Diffuse interstitial fibrosing pneumonitis and adenovirus infection

Thin-section computed tomography findings in 104 immunocompetent patients with adenovirus pneumonia

Background To date, there has been no computed tomography (CT) evaluation of adenovirus pneumonia in a large number of immunocompetent patients. Purpose To describe the thin-section CT findings of immunocompetent patients with adenovirus pneumonia. Material and Methods We prospectively enrolled 104 patients with adenovirus pneumonia from a military hospital. CT scans of each patient were retrospectively and independently assessed by two radiologists for the presence of abnormalities, laterality and zonal predominance of the parenchymal abnormalities, and dominant imaging patterns and their anatomic distributions. Results CT findings included consolidation (n = 92), ground-glass opacity (GGO; n = 82), septal thickening (n = 34), nodules (n = 46), bronchial wall thickening (n = 32), pleural effusion (n = 16), and lymphadenopathy (n = 3). Eighty-four patients (81%) exhibited unilateral parenchymal abnormalities and 57 (57%) exhibited lower lung zone abnormalities. The most frequently dominant CT pattern was consolidation with surrounding GGO (n = 50), with subpleural (70%) and peribronchovascular (94%) distributions. Consolidation-the second-most common pattern (n = 33)-also exhibited subpleural (79%) and peribronchovascular (97%) distributions. The dominant nodule pattern (n = 14) exhibited mixed (64%) and peribronchovascular (100%) distributions. A dominant GGO pattern was only observed in four patients; none had central distribution. Conclusion Although the manifestations of adenovirus pneumonia on CT are varied, we found the most frequent pattern was consolidation with or without surrounding GGO, with subpleural and peribronchovascular distributions. Parenchymal abnormalities were predominantly unilateral and located in the lower lung zone. If dominant consolidation findings are present in immunocompetent patients during the early stages, adenovirus pneumonia should be considered.

CT correlation with outcomes in 15 patients with acute Middle East respiratory syndrome coronavirus

OBJECTIVE

The purpose of this article is to retrospectively analyze chest CT findings for 15 patients with Middle East respiratory syndrome coronavirus and to identify features associated with survival.

MATERIALS AND METHODS

Patients were assigned to group 1 if they died (n=9) and to group 2 if they made a full recovery (n=6). Two reviewers scored chest radiographs and CT examinations for segmental involvement, ground-glass opacities, consolidation, and interstitial thickening.

RESULTS

Eight patients had ground-glass opacity (53%), five had ground-glass and consolidation in combination (33%), five had pleural effusion (33%), and four patients had interlobular thickening (27%). Of 281 CT findings, 151 (54%) were peripheral, 68 (24%) were central, and 62 (22%) had a mixed location. The number of involved lung segments was higher in group 1. The lower lobe was more commonly involved (mean, 12.2 segments) than in the upper and middle lobes combined (mean, 6.3 segments). The mean number of lung segments involved was 12.3 segments in group 1 and 3.4 segments in group 2. The CT lung score (mean±SD, 15.78±7.9 vs 7.3±5.7, p=0.003), chest radiographic score (20.8±1.7 vs 5.6±5.4; p=0.001), and mechanical ventilation duration (13.11±8.3 vs 0.5±1.2 days; p=0.002) were higher in group 1. All nine group 1 patients and three of six group 2 patients had pleural effusion (p=0.52).

CONCLUSION

CT of patients with Middle East respiratory syndrome coronavirus predominantly showed ground-glass opacities, with peripheral lower lobe preference. Pleural effusion and higher CT lung and chest radiographic scores correlate with poor prognosis and short-term mortality.

AAV2/8-hSMAD3 gene delivery attenuates aortic atherogenesis, enhances Th2 response without fibrosis, in LDLR-KO mice on high cholesterol diet

Background

Inflammation is a key etiologic component in atherogenesis and transforming growth factor beta 1 (TGFβ1) is a well known anti-inflammatory cytokine which potentially might be used to limit it. Yet TGFβ1 is pleiomorphic, causing fibrosis, cell taxis, and under certain circumstances, can even worsen inflammation. SMAD3 is an important member of TGFβ1′s signal transduction pathway, but is a fully intracellular protein.

Objectives

With the hope of attenuating TGFβ1′s adverse systemic effects (eg. fibrosis) and accentuating its anti-inflammatory activity, we proposed the use of human (h)SMAD3 as an intracellular substitute for TGFβ1.

Study design

To test this hypothesis adeno-associated virus type 2/8 (AAV)/hSMAD3 or AAV/Neo (control) was tail vein injected into the low density lipoprotein receptor knockout (LDLR-KO) mice, then placed on a high-cholesterol diet (HCD).

Results

The hSMAD3 delivery was associated with significantly lower atherogenesis as measured by larger aortic cross sectional area, thinner aortic wall thickness, and lower aortic systolic blood velocity compared with Neo gene-treated controls. HSMAD3 delivery also resulted in fewer aortic macrophages by immunohistochemistry for CD68 and ITGAM, and quantitative reverse transcriptase polymerase chain reaction analysis of EMR and ITGAM. Overall, aortic cytokine expression showed an enhancement of Th2 response (higher IL-4 and IL-10); while Th1 response (IL-12) was lower with hSMAD3 delivery. While TGFβ1 is often associated with increased fibrosis, AAV/hSMAD3 delivery exhibited no increase of collagen 1A2 or significantly lower 2A1 expression in the aorta compared with Neo-delivery. Connective tissue growth factor (CTGF), a mediator of TGFβ1/SMAD3-induced fibrosis, was unchanged in hSMAD3-delivered aortas. In the liver, all three of these genes were down-regulated by hSMAD3 gene delivery.

Conclusion

These data strongly suggest that AAV/hSMAD3 delivery gave anti-atherosclerosis therapeutic effect without the expected undesirable effect of TGFβ1-associated fibrosis.

Waterborne adenovirus

Adenoviruses are associated with numerous disease outbreaks, particularly those involving d-cares, schools, children's camps, hospitals and other health care centers, and military settings. In addition, adenoviruses have been responsible for many recreational water outbreaks, including a great number of swimming pool outbreaks than any other waterborne virus (Gerba and Enriquez 1997). Two drinking water outbreaks have been documented for adenovirus (Divizia et al. 2004; Kukkula et al. 1997) but none for food. Of the 51 known adenovirus serotypes, one third are associated with human disease, while other infections are asymptomatic. Human disease associated with adenovirus infections include gastroenteritis, respiratory infections, eye infections, acute hemorrhagic cystitis, and meningoencephalitis (Table 2). Children and the immunocompromised are more severely impacted by adenovirus infections. Subsequently, adenovirus is included in the EPA's Drinking Water Contaminant Candidate List (CCL), which is a list of unregulated contaminants found in public water systems that may pose a risk to public health (National Research Council 1999). Adenoviruses have been detected in various waters worldwide including wastewater, river water, oceans, and swimming pools (Hurst et al. 1988; Irving and Smith 1981; Pina et al. 1998). Adenoviruses typically outnumber the enteroviruses, when both are detected in surface waters. Chapron et al. (2000) found that 38% of 29 surface water samples were positive for infectious Ad40 and Ad41. Data are lacking regarding the occurrence of adenovirus in water in the US, particularly for groundwater and drinking water. Studies have shown, however, that adenoviruses survive longer in water than enteroviruses and hepatitis A virus (Enriquez et al. 1995), which may be due to their double-stranded DNA. Risk assessments have been conducted on waterborne adenovirus (Crabtree et al. 1997; van Heerden et al. 2005c). Using dose-response data for inhalation from Couch et al. (1966), human health risks of infection, illness and death have been determined for various adenovirus exposures. Crabtree et al. (1997) conclude that, even at an adenovirus concentration of 1 per 1,000 L of drinking water, annual risks of infection exceed the suggested risk recommendation of 1 x 10(-4) per yr (Regli et al. 1991) (Table 8). Using the same exposure and dose-response assumptions, van Heerden et al. (2005c) determined annual risks of infection to be 1-1.7 x 10(-1) for two drinking water samples from South Africa containing 1.40 and 2.45 adenoviruses per 10,000 L, respectively. This present study estimated annual risks of infection associated with varying levels of adenoviruses per 100 L (Table 9). By assuming a 2 L/d exposure and utilizing the exponential model at r = 0.4172 (Haas et al. 1993), yearly risks exceed the risk recommendation of 1 x 10(-4) at every exposure level. There are limited data regarding the removal of adenoviruses by conventional water treatment or other physical-chemical treatment processes, but studies do suggest that adenoviruses are of equal or greater sensitivity to oxidizing disinfectants, when compared to waterborne viruses (the most resistant to ultraviolet light). Data suggest that the chlorine doses applied to control other waterborne viruses are more effective against adenovirus, resulting in a greater than 4-log10 removal of adenoviruses by conventional treatment and chlorination. If treatment can achieve a 4-log10 removal of adenoviruses, then, based on the risk levels presented in Table 9, surface water concentrations should not exceed 0.5 adenoviruses per 100 L (Fig. 2). More data are needed regarding effectiveness of water treatment against adenovirus and the human-virus dose-response relationship to fully understand the role of adenovirus as a waterborne public health threat.

Viral pneumonias in adults: radiologic and pathologic findings

Numerous viruses, including influenza virus, measles virus, Hantavirus, adenovirus, herpesviruses, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus, can cause lower respiratory tract infection in adults. Viral pneumonia in adults can be classified into two clinical groups: so-called atypical pneumonia in otherwise healthy hosts and viral pneumonia in immunocompromised hosts. Influenza virus types A and B cause most cases of viral pneumonia in immunocompetent adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus, herpesviruses, measles virus, and adenovirus. The radiographic findings, which consist mainly of patchy or diffuse ground-glass opacity with or without consolidation and reticular areas of increased opacity, are variable and overlapping. Computed tomographic findings, which are also overlapping, consist of poorly defined centrilobular nodules, ground-glass attenuation with a lobular distribution, segmental consolidation, or diffuse ground-glass attenuation with thickened interlobular septa. The radiologic findings reflect the variable extents of the histopathologic features: diffuse alveolar damage (intraalveolar edema, fibrin, and variable cellular infiltrates with a hyaline membrane), intraalveolar hemorrhage, and interstitial (intrapulmonary or airway) inflammatory cell infiltration. Clinical information such as patient age, immune status, community outbreaks, symptom onset and duration, and presence of a rash remain important aids in diagnosis of viral causes.

Infection of TT virus in patients with idiopathic pulmonary fibrosis

The precipitating factors of idiopathic pulmonary fibrosis (IPF) have not been elucidated. Recently, a novel DNA virus named TTvirus (TTV) was discovered in a patient with post-transfusion hepatitis of unknown aetiology TTV is a circular, single-stranded DNA virus of 3.8 kB. To evaluate the relationship between TTV and IPF, the sera of 33 patients with IPF were tested for the presence of TTV DNA by semi-nested polymerase chain reaction. TTV DNA was detected in 12 (36.4%) IPF patients. The serum lactate dehydrogenase (LDH) level was significantly higher in the IPF patients withTTV than in those without TTV (802 +/- 121 vs. 530 +/- 49 IU l(-1), p < 0.05). Six (50%) of 12 patients in theTTV DNA-positive group died during the observation period, while only six (28.6%) of 21 patients in theTTV DNA-negative group died. The 3-year-survival rate was significantly lower in the TTV DNA-positive group than in theTTV DNA-negative group (58-3% vs. 95.2%, P <0-02). Replicative intermediate forms of TTV DNA were detected in the lung specimen from a TTV-infected IPF patient. TTV infection influences the disease activityand prognosis of IPF in some cases. Further studies are required to elucidate the clinical significance of TTV in IPF.

Analysis of bronchoalveolar lavage fluid in patients with chronic hepatitis C before and after treatment with interferon alpha

BACKGROUND

Previous studies have shown that patients with idiopathic pulmonary fibrosis (IPF) were more likely to be seropositive for hepatitis C virus (HCV) than normal controls, and that patients with chronic hepatitis C treated with interferon alpha (IFN-alpha) sometimes developed pulmonary fibrosis. The possibility that HCV infection and/or treatment with IFN-alpha are involved in the pathogenesis of pulmonary fibrosis or alveolitis was investigated.

METHODS

A prospective non-randomised study was performed in 13 healthy controls and in patients with chronic hepatitis C before (n = 13) and after (n = 10) treatment with IFN-alpha. Bronchoalveolar lavage (BAL) fluid cell counts, ratios and T cell subsets, and the concentrations of interleukin (IL)-1 beta, tumour necrosis factor(TNF)-alpha, and hepatocyte growth factor (HGF) were measured.

RESULTS

Lymphocyte counts in the BAL fluid were significantly increased in both groups of patients (median (range) values: before treatment, 36.8 (1.5-226.0); after treatment, 16.2 (4.5-97.6)) compared with the normal controls (3.3 (0.5-32.3)). In the pretreatment group the activated T cell (HLA-Dr positive) count was also increased (51 (40-74)) compared with that in the normal controls (27 (4-52)), but after treatment it was decreased (40 (0-76)) compared with the pretreatment count. Administration of IFN-alpha did not affect these parameters. IL-1 beta, TNF-alpha, and HGF were not detected.

CONCLUSIONS

These findings suggest that HCV infection is associated with increased counts of lymphocytes and neutrophils in BAL fluid and that treatment with IFN-alpha appears to alter lymphocyte surface markers.

Idiopathic pulmonary fibrosis and high prevalence of serum antibodies to hepatitis C virus

The prevalence of serum antibodies to hepatitis C virus (HCV) was assessed by an enzyme-linked immunosorbent assay (ELISA) in 66 patients (46 male and 20 female; mean age +/- SEM, 61.5 +/- 10.1 yr) with idiopathic pulmonary fibrosis (IPF). Nineteen (28.8%) were positive for this test. The frequency of HCV positiveness was significantly higher in the patients with IPF than in the 9,464 control subjects, whose ages were comparable with those of the patients (3.66%, p less than 0.05). Importantly, 12 of the 19 patients with IPF and positive ELISA results (63.2%) had positive results on the Chiron recombinant immunoblotting assay (RIBA), which is known to be more specific for HCV. We judged the 12 perceptible reactions as eight reactive and four indeterminate. When we examined liver function retrospectively, only two of eight patients who tested positive for the HCV had liver dysfunction, suggesting that anti-HCV positivity in IPF was not observed as a result of liver disease. These results lead us to speculate that HCV infection may play an important role in the pathogenesis of IPF, or that the sera of patients with IPF may contain some antibody against an unknown epitope and cross-react with the anti-HCV assay.

Diffuse pulmonary infiltrates in immunosuppressed patients. Prospective study of 80 cases

Over a two year period, we studied prospectively 80 cases of diffuse pneumonia at Memorial Sloan-Kettering Cancer Center. In 72 per cent of these, the patient had leukemia or lymphoma. Diagnostic procedures consisted of extensive serologic testing for antibody to known respiratory pathogens, including the agent of Legionnaire's disease, and culturing of biopsy specimens for bacteria, viruses, mycoplasmas and fungi. Of 44 cases in which open lung biopsy was performed, a specific cause was found in 61.4 per cent: Pneumocystis carinii in 38.6 per cent, other infections in 9.1 per cent and tumor involvement in 13.7 per cent. There were nonspecific pulmonary changes in 38.6 per cent. Of the 56 cases in which biopsy, autopsy or both were performed, a specific diagnosis was made in 69.7 per cent: P. carinii infection in 37.5 per cent and other infections in 12.5 per cent. In cases in which neither biopsy nor autopsy was performed, a specific infection was diagnosed in 33 per cent; no specific diagnosis was made in the remainder. One patient in the entire group had a significant antibody titer for Legionnaire's disease. Although diagnostic in some cases, extensive serologic testing proved relatively unfruitful. Pneumocystosis was the most frequent diagnosis in this study. The cause of some cases remained obscure, even after lung biopsy.