The continuing utility of bronchoalveolar lavage to diagnose opportunistic infection in AIDS patients

Detection of Cytokines and Collectins in Bronchoalveolar Fluid Samples of Patients Infected with Histoplasma capsulatum and Pneumocystis jirovecii

Histoplasmosis and pneumocystosis co-infections have been reported mainly in immunocompromised humans and in wild animals. The immunological response to each fungal infection has been described primarily using animal models; however, the host response to concomitant infection is unknown. The present work aimed to evaluate the pulmonary immunological response of patients with pneumonia caused either by Histoplasma capsulatum, Pneumocystis jirovecii, or their co-infection. We analyzed the pulmonary collectin and cytokine patterns of 131 bronchoalveolar lavage samples, which included HIV and non-HIV patients infected with H. capsulatum, P. jirovecii, or both fungi, as well as healthy volunteers and HIV patients without the studied fungal infections. Our results showed an increased production of the surfactant protein-A (SP-A) in non-HIV patients with H. capsulatum infection, contrasting with HIV patients (p < 0.05). Significant differences in median values of SP-A, IL-1β, TNF-α, IFN-γ, IL-18, IL-17A, IL-33, IL-13, and CXCL8 were found among all the groups studied, suggesting that these cytokines play a role in the local inflammatory processes of histoplasmosis and pneumocystosis. Interestingly, non-HIV patients with co-infection and pneumocystosis alone showed lower levels of SP-A, IL-1β, TNF-α, IFN-γ, IL-18, IL-17A, and IL-23 than histoplasmosis patients, suggesting an immunomodulatory ability of P. jirovecii over H. capsulatum response.

Evaluation of the clinical utility of reflex GMS and AFB stains on BAL specimens from lung transplant patients

INTRODUCTION

Bronchoalveolar lavage (BAL) has a useful role in the detection of infectious diseases. Grocott methenamine silver (GMS) and acid-fast bacilli (AFB) are ancillary stains that aid in the cytologic detection of fungal and mycobacterial organisms. However, the utility of these stains in conjunction with microbiological testing is unclear.

MATERIALS AND METHODS

BAL specimens from lung transplant patients between January 1, 2018, to December 31, 2018, were evaluated. Inclusion criteria included cases with both GMS and AFB stains and concurrent fungal and mycobacterial microbiology testing. The staining findings were correlated with concurrent microbiology findings, including cultures and immunofluorescent smears.

RESULTS

A total of 231 BAL specimens were identified. GMS stain was positive in 19.5% and AFB in 1.3%. Fungal microbiology was positive in 23.4% and mycobacterial microbiology in 6.1%. A total of 87.9% of cases had concordant findings between cytology stains and microbiology tests and 12.1% had discrepant findings. Notably of the discrepancies, 3.0% had positive GMS and negative fungal microbiology and 6.9% had positive fungal microbiology and negative GMS. No cases had positive AFB with negative mycobacterial microbiology whereas 4.8% had positive mycobacterial microbiology and negative AFB stain.

CONCLUSIONS

We show that staining for AFB on BAL material in lung transplant patients had limited benefit when concurrent microbiology was performed. GMS staining shows a small benefit. We recommend reflex testing for fungal organisms but not mycobacterial organisms in lung transplant patients.

A rare case of CMV pneumonia in HIV-infection

Cytomegalovirus (CMV) pneumonia is a rare opportunistic infection in the setting of HIV (Human Immunodeficiency Virus)-infection. Establishing accurate diagnosis of CMV pneumonia in HIV-infection can be challenging. Co-infections by multiple opportunistic pathogens are common and a high degree of clinical vigilance to evaluate for multiple infections, including CMV pneumonia, should be maintained. As there can be a degree of overlap in clinical and radiological features amongst different opportunistic infections affecting the lungs, definitive microbiological and cytohistologic evidences are needed. Reliance on microbiological evidence of CMV in respiratory specimens alone for the diagnosis of CMV pneumonia will lead to an over-diagnosis of the condition and unnecessary treatment.

In our case report, we describe a 53-year-old man with recently diagnosed HIV-infection who presented with non-resolving pneumonia. A diagnosis of CMV pneumonia was reached through consistent clinical, radiological, microbiological and cytologic investigations. The patient made a full clinical recovery after being started on anti-CMV treatment.

Management of Advanced HIV Disease

Great progress has been made in caring for persons with human immunodeficiency virus. However, a significant proportion of individuals still present to care with advanced disease and a low CD4 count. Careful considerations for selection of antiretroviral therapy as well as close monitoring for opportunistic infections and immune reconstitution inflammatory syndrome are vitally important in providing care for such individuals.

Histoplasma capsulatum and Pneumocystis jirovecii coinfection in hospitalized HIV and non-HIV patients from a tertiary care hospital in Mexico

BACKGROUND

Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital.

MATERIALS AND METHODS

BAL samples from 289 hospitalized patients were screened by PCR with specific markers for H. capsulatum (Hcp100) and P. jirovecii (mtLSUrRNA and mtSSUrRNA). The presence of these pathogens was confirmed by the generated sequences for each marker. The clinical and laboratory data for the patients were analyzed using statistical software.

RESULTS

The PCR findings separated three groups of patients, where the first was represented by 60 (20.8%) histoplasmosis patients, the second by 45 (15.6%) patients with pneumocystosis, and the last group by 12 (4.2%) patients with coinfection. High similarity among the generated sequences of each species was demonstrated by BLASTn and neighbor-joining algorithms. The estimated prevalence of H. capsulatum and P. jirovecii coinfection was higher in HIV patients.

Utility of bronchoalveolar lavage in the management of immunocompromised patients presenting with lung infiltrates

Background

Bronchoalveolar lavage (BAL) is utilized for diagnosing lung infiltrates in immunocompromised. There is heterogeneity in the data and reported diagnostic yields range from 26 to 69%. Therefore, selection criteria for BAL to maximize yield and minimize complications are unclear.

Objectives of this study were to determine the diagnostic yield and complication rate of BAL in immunocompromised patients presenting with lung infiltrates, and identify factors impacting these outcomes. Exploratory aims included characterization of pathogens, rate of treatment modification and mortality.

Methods

Retrospective study from January 2012 to December 2016. Patients on mechanical ventilation were excluded. Positive diagnostic yield was defined as confirmed microbiological or cytological diagnosis.

Results

A total of 217 patients were recruited (70.1% male and mean age: 51.7 ± 14.6 years). Diagnostic yield was 60.8% and complication rate 14.7%. Complications (hypoxemia and endobronchial bleeding) were all sell-limiting. Treatment modification based on BAL results was 63.3%. In 97.0% an infectious aetiology was identified. HIV infection (OR 5.304, 95% CI 1.611–17.458, p = 0.006) and severe neutropenia (OR 4.253, 95% CI 1.288–14.045, p = 0.018) were associated with positive yield. Leukemia (OR 0.317, 95% CI 0.102–0.982, p = 0.047) was associated with lower yield. No factors impacted complication rate. Overall mortality (90-day) was 17.5% and in those with hematologic malignancy, it was 28.3%.

Conclusion

BAL retains utility in diagnosis of immunocompromised patients with lung infiltrates. However, patients with hematologic malignancy have a high mortality and alternative sampling should be considered because of poor results with BAL.

Trial registration

ClinicalTrials.gov identifier NCT01374542. Registered June 16, 2011.

Concurrent Pneumocystis jirovecii and pulmonary histoplasmosis in an undiagnosed HIV patient

Concurrent Pneumocystis jirovecii (PJ) and pulmonary histoplasmosis (PHP) are rare in a single HIV individual. We present a challenging case of concomitant PJ and PHP in a young HIV individual. A 44-year-old man presented to the emergency department with progressive pulmonary symptoms. He was hypoxic with bilateral pulmonary opacities on chest radiograph. CT of the chest showed a geographical pattern of ground-glass attenuation. He started receiving intravenous antibiotics in addition to oral Bactrim for suspected PJ. He also began receiving itraconazole, given suspected PHP with recent bat-droppings exposure. HIV test was positive, though history was negative; the CD4 count was 5 cells/mm³ Later, he developed respiratory failure without clinical improvement. First bronchoalveolar lavage (BAL) failed to confirm opportunistic pathogens. Repeat BAL revealed PJ but no Histoplasma. Histoplasma antigens were positive, confirming histoplasmosis. The patient died despite aggressive treatment with intravenous Bactrim and amphotericin B.

Lesson of the month 1: Lobar pulmonary consolidation in an immunocompromised host

A 19-year-old male with a history of idiopathic panuveitis, currently taking methotrexate and infliximab, presented to our institution with 6 weeks of cough, dyspnoea and fevers. He had failed outpatient antimicrobial therapy. Computerised tomography (CT) of the chest revealed the presence of a lobar pneumonia and he was treated with broad spectrum antibiotics, which did not improve his symptoms. Bronchoalveolar lavage was performed with a transbronchial lung biopsy because of the diagnostic uncertainty of the patient's presentation. Pathology revealed non-budding yeasts, consistent with Pneumocystis Serological and urine studies were positive for both Histoplasma and Blastomyces The diagnosis of Histoplasma pneumonia was made because of the presentation being inconsistent with Pneumocystis pneumonia, and serology, urine and pathology testing being more consistent with Histoplasma The patient was treated with oral itraconazole and was doing well at follow-up 12 weeks after hospitalisation.

Life-Threatening Complications of HIV Infection

Few modern diseases have experienced as rapid and dramatic change in prognosis and treatment as HIV infection. The introduction of active antiretroviral therapy (ART) and effective prophylaxis of opportunistic infections ushered in a new era in the treatment of HIV infection and changed dramatically the natural history of this disease. The rates of admission to the intensive care unit (ICU) and intensive care mortality in patients with HIV infection have shifted repeatedly during the AIDS epidemic, influenced by attitudes of patients and providers toward utility of care. In the ART era, patients with HIV infection admitted to the ICU fall into 3 general categories: those with AIDS-related opportunistic infections, those who are experiencing complications related to ART, and those with medical problems unrelated to HIV infection. In this article, the authors provide a review of the most common life-threatening complications in patients with HIV infection.

A case report of pulmonary coinfection of Strongyloides stercoralis and Pneumocystis jiroveci

A case of pulmonary coinfection by Strongyloides stercoralis and Pneumocystis jiroveci has been detected in an AIDS patient treated in the Respiratory Intensive Care Unit of the Muñiz Hospital. At diagnosis, the patient presented cough with mucopurulent expectoration, dyspnea, fever, bilateral pulmonary infiltrates on the chest X-ray, negative bacilloscopy for acid fast bacteria and a CD4(+) T lymphocytes count of 52 cells/µL. The microbiological diagnosis was achieved by microscopic observation of the respiratory secretions obtained by bronchoalveolar lavage, while the wet mount examination revealed rhabditiform and filariform larvae of the nematode and foamy exudates, pathognomonic of the pulmonary pneumocystosis. It was the unique case of this association among about 3 000 samples performed in our laboratory in the last 10 years and diagnosed by microscopy. Other complementary stains (a rapid modification of Grocott, Kinyoun and Giemsa) were applied to the smears after the diagnosis of mycotic and parasitary infections achieved by fresh microscopy. Both physicians and microbiologists should take into account the possible coexistence of respiratory pathogens in immunocompromised patients, such as those with AIDS.

Co-infection of Mycobacterium tuberculosis and Pneumocystis jirovecii in the Iranian Patients With Human Immunodeficiency Virus

Background:

Based on the authors’ knowledge, there is no study on the co-infection of opportunistic agents such as Mycobacterium tuberculosis and Pneumocystis jirovecii in the lungs of Iranian patients with immunosuppression.

Objectives:

The current study aimed to show the rate of co-infection of M. tuberculosis and P. jirovecii in patients with Human Immunodeficiency Virus (HIV).

Patients and Methods:

Forty-five pulmonary samples were collected from 30 patients with HIV who also infected with Tuberculosis and Pneumonia. All of the patients were admitted to two university hospitals of Mycobacteriology and the Iranian HIV/AIDS research centers. DNA of P. jirovecii was detected using nested-Polymerase Chain Reaction (nested-PCR) assay.

Results:

All of the patients were male with the mean age of 32.95 ± 7.15 years. The mean of CD4 cell count was 109.25 cell/mm³. Of 30 patients with HIV, three (10%) were co-infected with M. tuberculosis and P. jirovecii. No other causes of pneumonia were found in those three patients and CD4 cell counts less than 50 cell/mm³ was reported.

Conclusions:

The results of the current study showed a high rate of co-infection of M. tuberculosis and P. jirovecii in the Iranian patients with HIV. As the immune system condition worsened, the probability of occurrence of Pneumocystis Pneumonia (PCP) increased. Therefore, more specific, most rapid and sensitive tests should be utilized for diagnosis of PCP in this group of patients.

Invasive diagnostic strategies in immunosuppressed patients with acute respiratory distress syndrome

Immunosuppression predisposes the host to development of pulmonary infections, which can lead to respiratory failure and the development of acute respiratory distress syndrome (ARDS). There are multiple mechanisms by which a host can be immunosuppressed and each is associated with specific infectious pathogens. Early invasive diagnostic modalities such as fiber-optic bronchoscopy with bronchoalveolar lavage, transbronchial biopsy, and open lung biopsy are complementary to serologic and noninvasive studies and assist in rapidly establishing an accurate diagnosis, which allows initiation of appropriate therapy and may improve outcomes with relative safety.

Opportunistic infections in HIV disease

Since the emergence of the HIV pandemic in the 1980s, there have been great advances in the treatment of HIV through potent and effective antiretroviral therapy. This has led to HIV-infected individuals presenting with fewer opportunistic infections and, subsequently, leading longer lives in better health. Nevertheless, there are HIV-positive people in both high- and low-resource settings who may present late with marked immunodeficiency or have no access to adequate medical care and antiretroviral therapy. Within these populations, opportunistic infections rate still remain unacceptably high. This article outlines the variety of opportunistic infections that can be seen in clinical practice, and highlights the way in which these infections can be pre-empted, diagnosed and treated according to best practice guidelines.

Evaluation of sensitivity of multiplex PCR for Detection of Mycobacterium tuberculosis and Pneumocystis jirovecii in clinical samples

A multiplex PCR assay for the simultaneous detection of Mycobacterium tuberculosis and Pneumocystis jirovecii was developed using IS6110-based detection for M. tuberculosis and mitochondrial large-subunit (mtLSU) rRNA gene detection for P. jirovecii. Ninety-five pulmonary blinded samples were examined using the developed multiplex PCR assay, and the results were compared with those obtained by the single nested PCRs targeting IS6110 for M. tuberculosis and mtLSU rRNA for P. jirovecii. Of the 95 pulmonary samples tested, the multiplex nested PCR developed here could detect 36 cases of M. tuberculosis infection, 35 cases of P. jirovecii infection, and 17 cases of M. tuberculosis and P. jirovecii coinfections. The sensitivities of the multiplex nested PCR in detecting M. tuberculosis and P. jirovecii were 92.1% and 81.4%, respectively, whereas the specificities in detecting M. tuberculosis and P. jirovecii were 98.2% and 100%, respectively.

Concurrent PCP and TB pneumonia in HIV infected patients

We aimed to assess the incidence and clinical characteristics of patients with HIV infection with concurrent Pneumocystis pneumonia (PCP) and tuberculosis (TB). We carried out a retrospective record review of HIV infected patients admitted with pulmonary TB and PCP during the same hospital admission at a large county hospital in Miami, from 1995 to 2004. 2651 patients with HIV infection and possible TB or PCP were identified. There were 99 cases of PCP (81 presumptive and 18 confirmed) and 35 were new cases of TB. There were 17 patients who had a new, concurrent diagnosis of pulmonary TB and PCP. Approximately half of these patients were unaware of their HIV infections and half of them had a negative AFB in sputum. Most were men and had a CD4 count less than 100 cells/mm(3). Chest X-ray disclosed bilateral infiltrates in most of the cases. All but 2 survived the hospital admission. Thus, concurrent TB and PCP in HIV infected patients were not uncommon in this large county hospital in Miami, Florida in the studied period, but its diagnosis was challenging.

[Bronchoalveolar lavage]

Bronchoalveolar lavage (BAL) has become an established method for the diagnosis of infectious and interstitial lung diseases. Using a bronchoscope material from the peripheral airways and alveolar spaces can be obtained. When standard protocols are followed the procedure is generally well tolerated and in combination with clinical tests allows a reliable diagnosis in many cases. Certain clinical entities, e.g. alveolar proteinosis and Langerhans cell histiocytosis can be diagnosed by BAL alone without resorting to invasive diagnostic tests. In other diseases, BAL allows to narrow the range of the differential diagnosis. However, biopsies can often still not be avoided completely. A combination of both methods together with the clinical findings represents a powerful tool for diagnosis and research into the pathologic alterations in inflammatory and fibroising lung diseases.

Diagnostic accuracy of bronchoalveolar lavage samples in immunosuppressed patients with suspected pneumonia: analysis of a protocol

BACKGROUND

Fast and accurate etiologic diagnosis of pneumonia in immunocompromised patients is essential for a good outcome. Utility of bronchoalveolar lavage (BAL) samples has already been established, but studies about them are scarce and limited to few countries. We aimed to evaluate the accuracy of a diagnostic protocol, emphasizing on local epidemiology, rapidity, and yield of different techniques.

METHODS

One year prospective study of 101 consecutive immunosuppressed patients admitted with suspected pneumonia to a university hospital. They all had bronchoscopic BAL (n=109) and respiratory sampling. Conventional microbiological studies, cytomegalovirus pp65 antigenemia and transbronchial biopsy (TBB), whenever considered pertinent, were done. Results were analyzed along with other diagnostic procedures, clinical course and final outcome.

RESULTS

HIV/AIDS infection was the most frequent cause of inclusion (n=80). Infections accounted for 79 out of 122 final diagnoses (64.8%). Our protocol identified 60 infectious and 3 noninfectious pathologies (general yield: 51.6%). Sensitivity in pulmonary infections was 75.9% (IC95%: 64.8-84.6%), specificity 86.0% (72.6-93.7%), positive predictive value 89.6% (79.1-95.3%), negative predictive value 69.4% (56.2-80.1%), accuracy 79.8% (71.7-86.2%). Mycobacterium spp. (n=27), bacteria (n=19), Pneumocystis jirovecii (n=18) and other fungi (histoplasmosis: 6, aspergillosis: 5, cryptococosis: 3) were the most common infectious pathogens. Direct microscopy allowed an early definite/presumptive diagnosis in 36/49 fungal and mycobacterial infections (73.5%). Up to 30% of mycobacterial infections were missed.

CONCLUSIONS

Systematical study of BAL samples has a high diagnostic yield in our immunocompromised patients with suspected pneumonia. As economical and epidemiological conditions of regions are different, it should be tried everywhere.

Acute respiratory failure associated with cryptococcal pneumonia and disseminated cryptococcosis in an AIDS patient

A 36-year-old homosexual Mexican man was admitted to our hospital, with a 30-day history of fever and headache. Upon cerebrospinal fluid examination, the patient's white blood cell count was 1,580/L, total protein was 26 mg/dL, sugar was 17 mg/dL, and his intracranial pressure was 23 cmH2O. The patient was diagnosed with HIV (Human Immunodeficiency Virus) infection by serum Western blotting. Cryptococcus neoformans was isolated in cultures of the patient's blood and cerebrospinal fluids. Chest computerized tomography revealed diffuse reticulonodular infiltration and a ground-glass appearance in both perihilar regions, suggestive of either Pneumocystis carinii pneumonia or cryptococcal pneumonia. On the patient's 6th day in our hospital, bronchoalveolar lavage and transbronchial lung biopsy were conducted via bronchoscopy, and a pathologic examination of lung biopsy specimens revealed signs of cryptococcal pneumonia. This patient died on his 14th day in our hospital, as the result of acute respiratory failure, associated with cryptococcal pneumonia and disseminated cryptococcosis.

Fungal infections as a complication of therapy for sarcoidosis

BACKGROUND

Treatment of symptomatic sarcoidosis usually includes systemic immunosuppressive agents. These agents may render the patient more susceptible to opportunistic infections. In addition, the fungal infection may be difficult to distinguish from the underlying sarcoidosis.

AIM

To examine the presentation and management of invasive fungal infections in sarcoidosis patients.

DESIGN

Retrospective record review.

METHODS

We reviewed the notes of all sarcoidosis patients (n = 753) seen at our clinic over an 18-month period.

RESULTS

Seven patients (0.9%) with previously diagnosed sarcoidosis developed fungal infections: two each with Histoplasma capsulatum and Blastomyces dermatitidis and three others with Cryptococcus neoformans. No cases of invasive aspergillus or tuberculosis were identified. The diagnosis of fungal infection was made by bronchoscopy (four cases), open-lung biopsy (one case), bone-marrow aspirate (one case), and spinal fluid examination (one case). All patients were receiving corticosteroids at the time of worsening chest X-ray or clinical status. Four patients were also receiving methotrexate prior to infection. No patient with systemic fungal infection was receiving either infliximab or cyclophosphamide. All patients responded to anti-fungal therapy and a reduction in immunosuppression.

DISCUSSION

Fungal infections occur rarely in treated patients with sarcoidosis. Deterioration of chest X-ray, especially a localized infiltrate, warrants investigation.

[Disseminated histoplasmosis and AIDS. The role of culture medium for the bronchoscopic clinical specimens]

Fiberoptic bronchoscopy is a useful procedure in the diagnosis of histoplasmosis, when the clinical material is adequately processed. Ten cases of disseminated histoplasmosis in patients with AIDS are presented here, with a mycological evaluation in culture, Mycosel and Sabouraud's chloramphenicol agar of clinical specimens obtained through fiberoptic bronchoscopy. The yield of Mycosel culture was 60%, while in Sabouraud's chloramphenicol agar it was 20%, supporting the importance of selective medium in the isolation of Histoplasma capsulatum var capsulatum from potentially contaminated clinical specimens, as well as the importance of clinical information for the laboratory as the key for a correct diagnosis.

The diagnosis of pneumonia in renal transplant recipients using invasive and noninvasive procedures

STUDY OBJECTIVES

We used invasive and noninvasive procedures to determine the causes of pneumonia in renal transplant recipients.

SUBJECTS AND METHODS

We retrospectively surveyed 565 renal transplant recipients (transplants received March 1984 to August 2001) to find those with pneumonia. Noninvasive diagnostic methods included serologic testing, and blood and sputum cultures with stains. Invasive procedures included fiberoptic bronchoscopy and percutaneous transthoracic procedures.

RESULTS

A total of 92 patients were enrolled. Of these, 71 patients had a definite etiologic diagnosis of pneumonia. The major infectious pathogens were bacterial (n = 21) and mixed bacterial infection (n = 10), Mycobacterium tuberculosis (TB) [n = 18], and fungi (n = 8). Noninvasive and invasive procedures led to the diagnosis of pneumonia in 31.5% (n = 29) and 45.6% (n = 42) of patients, respectively. Bronchoscopy was used in 64 patients, with a diagnostic yield of 38 cases (59.3%). Patients were 3.62 times more likely to contract pneumonia within 12 months of renal transplantation than they were > or =12 months thereafter (95% confidence interval, 1.33 to 9.84). Twenty-seven of the 92 patients (29.3%) died. The pneumonia mortality rate has dropped significantly since 1996 (41.8% vs 10.8%, p = 0.002).

CONCLUSION

Both invasive and noninvasive procedures are useful in the diagnosis of pneumonia, with declining mortality, in renal transplant recipients. Bacterial and mixed bacterial infection, TB, and fungal infection are the most common pathogens; cases are most likely to occur within 1 year after renal transplantation.

Utility of testing bronchoalveolar lavage fluid for cryptococcal ribosomal DNA

Bronchoalveolar lavage (BAL) specimens from 88 patients (33 infected with human immunodeficiency virus [HIV], 45 non-HIV immunosuppressed patients and 10 immunocompetent patients with primary pulmonary disease) were analysed for the presence of Cryptococcus neoformans. Staining, culture and an antigen testing were performed, and C. neoformans ribosomal DNA (rDNA) detected using the polymerase chain reaction (PCR). C. neoformans was detected, by staining and culture, in BAL specimens from two HIV-infected patients with pulmonary cryptococcosis, and the antigen test and rDNA assay were also positive in these samples. C. neoformans rDNA was detected by PCR in a non-HIV immunocompromised patient with Pneumocystis pneumonia, whose staining, culture and antigen tests were negative. The antigen test was positive for an immunocompetent patient with sarcoidosis, while staining, culture and the PCR assay were negative. These results do not support routine testing of BAL specimens for C. neoformans rDNA.

HIV disease in primary care

During the past decade, a large number of new drugs for treating HIV and its complications have been developed. The increasingly sophisticated use of these drugs in combination has led to a marked reduction in HIV-related morbidity and mortality in countries where they are available. HIV/AIDS patients receiving treatment are now expected to live into old age. The beneficial effect of HIV treatment has resulted in an expanding population of persons living with HIV/AIDS who will need the care of an HIV specialist because of the complexity of the treatment regimens and the rapidly changing HIV/AIDS knowledge base. However, this growing and aging population will also benefit from the care of a primary care physician. The primary care generalist is in the best position to recognize and diagnose HIV infection, evaluate HIV risk in his or her patient population, and help prevent HIV infection in persons at risk. In patients known to be infected, the primary care generalist will be best able to manage hyperlipidemia, diabetes, cardiovascular disease, and other disorders of an aging population with an increased risk of these and other conditions. Patients with HIV infection frequently accumulate a large number of specialist physicians, and the unique ability of the primary care physician to monitor their care and act as a knowledgeable patient advocate is a great benefit to the patient.

Role of bronchoalveolar lavage in interstitial lung disease

Bronchoalveolar lavage remains an important research tool in understanding ILD. It is still an important part of the clinical management of patients with ILD. It is most useful in detecting unusual forms of ILD. It helps the clinician narrow down the possible causes of the interstitial pattern. It also can confirm a clinical impression of certain conditions. Although rarely diagnostic, it is often supportive. In conjunction with high-resolution CT scan, most patients with ILD can be diagnosed using relatively noninvasive methods.

Dual pulmonary infection with Mycobacterium tuberculosis and Pneumocystis carinii in patients infected with human immunodeficiency virus

During a 22-month period, we identified 39 patients with human immunodeficiency virus (HIV) infection (mean CD4(+) count, 90 cells/mm(3)) who were hospitalized with pneumonia and who had sputum and/or other specimens that tested concurrently positive for both Mycobacterium tuberculosis and Pneumocystis carinii. The most common chest x-ray abnormality was a reticulonodular pattern or bilateral infiltrates (n=26). Serum lactate dehydrogenase levels were elevated in 17 (85%) of 20 of patients tested (mean value, 2208 U/L). Mean O(2) saturation and PO(2) were 89% and 64 mm Hg, respectively. A majority (24 patients [62%]) received both antituberculous and anti-PCP therapy (17 with steroids), and 22 improved. All ten patients who received no treatment for PCP improved and were discharged from the hospital, whereas 4 (80%) of the 5 persons who received no antituberculous treatment had a poor outcome (P<.001; OR=43). Patients with HIV or acquired immune deficiency syndrome may present with both TB and PCP; of the 2, TB seems to account for the most severe features of disease.

Diagnosis of pneumonia and monitoring of infection eradication

Pneumonia can be classified as community-acquired (CAP) or hospital-acquired (nosocomial). Both are frequent infections that demand a great amount of medical resources. The diagnosis of CAP is based on clinical signs and the presence of a pulmonary infiltrate visible on chest radiograph. For practical purposes, CAP has been classified as typical, with an acute onset in which the most representative microorganism is Streptococccus pneumoniae, and atypical, with a subacute onset (Mycoplasma pneumoniae). Nevertheless, so far no studies have clearly demonstrated the utility of this classification in predicting the aetiology. Guidelines on CAP recommend associating the aetiology of CAP with comorbidity, age and severity. The microbiological diagnosis relies mainly on Gram stain and sputum culture, but this technique has disadvantages such as frequent contamination of the sample with oropharyngeal commensal flora, frequent sterile cultures associated with previous antibiotic treatment, and the fact that approximately 40% of patients are not able to expectorate. Other diagnostic techniques such as blood cultures, serological tests and fibreoptic bronchoscopy must be reserved for patients who are hospitalised, especially if they need admission to an intensive care unit. Compared with CAP, nosocomial pneumonia has major diagnostic problems due to the presence of other diseases able to mimic pneumonia and frequent bacterial colonisation of the lower respiratory tract. Most of the diagnostic techniques produce a high percentage of false-negative and false-positive results. This is especially true for ventilator-associated pneumonia. There is controversy over using a comprehensive aetiological work-up based on bronchoscopic techniques or only on quantitative culture of endotracheal aspiration. By contrast, there is consensus about the importance of the adequacy of empirical antibiotic treatment, since mortality rates are higher in patients who are inadequately treated. Once treatment of pneumonia has begun, it must be maintained for 48 to 72 hours because this is the minimum time to evaluate a clinical response. Antibacterial agents have to be adjusted according to microbiological findings. In nonresponding patients, pneumonia-related complications and the presence of multiresistant micro-organisms or non-covered pathogens must be ruled out.

Geographic clustering of Pneumocystis carinii pneumonia in patients with HIV infection

To detect whether there was geographic clustering of Pneumocystis carinii pneumonia cases among patients with human immunodeficiency virus (HIV) infection, we performed a retrospective analysis of a clinical database. The rates of pneumocystosis were analyzed by zip code zones for evidence of geographical clustering. During the study period, 118 patients at our AIDS Treatment Center had a first episode of P. carinii pneumonia. An analysis of the 24 zip code zones for which a P. carinii pneumonia rate was calculated (requiring a denominator of at least 10 known HIV- infected individuals residing in that zone) showed a trend toward geographic clustering (p = 0.07); when all 45 Cincinnati zip code zones were included in the analysis, clustering of cases was observed (p = 0. 02). By contrast, no clustering was observed for 52 HIV-infected control subjects with respiratory disease or for 960 HIV-infected patients treated at our center during the same time period. These data raise intriguing questions about exposure to exogenous sources of P. carinii and suggest the need for prospective studies.

Improvements in outcomes of acute respiratory failure for patients with human immunodeficiency virus-related Pneumocystis carinii pneumonia

In the early 1990s, hospital survival among patients with human immunodeficiency virus (HIV)-related Pneumocystis carinii pneumonia (PCP) and respiratory failure was poor, approximately 20%. We examined ICU use and outcomes for patients with acute respiratory failure from PCP from 1995 to 1997. We conducted a retrospective medical record review using a random sample of 71 hospitals in seven regions of the United States. Among 1,660 patients with confirmed or presumed PCP, 155 (9%) received mechanical ventilation for respiratory failure. Factors that predicted use of mechanical ventilation, independent of severity of illness on hospital admission, included African-American ethnicity and geographic location (p </= 0.002). Hospital survival for patients receiving mechanical ventilation was 38% (95% CI 30, 46). Controlling for severity of illness, patients who were on PCP prophylaxis prior to developing PCP were less likely to survive to hospital discharge (p </= 0.02). There were no significant differences in hospital survival regardless of whether patients had received less than or more than 5 d of PCP treatment prior to respiratory failure (39 versus 29%; p = 0.5). In conclusion, from 1995 to 1997, hospital survival after PCP requiring mechanical ventilation was approximately 40%. Physicians caring for patients with severe HIV-related PCP should be aware of the improvements in outcomes for this disease before making recommendations about withholding or withdrawing ventilatory support for respiratory failure.

Development and evaluation of a molecular viability assay for Pneumocystis carinii

Despite recent declines in incidence, Pneumocystis carinii pneumonia (PCP) remains the most commonly occurring opportunistic illness among persons with AIDS in the United States. While P. carinii DNA has been detected in patient respiratory specimens and in air samples collected from various indoor environments housing PCP patients, the viability of these organisms is unknown. For this reason, we have developed and evaluated a molecular viability assay for P. carinii. This method is based upon the detection of P. carinii mRNA by a reverse transcription-PCR that employs specific primers from a member of the heat shock protein 70 family. Under optimal assay conditions, these primers were capable of detecting as few as 100 viable trophozoites as determined by ethidium bromide staining, while no signal was obtained from 10(6) trophozoites killed by heat, desiccation, or UV radiation. This assay was also capable of distinguishing P. carinii from other common fungi present in the air. Therefore, this molecular viability assay may be useful in conjunction with standard bioaerosol collection devices and procedures for the detection of viable P. carinii collected from various indoor environments. It may also be useful in confirming the presence of viable trophozoites in respiratory specimens collected by noninvasive techniques from putatively infected individuals.

Acid-fast-positive Legionella pneumophila: a possible pitfall in the cytologic diagnosis of mycobacterial infection in pulmonary specimens

The acid-fast stain is commonly used in the rapid cytologic assessment of bronchoalveolar lavage (BAL) fluid to detect pulmonary mycobacterial infections, particularly in immunocompromised patients. The identification of acid-fast, rod-shaped organisms may be taken as presumptive evidence of such an infection, in the appropriate clinical setting. However, this determination is made less specific by the occasional acid-fast positivity of microorganisms other than mycobacteria. We report on the occurrence of a fatal pneumonia caused by acid-fast positive Legionella pneumophila detected by BAL. This is a potential pitfall in the rapid diagnosis of pulmonary mycobacterial infections.

Sterols of Pneumocystis carinii hominis organisms isolated from human lungs

The opportunistic pathogen Pneumocystis carinii causes pneumonia (P. carinii pneumonia, or PCP) in immunocompromised individuals such as AIDS patients. Rat-derived P. carinii carinii organisms have distinct sterols which are not synthesized by mammals and not found in other microbes infecting mammalian lungs. The dominant sterol present in the organism is cholesterol (which is believed to be scavenged from the host), but other sterols in P. carinii carinii have an alkyl group at C-24 of the sterol side chain (C(28) and C(29) 24-alkylsterols) and a double bond at C-7 of the nucleus. Recently, pneumocysterol (C(32)), which is essentially lanosterol with a C-24 ethylidene group, was detected in lipids extracted from a formalin-fixed human P. carinii-infected lung, and its structures were elucidated by gas-liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectrometry in conjunction with analyses of chemically synthesized authentic standards. The sterol composition of isolated P. carinii hominis organisms has yet to be reported. If P. carinii from animal models is to be used for identifying potential drug targets and for developing chemotherapeutic approaches to clear human infections, it is important to determine whether the 24-alkylsterols of organisms found in rats are also present in organisms in humans. In the present study, sterol analyses of P. carinii hominis organisms isolated from cryopreserved human P. carinii-infected lungs and from bronchoalveolar lavage fluid were performed. Several of the same distinct sterols (e.g., fungisterol and methylcholest-7-ene-3beta-ol) previously identified in P. carinii carinii were also present in organisms isolated from human specimens. Pneumocysterol was detected in only some of the samples.

Role of bronchoscopy in AIDS

The differential diagnosis of pulmonary disorders in the HIV-infected individual is broad. Clinical features and chest radiographs may point towards a diagnosis but cannot reliably establish one. It is important to know the conditions in which bronchoscopy, BAL, and TBB are likely to be diagnostic, just as it is to know when other invasive or noninvasive procedures may be more useful. Finally, the incidence of transmission of infections such as tuberculosis during bronchoscopy and cross-contamination of patients with an improperly sterilized bronchoscope, cannot be overemphasized.

The diagnosis and treatment challenges in nosocomial pneumonia

Pneumonia is the second most common type of nosocomial infection and is most prevalent in patients who are mechanically ventilated. Nosocomial pneumonia (NP) is the leading contributor to mortality in patients, accounting for approximately 50% of deaths in patients with hospital-acquired infections. Several factors place patients at risk for developing NP, including prolonged length of hospital stay and local epidemiology. Gram-positive pathogens such as Streptococcus pneumoniae and, more recently, Staphylococcus aureus, as well as atypical organisms such as Legionella spp are increasingly associated with NP. Emerging antimicrobial resistance among these organisms confounds treatment interventions. Lack of local definitive information and patient comorbidities further complicate the physician's treatment decisions. The role of invasive pulmonary diagnostic techniques remains problematic and controversial. Studies, however, have shown that early initiation of appropriate empiric therapy is essential to improving patient outcome and reducing mortality. This article will review therapeutic options and appropriate antimicrobial agents for use in the treatment of nosocomial pneumonia in the era of emerging drug resistances.

Utility of routine testing of bronchoalveolar lavage fluid for cryptococcal antigen

All cryptococcal antigen (CrAg) testing performed at our institution between 1989 and 1994 was reviewed for utility of routinely testing of bronchoalveolar lavage fluid (BAL) for this antigen. Forty-two of 1,506 BAL specimens were positive. Seventeen of these were felt to represent false positives (sensitivity, 71%; positive predictive value, 0.59). The data on CrAg in cerebrospinal fluid and serum and the fungal culture and histological results of BAL specimens did not support continued, routine testing of BALs for CrAg to diagnose cryptococcosis.

Diagnosis of lower respiratory tract infections: what we have and what would be nice

STUDY OBJECTIVES

To review the various methods used to diagnose lower respiratory tract infections.

DESIGN

Review of literature with appropriate references to various techniques proposed to diagnose pneumonia.

INTERVENTION

Compare and contrast different proposed approaches to diagnose pneumonia.

RESULTS

Bronchoscopic techniques appear more clear cut for certain nonbacterial pathogens. Their role in immunocompromised patients is more clear cut, while in the nonimmunocompromised patient, invasive diagnostic techniques probably provide a higher certainty of the final diagnosis of the patient. Recent interest has focused on nonbronchoscopic techniques for the mechanically ventilated patient. None of these techniques has been demonstrated to change clinical outcome.

CONCLUSIONS

Diagnosis of lower respiratory tract infection has to be tailored for the individual patient. Decision about which procedure to do is influenced by the patient's underlying immune status, level of illness, and response to empiric therapy.

Sequences of Pneumocystis carinii f. sp. hominis strains associated with recurrent pneumonia vary at multiple loci

The sequences of the internal transcribed spacer (ITS) of Pneumocystis carinii f. sp. hominis strains from 7 of 15 AIDS patients were found to vary during discrete episodes of P. carinii pneumonia. Changes in the ITS sequence correlated with changes in the mitochondrial large-subunit rRNA sequence. The coincidence of changes in the sequences of the ITS, which is located in the nucleus, with changes in a mitochondrial gene excludes mutation as the cause of the genetic differences between P. carinii f. sp. hominis strains isolated during different episodes of P. carinii pneumonia and supports the hypothesis that recurrent P. carinii pneumonia is caused by reinfection rather than by reactivation of latent organisms. Thus, limiting the exposure of immunocompromised patients to P. carinii f. sp. hominis should help prevent P. carinii pneumonia.

Variations in medical care for HIV-related Pneumocystis carinii pneumonia: a comparison of process and outcome at two hospitals

BACKGROUND

Institutional variation in the quality of medical care may be evaluated by examining process measures, such as use of diagnostic procedures or treatment modalities, or outcome measures, such as mortality. We undertook this study to examine variations in both process and outcome of care for patients with HIV-related Pneumocystis carinii pneumonia (PCP) at two geographically diverse, HIV-experienced, public municipal hospitals.

DESIGN

Retrospective review of hospitalized patients diagnosed as having PCP cared for at two municipal hospitals from 1988 to 1990. At hospital A, charts of all patients diagnosed as having PCP were abstracted (n=209); at hospital B, a random sample of 15% were abstracted (=136).

RESULTS

Among all hospitalized patients diagnosed as having PCP, the frequency of making a definitive diagnosis of PCP (as opposed to treating empirically) differed markedly at the two hospitals (85% in hospital A vs 26% in hospital B; p<0.001), as did the use of intensive care (18% vs 3%; p<0.001) and "do-not-resuscitate" orders (39% vs 14%; p<0.001), although the timing of starting anti-Pneumocystis medications (89% vs 88% within the first 2 hospital days) and the use of corticosteroids (21% vs 23%) were similar. Despite differences in the process of care, survival rates were similar at the two institutions (75% vs 76%; p=0.8) and remained similar when logistic regression was used to control for demographic variables and severity of illness (odds ratio for survival, hospital B vs A, 1.2 [95% confidence interval, 0.7, 2.0]). The 95% confidence intervals (0.7, 2.0), however, were consistent with a considerable (and clinically significant) disparity in survival (from 30% lower to a twofold higher odds of survival). Sample size calculations showed that a sample of 10 cases in each hospital would be required to detect the observed difference in definitive diagnosis rates (85% vs 26%), but 722 cases in each hospital would be required to detect a relevant difference in mortality.

CONCLUSIONS

The process of care for hospitalized patients with PCP in these two institutions differed considerably, but the survival rates were not significantly different, even after adjusting for confounding factors. While sample sizes available at the individual institutions were sufficient for evaluation of the process of care, they did not provide the power necessary to evaluate outcomes. Comparisons of outcomes such as mortality between individual hospitals may not have the statistical power to exclude important differences.

Use of bronchoalveolar lavage semiquantitative cultures in cystic fibrosis

To assess bronchoalveolar lavage (BAL) in adult CF patients with respiratory symptoms, we studied BAL fluid (BALF) culture results from 28 bronchoscopies in 11 patients. Patients were asked to provide sputum for culture. All but two patients were receiving antibiotics at the time of bronchoscopy, with 13 bronchoscopies done on patients who had been receiving antibiotics for more than 10 d. Gram stain of the BALF was positive in 18 cases. In all but one BALF, > 10,000 colony-forming units per milliliter (cfu/ml) BALF of one or more pathogens was identified. The final case grew Burkholderia cepacia, which was not grown in the sputum. In only six cases (21%) were the sputum and BALF culture results the same. Prior to 11 bronchoscopies, the sputum was not adequate. The remaining 11 cases either had different pathogens in the BAL (six cases), or had some but not all of the BALF pathogens in the sputum. BALF cultures changed therapy in 13 (48%) of cases. Semiquantitative culture of BALF was a useful diagnostic tool in CF in patients in whom empiric therapy failed.