Acute lung disease in the immunocompromised host. Diagnostic accuracy of the chest radiograph

Chest X-ray Features of HIV-Associated Pneumocystis Pneumonia (PCP) in Adults: A Systematic Review and Meta-analysis

Background

The performance of chest x-ray (CXR) features for Pneumocystis pneumonia (PCP) diagnosis has been evaluated in small studies. We conducted a systematic review and meta-analysis to describe CXR changes in adults with HIV-associated laboratory-confirmed PCP, comparing these with non-PCP respiratory disease.

Methods

We searched databases for studies reporting CXR changes in people >15 years old with HIV and laboratory-confirmed PCP and those with non-PCP respiratory disease. CXR features were grouped using consensus terms. Proportions were pooled and odds ratios (ORs) generated using random-effects meta-analysis, with subgroup analyses by CD4 count, study period, radiology review method, and study region.

Results

Fifty-one studies (with 1821 PCP and 1052 non-PCP cases) were included. Interstitial infiltrate (59%; 95% CI, 52%-66%; 36 studies, n = 1380; I2 = 85%) and ground-glass opacification (48%; 95% CI, 15%-83%; 4 studies, n = 57; I2 = 86%) were common in PCP. Cystic lesions, central lymphadenopathy, and pneumothorax were infrequent. Pleural effusion was rare in PCP (0%; 95% CI, 0%-2%). Interstitial infiltrate (OR, 2.3; 95% CI, 1.4-3.9; I2 = 60%), interstitial-alveolar infiltrate (OR, 10.2; 95% CI, 3.2-32.4; I2 = 0%), and diffuse CXR changes (OR, 7.3; 95% CI, 2.7-20.2; I2 = 87%) were associated with PCP diagnosis. There was loss of association with alveolar infiltrate in African studies.

Conclusions

Diffuse CXR changes and interstitial-alveolar infiltrates indicate a higher likelihood of PCP. Pleural effusion, lymphadenopathy, and focal alveolar infiltrates suggest alternative causes. These findings could be incorporated into clinical algorithms to improve diagnosis of HIV-associated PCP.

Drug-Induced Interstitial Lung Disease: A Systematic Review

Background: Drug-induced interstitial lung disease (DIILD) occurs as a result of numerous agents, but the risk often only becomes apparent after the marketing authorisation of such agents. Methods: In this PRISMA-compliant systematic review, we aimed to evaluate and synthesise the current literature on DIILD. Results: Following a quality assessment, 156 full-text papers describing more than 6000 DIILD cases were included in the review. However, the majority of the papers were of low or very low quality in relation to the review question (78%). Thus, it was not possible to perform a meta-analysis, and descriptive review was undertaken instead. DIILD incidence rates varied between 4.1 and 12.4 cases/million/year. DIILD accounted for 3–5% of prevalent ILD cases. Cancer drugs, followed by rheumatology drugs, amiodarone and antibiotics, were the most common causes of DIILD. The radiopathological phenotype of DIILD varied between and within agents, and no typical radiological pattern specific to DIILD was identified. Mortality rates of over 50% were reported in some studies. Severity at presentation was the most reliable predictor of mortality. Glucocorticoids (GCs) were commonly used to treat DIILD, but no prospective studies examined their effect on outcome. Conclusions: Overall high-quality evidence in DIILD is lacking, and the current review will inform larger prospective studies to investigate the diagnosis and management of DIILD.

Management and diagnosis of tuberculosis in solid organ transplant candidates and recipients: Expert survey and updated review. J Clin Tuberc Other Mycobact Dis 2018;11:37-46. [PMID: 31720390 PMCID: PMC6830179 DOI: 10.1016/j.jctube.2018.04.001]

Background : Optimal screening and management of latent tuberculosis infection (LTBI) and active tuberculosis (TB) in solid organ transplant (SOT) candidates and recipients is necessary to prevent morbidity and mortality. Methods : We conducted a cross-sectional survey of TB and transplant experts across the United States reviewing the clinical practice preferences on key management issues related to LTBI and TB in SOT candidates and recipients. Results : Thirty TB and 13 SOT experts were surveyed (response rate = 53.8%). Both groups agreed that tuberculin skin test (TST) and chest x-ray screening in SOT candidates was useful (78.6% and 84.6%, respectively). TST after SOT was not useful for most transplant experts and TB experts (0% vs. 32.1%, respectively), but both groups were split on usefulness of interferon gamma release assays (IGRA) in SOT recipients (42.9% TB experts vs. 46.2% SOT experts). Most experts recommend LTBI treatment prior to SOT if close monitoring is assured (82.1% TB experts vs. 76.9% transplant experts). LTBI treatment with isoniazid was preferred for patients on calcineurin inhibitors. Evaluation for suspected TB in SOT recipients varied, but most TB experts favored sputum testing (88.9%) whereas most transplant experts favored bronchoscopic testing (69.2%). Preferred TB treatment regimens in SOT recipients were similar to regimens recommended for immunocompetent patients. Conclusions : Most TB and transplant experts recommend evaluation and treatment for LTBI in SOT candidates. Liver transplant candidates, however, should only be treated if close monitoring can be assured and after consulting with a hepatologist. Practice preferences varied regarding the initial diagnostic approach for suspected TB in SOT recipients; however, most experts agreed that SOT recipients should receive similar treatments as immunocompetent patients.

Viral Pneumonia in Patients with Hematologic Malignancy or Hematopoietic Stem Cell Transplantation

Viral pneumonias in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation cause significant morbidity and mortality. Advances in diagnostic techniques have enabled rapid identification of respiratory viral pathogens from upper and lower respiratory tract samples. Lymphopenia, myeloablative and T-cell depleting chemotherapy, graft-versus-host disease, and other factors increase the risk of developing life-threatening viral pneumonia. Chest imaging is often nonspecific but may aid in diagnoses. Bronchoscopy with bronchoalveolar lavage is recommended in those at high risk for viral pneumonia who have new infiltrates on chest imaging.

Benefit of CT scanning for assessing pulmonary disease in the immunodepressed patient

INTRODUCTION

Management of pulmonary disease in immunodepressed patients requires a clear diagnostic and therapeutic strategy and multidisciplinary cooperation.

DISCUSSION

The diagnostic approach should take into account the type of immunodepression, the clinical picture, the radiological signs and symptoms, and the microbiological, cytological and even histological examination of the pulmonary or extrapulmonary specimens. The high-resolution CT scan plays a central role and makes it possible to prioritize the diagnostic possibilities.

CONCLUSION

The analysis of the literature shows three important points: the chest X-ray has low diagnostic value; the CT scan of the chest can reveal lesions that cannot be detected on a standard chest X-ray; the CT scan is helpful for early detection and monitoring of invasive pulmonary aspergillosis.

Pulmonary complications in the non-HIV immunocompromised patient

The incidence of non-HIV immunocompromised patients is increasing. This is primarily due to improved immunosuppressive regimes for autoimmune diseases and also increases in stem cell transplantation. Pulmonary complications are a major cause of morbidity and mortality in these patients. Imaging is frequently used to assess these complications and to streamline therapies, as microbiological and/or pathological diagnosis can often be difficult, invasive, or protracted. This review provides the reader with a structured approach to interpret the imaging findings and differentiate between different infective and non-infective complications in these patients.

Comparison of initial high resolution computed tomography features in viral pneumonia between metapneumovirus infection and severe acute respiratory syndrome

OBJECTIVE

To review and compare initial high resolution computed tomography (HRCT) findings in patients with metapneumovirus pneumonia and severe acute respiratory syndrome (SARS-Coronovirus).

MATERIALS AND METHODS

4 cases of metapneumovirus pneumonia (mean age of 52.3 years) in an institutional outbreak (Castle Peak Hospital) in 2008 and 38 cases of SARS-coronovirus (mean age of 39.6 years) admitted to Tuen Mun hospital during an epidemic outbreak in 2003 were included. HRCT findings of the lungs for all patients were retrospectively reviewed by two independent radiologists.

RESULTS

In the metapneumovirus group, common HRCT features were ground glass opacities (100%), consolidation (100%), parenchymal band (100%), bronchiectasis (75%). Crazy paving pattern was absent. They were predominantly subpleural and basal in location and bilateral involvement was observed in 50% of patients. In the SARS group, common HRCT features were ground glass opacities (92.1%), interlobular septal thickening (86.8%), crazy paving pattern (73.7%) and consolidation (68%). Bronchiectasis was not seen. Majority of patient demonstrated segmental or lobar in distribution and bilateral involvement was observed in 44.7% of patients. Pleural effusion and lymphadenopathy were of consistent rare features in both groups.

CONCLUSION

Ground glass opacities, interlobular septal thickening and consolidations were consistent HRCT manifestations in both metapneumovirus infection and SARS. The presence of bronchiectasis (0% in SARS) may point towards metapneumovirus while crazy paving pattern is more suggestive of SARS.

Impact of clinical data on chest radiography sensitivity in detecting pulmonary abnormalities in immunocompromised patients with suspected pneumonia

PURPOSE

Chest radiography (CXR) of immunocompromised patients has low sensitivity in the early evaluation of pulmonary abnormalities suspected to be infectious. The purpose of the study was to evaluate whether the knowledge of clinical data improves the diagnostic sensitivity of CXR in the particular setting of immunocompromised patients after hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

Sixty-four CXRs of immunocompromised patients with clinically suspected pneumonia were retrospectively and independently evaluated by two radiologists to assess the presence of radiological signs of pneumonia, before (first reading) and after (second reading) the knowledge of clinical data. A chest computed tomography (CT) performed within 3 days was assumed as the standard of reference. For each reading, sensitivity of both radiologists was calculated.

RESULTS

Readers showed a sensitivity of 39% and 58.5% for the first reading, and 43.9% and 41.5% for the second reading, respectively. For both readers, these values were not significantly different from those obtained at first reading (McNemar's test, p>0.05). Interobserver agreement at second reading was fair (Cohen test, k=0.33).

CONCLUSIONS

The sensitivity of CXR is too low to consider it a stand-alone technique for the evaluation of immunocompromised patients after HSCT with suspected pneumonia, even if the radiologist knows detailed clinical data. For these patients, an early chest CT evaluation is therefore recommended.

[Pneumonias and immunosuppression]

Pneumonias are common, life threatening complications in immunodeficient patients. A rapid, targeted diagnosis and therapy are decisive for the course of the disease. The etiological spectrum is substantially broader than for immunocompetent patients. Important indications are provided by the type and intensity of the immunosuppression, gaps in the prophylactic concept and particular exposures. For diagnostic planning, high resolution computed tomogram of the thorax is necessary. The standard method for isolating the pathogen is flexible bronchoscopy with bronchoalveolar lavage. Indications for invasive bioptic measures depend on the individual situation, the expected spectrum of pathogens as well as risk factors and adverse effects. Non-invasive antigen and PCR tests complement the diagnostic spectrum, especially for difficult to cultivate pathogens such as fungi and Herpes viruses. The selection of the initial, targeted antimicrobial therapy is based on guidelines. The treatment should be followed after obtaining the relevant microbiological data.

Thin-Section CT Findings in Hematopoietic Stem Cell Transplantation Recipients with Respiratory Virus Pneumonia

OBJECTIVE

The purpose of this study was to use serial thin-section CT scans to assess the incidence of respiratory viral infection and lung abnormalities in a large patient population at high risk of pulmonary complications.

MATERIALS AND METHODS

The study population consisted of 26 recipients of hematopoietic stem cell transplants who had proven respiratory viral pneumonia. In all cases, thin-section CT scans were obtained before fiberoptic bronchoscopy and bronchoalveolar lavage. The study included only patients in whom bronchoalveolar lavage fluid showed no evidence of organisms other than respiratory viruses. The CT scans were assessed for the presence, extent, and anatomic distribution of ground-glass attenuation, air-space consolidation, nodules, centrilobular branching structures (tree-in-bud), thickening of the bronchovascular bundles, and pleural effusion.

RESULTS

Areas of ground-glass attenuation were identified in 24 (92%) of 26 patients and were the only finding in eight patients. Multiple nodules, seen in 17 (65%) of 26 patients, measured 3-10 mm in diameter or were larger than 10 mm. The nodules had a centrilobular or random distribution. A tree-in-bud appearance was seen in six of the patients with centrilobular nodules. This pattern had a bilateral distribution and involved mainly the lower lung zones. CT revealed thickening of the bronchovascular bundles in 16 (61%) of the patients. Thickening was bilateral in 14 and unilateral in two patients. Bronchial wall thickening involved the lower lobes in six patients and had a patchy random distribution in the remaining nine patients. Air-space consolidation was present in nine (35%) of the cases. It had a lobular or subsegmental distribution in eight of the patients and a segmental distribution in one patient. Areas of consolidation were randomly distributed throughout the lungs in all cases. Less common findings included bilateral pleural effusion and bronchial dilatation.

CONCLUSION

Respiratory viral infection is common among adult recipients of hematopoietic stem cell transplants, occurring over a wide time span after transplantation. The presence of respiratory viral infection must be considered in any patient with new respiratory symptoms, fever, or findings at CT such as extensive or patchy areas of ground-glass opacities or a mixture of patterns, most commonly ground-glass attenuation, thickening of the bronchial walls, and multiple small nodules.

Infectious pulmonary complications after stem cell transplantation or chemotherapy: diagnostic yield of bronchoalveolar lavage

Hematologic patients are at high risk for infectious pulmonary complications after stem cell transplantation (SCT) or chemotherapy. The aim of this study was to detect the range of pulmonary pathogens in these patients, analyzing 95 bronchoalveolar lavage (BAL) samples with classic and molecular (polymerase chain reaction [PCR]) detection methods. Human cytomegalovirus (HCMV) was detected in 33, herpes simplex virus in 21, human herpesvirus 6 in 24, and other viruses in 16 samples. Aspergillus species were detected in 19, Candida species in 25, and Gram-positive bacteria in 29 samples. The additional use of PCR detection methods increased the diagnostic yield from 56% to 73%, especially concerning viral and fungal infections in BAL samples. No infectious agent was detected in 26 samples. Interestingly, a high incidence of polymicrobial infections (50/95) was detected, dominated by HCMV co-infections, especially after allogeneic SCT. Within 3 years of follow-up, a poor outcome of co-infections of Aspergillus species with HCMV in 9 of 10 cases could be documented, whereas only 7 of 20 patients died with noninfectious BAL results. Herpesviruses, fungi, and Gram-positive bacteria were detected most frequently, and in 53%, polymicrobial infections were diagnosed.

High-resolution computed tomography (HRCT) of lung infections in non-AIDS immunocompromised patients

Non-AIDS immunocompromised patients are susceptible to infections by a wide range of organisms. In the past several decades, advances in the treatment of cancer, organ transplantation, and immunosuppressive therapy have resulted in large numbers of patients who develop abnormalities in their immune system. Moreover, mildly impaired host immunity as it occurs in chronic debilitating illness, diabetes mellitus, malnutrition, alcoholism, advanced age, prolonged corticosteroid administration, and chronic obstructive lung disease have also been regarded as predisposing factors of pulmonary infections. Imaging plays a crucial role in the detection and management of patients with pulmonary infectious diseases. When pulmonary infection is suspected, knowledge of the varied radiographic manifestations will narrow the differential diagnosis, helping to direct additional diagnostic measures and serving as an ideal tool for follow-up examinations. Combination of pattern recognition with knowledge of the clinical setting is the best approach to pulmonary infection occurring in the immunocompromised patients.

Pneumonia in hospitalized children

Pneumonia is one of the most common infections in the pediatric age group and one of the leading diagnoses that results in overnight hospital admission for children. Various micro-organisms can cause pneumonia, and etiologies differ by age. Clinical manifestations vary, and diagnostic testing is frequently not standardized. Hospital management should emphasize timely diagnosis and prompt initiation of antimicrobial therapy when appropriate. Issues of particular relevance to inpatient management are emphasized in this article.

Pulmonary Candidiasis after Hematopoietic Stem Cell Transplantation: Thin-Section CT Findings

PURPOSE

To retrospectively evaluate thin-section computed tomographic (CT) findings in hematopoietic stem cell transplant (ie, bone marrow transplant) patients with histopathologically proved pulmonary candidiasis.

MATERIALS AND METHODS

Ethical approval was obtained from the institutional review board of each of the three institutions; informed consent was not required. The study included 17 hematopoietic stem cell transplant recipients with proved pulmonary candidiasis. Histopathologic specimens were acquired at transbronchial biopsy (n = 8), open lung biopsy (n = 6), and autopsy (n = 3). The patients included seven men and 10 women (age range, 20-62 years; mean age, 37 years). The thin-section CT scans were retrospectively reviewed by two thoracic radiologists for the presence, appearance, and distribution of parenchymal abnormalities.

RESULTS

Multiple nodules were present in 15 (88%) patients, including centrilobular nodules and tree-in-bud pattern in seven (41%) patients. Nodules were bilateral in 12 patients and unilateral in three. An associated halo of ground-glass opacity was identified in five (33%) patients. Nodules were the only CT finding in five patients (29%). Areas of air-space consolidation were identified in 11 (65%) patients. Areas of ground-glass opacity were seen in six (35%) of 17 patients and were always associated with other abnormalities. Other less common CT findings included pleural effusion (n = 3), thickening of the bronchial walls (n = 2), and cavitation (n = 1).

CONCLUSION

The most common thin-section CT findings of pulmonary candidiasis in hematopoietic stem cell transplant patients are multiple bilateral nodular opacities often associated with areas of consolidation.

Human Metapneumovirus Infection in Hematopoietic Stem Cell Transplant Recipients

PURPOSE

To review the high-resolution computed tomography (CT) findings in hematopoietic stem cell transplant (HCT) recipients who had proven human metapneumovirus (HMPV) pneumonia.

MATERIALS AND METHODS

The study included 5 HCT recipients who had proven HMPV pneumonia. The patients included 4 men and 1 woman ranging in age from 23 to 58 years (mean age = 42 years). The CT scans were assessed for the presence, appearance, size, and distribution of parenchymal abnormalities.

RESULTS

Human metapneumovirus was isolated in all 5 patients in this series. None of these patients had any other infectious organism identified in cultures or bronchoalveolar lavage. The predominant CT findings were bilateral abnormalities in all patients, consisting primarily of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities. Areas of ground-glass opacification had no zonal predominance and were bilateral, asymmetric, and patchily distributed. Multiple nodules were identified in 4 (80%) of 5 patients. Nodules were multiple; less than 5 nodules were identified in 1 case, and 5 to 10 nodules were identified in 3 cases. All nodules in all cases were less than 10 mm in diameter. Areas of air-space consolidation were identified in 2 (40%) patients. All patients were available for follow-up; lesions improved in 4 patients.

CONCLUSION

The thin-section CT manifestations of HMPV pneumonia usually consist of a mixture of patterns, including, most commonly, ground-glass attenuation and nodular opacities.

Drug-induced and iatrogenic infiltrative lung disease

At present more than 350 drugs are known to cause injury of the lung parenchyma,upper and lower airways, pulmonary circulation, pleura, mediastinum, lymph nodes,and neuromuscular system. Infiltrative lung disease (ILD) is the most common pattern of drug-induced injury. This article, which is clinically oriented rather than drug oriented, reviews the patterns of ILD produced by therapeutic drugs and radiation therapy.

Thin-Section CT Findings in 32 Immunocompromised Patients with Cytomegalovirus Pneumonia Who Do Not Have AIDS

OBJECTIVE

The aim of this study was to review the thin-section CT findings in 32 immunocompromised patients without AIDS who had proven Cytomegalovirus pneumonia.

MATERIALS AND METHODS

The causes of immunocompromise included bone marrow (n = 25) or solid organ transplantation (n = 5) and corticosteroid therapy (n = 2). The patients included 16 men and 16 women ranging in age from 22 to 70 years (mean age, 43 years). The CT scans were retrospectively reviewed by two thoracic radiologists for the presence, appearance, and distribution of parenchymal abnormalities.

RESULTS

Bilateral abnormalities were seen in all patients. Areas of ground-glass opacification were seen in 21 (66%) of 32 patients. Ground-glass opacification was the predominant CT feature in nine cases (28%). In 19 of 32 patients, ground-glass attenuation was associated with other abnormalities. Multiple nodules were identified in 19 patients (59%). Nodules were bilateral in 15 patients and unilateral in four patients. Nodules were the only CT finding in three patients (9%). Areas of air-space consolidation were identified in 19 patients (59%). Air-space consolidation was the only CT finding in one patient (3%). Other less common CT findings included thickening of the bronchovascular bundles (n = 7) and the tree-in-bud appearance (n = 4). Pleural effusions were seen in seven patients.

CONCLUSION

The thin-section CT manifestations of Cytomegalovirus pulmonary infection usually consist of a mixture of patterns, most commonly ground-glass attenuation, areas of consolidation, and small nodules.

Infectious pulmonary nodules in immunocompromised patients: usefulness of computed tomography in predicting their etiology

PURPOSE

To review the high-resolution computed tomography (CT) findings in immunocompromised patients who had nodular opacities and a proven diagnosis to determine whether the various infectious pulmonary nodules have distinguishing features on CT.

MATERIALS AND METHODS

The high-resolution CT scans obtained in 78 immunocompromised patients with solitary or multiple nodular opacities of proven infectious etiology were reviewed retrospectively by 2 independent thoracic radiologists. Patients whose predominant abnormality consisted of branching linear or nodular opacities (tree-in-bud pattern) characteristic of infectious bronchiolitis and endobronchial spread of tuberculosis were excluded. The CT scans were assessed for the presence, appearance, size, and distribution of parenchymal nodules. Relations between findings at CT and the different infectious etiologies of nodules were assessed with regression analysis. Agreement between the 2 observers was assessed using the kappa statistic.

RESULTS

The infectious causes included mycobacteria (n = 24), fungi (n = 22), bacteria (n = 20), and viruses (n = 12). Multivariate analysis demonstrated that a diameter <10 mm was the only independent predictor of etiology (P < 0.0001) and that patients whose nodules all measured less than 10 mm in diameter were most likely to have a viral infection. Nodules limited in size to less than 10 mm in diameter were seen in 83% of viral infections compared with 5% of bacterial infections (odds ratio [OR] = 95.0; 95% confidence interval (CI): 6.08-4,321.5, P < 0.0001), 0% of mycobacterial infections (OR = 91.7; 95% CI: 7.21-4,090.22, P < 0.0001), and 14% of fungal infections (OR = 31.67; 95% CI: 3.56-375.09, P = 0.0003).

CONCLUSION

Although some overlap exists, nodule size is helpful in the differential diagnosis of infectious causes of nodules in immunocompromised patients. Patients whose nodules are all less than 10 mm in diameter are most likely to have a viral infection.

Acute lung disease in the immunocompromised host

The immunocompromised host is an individual with a decreased defense mechanism or immunity. Pulmonary complications commonly seen in these patients include infections, neoplasms, drug-induced lung disease, and pulmonary hemorrhage. High-resolution CT plays an invaluable role in confirming the presence of pulmonary disease and narrowing down the differential diagnosis in this group of patients. It also is helpful as a guide to the optimal type and site of biopsy. The pattern and prevalence of disease varies considerably between the AIDS and the non-AIDS group, and therefore, these two groups are considered separately.

Evaluation of pulmonary infiltrates in critically ill patients with cancer and marrow transplant

Pulmonary infiltrates in critically ill patients with cancer or marrow transplant can be evaluated by the differential diagnosis presented at the beginning of this article. The patient's quantitative immune system dysfunction, epidemiologic history and chest radiographic findings (pattern, rapidity, and time of onset) will help focus the differential diagnosis. In this patient population, however, common diagnoses can have atypical presentations, unusual diagnoses do occur, and more than one process may be responsible for a patient's infiltrates. Early bronchoscopy to rule out infection is the focus of diagnostic testing. Surgical lung biopsy in this patient population has a low yield.

Diagnostic yield of bronchoalveolar lavage following renal transplantation

Organ transplant recipients are at high risk of infectious pulmonary complications. In this retrospective study, the diagnostic yield of bronchoalveolar lavage (BAL) was evaluated in renal transplant recipients. The results were analysed in special regard to the clinical presentation of pulmonary infections and the possible impact of new immunosuppressive agents. Over a 5-year period 91 BAL were performed in 71 renal transplant recipients. Microorganisms were isolated from 69% of BAL (63/91): bacteria 32%; cytomegalovirus (CMV) 27%; Pneumocystis carinii (PC) 22%; other viruses 9% (HSV; EBV, RSV, adenovirus, HHV8); Aspergillus fumigatus 1%. Total cell counts and neutrophil counts in BAL were significantly elevated in bacterial infection, whereas BAL positive for PC showed eosinophilia (P<0.05). There was no association between clinical symptoms and the radiological pattern of infiltrates and the type of infection. Immunosuppression containing tacrolimus or mycophenolate mofetil was associated with a significantly higher percentage of PC and CMV infections compared to cyclosporin-based immunosuppression (65% vs. 30%, P<0.005). A considerable number of PC and CMV infections occurred beyond 6 months after transplantation. In conclusion, BAL has a high diagnostic yield in renal transplant recipients. Infection with CMV and PC should also be considered beyond 6 months after transplantation, and prophylaxis for opportunistic infections should be given if the immunosuppression is intensified.

Pulmonary tuberculosis in AIDS patients: transient chest radiographic worsening after initiation of antiretroviral therapy

OBJECTIVE

Immune function and inflammatory responses often increase in AIDS patients who receive antiretroviral therapy. We evaluated the occurrence and nature of transient worsening on chest radiographs in AIDS patients with tuberculosis after initiation of antiretroviral therapy and compared these findings with chest radiographs of patients undergoing antituberculous therapy alone.

MATERIALS AND METHODS

A retrospective review of sequential chest radiographs was performed of 87 patients undergoing therapy for pulmonary tuberculosis: AIDS patients receiving antiretroviral therapy (n = 31), HIV-positive patients not receiving antiretroviral therapy (n = 26), and HIV-negative patients (n = 30). Pulmonary consolidations, thoracic lymphadenopathy, and pleural effusions were evaluated for worsening, stability, or improvement. Patients with concurrent pulmonary infections were excluded.

RESULTS

Transient worsening on radiography was observed in 14 (45%) of 31 AIDS patients receiving antiretroviral therapy, including seven patients (23%) who showed severe worsening. Of 56 patients in the other two groups, 11 (20%) showed worsening (p = 0.023), two of whom showed severe worsening (p = 0.009). Worsening was first noted between 1 and 5 weeks after initiation of antiretroviral therapy, with improvement occurring between 2 weeks and 3 months later. Four patients with severe worsening converted their tuberculin purified protein derivative responses from anergic to positive after antiretroviral treatment.

CONCLUSION

Transient worsening is frequently seen on chest radiography in AIDS patients with tuberculosis who subsequently undergo antiretroviral therapy. This phenomenon may be related to improved immune function.

Aspergillus fumigatus and aspergillosis

Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Humans and animals constantly inhale numerous conidia of this fungus. The conidia are normally eliminated in the immunocompetent host by innate immune mechanisms, and aspergilloma and allergic bronchopulmonary aspergillosis, uncommon clinical syndromes, are the only infections observed in such hosts. Thus, A. fumigatus was considered for years to be a weak pathogen. With increases in the number of immunosuppressed patients, however, there has been a dramatic increase in severe and usually fatal invasive aspergillosis, now the most common mold infection worldwide. In this review, the focus is on the biology of A. fumigatus and the diseases it causes. Included are discussions of (i) genomic and molecular characterization of the organism, (ii) clinical and laboratory methods available for the diagnosis of aspergillosis in immunocompetent and immunocompromised hosts, (iii) identification of host and fungal factors that play a role in the establishment of the fungus in vivo, and (iv) problems associated with antifungal therapy.

Pulmonary aspergillosis and invasive disease in AIDS: review of 342 cases

Aspergillosis is an infrequent but commonly fatal infection among HIV-infected individuals. We review 342 cases of pulmonary Aspergillus infection that have been reported among HIV-infected patients, with a focus on invasive disease. Invasive pulmonary aspergillosis usually occurs among patients with <50 CD4 cells/mm3. Major predisposing conditions include neutropenia and steroid treatment. Fever, cough, and dyspnea are each present in >60% of the cases. BAL is often suggestive, but biopsy specimens are necessary for definite diagnosis. Amphotericin B is the mainstay of treatment and mortality is > 80%. Avoiding neutropenia and judicious use of steroids may be helpful in prevention. Aggressive diagnostic approach, early initiation of treatment, adequate dosing of antifungals, and close follow-up may improve the currently dismal prognosis.

Aspergillus infections of the lung: radiological signs

The variety of diseases and courses that may be povoqued by fungi in the lungs is consistent with an equal multitude of radiologically-morphologically visible alterations. Only a few of these radiological signs are characteristic with regard to differential diagnosis of the infection. As long as the pathogen has not been identified, a wide range of differential diagnoses must be considered which can only be restricted by careful overall view with all clinical findings. Nevertheless, detailed analysis of the often indistinct x-ray patterns is imperative in order to contribute to evaluating the course and therapy of aspergilloses.

Pulmonary invasive aspergillosis in patients infected with the human immunodeficiency virus: report of two cases

Patients infected with the human immunodeficiency virus (HIV) have an increased frequency of invasive aspergillosis. We report two cases of invasive pulmonary aspergillosis in patients infected with HIV. Patients had less than 10 CD4 (helper cell) cells/mm3 (2/2), presented with fever (2/2), dyspnea (1/2), and abnormal chest radiograph (2/2). Diagnosis was established by transbronchial biopsy (1/2) and autopsy (1/2). Patients died in spite of treatment with intravenous deoxycholate amphotericin B. Prognosis of invasive pulmonary aspergillosis among patients infected with HIV remains dismal, even with aggressive antifungal treatment.