Study of the radiologic features of Legionnaires' disease with mediastinal adenopathy: Legionella or lymphoma?

An index case of Legionnaires's disease with mediastinal adenopathy prompted us to review our recent experience with Legionnaires' disease to determine the incidence of mediastinal adenopathy of this finding in Legionnaires' disease. We reviewed the radiographic findings of 90 hospitalized adults with Legionnaires' disease from 2015 to 2017. Excluded were 11 patients with mediastinal adenopathy due to non-Legionnaires' disease causes, e.g., lymphoma. Thirty-seven of the remaining patients had both chest films and chest computed tomography (CT) scans. Of the 37 Legionnaires' disease cases, 13/37 (35%) had mediastinal adenopathy and 8/27 (24%) also had unilateral hilar adenopathy. These chest CT findings were not seen on chest films. Chest CT scans are needed to detect mediastinal adenopathy in Legionnaires' disease. Mediastinal adenopathy may be due to Legionnaires' disease or a malignancy. Some findings in Legionnaires' disease are also present in mediastinal adenopathy due to lymphomas, e.g., highly elevated erythrocyte sedimentation rate (ESR), lactate dehydrogenase (LDH), and ferritin. Hospitalized adults with Legionnaires' disease and mediastinal adenopathy should have serial chest CT scans to monitor resolution of the mediastinal adenopathy. In hospitalized adults with otherwise unexplained persistent mediastinal adenopathy, they should be considered as being due to another etiology, e.g., lymphoma, until proven otherwise.

Early Radiographic and Tomographic Manifestations of Legionnaires' Disease.

PURPOSE: Legionnaires' disease (LD) may occur sporadically or in the course of outbreaks, where the typical radiological manifestations of the disease may better be delineated. We took advantage of a rare community-based epidemic of LD (181 patients) that occurred in 2012 in Quebec City, Canada, to describe the radiographic features of LD and compare the its tomographic presentation with that of community-acquired pneumonia caused by common bacteria other than Legionella pneumophila. METHODS: From the 181 individuals affected in the outbreak, we obtained the chest radiographs of 159 individuals (mean 63 ± 15 years of age) for detailed analysis; 33 patients had a computed tomography (CT) scan performed during the course of their illness. In a case-control study, we compared the CT scans of patients with LD with those of patients who had received a diagnosis of community-acquired pneumonia caused by a pathogen other than Legionella and confirmed by chest CT scan. RESULTS: Overall, LD most often presented as an airspace consolidation involving 1 of the lower lobes. Pleural effusion and mediastinal adenopathies were apparent only in a minority, whereas no pneumothorax or cavitation was noted. We did not find any significant difference in chest CT scan findings in patients with LD vs those with community-acquired pneumonia from other bacterial origin. No radiological finding was clearly associated with an increased risk of intensive care unit admission or mortality. CONCLUSIONS: The early radiographic and tomographic manifestations of LD are nonspecific and similar to those found in community-acquired pneumonia from other bacterial origin.

Legionnaire's Disease and its Mimics: A Clinical Perspective.

Whenever the cardinal manifestations of a disorder occur in similar disorders, there is potential for a disease mimic. Legionnaire's disease has protean manifestations and has the potential to mimic or be mimicked by other community acquired pneumonias (CAPs). In CAPs caused by other than Legionella species, the more characteristic features in common with legionnaire's disease the more difficult the diagnostic conundrum. In hospitalized adults with CAP, legionnaire's disease may mimic influenza or other viral pneumonias. Of the bacterial causes of CAP, psittacosis and Q fever, but not tularemia, are frequent mimics of legionnaire's disease.

Detection of Legionella pneumophila serogroup 1 in blood cultures from a patient treated with tumor necrosis factor-alpha inhibitor.

A 65-year-old man was admitted to our hospital with a temperature of 39.3 °C, cough, sputum, and pharyngeal discomfort that had persisted for 3 days. He had been treated with methotrexate and adalimumab (a tumor necrosis factor-alpha [TNF-α] inhibitor) for rheumatoid arthritis for 2 years, and he had also been treated with S-1 (tegafur, gimeracil, and oteracil potassium) for pancreatic metastasis of gastric cancer for 2 months. Regardless of the underlying pathologies, his general condition was good and he had worked as an electrician until 2 days before admission. However, his appetite had suddenly decreased from the day before admission, and high fever and hypoxia were also evident upon admission. A chest X-ray and computed tomography scan revealed left pleural effusion and consolidation in both lungs. The pneumonia severity index score was 165 and the risk class was V. Accordingly, we started to treat the pneumonia with a combination of levofloxacin and meropenem. Thereafter, we received positive urinary antigen test findings for Legionella pneumophila. After hospitalization, hypoxia was progressed and hypotension was emerged. Despite the application of appropriate antibiotics, vasopressors, and oxygenation, the patient died 8 h after admission. Even after his death, blood cultures were continued to consider the possibility of bacterial co-infection. Although no bacteria were detected from blood cultures, Gimenez staining revealed pink bacteria in blood culture fluids. Subsequent blood fluid culture in selective medium revealed L. pneumophila serogroup 1. Recently, TNF-α inhibitors have been described as a risk factor for Legionnaires' disease. In consideration of the increased frequency of TNF-α inhibitors, we may need to recognize anew that L. pneumophila might be a pathogen of severe community-acquired pneumonia.

Legionella pneumophila lung abscess associated with immune suppression.

Legionella species are a common cause of community-acquired pneumonia, infrequently complicated by cavitary disease. We describe Legionella pneumophila pneumonia and abscess formation in an immunosuppressed patient receiving corticosteroid therapy for metastatic breast carcinoma. The predisposing role of corticosteroids is discussed and the management of this complication is reviewed.

Severe Legionella pneumophila pneumonia following infliximab therapy in a patient with Crohn's disease.

BACKGROUND: Immunosuppressive therapy with anti-TNF-alpha antibodies is effective in patients with inflammatory bowel disease (IBD). However, there is an increased risk for infections associated with this therapy. METHODS: Here, we report the case of a 58-year-old patient with Crohn's disease (CD) treated with steroids and azathioprine who developed severe Legionella pneumophila pneumonia after 3 infusions of infliximab. The patient presented at our IBD department with severe active CD complicated by inflammatory small bowel stenoses and entero-enteral fistulas despite long-term high-dose steroid therapy. To achieve steroid tapering and control of disease activity, immunosuppressive therapy with azathioprine was initiated. Due to persistent symptoms, infusion therapy with the anti-TNF-alpha antibody infliximab was started, subsequently leading to significant clinical improvement. However, after the third infliximab infusion the patient was hospitalized with fever, severe fatigue, and syncope. RESULTS: Laboratory findings and chest X-ray revealed left-sided pneumonia; cultural analysis showed L. pneumophila serogroup 1 leading to respiratory insufficiency, which required mechanical ventilation for 2 weeks in the intensive care unit. After discontinuation of all immunosuppressive agents and immediate antibiotic therapy the patient recovered completely. CONCLUSIONS: To our knowledge, this is the third case of L. pneumophila pneumonia in an IBD patient treated with infliximab. Similar to other published cases, concomitant treatment of immunosuppressives and anti-TNF agents is a major risk factor for the development of L. pneumophila infection, which should be ruled out in all cases of pneumonia in patients with such a therapeutic regimen. Appropriate prevention strategies should be provided in these patients.

Clinical features of two cases of Legionnaires' disease with persistence of Legionella urinary antigen excretion.

The advantages of diagnosing legionellosis by urinary antigen detection are widely recognized, and include early detection, rapidity of testing, and ease of specimen collection. However, the persistence of Legionella urinary antigen excretion has been suggested in some selected patients, although the clinical features of these patients have not yet been clearly described. Here, we describe the clinical features of two patients with Legionnaires' disease with persistence of Legionella urinary antigen excretion (117 days and 247 days). One patient had an underlying disease, adult T-cell leukemia, and the other patient had ulcerative colitis and was receiving oral corticosteroids. Unusual clinical and radiological findings as well as a review of the literature are presented.

Chest computed tomographic findings and clinical features of legionella pneumonia.

OBJECTIVE: To describe the chest radiographic and computed tomographic (CT) findings of legionella pneumonia. METHODS: Serial chest radiographs and CT scans obtained in 12 patients with serologically proven Legionella pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to patterns and distributions of pulmonary abnormalities. RESULTS: Nine of the 12 patients were in an immunocompromised state, that is, steroid therapy (n = 8) and myelodysplastic syndrome (n = 1), and 6 of the 8 steroid users were on high-dose steroid. All patients showed multilobar or multisegmental pulmonary infiltrates on CT scans. The CT findings were categorizable as; predominantly airspace consolidations (n = 6), mixed lesions with lobular consolidation and ground-glass opacity (GGO) (n = 3), and pure GGO lesions (n = 2). Five of the 6 patients on high-dose steroid therapy had lobar consolidations with (n = 4) or without a cavity (n = 1), and 1 patient had a mixed lesion. CONCLUSIONS: The most common CT findings in legionella pneumonia were multilobar or multisegmental consolidation and GGO. Cavitary lobar consolidation occurred commonly in patients on high-dose steroid therapy.

Hot spring bath and Legionella pneumonia: an association confirmed by genomic identification.

A 59-year-old man developed pneumonia 9 days after bathing in a hot spring spa. Bilateral shadows on his chest radiograph rapidly progressed after admission. He was successfully treated with erythromycin and rifampicin. Legionella pneumophila serogroup 6 was recovered from an intratrachial specimen and a significant elevation was observed in a paired indirect fluorescent antibody to Legionella. Persistent slight fever and chest rentogenographic shadows resolved after administering low-dose prednisolone to treat organizing pneumonia shown by transbronchial lung biopsy. The same serotype of Legionella was recovered from the water of the hot spring spa where the man had bathed. When the extracted DNA of these two strains showed identical restriction fragments by pulsed-field gel electrophoresis, we had direct evidence that hot spring spas can be a source of Legionella pneumonia.

Legionellosis in a lung transplant recipient obscured by cytomegalovirus infection and Clostridium difficile colitis.

A 52-year-old-white male underwent double lung transplantation for severe emphysema due to alpha-1-antitrypsin deficiency and heavy tobacco use. Following a postoperative course complicated by renal insufficiency, pulmonary emboli, and Clostridium difficile colitis, he was discharged in stable condition. Two months later, he was admitted to a local hospital with a fever, abdominal pain, diarrhea, nausea, and dyspnea. Computerized tomography (CT) of the chest revealed bilateral pleural effusions. Sigmoidoscopy was grossly normal but biopsy demonstrated cytomegalovirus (CMV) colitis, and the patient was placed on intravenous ganciclovir. Over the next week, he became progressively hypoxemic and was transferred to the University of Pittsburgh Medical Center (post-transplant day 81) for further evaluation. His medications on transfer included: ganciclovir, prednisone, tacrolimus, dapsone, fluconazole, ondansetron, lansoprazole, digoxin, and coumadin.

Rapidly expanding lung abscess caused by Legionella pneumophila in immunocompromised patients: a report of two cases.

We describe two cases of lung abscess caused by Legionella pneumophila in immunocompromised patients. The first case had been treated initially with 60 mg prednisolone for ulcerative colitis, and L. pneumophila serogroup 1 was isolated from sputum samples after cavitation of the lung lesion. The second case was diagnosed as plasma cell lymphoma at post-mortem examination. L. pneumophila serogroup 5 was isolated from the contents of lung abscess, together with Enterococcus faecium and Prevotella intermedia in the post-mortem examination. Lung abscess caused by Legionella is unusual. Here, we discuss the difficulty of diagnosis of legionellosis in patients with unusual chest radiographic findings.

Persistently positive culture results in a patient with community-acquired pneumonia due to Legionella pneumophila.

We describe a patient with community-acquired pneumonia due to Legionella pneumophila serogroup 6. This patient was found to have bronchoalveolar carcinoma of the lung by means of cytologic testing in 1 of 2 bronchoalveolar lavage samples, but no lesions were visible on bronchoscopy. Despite intravenous administration of azithromycin to the patient, repeat culture and polymerase chain reaction showed persistence of Legionella; the isolates remained susceptible to azithromycin. The patient did not respond to 14 doses of daily intravenously administered azithromycin. The poor outcome may have been partially due to the suspected underlying lung malignancy, as shown by cytologic examination, and by a delay in seeking medical attention.

Tubulointerstitial nephritis associated with Legionnaires' disease.

A 47-year-old man was admitted to our hospital for community-acquired pneumonia complicated with acute renal failure. Legionella pneumophila serogroup type 1 was grown in BCYE (buffered charcoal yeast extract) agar for sputum culture. Although his respiratory illness responded to intravenous erythromycin therapy, renal failure worsened and necessitated hemodialysis. Renal biopsy showed profound tubulointerstitial nephritis. After initiation of steroid therapy his renal function improved and he was discharged thereafter. These findings suggest that in Legionnaires' disease with acute renal failure, tubulointerstitial nephritis should also be considered and steroid therapy may be an effective modality for the renal complication.

[Legionella pneumophila: unusual lung and hepatic manifestations]. / Legionella pneumophila: présentation thoracique inhabituelle et localisations hépatiques.

We report an uncommon presentation of Legionella pneumophila infection following a placentalblood transplantation in an immunodeficient child. The patient presented with lung nodules and liver abscesses. We discuss how a digestive contamination can be suspected.

Isolation of Legionella pneumophila by centrifugation of shell vial cell cultures from multiple liver and lung abscesses.

A 7-year-old girl was admitted to the hospital with acute lymphoblastic leukemia and was treated with allogenic cord blood transplantation. At day 30 after graft, she developed a fever and multiple nodular lesions disseminated in the liver and lungs. All bacterial cultures attempted on liver and lung biopsy specimens and blood remained sterile on standard axenic media. However, inoculation of liver and lung biopsy specimens on eukaryotic cell monolayers by the centrifugation-shell vial technique (M. Marrero and D. Raoult, Am. J. Trop. Med. Hyg. 40:197-199, 1989) led to the recovery of a strain of Legionella pneumophila serogroup 1, identified by 16S rRNA gene amplification and sequencing and serotyping. Our findings demonstrate that the centrifugation-cell culture method, which has previously been useful for the isolation of other strictly or facultatively intracellular bacteria, can also serve as a method for the recovery of L. pneumophila from clinical material.

Radiological manifestations of Legionella/Legionella-like organisms.

The chest radiograph of Legionellosis has been described in many reports. Although some attempted to describe patterns which are specific for Legionella, in fact, the roentgenographic findings in Legionella infection vary widely and depend largely on when in the course of illness the radiograph is obtained. Certain temporal characteristics, however, can serve to enhance the likelihood of the diagnosis of Legionella pneumonitis. Initial focal infiltrates are most commonly poorly marginated with 10% presenting with concomitant pleural effusion. The infiltrates often spread to contiguous lobes eventually becoming bilateral, with incidence of pleural effusions reaching 35%. This progression often occurs despite appropriate antimicrobial therapy and often in the face of clinical improvement. A similar pattern of progression also occurs in immunocompromised individuals; in addition, a high rate of cavitation and hilar adenopathy is seen in this subset of patients. A prolonged resolution phase of up to 6 months is common with rare development of residual densities. Correlating radiographic features with disease severity and mortality have largely been unsuccessful.

Nosocomial and community-acquired Legionella pneumonia: clinical comparative analysis.

Previous reports have suggested that nosocomial and community Legionella pneumonia cases are similar. However, community and hospital characteristics, such as aquatic environment, antibiotic pressure (usage) and populations, are quite different, leading to the suspicion that Legionella infection may differ in the two settings. Univariate and multivariate analyses were performed to compare demographic data, risk factors, clinical, radiological and outcome data between 125 nosocomial and 33 community-acquired cases of Legionella pneumophila infection. Patients in the nosocomially acquired Legionella pneumonia (NALP) group were older than those in the community-acquired Legionella pneumonia (CALP) group. Univariate analysis showed that smoking habit, cough, thoracic pain, and extrapulmonary manifestations were more prevalent in the CALP group, whilst chronic lung disease and cancer were more prevalent in the NALP group. Moreover, patients in the NALP group were more likely to have received oxygen and corticosteroid therapy and also to have altered creatinine values than patients in the CALP group, whilst more patients in the latter group had altered alanine amino-transferase values. However, multivariate analysis failed to confirm most of these differences. Smoking habit and blood creatinine levels were the only variables remaining significant. In conclusion, demographic, clinical, laboratory, radiological and outcome data in nosocomial and community-acquired Legionella pneumonia are quite similar.

Legionella pneumophila: denizen of defenders.

Legionella pneumophila, the causative agent of legionellosis, is an intracellular parasite of human monocytic cells and neutrophils. The life cycle of Legionella within phagocytic cells is distinct from that of other bacterial pathogens. Adherence of L pneumophila to phagocytes is mediated by attachment of complement proteins to the Legionella cell surface, followed by binding to complement receptors of phagocytes. Opsonized Legionella also may enter phagocytes after engagement of the Fc receptors. Within the host cell, the parasites reside in a membrane-bound vacuole that does not fuse with lysosomes. Activation of mononuclear phagocytes by the cell-mediated immune system serves to limit intracellular bacterial growth. Polymorphonuclear leukocytes are better at killing L pneumophila than are macrophages. However, Legionella also can invade and parasitize granulocytes. Although significant progress has been made in understanding some aspects of the pathogenesis of legionellosis, we know very little about the mechanisms by which these facultative intracellular parasites avoid killing by host defense mechanisms. This is an important area for future research and should lead to a better understanding of host-parasite interactions.

[Legionnaires' disease in children]. / Legionarska bolest u djece.

During the first nine months of 1987, the bacteriological and virological tests as well as the indirect fluorescence test to Legionella pneumophila were performed in 40 children with bronchopneumonia (one- or both-sided) or pleuropneumonia and in 10 children with protracted bronchitis. In a 15 month old boy we have proved (by titer dynamics) the infection with Legionella pneumophila serotype 5, and in a 15 month old girl and in a 16 month old boy serotype 1. The infection was sporadic and the possible source of infection was unknown. The course of the disease was not wasting and the infection was accompanied with fever. The patients had an increased sedimentation rate of red cells and leukocytosis. All the other laboratory findings were within normal limits. In seven children seropositiveness 1:256 to Legionella pneumophila serotype 1, and in two children an increased titer to adenovirus was proved. The high titer to Legionella pneumophila in those seven children indicates an early contact with the causal agent. The patients were successfully treated with cefuroxim, which is not the drug of choice. Infection due to Legionella pneumophila in children does not exhibit a clinical or laboratory characteristic features that differ from those of the other respiratory diseases in children. It means that Legionnaires' disease in children with intact immunity is not the wasting illness. We stress the importance of using serologic examination to Legionella pneumophila as a routine procedure in the aetiological diagnosis of respiratory diseases in children.

Diagnosis of Legionella lung abscess by percutaneous needle aspiration.

Pneumonia is a life-threatening infection of immunocompromised patients, and accurate identification of the causative agent is essential for early initiation of appropriate antibiotic therapy. Percutaneous needle aspiration was used to identify Legionella pneumonia after sputum and bronchoscopy specimens had failed to provide a diagnosis in a 13-year-old leukemic patient with a lung abscess. We believe this is the first report of a child with this disease diagnosed in this way.