPD and pneumonia, the leading infectious cause of death globally in children under 5 years. In this review, we discuss the known risk factors of COPD that are also shared with pneumonia including smoking, air pollution, age and immune suppression. We review how lung pathology linked to a previous history of pneumonia may heighten susceptibility to the development of COPD in later life. Furthermore, we examine how specific aspects of COPD immunology could contribute to the manifestation of pneumonia. Based on the available evidence, a convergent relationship is becoming apparent with respect to the pathogenesis of COPD and pneumonia. This has implications for the management of both diseases, and the development of new interventions.

Incidence and Risk Factors for Severe Bacterial Infections in People Living with HIV. ANRS CO3 Aquitaine Cohort, 2000-2012

Severe non-AIDS bacterial infections (SBI) are the leading cause of hospital admissions among people living with HIV (PLHIV) in industrialized countries. We aimed to estimate the incidence of SBI and their risk factors in a large prospective cohort of PLHIV patients over a 13-year period in France. Patients followed up in the ANRS CO3 Aquitaine cohort between 2000 and 2012 were eligible; SBI was defined as a clinical diagnosis associated with hospitalization of ≥48 hours or death. Survival analysis was conducted to identify risk factors for SBI.Total follow-up duration was 39,256 person-years [PY] (31,370 PY on antiretroviral treatment [ART]). The incidence of SBI decreased from 26.7/1000 PY [95% CI: 22.9–30.5] over the period 2000–2002 to 11.9/1000 PY [10.1–13.8] in 2009–2012 (p <0.0001). Factors independently associated to increased risk of SBI were: plasma HIVRNA>50 copies/mL (Hazard Ratio [HR] = 5.1, 95% Confidence Interval: 4.2–6.2), CD4 count <500 cells/mm³ and CD4/CD8 ratio <0.8 (with a dose-response relationship for both markers), history of cancer (HR = 1.4 [1.0–1.9]), AIDS stage (HR = 1.7 [1.3–2.1]) and HCV coinfection (HR = 1.4, [1.1–1.6]). HIV-positive patients with diabetes were more prone to SBI (HR = 1.6 [0.9–2.6]). Incidence of SBI decreased over a 13-year period due to the improvement in the virological and immune status of PLHIV on ART. Risk factors for SBI include low CD4 count and detectable HIV RNA, but also CD4/CD8 ratio, HCV coinfection, history of cancer and diabetes, comorbid conditions that have been frequent among PLHIV in recent years.

Pneumococcal vaccination among HIV-infected adult patients in the era of combination antiretroviral therapy

HIV-infected patients remain at higher risk for pneumococcal disease than the general population despite immune reconstitution and suppression of HIV replication with combination antiretroviral therapy. Vaccination with 23-valent pneumococcal polysaccharide vaccine (PPV23) composed of T-cell-independent antigens has been recommended to reduce the risk of pneumococcal disease in HIV-infected adults. However, given the heterogeneity of study design, execution and subjects enrolled, studies examining serological responses to PPV23 yielded conflicting results and observational studies of clinical effectiveness only provided moderate evidence to support the routine use of PPV23 in HIV-infected adults. Pneumococcal conjugate vaccine (PCV), with conjugation of the capsular polysaccharide to a protein carrier, is more immunogenic than PPV23 and has been demonstrated to protect against pneumococcal disease in HIV-infected children and recurrent invasive pneumococcal disease in HIV-infected adolescents and adults. Guidelines have recently been revised to recommend that HIV-infected patients aged 19 y or older receive one dose of 13-valent pneumococcal conjugate vaccine (PCV13) followed by a booster vaccination with PPV23. In this paper, we review the studies using different vaccination strategies to improve immunogenicity among HIV-infected adult patients.

Mucociliary dysfunction in HIV and smoked substance abuse

Impaired mucociliary clearance (MCC) is a hallmark of acquired chronic airway diseases like chronic bronchitis associated with chronic obstructive pulmonary disease (COPD) and asthma. This manifests as microbial colonization of the lung consequently leading to recurrent respiratory infections. People living with HIV demonstrate increased incidence of these chronic airway diseases. Bacterial pneumonia continues to be an important comorbidity in people living with HIV even though anti-retroviral therapy has succeeded in restoring CD4+ cell counts. People living with HIV demonstrate increased microbial colonization of the lower airways. The microbial flora is similar to that observed in diseases like cystic fibrosis and COPD suggesting that mucociliary dysfunction could be a contributing factor to the increased incidence of chronic airway diseases in people living with HIV. The three principal components of the MCC apparatus are, a mucus layer, ciliary beating, and a periciliary airway surface liquid (ASL) layer that facilitates ciliary beating. Cystic fibrosis transmembrane conductance regulator (CFTR) plays a pivotal role in regulating the periciliary ASL. HIV proteins can suppress all the components of the MCC apparatus by increasing mucus secretion and suppressing CFTR function. This can decrease ASL height leading to suppressed ciliary beating. The effects of HIV on MCC are exacerbated when combined with other aggravating factors like smoking or inhaled substance abuse, which by themselves can suppress one or more components of the MCC system. This review discusses the pathophysiological mechanisms that lead to MCC suppression in people living with HIV who also smoke tobacco or abuse illicit drugs.

The controversial impact of B cells subsets on immune response to pneumococcal vaccine in HIV-1 patients

BACKGROUND

Chronic HIV infection leads to severe perturbations of the B cell populations and hypo-responsiveness to vaccines. The associations between circulating B cell subpopulations and the antibody response to pneumococcal polysaccharide vaccine in antiretroviral-naïve and treated patients were studied.

METHODS

Sixty-six HIV-infected adults were grouped according to antiretroviral therapy (ART) and CD4+ cell count; 31 were ART-naïve and 35 were ART-treated, and they were matched for age, CD4 cell count, and duration of HIV infection. All subjects were immunized with the 23-valent polysaccharide vaccine against Streptococcus pneumoniae. Pre- and post-vaccination B cell subpopulations were assessed by flow cytometry. Serum IgG concentrations for vaccine serotypes were quantified by ELISA at baseline and at 4 and 48 weeks post-vaccination.

RESULTS

Patients under highly active antiretroviral therapy (HAART) had significantly higher antibody levels against pneumococcal vaccine antigens, while an adequate number of patients responded to vaccination. Memory B cells were diminished over time, although treated patients maintained higher levels of all subsets studied, with the exception of activated memory and isotype-switched memory B cells.

CONCLUSIONS

Low concentrations of total B cells and exhausted memory B cells was the strongest independent predictor of poor pneumococcal vaccine responsiveness, emphasizing that B cell subset disturbances are associated with a poor vaccine response among HIV-infected patients.

A Clinical Predictor Score for 30-Day Mortality among HIV-Infected Adults Hospitalized with Pneumonia in Uganda

Background

Pneumonia is a major cause of mortality among HIV-infected patients. Pneumonia severity scores are promising tools to assist clinicians in predicting patients’ 30-day mortality, but existing scores were developed in populations infected with neither HIV nor tuberculosis (TB) and include laboratory data that may not be available in resource-limited settings. The objective of this study was to develop a score to predict mortality in HIV-infected adults with pneumonia in TB-endemic, resource-limited settings.

Methods

We conducted a secondary analysis of data from a prospective study enrolling HIV-infected adults with cough ≥2 weeks and <6 months and clinically suspected pneumonia admitted to Mulago Hospital in Kampala, Uganda from September 2008 to March 2011. Patients provided two sputum specimens for mycobacteria, and those with Ziehl-Neelsen sputum smears that were negative for mycobacteria underwent bronchoscopy with inspection for Kaposi sarcoma and testing for mycobacteria and fungi, including Pneumocystis jirovecii. A multivariable best subsets regression model was developed, and one point was assigned to each variable in the model to develop a clinical predictor score for 30-day mortality.

Results

Overall, 835 patients were studied (mean age 34 years, 53.4% female, 30-day mortality 18.2%). A four-point clinical predictor score was identified and included heart rate >120 beats/minute, respiratory rate >30 breaths/minute, oxygen saturation <90%, and CD4 cell count <50 cells/mm³. Patients’ 30-day mortality, stratified by score, was: score 0 or 1, 12.6%, score 2 or 3, 23.4%, score 4, 53.9%. For each 1 point change in clinical predictor score, the odds of 30-day mortality increased by 65% (OR 1.65, 95% CI 1.39-1.96, p <0.001).

Conclusions

A simple, four-point scoring system can stratify patients by levels of risk for mortality. Rapid identification of higher risk patients combined with provision of timely and appropriate treatment may improve clinical outcomes. This predictor score should be validated in other resource-limited settings.

Interleukin-37 Expression Is Increased in Chronic HIV-1-Infected Individuals and Is Associated with Inflammation and the Size of the Total Viral Reservoir

Interleukin-37 (IL-37) is a recently identified cytokine with potent antiinflammatory and immunosuppressive functions. The objective of this study was to compare levels of IL-37 mRNA in immunological subgroups of chronic human immunodeficiency virus-1 (HIV-1)-infected individuals and noninfected controls, to determine IL-37's association with biomarkers of inflammation and reservoir size. This was a cross-sectional study. The HIV-1-infected patients were categorized in three subgroups depending on their combination antiretroviral therapy (cART) treatment status and CD4(+) T-cell count. Quantitative RT-PCR was used for the detection of IL-37 mRNA and HIV-1 DNA in peripheral blood mononuclear cells (PBMCs). Biomarkers in plasma were quantified by enzyme-linked immunosorbent assay (ELISA), whereas T-cell activation was determined by flow cytometry. Lastly, lipopolysaccharide (LPS) stimulations of patients PBMCs were carried out to determine differences in IL-37 mRNA response between the subgroups. Sixty HIV-1-infected patients and 20 noninfected controls were included in the study. Steady-state IL-37 mRNA levels in PBMCs were significantly higher in HIV-1-infected individuals compared with noninfected controls: 2.4-fold (p ≤ 0.01) cART-naïve subjects; 3.9-fold (p ≤ 0.0001) inadequate immunological responders; and 4.0-fold (p ≤ 0.0001) in immunological responders compared with non-infected controls. Additionally, levels of the monocyte inflammatory marker sCD14 correlated with IL-37 mRNA (p = 0.03), whereas there was no association with T-cell activation. Finally, we observed a significant correlation between total viral HIV-1 DNA and IL-37 mRNA in PBMCs (p < 0.0001). Collectively, our data shows that the level of IL-37 mRNA is affected by chronic HIV-1-infection. A relationship with the activation of the monocyte compartment is suggested by the correlation with sCD14 and, interestingly, IL-37 could be related to the size of the total viral HIV-1 reservoir.

Incidence and risk factors for invasive pneumococcal disease in HIV-infected and non-HIV-infected individuals before and after the introduction of combination antiretroviral therapy: persistent high risk among HIV-infected injecting drug users

BACKGROUND

Invasive pneumococcal disease (IPD) is an important cause of morbidity among individuals infected with human immunodeficiency virus (HIV). We described incidence and risk factors for IPD in HIV-infected and uninfected individuals.

METHODS

Nationwide population-based cohort study of HIV-infected adults treated at all Danish HIV treatment centers during 1995-2012. Nineteen population-matched controls per HIV-infected individual were retrieved. The risk of IPD was assessed using Poisson regression.

RESULTS

The incidence of IPD was 304.7 cases per 100 000 person-years of follow-up (PYFU) in HIV-infected and 12.8 per 100 000 PYFU in HIV-uninfected individuals. After adjusting for confounders, HIV infection (relative risk [RR], 24.4 [95% confidence interval [CI], 23.7-25.1]), male sex (RR, 1.20 [95% CI, 1.16-1.24]), increasing age (per year) (RR, 1.03 [95% CI, 1.03-1.04]), and calendar period (pre-cART RR, 2.80 [95% CI, 2.70-2.91] compared with late cART) were significantly associated with an increased risk of IPD. Among HIV-infected individuals, male sex (RR, 1.57 [95% CI, 1.49-1.66]), smoking (RR, 1.34 [95% CI, 1.26-1.42]), and injecting drug use (RR, 2.51 [95% CI, 2.26-2.67]) were associated with an increased risk of IPD. Detectable viral loads (RR, 1.88 [95% CI, 1.79-1.98]) and a relative fall in CD4 T-cell counts were also associated with an increased risk (≥500 to 350-500 CD4 T cells/µL: RR, 1.29 [95% CI, 1.21-1.37] and <100 cells/µL: RR, 7.4 [95% CI, 6.87-8.02]). The risk of IPD declined over time, although this was not the case for IDUs where the risk remained unchanged.

CONCLUSIONS

The incidence of IPD in HIV-infected individuals remained significantly higher than the incidence observed in non-HIV-infected subjects, despite the widespread use of cART. IDUs have a persistently high risk of IPD. Injecting drug use, smoking, and the receipt of cART are suitable targets for preventive measures in the future.

Socioeconomic inequalities in risk of hospitalization for community-acquired bacteremia: a Danish population-based case-control study

In a Danish population-based case-control study, we examined the association between socioeconomic status (SES) and risk of community-acquired bacteremia, as well as the contribution of chronic diseases and substance abuse to differences in bacteremia risk. Analyses were based on 4,117 patients aged 30-65 years who were hospitalized with first-time community-acquired bacteremia during 2000-2008 and 41,170 population controls matched by sex, age, and region of residence. Individual-level information on SES (education and income), chronic diseases, and substance abuse was retrieved from public and medical registries. Conditional logistic regression was used to compute odds ratios for bacteremia. Persons of low SES had a substantially higher risk of bacteremia than those of high SES (for short duration of education vs. long duration, odds ratio = 2.30 (95% confidence interval: 2.10, 2.52); for low income vs. high income, odds ratio = 2.77 (95% confidence interval: 2.54, 3.02)). A higher prevalence of chronic diseases and substance abuse in low-SES individuals versus high-SES individuals explained 43%-48% of the socioeconomic differences in bacteremia risk. In a country with a universal welfare system, differences in the burden of chronic diseases and substance abuse seem to have major importance in explaining inequalities in bacteremia risk.

Impact of hepatitis coinfection on hospitalization rates and causes in a multicenter cohort of persons living with HIV

BACKGROUND

Chronic viral hepatitis is a potentially important determinant of health care utilization among persons living with HIV. We describe hospitalization rates and reasons for hospitalization among persons living with HIV stratified by coinfection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV).

METHODS

Laboratory, demographic, and hospitalization data were obtained for all patients receiving longitudinal HIV care during 2010 at 9 geographically diverse sites. Hepatitis serostatus was assessed by hepatitis B surface antigen and/or hepatitis C antibody. ICD-9 codes were used to assign hospitalizations into diagnostic categories. Negative binomial regression was used to assess factors associated with all-cause and diagnostic category-specific hospitalizations.

RESULTS

A total of 2793 hospitalizations were observed among 12,819 patients. Of these patients, 49.3% had HIV monoinfection, 4.1% HIV/HBV, 15.4% HIV/HCV, 2.5% HIV/HBV/HCV, and 28.7% unknown hepatitis serostatus. Compared with HIV monoinfection, the risk of all-cause hospitalization was increased with HIV/HBV [adjusted incidence rate ratio 1.55 (1.17 to 2.06)], HIV/HCV [1.45 (1.21 to 1.74)], and HIV/HBV/HCV [1.52 (1.04 to 2.22)]. Risk of hospitalization for non-AIDS-defining infection was also higher among patients with HIV/HBV [2.07 (1.38 to 3.11)], HIV/HCV [1.81 (1.36 to 2.40)], and HIV/HBV/HCV [1.96 (1.11 to 3.46)]. HIV/HBV was associated with hospitalization for gastrointestinal/liver disease [2.55 (1.30 to 5.01)]. HIV/HCV was associated with hospitalization for psychiatric illness [1.89 (1.11 to 3.26)].

CONCLUSIONS

HBV and HCV coinfection are associated with increased risk of all-cause hospitalization and hospitalization for non-AIDS-defining infections, as compared with HIV monoinfection. Policy-makers and third-party payers should be aware of the heightened risk of hospitalization associated with coinfection when allocating health care resources and considering models of health care delivery.

Incidence and determinants of severe morbidity among HIV-infected patients from Rio de Janeiro, Brazil, 2000-2010

BACKGROUND

Reliable information on severe morbidity is essential for identifying priorities for case management and to guide resource allocation within the health sector.

METHODS

This study describes overall, AIDS- and non-AIDS-related severe morbidity as well as mortality and its determinants in an urban cohort of HIV-infected individuals from a public healthcare institution, the Evandro Chagas Research Institute (IPEC) of the Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. Severe morbid events were defined as all clinical diagnoses listed in hospitalization discharge records; all diagnoses were checked and validated. Generalized estimating equation models were used to estimate incidence rates while adjusting for within-subject correlation.

RESULTS

Between 2000 and 2010, 3,537 patients were followed for a total of 16,960 person-years (PY) of follow-up. Over the years, annual incidence rate of severe morbid events, AIDS-related events, non-AIDS-related events, and deaths significantly decreased from, respectively, 36.6, 12.9, 23.7 and 3.2 per 100 PY in 2000 to 25.3, 7.9, 17.4 and 1.9 per 100 PY in 2010. Patients' immunological profiles significantly improved with time; 84% of the patients used combination antiretroviral therapy (cART) per year. Immunodeficiency was associated with a higher incidence rate of AIDS- and non-AIDS-related events as well as with the incidence rate of specific non-AIDS events (bacterial infections, toxicities, cardiovascular, renal and respiratory diseases).

CONCLUSIONS

Our results show that in a middle income country with access to cART, non-AIDS-related events represent an important cause of severe morbidity alongside a still high incidence rate of AIDS-related events.

Risk factors for community-acquired pneumonia in adults in Europe: a literature review

Background

Community-acquired pneumonia (CAP) causes considerable morbidity and mortality in adults, particularly in the elderly.

Methods

Structured searches of PubMed were conducted to identify up-to-date information on the incidence of CAP in adults in Europe, as well as data on lifestyle and medical risk factors for CAP.

Results

The overall annual incidence of CAP in adults ranged between 1.07 to 1.2 per 1000 person-years and 1.54 to 1.7 per 1000 population and increased with age (14 per 1000 person-years in adults aged ≥65 years). Incidence was also higher in men than in women and in patients with chronic respiratory disease or HIV infection. Lifestyle factors associated with an increased risk of CAP included smoking, alcohol abuse, being underweight, having regular contact with children and poor dental hygiene. The presence of comorbid conditions, including chronic respiratory and cardiovascular diseases, cerebrovascular disease, Parkinson's disease, epilepsy, dementia, dysphagia, HIV or chronic renal or liver disease all increased the risk of CAP by twofold to fourfold.

Conclusion

A range of lifestyle factors and underlying medical conditions are associated with an increased risk of CAP in European adults. Understanding of the types of individual at greatest risk of CAP can help to ensure that interventions to reduce the risk of infection and burden of disease are targeted appropriately.

Epidemic of lung cancer in patients with HIV infection

The survival of patients with HIV infection has improved dramatically over the past 20 years, largely owing to a significant reduction in opportunistic infections and AIDs-defining malignancies, such as lymphoma and Kaposi sarcoma. However, with improved survival, patients with HIV are experiencing morbidity and mortality from other (non-AIDs-defining) complications, such as solid organ malignancies. Of these, the leading cause of mortality in the HIV-infected population is lung cancer, accounting for nearly 30% of all cancer deaths and 10% of all non-HIV-related deaths. Importantly, the average age of onset of lung cancer in the HIV-infected population is 25 to 30 years earlier than that in the general population and at lower exposure to cigarette smoke. This article provides an overview of the epidemiology of lung cancer in the HIV-infected population and discusses some of the important risk factors and pathways that may enhance the risk of lung cancer in this population.

Immunization against pneumococcal disease in HIV-infected patients: conjugate versus polysaccharide vaccine before or after reconstitution of the immune system (CTN-147)

To investigate whether patients should be immunized immediately or delay immunization until after reconstitution of the immune system and whether a conjugate or polysaccharide vaccine results in a better immunologic response. Seventy-nine patients were randomly assigned, utilizing a two by two factorial design to receive immediate immunization or delay immunization. Baseline characteristics were similar for the four arms: 78% men, median age 41 years, median time since HIV diagnosis 0.3 years, median CD4 60 cells/mm(3) and median HIV viral load 5.02 log copies/mL. Results in favour of delayed immunization were observed for those serotypes showing a response. The proportional odds ratios for delayed versus immediate immunization were 0.341 (P = 0.04) and 0.204 (P = 0.004) at months 6 and 12, respectively. No differences in immunological response were observed between the two individual vaccines for the shared serotypes studied. HIV-infected adults produced a higher immunological response to pneumococcal vaccine after reconstitution of the immune system.