Pulmonary complications of solid organ and hematopoietic stem cell transplantation

Diagnostic yield of flexible bronchoscopy for immunocompromised patients with lung infiltrates: A single-center, retrospective study

BACKGROUND

Pulmonary complications are associated with mortality in immunocompromised patients. The usefulness of bronchoscopy has been reported. However, clinical factors and procedures that influence diagnostic yield are still not established.

MATERIALS AND METHODS

We retrospectively analyzed 115 bronchoscopies performed on 108 immunocompromised patients, defined as those who take corticosteroids and/or immunosuppressants. We evaluated clinical factors, sampling procedures, final diagnosis, and severe complications of bronchoscopy.

RESULTS

The clinical diagnosis was obtained in 51 patients (44%). Of those, 33 cases were diagnosed as infectious diseases and 18 as non-infectious diseases. Nine out of 115 cases (7.8%) initiated new immunosuppressive treatment for an underlying disorder based on the negative microbiological results obtained with bronchoscopy. Collagen vascular disease was the most common underlying disorders (62 patients, 54%). Bronchoscopy was useful regardless of whether the patient was immunosuppressed to treat collagen vascular disease (P = 0.47). Performing transbronchial biopsy correlated with better diagnostic yield of bronchoscopy (54.7% vs 35.5%, P = 0.049). Other clinical factors, such as radiological findings, respiratory failure or antibiotic use at the time of bronchoscopy did not significantly influence diagnostic yield. Respiratory failure requiring intubation after bronchoscopy occurred only in one case (0.9%).

CONCLUSIONS

Our study implied the transbronchial biopsy may be a useful procedure for reaching a diagnosis in immunocompromised patients with pulmonary infiltrates. In addition, our data suggest the usefulness of bronchoscopy for immunocompromised patients due to the treatment of collagen vascular disease as well as other underlying disorders.

Isolated massive pleural effusion as a manifestation of chronic graft versus host disease successfully treated with corticosteroid

Isolated pleural effusion is a rare manifestation of chronic graft versus host disease (cGVHD) after hematopoietic stem cell transplantation (HSCT). We herein report a 58-year-old woman presenting with massive pleural effusion approximately 1 year after allogeneic HSCT, who was successfully treated with corticosteroid. She had discontinued tacrolimus approximately 1 month before she presented with pleural effusion, which was attributed to cGVHD after a thorough exclusion process. This case illustrates a unique manifestation of atypical cGVHD and highlights the need for prompt therapy initiation.

Clinical characteristics and risk factors of acute lymphoblastic leukemia in children with severe infection during maintenance treatment

BACKGROUND

Infection is the most common adverse event of acute lymphoblastic leukemia (ALL) treatment and is also one of the main causes of death.

METHODS

To investigate the clinical characteristics and risk factors of severe infections during the maintenance phase of ALL treatment, we conducted a retrospective study.

RESULTS

A total of 181 children were eligible and 46 patients (25.4%) suffered from 51 events of severe infection, most of which occurred in the first half year of the maintenance phase (52.9%). The most common infection was pulmonary infection (86.3%) followed by bloodstream infection (19.6%). The main symptoms of ALL patients with pulmonary infection were fever, cough, and shortness of breath. The main manifestations of computer tomography (CT) were ground glass shadow (56.8%), consolidation shadow (27.3%), and streak shadow (25%). Multivariate binary logistic regression analysis showed that agranulocytosis, agranulocytosis ≥7 days, anemia, and low globulin level were independent risk factors for severe infection during the maintenance phase (all p < 0.05).

CONCLUSIONS

Taken together, blood routine examinations and protein levels should be monitored regularly for ALL patients in the maintenance phase, especially in the first 6 months. For ALL patients with risk factors, preventive anti-infective or supportive therapies can be given as appropriate to reduce the occurrence of severe infections.

Unique presentation of late-onset Pneumocystis pneumonia in a pediatric kidney transplant recipient

BACKGROUND

Restrictive lung disease leading to abnormal lung function in kidney transplant recipients is commonly associated with noninfectious complications or medications used for post-transplant immunosuppression. Herein, we report an interesting case of pediatric kidney transplant recipient with weight loss and abnormal spirometry who was diagnosed to have late-onset Pneumocystis pneumonia.

CASE REPORT

A 17-year-old male patient with a history of allergic rhinitis, mild persistent asthma, and deceased donor kidney transplant, performed 18 months prior, presented for routine evaluation of his asthma to the pulmonology clinic. He was clinically asymptomatic except for a weight loss of 8 kg over 6-month period prior to presentation. Patient's spirometry was suggestive of a restrictive pattern and further investigation using a high-resolution computed tomography (HRCT) of the chest showed bilateral diffuse ground-glass reticulonodular opacities with subpleural sparing suggestive of interstitial pneumonitis. A bronchoscopy with bronchoalveolar lavage revealed organisms consistent with Pneumocystis jirovecii on gomori-methenamine-silver (GMS) staining. Beta-d-glucan testing in serum revealed a level of >500 pg/mL (normal 0-59 pg/mL) further supportive of Pneumocystis jirovecii infection. Patient was treated with a 6-week course of trimethoprim-sulfamethoxazole. His weight loss and beta-d-glucan levels improved over a course of 6 months, and he continues to be on trimethoprim-sulfamethoxazole prophylaxis.

CONCLUSION

Late-onset Pneumocystis jirovecii infection in kidney transplant recipients can have an atypical presentation. Treating physicians should consider PJP in the differential diagnosis of unexplained weight loss in pediatric kidney transplant recipients, especially those receiving a large cumulative burden of immunosuppression.

High-Dose Busulfan-Fludarabine Conditioning and Low Alveolar Volume as Predictors of Pulmonary Complications after Allogeneic Peripheral Blood Stem Cell Transplantation in Children

This study was conducted to investigate risk factors and predictors of infectious and noninfectious pulmonary complications (PCs) after allogeneic hematopoietic stem cell transplantation in children. We conducted a retrospective analysis of the post-transplantation PCs of 240 patients who underwent allogeneic peripheral blood stem cell transplantation (allo-PBSCT) between 2009 and 2018. Transplantation-related variables, pretransplantation baseline spirometry, body plethysmography, and CO diffusing capacity were analyzed for association with the development of infectious PCs (IPCs) and noninfectious PCs (NIPCs). Compared with the control group, the PC group had statistically significantly lower overall survival (50.6% versus 77.8%; P < .001), higher disease-related mortality (26.6% versus 54.4%; P < .001), and higher nonrelapse mortality (31.6% versus 5.9%; P < .001). A greater number of patients received pretransplantation conditioning with high-dose busulfan (520 mg/m²; Bu 520) and fludarabine (160 mg/m²; Flu 160) in both the IPC and NIPC groups. In the multivariate Cox hazard regression analysis, Bu 520 significantly increased the risk of NIPCs (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.13 to 3.49; P = .016), and Flu 160 was a predictor of IPCs (HR, 1.99; 95% CI, 1.13 to 3.49; P = .016). The Bu 520 + Flu 160 regimen was associated with a statistically significant increase in the risk of NIPC (HR, 1.92; 95% CI, 1.09 to 3.37; P = .023). In a multivariate analysis using pretransplantation baseline lung function, alveolar volume (VA) grades 3 and 4 and lung function score (LFS) VA categories III and IV were associated with increased risk for both IPCs and NIPCs. Our data identify receipt of the high-dose Bu-Flu conditioning regimen as an independent risk factor for NIPCs after allo-PBSCT. Impaired CO diffusing capacity before transplantation, especially VA reduction, contributes to the risk of post-transplantation pulmonary complications, and pretransplantation risk can be estimated by grading the degree of insufficiency of VA and LFS VA.

Lineage tracking to reveal the fate of hematopoietic stem cells influenced by Flk2- multipotent progenitors after transplantation

After transplantation, hematopoietic stem cells (HSCs) sustain blood cell regeneration throughout the patient's life. Recent studies suggest that several types of mature blood cells provide feedback signals to regulate HSC fate. However, the potential feedback effect of hematopoietic progenitor cells has not been characterized to date. The present investigation demonstrated that multipotent progenitors (MPPs) promoted T cell production of HSCs when both cell types were cotransplanted in mice. Using genetic barcodes to track individual HSCs in mice, we found that the increased T cell production by HSCs was associated with the combined effects of altered lineage bias and clonal expansion during HSC differentiation. We showed that MPP and HSC co-transplantation promoted the multilineage differentiation of HSCs in the short term while preserving lymphoid-specialized HSC differentiation in the long term. Our findings indicate that MPPs derived from HSCs regulate the fate of HSCs after bone marrow transplantation.

Pulmonary Complications in Renal Transplant Recipients

Background Kidney transplantation recipients are at an increased risk of lung complications due to infectious or non-infectious reasons. We aimed to determine the lung complications after transplantation and what we could do to prevent the complications during the follow-up, retrospectively. Material and Methods The 296 patients who underwent kidney transplantation surgery in our centre between the years 1999 to 2006 were included in the study. Results 75% of the patients were male (n: 222). 77% of the patients (n: 228) had a living-related donor. The mean hospitalisation duration in the post-transplantation period was 13.3±9.07 days. During the follow-up, 37.2% of the patients (n: 110) had rejection, and pulse steroid treatments were given to the 74.5% of these patients. In our study, the lung complication development ratio was 16.2%, and 84% of these complications were due to infections. A specific aetiology was not identified in 63.5% of patients. The patients with a living-related donor had more lung complications due to infection (p

Characteristics of lower respiratory tract microbiota in the patients with post-hematopoietic stem cell transplantation pneumonia

Background

Pneumonia is a leading cause of non-relapse mortality after hematopoietic stem cell transplantation (HSCT), and the lower respiratory tract (LRT) microbiome has been proven to be associated with various respiratory diseases. However, little is known about the characteristics of the LRT microbiome in patients with post-HSCT compared to healthy controls (HC) and community-acquired pneumonia (CAP).

Methods

Bronchoalveolar lavage samples from 55 patients with post-HSCT pneumonia, 44 patients with CAP, and 30 healthy volunteers were used to detect microbiota using 16S rRNA gene sequencing.

Results

The diversity of the LRT microbiome significantly decreased in patients with post-HSCT pneumonia, and the overall community was different from the CAP and HC groups. At the phylum level, post-HSCT pneumonia samples had a high abundance of Actinobacteria and a relatively low abundance of Bacteroidetes. The same is true for non-survivors compared with survivors in patients with post-HSCT pneumonia. At the genus level, the abundances of Pseudomonas, Acinetobacter, Burkholderia, and Mycobacterium were prominent in the pneumonia group after HSCT. On the other hand, gut-associated bacteria, Enterococcus were more abundant in the non-survivors. Some pathways concerning amino acid and lipid metabolism were predicted to be altered in patients with post-HSCT pneumonia.

Conclusions

Our results reveal that the LRT microbiome in patients with post-HSCT pneumonia differs from CAP patients and healthy controls, which could be associated with the outcome. The LRT microbiota could be a target for intervention during post-HSCT pneumonia.

Clinical diagnostic accuracy of respiratory failure in critically ill hematopoietic stem cell transplant patients

RATIONALE

Acute respiratory failure (ARF) is a frequent complication following hematopoietic cell transplantation (HCT). We aimed to characterize the etiologies of ARF in patients who died in the intensive care unit following HCT based on autopsy findings. We then evaluated agreement between the clinical and pathologic diagnosis.

METHODS

We performed a chart review of all HCT patients who died and underwent autopsy in our ICU between 2006-2016. We evaluated the presumed clinical diagnosis and confidence in the diagnosis by chart review, the pathologic diagnosis on autopsy, and whether the clinical-pathologic diagnoses were concordant. When there was discordance, we evaluated whether knowledge of the pathology could have changed management.

RESULTS

Thirteen patients underwent autopsy after dying. Infection was the presumed cause in 11/13 cases. The clinical and pathologic diagnoses were concordant in 6/13(46%). In the seven discordant cases (all clinically diagnosed as infection), autopsy revealed two non-infectious inflammatory causes, one post-transplant lymphoproliferative disorder, and three non-bacterial infectious etiology. Pathologic findings may have changed management in 7/13(54%) cases.

CONCLUSIONS

In a subset of HCT-recipients who died from respiratory failure, discordance was frequent between clinical and pathologic diagnoses. The risks and benefits of obtaining tissue to improve our diagnostic accuracy requires further evaluation.

Bronchiolitis obliterans syndrome after lung or haematopoietic stem cell transplantation: current management and future directions

Bronchiolitis obliterans syndrome (BOS) may develop after either lung or haematopoietic stem cell transplantation (HSCT), with similarities in histopathological features and clinical manifestations. However, there are differences in the contributory factors and clinical trajectories between the two conditions. BOS after HSCT occurs due to systemic graft-versus-host-disease (GVHD), whereas BOS after lung transplantation is limited to the lung allograft. BOS diagnosis after HSCT is more challenging, as the lung function decline may occur due to extrapulmonary GVHD, causing sclerosis or inflammation in the fascia or muscles of the respiratory girdle. Treatment is generally empirical with no established effective therapies. This review provides rare insights and commonalities of both conditions, that are not well elaborated elsewhere in contemporary literature, and highlights the importance of cross disciplinary learning from experts in other transplant modalities. Treatment algorithms for each condition are presented, based on the published literature and consensus clinical opinion. Immunosuppression should be optimised, and other conditions or contributory factors treated where possible. When initial treatment fails, the ultimate therapeutic option is lung transplantation (or re-transplantation in the case of BOS after lung transplantation) in carefully selected candidates. Novel therapies under investigation include aerosolised liposomal cyclosporine, Janus kinase inhibitors, antifibrotic therapies, and (in patients with BOS after lung transplantation) B-cell–directed therapies. Effective novel treatments that have a tangible impact on survival and thereby avoid the need for lung transplantation or re-transplantation are urgently required.

Atypical pathogens presenting with pulmonary consolidations detected by cell-free DNA next-generation sequencing in patients with hematologic malignancies

Identification of pathogens with pulmonary presentation in patients with hematologic malignancies may be challenging due to diagnostic difficulty related to the underlying malignancy and limitations of conventional microbiologic methods. Herein, we present a case series of three patients with pulmonary consolidations due to Legionella bozemanae necrotizing pneumonia, Pneumocystis jirovecii pneumonia, and disseminated Scedosporium infection, who were diagnosed by microbial cell-free DNA next-generation sequencing. We observed that this new sequencing modality was in agreement with gold-standard diagnostics, posing a potential solution to the problem of limited capability in diagnosing infections in hematological malignancy patients.

Pulmonary Complications in Hematopoietic Stem Cell Transplant Recipients-A Clinician Primer

Hematopoietic stem cell transplants (HSCT) are becoming more widespread as a result of optimization of conditioning regimens and prevention of short-term complications with prophylactic antibiotics and antifungals. However, pulmonary complications post-HSCT remain a leading cause of morbidity and mortality and are a challenge to clinicians in both diagnosis and treatment. This comprehensive review provides a primer for non-pulmonary healthcare providers, synthesizing the current evidence behind common infectious and non-infectious post-transplant pulmonary complications based on time (peri-engraftment, early post-transplantation, and late post-transplantation). Utilizing the combination of timing of presentation, clinical symptoms, histopathology, and radiographic findings should increase rates of early diagnosis, treatment, and prognostication of these severe illness states.

Risk factor for lung infection in recipients after liver transplantation: A meta-analysis

Lung infection (LI) often occurs in patients with liver transplantation (LT). This meta-analysis was conducted to determine the risk factors associated with LI after LT. We retrieved relevant research published as of February 2020 from eight electronic databases. The studies were reviewed against the inclusion and exclusion criteria. The Z test was used to determine the combined odds ratio (OR) or the standardized mean difference (SMD) of the risk factors. We used the OR and its corresponding 95% confidence interval (CI) or the SMD and its corresponding 95% CI to identify significant differences in risk factors. A total of nine studies were included, comprising a total of 1624 recipients. Six risk factors associated with LI were identified after LT: Model for end-stage liver disease score (MELD score) (SMD = 0.40), Child-Pugh class C (OR = 3.00), intensive care unit (ICU) hospital stay (SMD = 1.35), mechanical ventilation (SMD = 1.03), bilirubin (SMD = 0.39), and atelectasis (OR = 7.28). Although certain risk factors have been identified as important factors for LI after LT, which may provide a basis for clinical prevention, a well-designed prospective study should be conducted to validate the findings of this study.

[Potential of ultrasound in allogeneic stem cell transplantation and transplant-related complications]

Allogeneic hematopoietic stem cell transplantation (HCT) is a complex therapeutic procedure causing significant morbidity and mortality, including the gastrointestinal tract. Early diagnosis and treatment of HCT-associated complications are, therefore, of utmost importance to improve overall HCT outcome. Sonography can be a powerful diagnostic tool and is easily accessible at the bedside of HCT patients. In the hands of a sonography-experienced physician, it allows for instant diagnosis and can also rule out several important transplant-associated complications. Here we review available evidence on the diagnostic and clinical value of ultrasound prior, during and after HCT.

The Incidence and Effect of Cytomegalovirus Disease on Mortality in Transplant Recipients and General Population: Real-world Nationwide Cohort Data

Background: In addition to the conventional opportunistic infections in solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) recipients, cytomegalovirus (CMV) infection is associated with various chronic inflammatory diseases or poor outcomes in non-immunocompromised critically ill patients. To evaluate the burden or outcome of CMV replication in non-transplant individuals, we compared the incidence rates (IRs) for CMV disease and all-cause mortality between SOT recipients, HSCT recipients, and non-transplant population. Methods: The SOT (N=16,368) and HSCT (N=10,206) cohorts between 2010 and 2015 were established using the WHO ICD-10 from the whole population-based large database of the Health Insurance Review & Assessment Service (HIRA). CMV cases, defined as symptomatic disease with isolation of virus, DNA, pp65 antigen, and pathology except CMV syndrome, were extracted with the unique codes for relief of medical costs of HIRA in the same dataset. Cox's proportional hazard regression analyses and log-rank test in the Kaplan-Meier curves were performed to compare all-cause mortality between the three groups. Results: The CMV IRs adjusted by age and sex were significantly higher in the SOT (adjusted IR [95% confidence intervals], 33.1 [28.8-38.0] per 1,000 person-years) and HSCT recipients (5.1 [4.6-6.1] per 1,000 person-years) than in the whole population (0.58 [0.49-0.67] per 100,000 person-years). However, SOT recipients with CMV (18/283, 6.4%) had significantly lower all-cause mortality than non-transplant individuals with CMV (207/1,258, 16.5%) (adjusted hazard ratio [95% CI], 0.42 [0.25-0.67], log-rank P < 0.001). Conclusion: These data suggest that CMV disease in patients without transplants is associated with poor outcomes.

Potential role of exosome-based allorecognition pathways involved in lung transplant rejection

Innate and adaptive immunity both contribute to allorecognition mechanisms that drive rejection after lung transplantation. Classic allorecognition pathways have been extensively described, but there continues to be several unanswered questions. Exosome research appears to be a novel and potentially significant area of allorecognition research and could be the missing link that answers some existing questions. This article reviews literature that is associated with allorecognition pathways and the role of exosomes in alloreactivity.

Pulmonary Infectious Complications in Children with Hematologic Malignancies and Chemotherapy-Induced Neutropenia

Infections frequently complicate the treatment course in children with hematologic malignancies undergoing chemotherapy. Febrile neutropenia (FN) remains a major cause of hospital admissions in this population, and respiratory tract is often proven to be the site of infection even without respiratory signs and symptoms. Clinical presentation may be subtle due to impaired inflammatory response. Common respiratory viruses and bacteria are widely identified in these patients, while fungi and, less commonly, bacteria are the causative agents in more severe cases. A detailed history, thorough clinical and basic laboratory examination along with a chest radiograph are the first steps in the evaluation of a child presenting signs of a pulmonary infection. After stratifying patient’s risk, prompt initiation of the appropriate empirical antimicrobial treatment is crucial and efficient for the majority of the patients. High-risk children should be treated with an intravenous antipseudomonal beta lactam agent, unless there is suspicion of multi-drug resistance when an antibiotic combination should be used. In unresponsive cases, more invasive procedures, including bronchoalveolar lavage (BAL), computed tomography (CT)-guided fine-needle aspiration or open lung biopsy (OLB), are recommended. Overall mortality rate can reach 20% with higher rates seen in cases unresponsive to initial therapy and those under mechanical ventilation.

The Use of Aerosolized Ribavirin in Respiratory Syncytial Virus Lower Respiratory Tract Infections in Adult Immunocompromised Patients: A Systematic Review

Introduction: Respiratory syncytial virus (RSV)-associated lower respiratory tract infection (LRTI) is a concern in immunocompromised patients. Aerosolized ribavirin (RBV AER) is used for treatment of RSV LRTI; however, adverse events and rising drug costs remain a challenge for patient management. The purpose of this systematic review is to summarize the efficacy and adverse event profile of RBV AER for the treatment of hospitalized RSV LRTI in immunocompromised adult patients. Methods: A Medline/PubMed, Embase, Google Scholar, Clinicaltrials.gov, and Cochrane Library database search was conducted from 1966 to January 2019 for the use of RBV AER. Search strategy: [(ribavirin OR ICN1229) AND ("administration, oral" OR "oral" OR "administration, inhalation" OR "inhalation)] AND ("respiratory tract infection" OR "pneumonia"). Studies were reviewed if adult patients were hospitalized, immunocompromised, had RSV LRTI, received RBV AER, and included the outcome of mortality and/or adverse reactions. Methodological quality was assessed using the Cochrane Collaboration GRADE approach. Results: A total of 1787 records were identified and 15 articles met inclusion criteria: hematopoietic stem cell transplant (HSCT)/bone marrow transplant (n = 8), other malignancy/neutropenic (n = 2), solid organ transplant (n = 5). All of the trials are observational with a low quality rating; therefore, a meta-analysis was not performed. The 30-day mortality in studies that contain >10 patients with HSCT, malignancy, and transplant range from 0 to 15.4%, 6.3%, and 0 to 27%, respectively. Improved mortality was cited in 4 studies when RBV AER started before mechanical ventilation or within 2 weeks of symptom onset. Only 3 studies had comparative mortality data with RBV AER and RBV PO. Adverse reactions were reported in 5 studies and included psychiatric manifestations (anxiety, depression, feeling of isolation; n = 14), wheezing/bronchospasm (n = 6), snowflakes/hail blowing in face (n = 6), and precipitation in ventilator tubing (n = 5). Conclusion: There is a lack of high quality, comparative trials on the use of RBV AER for the treatment of RSV LRTI in adult hospitalized immunocompromised patients. There may be a mortality benefit when RBV AER is initiated early after diagnosis or prior to mechanical ventilation, but requires further study. Patient isolation and psychological effects must be weighed against the benefit of therapy.

Etiologies and Outcomes of Acute Respiratory Failure in Solid Organ Transplant Recipients: Insight Into the EFRAIM Multicenter Cohort

BACKGROUND

Respiratory complications of solid organ transplant (SOT) are a diagnostic and therapeutic challenge when requiring intensive care unit (ICU) admission. We aimed at describing this challenge in a prospective cohort of SOT recipients admitted in the ICU.

METHODS

In this post hoc analysis of an international cohort of immunocompromised patients admitted in the ICU for an acute respiratory failure, we analyzed all SOT recipients and compared their severity, etiologic diagnosis, prognosis, and outcome according to the performance of an invasive diagnostic strategy (encompassing a fiber-optic bronchoscopy and bronchoalveolar lavage), the type of transplanted organ, and the need of invasive ventilation at day 1.

RESULTS

Among 1611 patients included in the primary study, 142 were SOT recipients (kidney, n = 73; 51.4%; lung, n = 33; 23.2%; liver, n = 29; 20.4%; heart, n = 7; 4.9%). Lung transplant recipients were younger than other SOT recipients, and severity did not differ across type of received organ. An invasive diagnostic strategy was more frequently performed in lung transplant recipients with a trend toward a higher rate of bacterial etiology in lung than kidney transplant recipients. Overall ICU survival of SOT recipients was 75.4%. Invasive diagnostic strategy, type of transplanted organ, and need of invasive mechanical ventilation at day 1 did not affect ICU prognosis.

CONCLUSIONS

ICU management of hypoxemic acute respiratory failure in SOT recipients translated into a low ICU mortality rate, whatever the transplanted organ or the acute respiratory failure cause. The post-ICU burden of acute respiratory failure SOT recipients remains to be investigated.

Use of High-Flow Nasal Cannula for Immunocompromise and Acute Respiratory Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Acute respiratory failure (ARF) is a common cause of emergency department (ED) and intensive care unit (ICU) admissions. High-flow nasal cannula oxygen therapy (HFNC) is widely used for patients with ARF.

OBJECTIVE

Our aim was to evaluate the latest evidence regarding the application of HFNC in immunocompromised patients with ARF.

METHODS

We searched PubMed, Embase, and Cochrane databases from inception to January 2019. The primary outcome was short-term mortality and the secondary outcomes were intubation rate and length of ICU stay.

RESULTS

Eight studies involving 2,179 immunocompromised subjects with ARF were included. No significant differences for short-term mortality were observed when comparing HFNC with conventional oxygen therapy (COT) (risk ratio [RR] 0.89; 95% confidence interval [CI] 0.73 to 1.09; p = 0.25, I² = 47%) and with noninvasive ventilation (NIV) (RR 0.66; 95% CI 0.37 to 1.18; p = 0.16, I² = 58%). Lower intubation rates were found when comparing HFNC with COT (RR 0.89; 95% CI 0.80 to 0.99; p = 0.03, I² = 0%) and no significant difference was found between HFNC and NIV (RR 0.74; 95% CI 0.46 to 1.19; p = 0.22, I² = 67%). The length of ICU stay was similar when comparing HFNC with COT (mean difference [MD] 0.59; 95% CI -1.68 to 2.85; p = 0.61, I² = 56%), but was significantly shorter when HFNC was compared with NIV (MD -2.13; 95% CI -3.98 to -0.29; p = 0.02, I² = 0%).

CONCLUSIONS

There was no significant difference in short-term mortality with use of HFNC when compared with COT or NIV for immunocompromised patients with ARF. A lower intubation rate than COT and a shorter length of ICU stay than NIV were observed in the HFNC group.

Causes of acute respiratory failure in the immunocompromised host

PURPOSE OF REVIEW

A wide spectrum of heterogeneous conditions can render a patient immunocompromised. Recent years have seen an increase in the number of immunocompromised patients given the earlier detection of conditions that require immunosuppressive therapies, changes in immunosuppressive regimens leading to increased survival or novel therapeutic advancements in oncologic care. Acute respiratory failure (ARF) is the leading cause of critical illness and mortality in this population. This review highlights the spectrum of causes of ARF in immunocompromised patients with a particular focus on acute toxicities of novel oncologic treatments.

RECENT FINDINGS

Recent years have seen improved survival amongst critically ill immunocompromised patients with ARF. This is likely attributable to patient selection of immunosuppressive therapy, improved noninvasive microbiologic diagnostic techniques, improved antimicrobial prophylaxis, treatment, stewardship, and advancements in supportive care including intensive care. Infectious complications remain the leading cause of ARF in this population. However, one of the greatest challenges physicians continue to face is accurate identification of the cause of ARF, given the vast (and increasing) noninfectious causes of ARF across these patients. Emerging therapies, such as immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR T-cell) have contributed to this problem. Finally, undetermined ARF is reported in approximately 13% of immunocompromised and is associated with a worse prognosis.

SUMMARY

Infectious complications are still the leading cause of ARF in immunocompromised patients. However, noninfectious complications, derived from the underlying disease or treatment, should be always considered, including novel therapies, such as ICIs and CAR T cells. Further research should focus in improving the diagnostic rate in this subgroup.

Acute and Chronic Respiratory Failure in Cancer Patients

In 2016, there was an estimated 1.8 million new cases of cancer diagnosed in the United States. Remarkable advances have been made in cancer therapy and the 5-year survival has increased for most patients affected by malignancy. There are growing numbers of patients admitted to intensive care units (ICU) and up to 20% of all patients admitted to an ICU carry a diagnosis of malignancy. Respiratory failure remains the most common reason for ICU admission and remains the leading causes of death in oncology patients. There are many causes of respiratory failure in this population. Pneumonia is the most common cause of respiratory failure, yet there are many causes of respiratory insufficiency unique to the cancer patient. These causes are often a result of immunosuppression, chemotherapy, radiation treatment, or hematopoietic stem cell transplant (HCT). Treatment is focused on supportive care and specific therapy for the underlying cause of respiratory failure. Noninvasive modalities of respiratory support are available; however, careful patient selection is paramount as indiscriminate use of noninvasive positive pressure ventilation is associated with a higher mortality if mechanical ventilation is later required. Historically, respiratory failure in the cancer patient had a grim prognosis. Outcomes have improved over the past 20 years. Survivors are often left with significant disability.

Noninvasive Oxygen Therapies in Oncologic Patients

Acute hypoxemic respiratory failure (ARF) is the most common cause of critical illness in oncologic patients. Despite significant advancements in survival of oncologic patients who develop critical illness, mortality rates in those requiring invasive mechanical ventilation have improved but remain high. Avoiding intubation is paramount to the management of oncologic patients with ARF. There are important differences between the oncologic patient with ARF compared to the general ICU population that likely underlie the increased mortality once intubated. Noninvasive oxygen modalities have been recognized as an important therapeutic approach to prevent intubation. Continuous low-flow oxygen therapy, noninvasive ventilation, and high-flow nasal cannula are the most commonly used noninvasive oxygen therapies in recent years. They have unique physiologic properties. The data surrounding their efficacy in the general ICU population and oncologic population has evolved over time reflecting the changes in the oncologic population. This chapter reviews the three different noninvasive oxygen modalities, their physiologic impact, and evidence surrounding their effectiveness.

American Thoracic Society 2019 Pediatric Core Curriculum

The American Thoracic Society Pediatric Core Curriculum updates clinicians annually in pediatric pulmonary disease in a 3 to 4 year recurring cycle of topics. The 2019 course was presented in May during the Annual International Conference. An American Board of Pediatrics Maintenance of Certification module and a continuing medical education exercise covering the contents of the Core Curriculum can be accessed online at www.thoracic.org.

The utility of bronchoscopy in immunocompromised patients: a review

Bronchoscopy is an important tool for the diagnosis of pulmonary disorders in immunocompromised patients. The addition of biopsies to bronchoalveolar lavage improves the diagnostic yield of non-infectious etiologies, although the underlying etiology of the immunocompromised state must be considered and may be influential. Certain unknowns remain, including timing of bronchoscopy and its impact on medical management and mortality. The ongoing role of non-invasive testing for infectious complications prior to bronchoscopy also remains to be defined. This review addresses the role of bronchoscopy in immunocompromised states related to underlying hematologic malignancies, prescription drug use or chemotherapy, and other disorders that predispose patients to infectious or non-infectious pulmonary diseases.

First-Onset Herpesviral Infection and Lung Injury in Allogeneic Hematopoietic Cell Transplantation

Rationale: "Noninfectious" pulmonary complications are significant causes of morbidity and mortality after allogeneic hematopoietic cell transplant. Early-onset viral reactivations or infections are common after transplant. Whether the first-onset viral infection causes noninfectious pulmonary complications is unknown. Objectives: To determine whether the first-onset viral infection within 100 days after transplant predisposes to development of noninfectious pulmonary complications. Methods: We performed a retrospective review of 738 allogeneic hematopoietic cell transplant patients enrolled from 2005 to 2011. We also established a novel bone marrow transplantation mouse model to test whether herpesviral reactivation after transplant causes organ injury. Measurements and Main Results: First-onset viral infections with human herpesvirus 6 or Epstein-Barr virus within 100 days after transplant increase the risk of developing idiopathic pneumonia syndrome (adjusted hazard ratio [aHR], 5.52; 95% confidence interval [CI], 1.61-18.96; P = 0.007; and aHR, 9.21; 95% CI, 2.63-32.18; P = 0.001, respectively). First infection with human cytomegalovirus increases risk of bronchiolitis obliterans syndrome (aHR, 2.88; 95% CI, 1.50-5.55; P = 0.002) and grade II-IV acute graft-versus-host disease (aHR, 1.59; 95% CI, 1.06-2.39; P = 0.02). Murine roseolovirus, a homolog of human herpesvirus 6, can also be reactivated in the lung and other organs after bone marrow transplantation. Reactivation of murine roseolovirus induced an idiopathic pneumonia syndrome-like phenotype and aggravated acute graft-versus-host disease. Conclusions: First-onset herpesviral infection within 100 days after allogeneic hematopoietic cell transplant increases risk of pulmonary complications. Experimentally reactivating murine roseolovirus causes organ injury similar to phenotypes seen in human transplant recipients.

Xenon-129 MRI detects ventilation deficits in paediatric stem cell transplant patients unable to perform spirometry

BACKGROUND

Early detection of pulmonary morbidity following haematopoietic stem cell transplantation (HSCT) remains an important challenge for intervention, primarily due to the insensitivity of spirometry to early change, and in paediatrics, patient compliance provides additional challenges. Regional lung ventilation abnormalities in paediatric HSCT patients were quantified using hyperpolarised xenon-129 (129Xe) magnetic resonance imaging (MRI) and compared to spirometry.

METHODS

Medically stable, paediatric allogeneic HSCT patients (n=23, ages 6-16 years) underwent an outpatient MRI scan where regional ventilation was quantified with a breath-hold of hyperpolarised 129Xe gas. Ventilation deficits, regions of the lung that ventilate poorly due to obstruction, were quantified as a ventilation defect percentage (VDP) and compared to forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC) ratio, and forced expiratory flow at 25-75% of FVC (FEF25-75%) from spirometry using linear regression.

RESULTS

The mean±sd 129Xe VDP was 10.5±9.4% (range 2.6-41.4%). 129Xe VDP correlated with FEV1, FEV1/FVC ratio and FEF25-75% (p≤0.02 for all comparisons). Ventilation deficits were detected in patients with normal spirometry (i.e. FEV1 >80%), supporting the sensitivity of 129Xe MRI to early obstruction reported in other pulmonary conditions. Seven (30%) patients could not perform spirometry, yet ventilation deficits were observed in five of these patients, detecting abnormalities that otherwise may have gone undetected and untreated until advanced.

CONCLUSION

Lung ventilation deficits were detected using hyperpolarised 129Xe gas MRI in asymptomatic paediatric HSCT patients and in a subgroup who were unable to perform reliable spirometry. 129Xe MRI provides a reliable imaging-based assessment of pulmonary involvement in this potentially difficult to diagnose paediatric population.

Diagnostic and therapeutic approach to infectious diseases in solid organ transplant recipients

Purpose

Prognosis of solid organ transplant (SOT) recipients has improved, mainly because of better prevention of rejection by immunosuppressive therapies. However, SOT recipients are highly susceptible to conventional and opportunistic infections, which represent a major cause of morbidity, graft dysfunction and mortality.

Methods

Narrative review.

Results

We cover the current epidemiology and main aspects of infections in SOT recipients including risk factors such as postoperative risks and specific risks for different transplant recipients, key points on anti-infective prophylaxis as well as diagnostic and therapeutic approaches. We provide an up-to-date guide for management of the main syndromes that can be encountered in SOT recipients including acute respiratory failure, sepsis or septic shock, and central nervous system infections as well as bacterial infections with multidrug-resistant strains, invasive fungal diseases, viral infections and less common pathogens that may impact this patient population.

Conclusion

We provide state-of the art review of available knowledge of critically ill SOT patients with infections.

Combination antifungal treatment for invasive fungal disease after hematopoietic stem cell transplantation in children with hematological disorders

BACKGROUND

Invasive fungal disease (IFD) has a poor prognosis in children with hematological disorders after hematopoietic stem cell transplantation (HSCT). We assessed if drug combinations with different targets may improve the outcome.

METHODS

Retrospective study to assess the outcome of combination antifungal therapy (CAT) for proven-probable IFD (PP-IFD) in children with hematological disorders after HSCT from January 2008 to June 2018.

RESULTS

Over the 10-year period, 95 PP-IFD were diagnosed in pediatric recipients, median age of 5.6 years. Twenty-seven patients received combinations of caspofungin and voriconazole, 28 patients received combinations of caspofungin and amphotericin B, and 40 patients received combinations of voriconazole and amphotericin B. The overall response rate of PP-IFD was 77.9%, while the 100-day overall survival rates were 66.8%. Univariate analysis showed that factors that significantly affected the response to combination treatments were type of combination (P = 0.02), the stem cell source (P = 0.04), the donor type (P = 0.03), HLA-match (P = 0.03), aGVHD (P = 0.02), period of treatment (P = 0.044), use of corticosteroids (0.036), CD4:CD8 ratio (P = 0.014), and CMV viremia (P = 0.033). In addition, multivariate analysis demonstrated that only the type of combination remained a significant factor (odds ratio = 0.335, 95% confidence interval: 0.071-0.812, P = 0.042). Forty-three children suffered from mild and reversible adverse reactions, no serious side effects during treatment.

CONCLUSION

A variety of factors can affect the outcome of CAT. Combination of caspofungin with voriconazole is a safe and helpful treatment option for HSCT recipients with IFD.

The Incidence and Risk Factors of Low Oxygenation After Orthotropic Liver Transplantation

Background

This study was designed to observe incidence and risk factors of low oxygenation after orthotropic liver transplantation (OLT).

Material/Methods

We retrospectively evaluated all adult patients who underwent living-donor OLT between January 1, 2017 and December 31, 2017. Postoperative low oxygenation was defined as PaO₂/FiO₂ <300 mmHg within 24 hours after surgery. Early acute kidney injury (AKI) after OLT was also defined when AKI was happened with 24 hours after operative.

Results

A total of 301 patients, aged 50.35±10.29 years were enrolled. Of these patients, 100 patients (33.2%) suffered postoperative low oxygenation (PaO₂/FiO₂=251.80±35.84). Compared with the normal oxygenation group, body mass index (BMI) (24.48±3.53 versus 23.1±3.27 kg/m², P=0.001), preoperative hemoglobin (115.79±29.27 versus 111.52±29.80 g/L, P=0.033), preoperative MELD (22.25±6.54 versus 20.24±5.74, P=0.008), and intraoperative urinary volume (1.25 [0.76, 1.89] versus 2.04 [1.49, 3.68] mL/kg/h, P=0.003) were higher in low oxygenation group. There were more cases of earlier AKIs that occurred after OLT in low oxygenation patients than that in normal group (47% versus 23.4%, P<0.001). Logistic analysis showed that the preoperative BMI (hazard ration [HR]=1.107, [1.010, 1.212], P=0.029) and early AKI after OLT (HR=2.115, [1.161, 3.855], P=0.014) were independent risk factors for postoperative low oxygenation.

Conclusions

The incidence of postoperative low oxygenation after liver transplantation in adults was 33.2%. BMI and early AKI after OLT were correlated with postoperative hypoxemia.

Emergency general surgery procedures in hematopoietic stem cell transplant recipients

BACKGROUND

Outcomes of emergency general surgery (EGS) procedures on hematopoietic stem cell transplant (HST) recipients have not been defined in a large, national database. Whether EGS during HST engraftment admission, or in HST patients with graft versus host disease (GVHD) results in worse outcomes is unknown.

METHODS

The National Inpatient Sample (NIS) was examined for patients with a history of BMT between 2001 and 2014.

RESULTS

There were 520,000 HST admissions meeting inclusion criteria, of which, 14,143 (2.7%) required EGS. Of those requiring EGS, 378 (2.7%) were during engraftment admission and 13,765 (97.3%) on subsequent admission. For those requiring EGS during subsequent admission, 9,920 (72.1%) had a history of GVHD and 3,845 (27.9%) did not. On multivariate analysis, requirement of EGS was associated with mortality (OR: 1.71, 95%CI: 1.47-1.99, p < 0.001). For patients requiring EGS, engraftment admission or GVHD was not associated with mortality.

CONCLUSIONS

While EGS results in worse survival for the HST population, patients in their engraftment admission do not appear to be at increased mortality risk. In addition, GVHD does not worsen survival.

Respiratory Tract Infections: Sinusitis, Bronchitis, and Pneumonia

Solid organ and hematopoietic stem cell transplant recipients are at increased risk of upper and lower respiratory tract infections. While these infections are frequently encountered in the general population, the spectrum of their clinical presentation including morbidity and mortality is increased in patients undergoing transplantation procedures. Impaired innate and adaptive immunity, potential anatomical abnormalities resulting from extensive surgical procedures, presences of indwelling medical devices, and increased healthcare exposure put transplant recipients at particularly high risk for respiratory tract disease. Infections of the respiratory tract can be divided into those affecting the paranasal sinuses, the upper airways such as bronchitis and tracheobronchitis, and the lower airways like pneumonia. Each of these clinical syndromes can further be classified based on their chronicity, acute vs. chronic; their setting, community vs. nosocomial; and the etiology such as bacteria, viruses, fungi, and rarely parasites. It is also important to realize that such immunologically vulnerable patients are at risk for polymicrobial infection that may present concurrently or in a sequential, consecutive fashion. This chapter reviews the common respiratory tract infections affecting transplant recipients with particular attention directed toward epidemiological risk factors, clinical presentations, diagnostic strategies, and common pathogens. Specific causes of opportunistic pneumonias are also reviewed.

The Diagnostic Yield, Safety, and Impact of Flexible Bronchoscopy in Non-HIV Immunocompromised Critically Ill Patients in the Intensive Care Unit

Background

Flexible bronchoscopy (FB) and bronchoalveolar lavage (BAL) have major roles in the evaluation of parenchymal lung diseases in immunocompromised patients. Given the limited evidence, lack of standardized practice, and variable perception of procedural safety, uncertainty still exists on what constitutes the best approach in critically ill patients with immunocompromised state who present with pulmonary infiltrates in the era of prophylactic antimicrobials and the presence of new diagnostic tests.

Objective

To evaluate the diagnostic yield, safety and impact of FB and BAL on management decisions in immunocompromised critically ill patients admitted to the intensive care unit (ICU).

Methods

A prospective, observational study of 106 non-HIV immunocompromised patients admitted to the intensive care unit with pulmonary infiltrates who underwent FB with BAL.

Results

FB and BAL established the diagnosis in 38 (33%) of cases, and had a positive impact on management in 44 (38.3%) of cases. Escalation of ventilator support was not required in 94 (81.7%) of cases, while 18 (15.7%) required invasive and 3 (2.6%) required non-invasive positive pressure ventilation after the procedure. Three patients (2.6%) died within 24 h of bronchoscopy, and 46 patients (40%) died in ICU. Significant hypoxemia developed in 5% of cases.

Conclusion

FB can be safely performed in immunocompromised critically ill patients in the ICU. The yield can be improved when FB is done prior to initiation of empiric antimicrobials, within 24 h of admission to the ICU, and in patients with focal disease.

Invasive mediastinal aspergillosis presenting as superior vena cava syndrome in an immunocompetent patient

Invasive aspergillosis (IA) is a disease of the immunocompromised with a predilection for the lungs, although dissemination to all organs is possible. Its diagnosis remains a challenge due to the absence of specific clinical manifestations and laboratory findings. In most cases, diagnosis is eventually made via invasive methods. It carries with it a high mortality due to late diagnosis and delayed treatment. Here, we report a fascinating case of a young, otherwise healthy, immunocompetent patient that presented to us with superior vena cava syndrome and a mediastinal mass. It was anticipated that a malignancy would be found on further workup but, in fact, what was eventually discovered was a case of IA. Our report accentuates the significance of including IA as a differential while diagnosing a mediastinal mass in an immunocompetent host as patient outcome is determined by timely diagnosis and treatment.

The evaluation of critically ill transplant patients with infectious diarrhea

PURPOSE OF REVIEW

The review summarizes the epidemiology, risk factors, clinical presentation, diagnosis and management of the most important etiologic agents of infectious diarrhea in critically ill transplant recipients.

RECENT FINDINGS

Diarrhea, frequently caused by infectious pathogens, can cause significant morbidity and mortality in transplant recipients. Diarrhea can lead to severe dehydration, acute renal failure, medication toxicity, rejection, graft-versus-host disease and impairs patients' quality of life. Opportunistic infectious pathogens can pose significant diagnostic and therapeutic challenges in immunocompromised hosts.

SUMMARY

In transplant recipients, it is vital to differentiate infectious from noninfectious diarrhea to adequately manage their therapeutic approach. Supportive measures and reduction in immunosuppression are essential for the treatment management.

Severe infections in critically ill solid organ transplant recipients

BACKGROUND

Severe infections are among the most common causes of death in immunocompromised patients admitted to the intensive care unit. The epidemiology, diagnosis and treatment of these infections has evolved in the last decade.

AIMS

We aim to provide a comprehensive review of these severe infections in this population.

SOURCES

Review of the literature pertaining to severe infections in critically ill solid organ transplant recipients. PubMed and Embase databases were searched for documents published since database inception until November 2017.

CONTENT

The epidemiology of severe infections has changed in the immunocompromised patients. This population is presenting to the intensive care unit with specific transplantation procedure-related infections, device-associated infections, a multitude of opportunistic viral infections, an increasing number of nosocomial infections and bacterial diseases with a more limited therapeutic armamentarium. Both molecular diagnostics and imaging techniques have had substantial progress in the last decade, which will, we hope, translate into faster and more precise diagnoses, as well as more optimal empirical treatment de-escalation.

IMPLICATIONS

The key clinical elements to improve the outcome of critically ill solid organ transplant recipients depend on the knowledge of geographic epidemiology, specific surgical procedures, net state of immunosuppression, hospital microbial ecology, aggressive diagnostic strategy and search for source control, rapid initiation of antimicrobials and minimization of iatrogenic immunosuppression.

Diagnóstico y tratamiento empírico de la neumonía adquirida en la comunidad en situaciones especiales: pacientes inmunocomprometidos sin infección por el VIH y ancianos

La neumonía en el anciano tiene con frecuencia una presentación clínica menos florida que en el adulto de menor edad y que a menudo se complica por la descompensación de patologías concomitantes. En el anciano existen particularidades relativas a los gérmenes implicados en la neumonía, entre otros motivos por el mayor riesgo de infecciones por gérmenes multirresistentes al tratarse de enfermos con un contacto frecuente con los servicios de asistencia sanitaria. Las infecciones pulmonares en el individuo inmunodeprimido presentan causas diferentes en función del déficit inmune del que se trate. Tras una estratificación del riesgo, se decidirá el ingreso hospitalario o el tratamiento ambulatorio; tratamiento este determinado por las particularidades del momento de aparición de la neumonía, la situación epidemiológica local referida al porcentaje de resistencias a antibióticos en el área y las particularidades clínicas.

Pneumonia in Renal Transplant Recipients: A Single-Center Study

OBJECTIVES

Pulmonary infections are a significant cause of morbidity and mortality in solid-organ transplant recipients despite enhanced facilities for perioperative care. The aim of this study was to evaluate the demographic characteristics, clinical course, and outcomes of renal transplant recipients with pneumonia.

MATERIALS AND METHODS

The medical records of all renal transplant recipients from January 2010 to December 2014 were retrospectively reviewed, and patients diagnosed with pneumonia according to Centers for Disease Control and Prevention criteria were evaluated. Pneumonia was classified as community acquired or nosocomial. Patient demographics, microbiologic findings, need for intensive care/mechanical ventilation over the course of treatment, and information about clinical follow-up and mortality were all recorded.

RESULTS

Eighteen (13.4%) of 134 renal transplant recipients had 25 pneumonia episodes within the study period. More than half (56%) of the pneumonia episodes developed within the first 6 months of transplant, whereas 44% developed after 6 months (all > 1 year). Eight cases (32%) were considered nosocomial pneumonia, and 17 (68%) were considered community-acquired pneumonia. Bacteria were the most common cause of pneumonia (28%), and fungi ranked second (8%). No viral or mycobacterial agents were detected. No patients required prolonged mechanical ventilation. No statistically significant difference was found in the need for intensive care or regarding mortality between patients with nosocomial and community-acquired pneumonia. Two patients (11%) died, and all remaining patients recovered.

CONCLUSIONS

The present study confirmed that pneumonia after renal transplant is not a rare complication but a significant cause of morbidity. Long-term and close follow-up for pneumonia is necessary after renal transplant.

A systems-based approach to patient care after liver transplantation

Liver transplantation is a cure to many devastating acute and end-stage liver diseases. In the immediate postoperative period, patients are prone to graft, end-organ, and immunosuppressive complications. This article reviews the causes, diagnosis, and treatment of acute postoperative liver transplant complications.

[Pneumonia in immunosuppressed patients]

CLINICAL/METHODICAL ISSUE

Pulmonary infections are a common complication in immunosuppressed patients with a frequently fatal prognosis despite modern prophylactic therapy. An early and correct diagnosis is important for initiation of the appropriate therapy.

STANDARD RADIOLOGICAL METHODS

Chest radiography is the preferred initial imaging examination but is not accurate enough for the detection of pulmonary infections in immunosuppressed patients.

METHODICAL INNOVATIONS

Pneumonia is caused by a broad spectrum of pathogens in immunocompromised patients. In addition to imaging, the clinical history and epidemiology also play an important role in the diagnostics.

PERFORMANCE

Using epidemiological and anamnestic information, computed tomography (CT) shows a significantly better sensitivity and specificity particularly for the diagnosis of atypical forms of pneumonia. Due to the exact imaging of the different infiltration patterns CT provides an increased sensitivity with respect to the etiological classification of pulmonary infections.

PRACTICAL RECOMMENDATIONS

This article reviews in particular the radiological findings of commonly occurring pulmonary infections in immunosuppressed patients.