Radiological and clinical findings of pulmonary aspergillosis following solid organ transplant

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

Invasive aspergillosis in liver transplant recipients

BACKGROUND

Liver transplantation is increasing worldwide with underlying pathologies dominated by metabolic and alcoholic diseases in developed countries.

METHODS

We provide a narrative review of invasive aspergillosis (IA) in liver transplant (LT) recipients. We searched PubMed and Google Scholar for references without language and time restrictions.

RESULTS

The incidence of IA in LT recipients is low (1.8%), while mortality is high (∼50%). It occurs mainly early (<3 months) after LT. Some risk factors have been identified before (corticosteroid, renal, and liver failure), during (massive transfusion and duration of surgical procedure), and after transplantation (intensive care unit stay, re-transplantation, re-operation). Diagnosis can be difficult and therefore requires full radiological and clinicobiological collaboration. Accurate identification of Aspergillus species is recommended due to the cryptic species, and susceptibility testing is crucial given the increasing resistance of Aspergillus fumigatus to azoles. It is recommended to reduce the dose of tacrolimus (50%) and to closely monitor the trough level when introducing voriconazole, isavuconazole, and posaconazole. Surgery should be discussed on a case-by-case basis. Antifungal prophylaxis is recommended in high-risk patients. Environmental preventative measures should be implemented to prevent outbreaks of nosocomial aspergillosis in LT recipient units.

CONCLUSION

IA remains a very serious disease in LT patients and should be promptly sought and, if possible, prevented by clinicians when risk factors are identified.

Invasive aspergillosis in solid organ transplant patients: diagnosis, prophylaxis, treatment, and assessment of response

BACKGROUND

Invasive aspergillosis (IA) is a rare complication in solid organ transplant (SOT) recipients. Although IA has significant implications on graft and patient survival, data on diagnosis and management of this infection in SOT recipients are still limited.

METHODS

Discussion of current practices and limitations in the diagnosis, prophylaxis, and treatment of IA and proposal of means of assessing treatment response in SOT recipients.

RESULTS

Liver, lung, heart or kidney transplant recipients have common as well as different risk factors to the development of IA, thus each category needs a separate evaluation. Diagnosis of IA in SOT recipients requires a high degree of awareness, because established diagnostic tools may not provide the same sensitivity and specificity observed in the neutropenic population. IA treatment relies primarily on mold-active triazoles, but potential interactions with immunosuppressants and other concomitant therapies need special attention.

CONCLUSIONS

Criteria to assess response have not been sufficiently evaluated in the SOT population and CT lesion dynamics, and serologic markers may be influenced by the underlying disease and type and severity of immunosuppression. There is a need for well-orchestrated efforts to study IA diagnosis and management in SOT recipients and to develop comprehensive guidelines for this population.

Clinical characteristics and CT manifestations of invasive pulmonary aspergillosis in hospitalised patients with systemic lupus erythematosus

AIM

To investigate clinical and computed tomography (CT) findings of invasive pulmonary aspergillosis (IPA) in patients with systemic lupus erythematosus (SLE) and to explore the relationships of CT findings with clinical characteristics and outcomes.

MATERIALS AND METHODS

Clinical and CT findings of 14 SLE patients with proven (n=4) and probable (n=10) IPA between January 2006 and April 2013 were reviewed retrospectively and related to patients' outcomes.

RESULTS

All patients (mean age, 42.3 ± 15.1 years; 11 women, three men) had active SLE, prior corticosteroid, and/or immunosuppressive therapy. Dominant CT findings performed within 10 days of the clinical onset consisted of nodules/masses (100%, 14/14), consolidations (92.9%, 13/14), and ground-glass opacity (85.7%, 12/14). Bilateral, multilobar, and upper-lobe involvement was common. Regardless of dominant patterns, the halo, reversed halo, air-crescent, hypodense, and feeding vessel signs were found in 12 (85.7%), one (7.1%), three (21.3%), seven (50%), and seven (50%) patients, respectively. There was no significant difference in CT findings between the IPA alone (n=5) and co-infection (n=9) groups and between survived (n=4) and non-survived (n=10) patients. The IPA-alone group more frequently had alcohol consumption (p=0.018), haemoptysis (p=0.023), and disseminated aspergillosis (p=0.027) than did the co-infection group. Non-survived patients tended to be older and have a history of recent hospitalisation.

CONCLUSIONS

IPA is a rare, life-threatening disease affecting SLE patients in the early course of disease with high disease activity requiring corticosteroid and/or immunosuppressive therapy. Dominant CT findings are characteristics of angio-invasive form with a high frequency of the halo sign and bilateral, multilobar, and upper-lobe involvement.

Defining standards of CARE for invasive fungal diseases in solid organ transplant patients

Fungal infection in solid organ transplant (SOT) recipients is a challenge for physicians. Our aim was to review progress made within the past decade in managing the most important invasive fungal diseases in SOT recipients. Standards of care for candidosis, aspergillosis, mucormycosis and cryptococcosis in this special population are summarized.

High prevalence of peribronchial focal lesions of airway invasive aspergillosis in hematological cancer patients with prolonged neutropenia

OBJECTIVE

The aim of this study is to characterize chest CT findings of neutropenic patients with proven/probable invasive pulmonary aspergillosis (IPA).

METHODS

Hematological cancer patients admitted to our institution (2007-2017) were retrospectively enrolled if the diagnostic criteria of proven/probable IPA during the neutropenia were met (EORTC/MSG). Galactomannan (GM) was routinely measured in serum and chest CT-scan was routinely performed in case of recurrent/persistent fever. Bronchoscopy was performed in case of chest CT-scan abnormalities. Chest CT-scan and GM dosage were analyzed at the time of IPA suspicion. Chest lesions were classified using a clinical report form by two expert radiologists.

RESULTS

35 patients were identified. Peribronchial focal lesions were observed in 29 IPA (82.9%) by the first radiologist and in 31 (88.5%) by the second (k = 0.768). 12 weeks mortality was 20%.

CONCLUSION

Peribronchial focal lesions are a common finding in early-IPA whatever the GM value during neutropenia and our findings reinforce the efficiency of a preemptive approach.

ADVANCES IN KNOWLEDGE;

Peribronchial focal lesions, which are classically described in airway invasive aspergillosis, are a common finding in early-IPA in hematological cancer patients with prolonged neutropenia regardless of the GM value, and such peribronchial lesions should reinforce the possibility of IPA.

Lee C, Colletti PM, Chung JH, Ackman JB, Berry MF, Carter BW, de Groot PM, Hobbs SB, Johnson GB, Maldonado F, McComb BL, Tong BC, Walker CM, Kanne JP. ACR Appropriateness Criteria® Acute Respiratory Illness in Immunocompromised Patients

The immunocompromised patient with an acute respiratory illness (ARI) may present with fever, chills, weight loss, cough, shortness of breath, or chest pain. The number of immunocompromised patients continues to rise with medical advances including solid organ and stem cell transplantation, chemotherapy, and immunomodulatory therapy, along with the continued presence of human immunodeficiency virus and acquired immunodeficiency syndrome. Given the myriad of pathogens that can infect immunocompromised individuals, identifying the specific organism or organisms causing the lung disease can be elusive. Moreover, immunocompromised patients often receive prophylactic or empiric antimicrobial therapy, further complicating diagnostic evaluation. Noninfectious causes for ARI should also be considered, including pulmonary edema, drug-induced lung disease, atelectasis, malignancy, radiation-induced lung disease, pulmonary hemorrhage, diffuse alveolar damage, organizing pneumonia, lung transplant rejection, and pulmonary thromboembolic disease. As many immunocompromised patients with ARI progress along a rapid and potentially fatal course, timely selection of appropriate imaging is of great importance in this setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking, or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

Epidemiology, risk factors and outcomes of invasive aspergillosis in solid organ transplant recipients in the Swiss Transplant Cohort Study

BACKGROUND

There is lack of recent multicenter epidemiological data on invasive aspergillosis (IA) among solid organ transplant recipient (SOTr) in the mold-acting antifungal era. We describe the epidemiology and outcomes of IA in a contemporary cohort of SOTr using the Swiss Transplant Cohort Study.

METHODS

All consecutive SOTr with proven or probable IA between 01.05.2008 and 31.12.2014 were included. A case-control study to identify IA predictors was performed: 1-case was matched with 3-controls based on SOT type, transplant center, and time post-SOT.

RESULTS

Among 2868 SOTr, 70 (2.4%) patients were diagnosed with proven (N: 30/70, 42.9%) or probable (N: 40/70, 57.1%) IA. The incidence of IA was 8.3%, 7.1%, 2.6%, 1.3%, and 1.2% in lung, heart, combined, kidney, and liver transplant recipients, respectively, Galactomannan immunoassay was positive in 1/3 of patients tested. Only 33/63 (52.4%) of patients presented with typical pulmonary radiographic findings. Predictors of IA included: renal insufficiency, re-operation, and bacterial and viral infections. 12-week mortality was higher in liver (85.7%, 6/7) compared to other (15.9%, 10/63; P < .001) SOTr.

CONCLUSIONS

Invasive aspergillosis remains a rare complication post-SOT, with atypical radiographic presentations and low positivity rates of biomarkers posing significant diagnostic challenges. Although overall mortality has decreased in SOTr, it remains high in liver SOTr.

Radiologically Occult Invasive Pulmonary Aspergillosis in a Patient With Liver Transplant

Invasive pulmonary aspergillosis is an infection seen in patients receiving intensive immunosuppressive regimens, such as transplant recipients. Some risk factors that increase the incidence of infection have been determined, and patients defined as having high risk are recommended to take antifungal prophylaxis and be monitored closely. Here, we present a liver transplant patient with mild respiratory symptoms and a normal chest radiography on day 26 posttransplant. However, he had acute renal failure and underwent hemodialysis, which are both defined to increase significantly the risk of aspergillosis. Although the radiographic scan was initially normal, thorax tomography and later bronchoscopy showed findings compatible with pulmonary aspergillosis, and the patient was started on antifungal treatment. The nonspecific mild symptoms and an initial normal radiology can make diagnosis of invasive fungal infections difficult; thus caution and close follow-up of high-risk patients should be performed.

Diagnosis and treatment of pulmonary cavity after liver transplantation

BACKGROUND

Although the outcomes have improved in the current era, pulmonary infection remains a significant post-transplant complication in liver transplant (LT) recipients. Pulmonary infection with cavity formation often leads to higher mortality rates after LT. We wished to investigate the diagnosis and treatment of pulmonary cavity (PC) formation after LT.

METHODS

We evaluated (retrospectively) five cases of PC formation, shown on CT scans of the chest after LT, by analyzing imaging features, diagnosis, treatment, liver function, and the concentration changes and efficacy of immunosuppressants.

RESULTS

According to the results from the CT scan, serum Aspergillus galactomannan (GM) assay, the purified protein derivative (PPD) skin test, and the sputum smears and blood culture, three cases were diagnosed with Aspergillus infection, and the other two cases were diagnosed with Mycobacterium tuberculosis infection. Liver function and FK506 concentration were monitored during treatment. Antibiotics used for treatment of Aspergillus and Mycobacterium tuberculosis infections affected liver function and FK506 concentration. However, after adjustment of drug doses, antibiotic treatment was tolerated in all patients. Four cases were cured, but 1 patient died of Aspergillus infection.

CONCLUSIONS

Distinguishing between Aspergillus infection and Mycobacterium tuberculosis infection for PCs after liver transplantation (LT) using a CT scan is difficult. The diagnosis can be confirmed using clinical characteristics, sputum culture, GM assay, PPD, and sputum smears. Early diagnosis and treatment could lead to a better prognosis.

What can happen after lung transplantation and the importance of the time since transplantation: radiological review of post-transplantation complications

Lung transplantation is the best treatment option in the final stages of diseases such as cystic fibrosis, pulmonary hypertension, chronic obstructive pulmonary disease, or idiopathic pulmonary fibrosis. Better surgical techniques and advances in immunosuppressor treatments have increased survival in lung transplant recipients, making longer follow-up necessary because complications can occur at any time after transplantation. For practical purposes, complications can be classified as early (those that normally occur within two months after transplantation), late (those that normally occur more than two months after transplantation), or time-independent (those that can occur at any time after transplantation). Many complications have nonspecific clinical and radiological manifestations, so the time factor is key to narrow the differential diagnosis. Imaging can guide interventional procedures and can detect complications early. This article aims to describe and illustrate the complications that can occur after lung transplantation from the clinical and radiological viewpoints so that they can be detected as early as possible.

Approach to the Solid Organ Transplant Patient with Suspected Fungal Infection

In solid organ transplant (SOT) recipients, invasive fungal infections (IFIs) are associated with significant morbidity and mortality. Detection of IFIs can be difficult because the signs and symptoms are similar to those of viral or bacterial infections, and diagnostic techniques have limited sensitivity and specificity. Clinicians must rely on knowledge of the patient's risk factors for fungal infection to make a diagnosis. The authors describe their approach to the SOT recipient with suspected fungal infection. The epidemiology of IFIs in the SOT population is reviewed, and a syndromic approach to suspected IFI in SOT recipients is described.

Diagnostic Modalities for Invasive Mould Infections among Hematopoietic Stem Cell Transplant and Solid Organ Recipients: Performance Characteristics and Practical Roles in the Clinic

The morbidity and mortality of hematopoietic stem cell and solid organ transplant patients with invasive fungal infections (IFIs) remain high despite an increase in the number of effective antifungal agents. Early diagnosis leading to timely administration of antifungal therapy has been linked to better outcomes. Unfortunately, the diagnosis of IFIs remains challenging. The current gold standard for diagnosis is a combination of histopathology and culture, for which the sensitivity is <50%. Over the past two decades, a plethora of non-culture-based antigen and molecular assays have been developed and clinically validated. In this article, we will review the performance of the current commercially available non-cultural diagnostics and discuss their practical roles in the clinic.

Infections after orthotopic liver transplantation

Opportunistic infections are a leading cause of morbidity and mortality after orthotopic liver transplantation. Systemic immunosuppression renders the liver recipient susceptible to de novo infection with bacteria, viruses and fungi post-transplantation as well to reactivation of pre-existing, latent disease. Pathogens are also transmissible via the donor organ. The time from transplantation and degree of immunosuppression may guide the differential diagnosis of potential infectious agents. However, typical systemic signs and symptoms of infection are often absent or blunted after transplant and a high index of suspicion is needed. Invasive procedures are often required to procure tissue for culture and guide antimicrobial therapy. Antimicrobial prophylaxis reduces the incidence of opportunistic infections and is routinely employed in the care of patients after liver transplant. In this review, we survey common bacterial, fungal, and viral infections after orthotopic liver transplantation and highlight recent developments in their diagnosis and management.

Invasive fungal infections in solid organ transplant recipients

Invasive fungal infections are a major problem in solid organ transplant (SOT) recipients. Overall, the most common fungal infection in SOT is candidiasis, followed by aspergillosis and cryptococcosis, except in lung transplant recipients, where aspergillosis is most common. Development of invasive disease hinges on the interplay between host factors (e.g., integrity of anatomical barriers, innate and acquired immunity) and fungal factors (e.g., exposure, virulence and resistance to prophylaxis). In this article, we describe the epidemiology and clinical features of the most common fungal infections in organ transplantation. Within this context, we review recent advances in diagnostic modalities and antifungal chemotherapy, and their impact on evolving prophylaxis and treatment paradigms.

ACR appropriateness criteria(®)acute respiratory illness in immunocompromised patients

The respiratory system is often affected by complications of immunodeficiency, typically manifesting clinically as acute respiratory illness. Ongoing literature reviews regarding the appropriateness of imaging in these patients are critical, as advanced medical therapies such as stem cell transplantation, chemotherapy, and immunosuppressive therapies for autoimmune disease continue to keep high the population of immunosuppressed patients in our health care system today. This ACR Appropriateness Criteria(®) topic describes clinical scenarios of acute respiratory illness in immunocompromised patients with cough, dyspnea, chest pain, and fever; in those with negative, equivocal, or nonspecific findings on chest radiography; in those with diffuse or confluent opacities on chest radiography; and in those in whom noninfectious disease is suspected. The use of chest radiography, chest CT, transthoracic needle biopsy, and nuclear medicine imaging are all discussed in the contexts of these clinical scenarios. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Radiological and clinical findings of 25 patients with invasive pulmonary aspergillosis: retrospective analysis of 2150 liver transplantation cases

OBJECTIVE

The purpose of this study was to evaluate the radiological and clinical findings of invasive pulmonary aspergillosis (IPA) after liver transplantation.

METHODS

This study included 25 consecutive liver transplant recipients with histologically confirmed IPA after liver transplantation. Radiological examinations performed for diagnosis were available in all patients. Clinical findings and changes in clinical response and radiological findings after treatment were also evaluated.

RESULTS

3 main radiological findings were identified: nodules, 64% (16/25); masses, 36% (9/25); and consolidations in a patchy pattern, 20% (5/25). A tree-in-bud pattern was found in 12% (3/25) of patients. In 8 (32%) of 25 patients, we found a combination of 2 or more of these signs: 5 (20%) patients presented with concurrent nodules accompanied by patchy consolidations and/or tree-in-bud, and 3 (12%) patients showed masses accompanied by large consolidations. A halo sign was observed in 20 (80%) of 25 patients. Hypodense sign and cavitary lesions were encountered in 17 (68%) of 25 patients. Follow-up radiological findings after treatment showed improvement in 18 patients, no change in 4 patients and progression in 3 patients. There were three aspergillosis-associated deaths during the follow-up period. The onset time of IPA was a median of 31 days after transplantation. The most common symptom at diagnosis was fever (n=15). None of the 25 patients had leukopaenia at the time of the diagnosis of IPA.

CONCLUSIONS

The most common radiological findings of IPA after liver transplantation are multiple nodules with or without halo sign, masses and consolidations, which usually appear about 1 month after transplantation.

Respiratory infections in immunocompromised patients

PURPOSE OF REVIEW

Immunosuppressive states and therapies are becoming common in clinical practice. Recent advances and trends in bacterial, fungal, viral and parasitic pulmonary infections in immunosuppressed patients are described.

RECENT FINDINGS

Pulmonary infections can jeopardize the prognosis of immunosuppressed patients. The number of patients infected with multidrug-resistant bacteria or opportunistic pathogens like rapid-growing environmental mycobacteria, Strongyloides stercoralis or Rhodococcus equi is increasing with the increased numbers of immunosuppressed patients due to HIV/AIDS and the potent immunosuppressive therapies used in solid-organ and haematopoietic transplantations, cancer and systemic illnesses. The slow development of more effective antibiotics underlines the necessity of preventive measures, development of rapid detection tests for pathogens and appropriate treatment regimens to avoid development of further resistance.

SUMMARY

Adequate prophylaxis, clinical suspicion, microbiological and molecular investigations, drug susceptibility-based antibiotic treatment and new drug development are strategies required to face up to the challenge of pulmonary infections in immunodepressed patients.