HIV-related pulmonary disorders: practice issues

Brief Report: Cofactors of Mortality Among Hospitalized HIV-Infected Children Initiating Antiretroviral Therapy in Kenya

OBJECTIVES

Identifying factors associated with mortality among acutely ill HIV-infected children presenting with advanced HIV disease may help clinicians optimize care for those at highest risk of death.

DESIGN

Using data from a randomized controlled trial (NCT02063880), we determined baseline sociodemographic, clinical, and laboratory cofactors of mortality among HIV-infected children in Kenya.

METHODS

We enrolled hospitalized, HIV-infected, antiretroviral therapy-naive children (0-12 years), initiated antiretroviral therapy, and followed up them for 6 months. We used Cox proportional hazards regression to estimate hazard ratios (HRs) for death and 95% confidence intervals (CIs).

RESULTS

Of 181 enrolled children, 39 (22%) died. Common diagnoses at death were pneumonia or suspected pulmonary tuberculosis [23 (59%)] and gastroenteritis [7 (18%)]. Factors associated with mortality in univariate analysis included age <2 years [HR 3.08 (95% CI: 1.50 to 6.33)], orphaned or vulnerable child (OVC) [HR 2.05 (95% CI: 1.09 to 3.84)], weight-for-age Z score <-2 [HR 2.29 (95% CI: 1.05 to 5.00)], diagnosis of pneumonia with hypoxia [HR 5.25 (95% CI: 2.00 to 13.84)], oral thrush [HR 2.17 (95% CI: 1.15 to 4.09)], persistent diarrhea [HR 3.81 (95% CI: 1.89 to 7.69)], and higher log10 HIV-1 viral load [HR 2.16 (95% CI: 1.35 to 3.46)] (all P < 0.05). In multivariable analysis, age <2 years and OVC status remained significantly associated with mortality.

CONCLUSIONS

Young age and OVC status independently predicted mortality. Hypoxic pneumonia, oral thrush, and persistent diarrhea are important clinical features that predict mortality. Strategies to enhance early diagnosis in children and improve hospital management of critically ill HIV-infected children are needed.

Burden of respiratory tract infections at post mortem in Zambian children

BACKGROUND

Autopsy studies are the gold standard for determining cause-of-death and can inform on improved diagnostic strategies and algorithms to improve patient care. We conducted a cross-sectional observational autopsy study to describe the burden of respiratory tract infections in inpatient children who died at the University Teaching Hospital in Lusaka, Zambia.

METHODS

Gross pathology was recorded and lung tissue was analysed by histopathology and molecular diagnostics. Recruitment bias was estimated by comparing recruited and non-recruited cases.

RESULTS

Of 121 children autopsied, 64 % were male, median age was 19 months (IQR, 12-45 months). HIV status was available for 97 children, of whom 34 % were HIV infected. Lung pathology was observed in 92 % of cases. Bacterial bronchopneumonia was the most common pathology (50 %) undiagnosed ante-mortem in 69 % of cases. Other pathologies included interstitial pneumonitis (17 %), tuberculosis (TB; 8 %), cytomegalovirus pneumonia (7 %) and pneumocystis Jirovecii pneumonia (5 %). Comorbidity between lung pathology and other communicable and non-communicable diseases was observed in 80 % of cases. Lung tissue from 70 % of TB cases was positive for Mycobacterium tuberculosis by molecular diagnostic tests. A total of 80 % of TB cases were comorbid with malnutrition and only 10 % of TB cases were on anti-TB therapy when they died.

CONCLUSIONS

More proactive testing for bacterial pneumonia and TB in paediatric inpatient settings is needed.

Dysregulation of claudin-5 in HIV-induced interstitial pneumonitis and lung vascular injury. Protective role of peroxisome proliferator-activated receptor-γ

RATIONALE

HIV-1-induced interstitial pneumonitis (IP) is a serious complication of HIV-1 infection, characterized by inflammation and cellular infiltration in lungs, often leading to respiratory failure and death. The barrier function of the pulmonary endothelium is caused in part by tight junction (TJ) proteins, such as claudin-5. Peroxisome proliferator-activated receptor (PPAR)-γ is expressed in lung tissues and regulates inflammation. We hypothesize that HIV-1 induces vascular lung injury, and HIV-1-mediated damage of the pulmonary endothelium and IP is associated with dysregulation of PPAR-γ.

OBJECTIVES

Investigate the effects of HIV-1 infection on the pulmonary microvasculature and the modulatory effects of the PPAR-γ ligands.

METHODS

Using human lung tissues, we demonstrated down-regulation of claudin-5 (marker of pulmonary barrier integrity), down-regulation of PPAR-γ transcription, and expression in lung tissues of HIV-1-infected humans with IP.

MEASUREMENTS AND MAIN RESULTS

Human lung microvascular endothelial cells expressed the TJ proteins claudin-5, ZO-1, and ZO-2; HIV-1 decreased TJ proteins expression and induced nuclear factor-κB promoter activity, which was reversed by PPAR-γ agonist. Using two murine HIV/AIDS models, we demonstrated decreased claudin-5 expression and increased macrophage infiltration in the lungs of HIV-1-infected animals. Activation of PPAR-γ prevented HIV-1-induced claudin-5 down-regulation and significantly reduced viremia and pulmonary macrophage infiltration.

CONCLUSIONS

HIV-induced IP is associated with injury to the lung vascular endothelium, with decreased TJ and PPAR-γ expression, and increased pulmonary macrophage infiltration. PPAR-γ ligands abrogated these effects. Thus, regulation of PPAR-γ can be a therapeutic approach against HIV-1-induced vascular damage and IP in infected humans. Removal of Expression of Concern: Issues leading to the previous expression of concern for this article have been resolved after further revisions and editorial review. No further concerns exist.

Pneumococcal vaccine and patients with pulmonary diseases

Chronic pulmonary diseases are chronic diseases that affect the airways and lung parenchyma. Examples of common chronic pulmonary diseases include asthma, bronchiectasis, chronic obstructive lung disease, lung fibrosis, sarcoidosis, pulmonary hypertension, and cor pulmonale. Pulmonary infection is considered a significant cause of mortality in patients with chronic pulmonary diseases. Streptococcus pneumoniae is the leading isolated bacteria from adult patients with community-acquired pneumonia, the most common pulmonary infection. Vaccination against S. pneumoniae can reduce the risk of mortality, especially from more serious infections in both immunocompetent and immunocompromised patients. Patients with chronic pulmonary diseases who take steroids or immunomodulating therapy (eg, methotrexate, anti-tumor necrosis factor inhibitors), or who have concurrent sickle cell disease or other hemoglobinopathies, primary immunodeficiency disorders, human immunodeficiency virus infection/acquired immunodeficiency syndrome, nephrotic syndrome, and hematologic or solid malignancies should be vaccinated with both 13-valent pneumococcal conjugate vaccine and the pneumococcal polysaccharide vaccine 23-valent.

Clinical and immunological correlates of chest X-ray abnormalities in HIV-infected South African children with limited access to anti-retroviral therapy

BACKGROUND

The chest X-ray (CXR) abnormalities of human immunodeficiency virus (HIV)-infected children in low/middle income countries (LMIC's) have not been well studied.

OBJECTIVE

To describe the CXR abnormalities and associated clinical/immunological features in HIV-infected South African children.

MATERIALS AND METHODS

A prospective study of HIV-infected children who underwent baseline chest radiography and clinical and immunological HIV-staging. CXR abnormalities were stratified as grade 1 (mild) or grade 2 (moderate/severe). Univariate and multiple logistic regression analyses assessed associations between radiological severity and clinical/immunological parameters.

RESULTS

Three hundred thirty children (53% male), median age 23.8 months, were included; 303 (92%) had moderate/severe clinical disease and 225 (68%) moderate/severe immune suppression; 52 (16%) had a normal CXR; 169 (51%) had grade 2 CXR abnormalities, manifesting as: confluent opacification (n = 91, 28%), nodules (n = 37, 11%), or nodules with opacification (n = 41, 12%) Grade 2 abnormality was associated with more advanced clinical HIV disease (OR: 6.9; 95% CI: 1.9-25.6), CD4+ less than 20% (OR: 1.8; 95% CI: 1.0-3.0) and age over 24 months (OR: 4.1; 95% CI: 2.1-8.0).

CONCLUSION

CXR abnormalities are common in HIV-infected children in LMIC's. The extent of radiological abnormality correlates with age and clinical and immunological severity of HIV-disease.

Pneumocystis pneumonia in South African children diagnosed by molecular methods

Background

Pneumocystis pneumonia (PCP) is an important cause of hospitalization and mortality in HIV-infected children. However, the incidence of PCP has been underestimated due to poor sensitivity of diagnostic tests. The use of polymerase chain reaction (PCR) for pneumocystis has enabled more reliable diagnosis. This study describes the incidence, clinical features and outcome of PCP in South African children diagnosed using PCR.

Methods

A prospective study of children hospitalised in South Africa with suspected PCP was done from November 2006 to August 2008. Clinical, laboratory and radiological information were collected. Lower respiratory tract specimens were obtained for PCP immunofluorescence (IF), real- time PCR for pneumocystis, bacterial and mycobacterial culture. Nasopharyngeal aspirates were taken for immunofluorescence (IF), real-time PCR for pneumocystis and PCR for respiratory viruses. A blood specimen for bacterial culture and for cytomegalovirus PCR was taken. Children were followed for the duration of their hospitalisation and the outcome was recorded.

Results

202 children [median (interquartile range, IQR) age 3.2 (2.1– 4.6) months] were enrolled; 124 (61.4%) were HIV infected. PCP was identified in 109 (54%) children using PCR, compared to 43 (21%) using IF and Grocott staining (p < 0.0001). Most PCP cases (88, 81%) occurred in HIV-infected children. All 21 cases (19%) occurring in HIV- negative children had another risk factor for PCP. On logistic regression, predictive factors for PCP were HIV infection, lack of fever, high respiratory rate and low oxygen saturation whilst cotrimoxazole prophylaxis was protective (OR 0.24; 95% CI 0.1 to 0.5; p < 0.002). The case fatality of children with PCP was higher than those without PCP (32.1% versus 17.2%; relative risk 1.87; 95% confidence interval (CI) 1.11 – 3.15). Amongst HIV-infected children, a CD4 less than 15% was the only independent predictor of mortality.

Conclusions

The diagnostic yield for PCP is more than 2.5 times higher on PCR than other detection methods. PCP is a very common cause of severe hypoxic pneumonia and is associated with high mortality in HIV-infected African infants.

Interstitial lung disease associated with Equine Infectious Anemia Virus infection in horses

EIA (Equine Infectious Anemia) is a blood-borne disease primarily transmitted by haematophagous insects or needle punctures. Other routes of transmission have been poorly explored. We evaluated the potential of EIAV (Equine Infectious Anemia Virus) to induce pulmonary lesions in naturally infected equids. Lungs from 77 EIAV seropositive horses have been collected in Romania and France. Three types of lesions have been scored on paraffin-embedded lungs: lymphocyte infiltration, bronchiolar inflammation, and thickness of the alveolar septa. Expression of the p26 EIAV capsid (CA) protein has been evaluated by immunostaining. Compared to EIAV-negative horses, 52% of the EIAV-positive horses displayed a mild inflammation around the bronchioles, 22% had a moderate inflammation with inflammatory cells inside the wall and epithelial bronchiolar hyperplasia and 6.5% had a moderate to severe inflammation, with destruction of the bronchiolar epithelium and accumulation of smooth muscle cells within the pulmonary parenchyma. Changes in the thickness of the alveolar septa were also present. Expression of EIAV capsid has been evidenced in macrophages, endothelial as well as in alveolar and bronchiolar epithelial cells, as determined by their morphology and localization. To summarize, we found lesions of interstitial lung disease similar to that observed during other lentiviral infections such as FIV in cats, SRLV in sheep and goats or HIV in children. The presence of EIAV capsid in lung epithelial cells suggests that EIAV might be responsible for the broncho-interstitial damages observed.

Improving survival of children with severe acute malnutrition in HIV-prevalent settings

The care of severely malnourished children in sub-Saharan Africa is challenging, especially in HIV-prevalent settings. Recent improvements to facility-based individual case management, and increased community-based management focusing on early identification and high programme coverage have led to reductions in mortality. Further interventions are urgently needed to address resistant mortality, mostly attributable to HIV. This paper explores strategies in three main areas to improve survival for children with severe acute malnutrition (SAM): identifying HIV and improving case management for HIV-infected children; strengthening existing strategies to improve outcomes for all children with SAM, regardless of HIV status; and improving early identification and increasing programme coverage. Although interventions to further improve survival among children with SAM in sub-Saharan Africa must firstly ensure best care for all children, HIV-infected children are at particular risks for mortality. Integration of specific interventions for HIV testing and treatment into SAM care is essential. International guidelines should reflect best evidence, and are in urgent need of updating and adapting to local country context. Effective interventions already exist that can improve survival in children with SAM in HIV-prevalent settings. The challenge is to implement what we know and to research what we do not.

Global burden of childhood pneumonia and diarrhoea

Diarrhoea and pneumonia are the leading infectious causes of childhood morbidity and mortality. We comprehensively reviewed the epidemiology of childhood diarrhoea and pneumonia in 2010-11 to inform the planning of integrated control programmes for both illnesses. We estimated that, in 2010, there were 1·731 billion episodes of diarrhoea (36 million of which progressed to severe episodes) and 120 million episodes of pneumonia (14 million of which progressed to severe episodes) in children younger than 5 years. We estimated that, in 2011, 700,000 episodes of diarrhoea and 1·3 million of pneumonia led to death. A high proportion of deaths occurs in the first 2 years of life in both diseases--72% for diarrhoea and 81% for pneumonia. The epidemiology of childhood diarrhoea and that of pneumonia overlap, which might be partly because of shared risk factors, such as undernutrition, suboptimum breastfeeding, and zinc deficiency. Rotavirus is the most common cause of vaccine-preventable severe diarrhoea (associated with 28% of cases), and Streptococcus pneumoniae (18·3%) of vaccine-preventable severe pneumonia. Morbidity and mortality from childhood pneumonia and diarrhoea are falling, but action is needed globally and at country level to accelerate the reduction.

The immune response and its therapeutic modulation in bronchiectasis

Bronchiectasis (BC) is a chronic pulmonary disease with tremendous morbidity and significant mortality. As pathogen infection has been advocated as a triggering insult in the development of BC, a central role for the immune response in this process seems obvious. Inflammatory cells are present in both the airways as well as the lung parenchyma, and multiple mediators of immune cells including proteases and cytokines or their humoral products are increased locally or in the periphery. Interestingly, a defect in the immune system or suppression of immune response during conditions such as immunodeficiency may well predispose one to the devastating effects of BC. Thus, the outcome of an active immune response as detrimental or protective in the pathogenesis of BC may be dependent on the state of the patient's immunity, the severity of infection, and the magnitude of immune response. Here we reassess the function of the innate and acquired immunity in BC, the major sites of immune response, and the nature of the bioactive mediators. Furthermore, the potential link(s) between an ongoing immune response and structural alterations accompanying the disease and the success of therapies that can modulate the nature and extent of immune response in BC are elaborated upon.

Development of the Respiratory Index of Severity in Children (RISC) score among young children with respiratory infections in South Africa

Objective

Pneumonia is a leading cause of death in children worldwide. A simple clinical score predicting the probability of death in a young child with lower respiratory tract infection (LRTI) could aid clinicians in case management and provide a standardized severity measure during epidemiologic studies.

Methods

We analyzed 4,148 LRTI hospitalizations in children <24 months enrolled in a pneumococcal conjugate vaccine trial in South Africa from 1998–2001, to develop the Respiratory Index of Severity in Children (RISC). Using clinical data at admission, a multivariable logistic regression model for mortality was developed and statistically evaluated using bootstrap resampling techniques. Points were assigned to risk factors based on their coefficients in the multivariable model. A child's RISC score is the sum of points for each risk factor present. Separate models were developed for HIV-infected and non-infected children.

Results

Significant risk factors for HIV-infected and non-infected children included low oxygen saturation, chest indrawing, wheezing, and refusal to feed. The models also included age and HIV clinical classification (for HIV-infected children) or weight-for-age (for non-infected children). RISC scores ranged up to 7 points for HIV-infected or 6 points for non-infected children and correlated with probability of death (0–47%, HIV-infected; 0–14%, non-infected). Final models showed good discrimination (area under the ROC curve) and calibration (goodness-of-fit).

Conclusion

The RISC score incorporates a simple set of risk factors that accurately discriminate between young children based on their risk of death from LRTI, and may provide an objective means to quantify severity based on the risk of mortality.

Impact of HIV on standard case management for severe pneumonia in children

It is estimated that 2 million children under 5 years of age die from pneumonia each year and that half of these deaths occur in sub-Saharan Africa. Over 85% of the more than 2.3 million children living with HIV worldwide reside in sub-Saharan Africa. HIV infection is likely to have a major impact on current recommendations for the standard case management of pneumonia in children and is the rationale for undertaking this review of published studies. The studies identified indicate an overall sixfold (range 2.5-13.5-fold) increase in pneumonia-related fatality in HIV-infected compared with HIV-uninfected African infants and children. They are more likely to have disease due to mixed infection and from a wider range of pathogens including Pneumocystis pneumonia, TB and cytomegalovirus. Scaling-up of the implementation of strategies that prevent HIV and Pneumocystis pneumonia remains an important strategy to reduce the burden of HIV-related pneumonia in the region. Research is urgently required to address the most effective pneumonia case management strategy in HIV-infected infants and children.

Multiple sampling in one day to optimize smear microscopy in children with tuberculosis in Yemen

Background and Aim

The diagnosis of pulmonary Tuberculosis (TB) in children is difficult and often requires hospitalization. We explored whether the yield of specimens collected for smear microscopy from different anatomical sites in one visit is comparable to the yield of specimens collected from a single anatomical site over several days.

Methodology and Principal Findings

Children with signs/symptoms of pulmonary TB attending a reference hospital in Sana'a Yemen underwent one nasopharyngeal aspirate (NPA) the first day of consultation and three gastric aspirates (GA) plus three expectorated/induced sputa over 3 consecutive days. Specimens were examined using smear microscopy (Ziehl-Neelsen) and cultured in solid media (Ogawa). Two hundred and thirteen children (aged 2 months–15 years) were enrolled. One hundred and ninety seven (93%) underwent nasopharyngeal aspirates, 196 (92%) GA, 122 (57%) expectorated sputum and 88 induced sputum. A total 1309 specimens were collected requiring 237 hospitalization days. In total, 29 (13.6%) children were confirmed by culture and 18 (8.5%) by smear microscopy. The NPA identified 10 of the 18 smear-positives; three consecutive GA identified 10 and induced/expectorated sputa identified 13 (6 by induced, 8 by expectorated sputum and one positive by both). In comparison, 22 (3.7%) of 602 specimens obtained the first day were smear-positive and identified 14 (6.6%) smear-positive children.

Conclusion/Significance

The examination of multiple tests the first day of consultation identified a similar proportion of smear-positive children than specimens collected over several days; would require half the number of tests and significantly less hospitalization. Optimized smear microscopy approaches for children should be explored further.

Challenges to improving case management of childhood pneumonia at health facilities in resource-limited settings

Effective case management is an important strategy to reduce pneumonia-related morbidity and mortality in children. Guidelines based on sound evidence are available but are used variably. This review outlines current guidelines for childhood pneumonia management in the setting where most child pneumonia deaths occur and identifies challenges for improved management in a variety of settings and different "at-risk" groups. These include appropriate choice of antibiotic, clinical overlap with other conditions, prompt and appropriate referral for inpatient care, and management of treatment failure. Management of neonates, and of HIV-infected or severely malnourished children is more complicated. The influence of co-morbidities on pneumonia outcome means that pneumonia case management must be integrated within strategies to improve overall paediatric care. The greatest potential for reducing pneumonia-related deaths in health facilities is wider implementation of the current guidelines built around a few core activities: training, antibiotics and oxygen. This requires investment in human resources and in equipment for the optimal management of hypoxaemia. It is important to provide data from a variety of epidemiological settings for formal cost-effectiveness analyses. Improvements in the quality of case management of pneumonia can be a vehicle for overall improvements in child health-care practices.