Determinants of radiological patterns and severity in immunocompromised adults with Metapneumovirus infection

BACKGROUND

Human Metapneumovirus (HMPV) belongs to the Pneumoviridae family and is responsible for respiratory infections. Mild infections are well-recognized in children, while its precise impact in various categories of immunocompromised adults has not been well addressed.

RESEARCH QUESTION

We retrospectively studied HMPV infections in immunocompromised adults followed in two large French university medical centers.

STUDY DESIGN AND METHODS

We identified immunocompromised adults with positive HMPV Polymerase Chain Reaction (PCR) for 36 months and reviewed their medical charts. For lung transplant recipients (LTR), FEV1 was collected at baseline, during and after infection. Imaging was centralized and chest involvement was categorized by dominant CT patterns. We compared severe patients (requiring oxygen or ventilation) and non hypoxemic patients.

RESULTS

Seventy-two patients were included, 27 were LTR, 25 had a hematological malignancy or were hematopoietic stem cell recipients, 20 had another immunocompromised status. Twenty patients (28%) presented a hypoxemic infection, requiring hospitalization and intensive care units transfers in 50/72 (69.4%) and 9/72 (12.5%) respectively, with only one death. Hypoxemia was less pronounced in LTRs (p = 0.014). Finally, age and dyspnea remained independent factors associated with hypoxemia (p < 0.005). The most frequent radiological patterns were bronchopneumonia (34.2%) and bronchiolitis (39.5% and 64.3% in the overall population and in LTRs respectively, p = 0.045). FEV1 improved in LTRs at one month and 85% had recovered their baseline FEV1 within 6 months.

INTERPRETATIONS

In immunocompromised adults, HMPV infections required frequent hospitalizations and ICU transfers, while mortality is low. In LTRs, bronchiolitis pattern was predominant with short and long-term favorable outcome.

[Pulmonary complications of Chronic Granulomatous Disease]

Chronic Granulomatosis Disease (CGD) is an inherited immune deficiency due to a mutation in the genes coding for the subunits of the NADPH oxidase enzyme that affects the oxidative capacity of phagocytic cells. It is characterized by increased susceptibility to bacterial and fungal infections, particularly Aspergillus, as well as complications associated with hyperinflammation and granulomatous tissue infiltration. There exist two types of frequently encountered pulmonary manifestations: (1) due to their being initially pauci-symptomatic, possibly life-threatening infectious complications are often discovered at a late stage. Though their incidence has decreased through systematic anti-bacterial and anti-fungal prophylaxis, they remain a major cause of morbidity and mortality; (2) inflammatory complications consist in persistent granulomatous mass or interstitial pneumoniae, eventually requiring immunosuppressive treatment. Pulmonary complications recurring since infancy generate parenchymal and bronchial sequelae that impact functional prognosis. Hematopoietic stem cell allograft is a curative treatment; it is arguably life-sustaining and may limit the morbidity of the disease. As a result of improved pediatric management, life expectancy has increased dramatically. That said, new challenges have appeared with regard to adults: difficulties of compliance, increased inflammatory manifestations, acquired resistance to anti-infectious therapies. These different developments underscore the importance of the transition period and the need for multidisciplinary management.

Amikacin Liposomal Inhalation Suspension (ALIS) in the treatment of Mycobacterium abscessus lung infection: a French observational experience

Background

Mycobacterium abscessus infections remain difficult to manage in both cystic fibrosis (CF) and non-CF patients and reported clinical outcomes are largely unsatisfactory. Clinical trial data are limited and no approved therapies are currently available for the management of M abscessus lung diseases. As an alternative, cohort studies may provide insightful information into the management of M abscessus pulmonary disease.

Methods

Based on a retrospective observational cohort study, we investigated the safety and efficacy of amikacin liposome inhaled suspension (ALIS) as an adjunct to a standard antibiotic regimen for M abscessus lung infection in both CF and non-CF patients. We also assessed the association of patient drug compliance with culture conversion and clinical outcomes.

Results

Twenty-six patients had long-term follow-up data available. Culture conversion was achieved in 54% (14/26) of the patients with no difference between CF and non-CF patients after an average treatment duration of 10 months. Patient treatment compliance was significantly better in the converter group compared to nonconverters with an odds ratio of 44.78 associated with good compared to poor patient compliance. Overall, 9 patients (35%) experienced an adverse event that led to treatment discontinuation.

Conclusions

ALIS appears beneficial in both CF and non-CF populations with M abscessus lung disease.

Neumonía aguda extrahospitalaria

La neumonía aguda extrahospitalaria sigue estando asociada a una elevada morbimortalidad. Durante estos últimos años, y gracias al desarrollo de técnicas de biología molecular, se han realizado importantes progresos en los métodos diagnósticos. Estas técnicas permiten mejorar la detección de bacterias atípicas y de virus respiratorios estacionales. Han permitido asimismo subrayar el lugar de los virus respiratorios en su aparición. El protocolo terapéutico se basa siempre en la instauración precoz de una antibioticoterapia que casi siempre es empírica. Las recomendaciones europeas para el tratamiento de las neumonías extrahospitalarias han sido puestas al día en 2011, como también lo han sido recientemente las pautas vacunales frente al neumococo. En este artículo, se resumen las etiologías de las neumonías, su diagnóstico, las escalas que permiten evaluar su gravedad y orientar el tratamiento del paciente, los datos sobre la sensibilidad a los antibióticos y las recomendaciones terapéuticas resultantes, así como las estrategias de prevención.

[Lung surgery in haematological patients: useful? hazardous?]

Respiratory complications are frequent in haematological patients. Lung surgery, either for diagnosis or treatment, is considered useful but hazardous in these patients. We performed a reappraisal study of this purpose; retrospective study in a university centre, located in the Paris area, France. We analysed the entire records of all the haematological patients admitted in the Thoracic Surgery department from October 2001 to January 2009, among 400 haematological patients with pulmonary complications admitted to the Respiratory Diseases department. Seventeen patients (male: n=13, mean age 47 ± 15 years) underwent lung surgery. Underlying haematological disease was acute (n=7) or chronic (n=5) leukaemia, lymphoma (n=4), and eight have had stem cell transplantation. Thirteen patients had been exposed to a cytotoxic chemotherapy with known pulmonary toxicity. Respiratory diseases have been evolving for 112 days (10-663 days), and 14 patients received previously antibiotic and/or antifungal therapy. One patient was neutropenic and three had thrombopenia. Five patients underwent curative surgery for a residual pulmonary nodule after medical treatment of invasive aspergillosis, and 12 had a diagnostic procedure (open lung biopsy by video-assisted thoracoscopy [n=2]; thoracotomy [n=8]). Surgery permitted a final diagnosis in all 12 cases: non-specific infiltrative pneumonia (n=4), pulmonary graft versus host disease (n=3), granulomatous pneumocystosis (n=1), invasive aspergillosis (n=1), bronchial carcinoma (n=1), EBV-related lymphoproliferation (n=1), and tuberculosis (n=1). Therapeutic regimens were modified according to the surgical results in ten cases (84%). All patients were extubated at the end of surgery. Post-operative complications were: prolonged air leaks (n=3), pneumonia (n=1), parenchymal hematoma (n=1), acute coronary syndrome (n=1). Seven patients were admitted in the Intensive Care Unit, and five had non-invasive ventilation. Three patients died from respiratory failure: NSIP (n=2), pneumocystosis (n=1). Lung surgery for selected haematological patients has two indications: (1) curative surgery, for a residual pulmonary nodule after medical treatment of invasive aspergillosis; (2) diagnostic procedure, leading frequently to modifications of therapeutic regimens, with low rate of complications, in highly selected patients.

[Are investigations for underlying causes needed for the management of an adult patient with bronchiectasis?]

Bronchiectasis may result from various causes. Recognition of these underlying causes may lead to specific management. Focal bronchiectasis are related to luminal blockage or extrinsic narrowing. The causative factors of diffuse bronchiectasis may be suggested by the predominant distribution of the disease and associated extrapulmonary manifestations. Primary immunodeficiencies cystic fibrosis, allergic bronchopulmonary aspergillosis, chronic Mycobacterium avium complex infection, and systemic diseases have to be looked for, even in patients with knowledge of a childhood respiratory infection.

[Obesity, poor prognostic factor in pandemic influenza A (H1N1) 2009: the role of adipokines in the modulation of respiratory defenses]

Pandemic influenza A (H1N1), which occurred during 2009, revealed some unexpected epidemiologic characteristics, notably the high number of obese subjects among the severe cases of influenza. Generally, obesity seems to be associated with a weakness when it comes to respiratory infections. This susceptibility may be the result of a concurrence of mechanical and hormonal factors due to the excess weight. Obesity leads to changes in the ventilatory mechanics and an increase in the metabolic load during exercise. It is associated with immune system changes. Adipokines, cytokines produced by adipocytes, including leptin, play a central role by modulating the activity of all the cells of the immune system. Finally, obesity is associated with an increased risk of thrombosis, which has an adverse effect on the prognosis of infections. All of these observations can explain that obesity has been a risk factor in serious cases of influenza.

[Pulmonary arterial hypertension related to HIV: is inflammation related to IL-6 the cornerstone?]

Vascular diseases have become the leading cause of mortality in the population treated for HIV infection. Pulmonary arterial hypertension (PAH) related to HIV (PAH-HIV), the fourth cause of PAH in France, has the same histological pattern as other PAH from the group 1 of Dana Point classification. But, conversely to idiopathic PAH in the general population, PAH-HIV is particular by its high frequency in HIV-infected population. This raises the question for the role of inflammation in the PAH-HIV pathophysiology. Its constant occurrence over the decades, despite introduction of combination antiretroviral therapy (CAT), does not preclude the hypothesis of an involvement of inflammation in the genesis of PAH-HIV. Indeed, it is well known that normalization of CD4+ by the CAT does not mean no inflammation. Especially, it persists an increased and continuous production of IL-6, a main cytokine in the genesis of PAH lesions. This inflammation mainly involves the endothelin-1 pathway, which has an action on endothelium and macrophages, leading to high production of IL-6. Moreover, plasmatic level of IL-6 has a prognostic value in PAH-HIV, independently from conventional (functional or hemodynamic) parameters. The use of endothelin receptor antagonist permits major effect on IL-6 production and dramatic effect on PAH in so-called "bosentan responders".

[Bronchiolitis obliterans postallogeneic stem cell transplantation: what is new?]

Bronchiolitis obliterans (BO) is a severe complication of hematopoietic stem cell transplantation (HSCT). It is considered as a respiratory manifestation of chronic graft-versus-host disease. It is quite similar to the bronchiolitis obliterans after lung transplantation. Classical therapy associates steroids and immunosuppressive drugs, however theses procedure showed a modest efficacy and have an important morbidity. Recent progresses in the physiopathology of BO post-HSCT allow to use new treatments: mTOR inhibitors, immunotherapy, extra-corporeal photochemotherapy, and bronchial anti-inflammatory effects of azithromycin, statins or antileucotriens. This review will focus on the use of these new therapies in BO post-HSCT.

[Pulmonary non-infectious diseases in common variable immunodeficiency]

Few studies have described pulmonary non-infectious diseases (PNID) in patients with common variable immunodeficiency (CVID). Indeed the most frequent complications in these patients are infectious. The aim of our study is to analyze the characteristics of PNID in a retrospective study of patients with CVID of two pneumology departments in Paris (France), from 1990 to 2008. PNID was observed in 11 patients. Mean immunoglobulin serum level was 3.46g/L. The PNID observed were: arteriovenous pulmonary fistula: three; interstitial lung disease: three; asthma: two; mediastinal lymphadenopathy: four; emphysema: one; mesothelioma: one. Our study outlines the broad spectrum of pulmonary manifestations related to CVID. Clinicians should be aware of the diagnosis of PNID even in patients without classic infectious manifestations.

[Pneumocystis jirovecii pneumonia in non-HIV infected patients: a study of 41 cases]

BACKGROUND

The increasing use of immunosuppressive and cytotoxic therapies leads to a growing number of opportunistic infections especially Pneumocystis jirovecii pneumonia (PCP). The purpose of our study was to describe the population involved, and to assess clinical, biological, and mortality data.

METHODS

We collected retrospectively the whole medical file of all PCP cases diagnosed in non-HIV infected patients, in two French University Hospitals in the last decade (1999-2009). Diagnosis was made on standard coloration and/or immunofluorescence analysis of bronchoalveolar lavage fluid (BAL).

RESULTS

Forty-one patients were included in the study, mean age 56 (±12.5) years, sex ratio 0.71 men/woman. Underlying diseases were as follow: 12 patients (29%) were renal transplant recipients, 13 (32%) were treated for solid cancers, and 16 (39%) suffered from various diseases (three allogenic bone-marrow transplantation, 11 hematological malignancies, one pulmonary transplantation, one vasculitis). Twelve patients died (i.e. 29%). Median lymphocyte count was 542/mm(3). More than 85% patients received corticosteroids at a median cumulative 6-month dose of 2700mg. Seven patients (17%) had a PCP prophylaxis. Clinical worsening at day 5 (P<0.003), poor control of the underlying disease (P<0.015), WHO performans status superior than 2 (P<0.025), high temperature (P<0.04), and high oxygen flow (P<0.042) were linked to a poor prognosis.

DISCUSSION/CONCLUSION

The prognosis factors found are mostly linked to the patients' clinical severity. We would like to highlight: first, near to 30% mortality rate, secondly, a lack of prophylaxis in 34 patients, reflecting the difficulty to define PCP's risk in non HIV-infected patients.

[Management of the pulmonary complications of haematological malignancy]

The high frequency of pulmonary complications of haematological malignancy and the increasing number of patients treated for these disorders make it important that the respiratory physician has a structured diagnostic approach according to: 1 the immune deficiency due to the malignancy and/or the treatment administered; 2 the factors that can modify the risk of infection (anti infection prophylaxis and/or pre-emptive treatment); 3 co-morbidities; 4 extra-pulmonary manifestations. Two main situations can be identified: The patient is aplasic: Initially the pneumonias are predominantly of bacterial origin but may be fungal if the neutropenia is prolonged. The respiratory physician is faced with two problems: 1 the diagnosis of pneumonia; this may be helped by CT scanning; 2 The choice of antibiotics; this will depend on previous investigations. The patient is not aplasic: The lung disease may have many causes, mainly infectious but also drug related, tumoral, haemorrhagic or embolic. The main problem is the correct choice of investigations to establish an aetiological diagnosis. The collection of data according to a pre-established protocol based on simple factors (study of the notes and clinical examination) is one of the key elements for improving the prognosis of these patients whose management should be multidisciplinary following a pre-defined plan.

Hypervirulence of a rough variant of the Mycobacterium abscessus type strain

We isolated a rough variant of Mycobacterium abscessus CIP 104536T during experimental infection of mice. We show that this variant has lost the ability to produce glycopeptidolipids, is hyperlethal for C57BL/6 mice infected intravenously, and induces a strong tumor necrosis factor-alpha response by murine monocyte-derived macrophages.

Syndrome de susceptibilite mendélienne aux infections mycobacteriennes : défauts de l’axe Interleukine-12 - Interféron

INTRODUCTION

Environmental non tuberculous mycobacteria and Bacillus Calmette-Guerin vaccines are weakly virulent mycobacteria. Nevertheless they may cause severe diseases in otherwise healthy children with no overt immunodeficiency. Parental consanguinity and familial forms are frequently observed among these patients, therefore this syndrome was named "Mendelian Susceptibility to Mycobacterial Disease".

STATE OF THE ART

In the last nine years, fife genes have been found to be mutated in patients with this syndrome: IFNGR1, IFNGR2, STAT1, IL12B, IL12RB1. Allelic heterogeneity accounts for ten distinct genetic disorders. Clinical phenotype differs between patients. The spectrum of disease extends from early-onset overwhelming mycobacterial infection to adult-onset localized disease and tuberculosis. Impaired IFN-gamma-mediated immunity is the common mechanism of the disease, outlining its major role in mycobacterial immunity.

PERSPECTIVES AND CONCLUSIONS

Better understanding of these disorders reveals an expanding clinical phenotype which justifies studying adult patients with pulmonary non tuberculous mycobacterial infection without known risk factors, severe BCGitis and recurrent tuberculosis. Molecular diagnosis makes it possible to introduce a specific regimen based on physiopathology.

Mycobactéries atypiques et mucoviscidose

Patients with cystic fibrosis are particularly at risk of infection with non-tuberculous mycobacteria (NTM). Prevalence of these infections increases with age to around 15 %. The main species involved are M. abscessus and M. avium, the latter not found in children under 15. Diagnosis relies on clinical, radiological and above all bacteriological criteria defined by the ATS. Identification of the causal species of NTM is essential and requires genetic techniques, some of which are currently evaluated. Treatment depends on the mycobacterial species. For M. avium, combined therapy with rifampicin, clarithromycin and ethambutol must be extended 12 months after negativation. M. abscessus infection is particularly resistant to therapy. Usual treatment is a one month course of intravenous imipenem or cefoxitin plus amikacin followed by oral clarithromycin plus ethambutol for at least 12 months after negativation. In case of local lesions, surgery is an option.