Role of bronchoalveolar lavage in the evaluation of interstitial pneumonitis in recipients of bone marrow transplants

Microbiologic yield of bronchoalveolar lavage specimens from stem cell transplant recipients

PURPOSE

Stem cell transplant (SCT) recipients commonly undergo bronchoalveolar lavage (BAL) collection as an infectious pulmonary work-up. Previous studies report the utility and overall diagnostic yield of fiberoptic bronchoscopy with BAL in this vulnerable population, though none focused purely on microbiologic yield or made comparisons with less invasive means of pathogen detection. We sought to determine and elaborate on the microbiologic yield of BAL in SCT recipients, assess a correlation between BAL studies and less invasive means of pathogen detection, and assess the utility of repeating a BAL within 30 days.

METHODS

Between January 1, 2009, and July 31, 2013, we reviewed medical records of 125 SCT recipients who underwent 179 BALs. In addition to demographic information and details pertaining to their SCT, a comprehensive review of their microbiologic data was performed and recorded.

RESULTS

Our study showed an overall BAL microbiologic yield of 40%, despite 92% of patients receiving broad-spectrum antimicrobial therapy at the time of the BAL procedure.

CONCLUSIONS

Although an initial BAL sample in this population provides crucial microbiologic information, repeating the procedure within 30 days may have minimal additional microbiologic yield. BAL continues to be an essential diagnostic tool in SCT recipients undergoing an infectious pulmonary work-up.

Bronchoalveolar lavage and lung biopsy in patients with cancer and hematopoietic stem-cell transplantation recipients: a systematic review and meta-analysis

PURPOSE

The objective of this study was to describe the diagnostic yield and complication rate of bronchoalveolar lavage (BAL) and lung biopsy in the evaluation of pulmonary lesions in patients with cancer and recipients of hematopoietic stem-cell transplantation (HSCT).

METHODS

We conducted a systematic literature review and performed electronic searches of Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. Studies were included if patients had cancer or were recipients of HSCT, and if they underwent BAL or lung biopsy for the evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 14,148 studies were screened; 72 studies of BAL and 31 of lung biopsy were included. The proportion of procedures leading to any diagnosis was similar by procedure type (0.53 v 0.54; P = .94) but an infectious diagnosis was more common with BAL compared with lung biopsy (0.49 v 0.34; P < .001). Lung biopsy more commonly led to a noninfectious diagnosis (0.43 v 0.07; P < .001) and was more likely to change how the patient was managed (0.48 v 0.31; P = .002) compared with BAL. However, complications were more common with lung biopsy (0.15 v 0.08; P = .006), and procedure-related mortality was four-fold higher for lung biopsy (0.0078) compared with BAL (0.0018).

CONCLUSION

BAL may be the preferred diagnostic modality for the evaluation of potentially infectious pulmonary lesions because of lower complication and mortality rates; thus, choice of procedure depends on clinical suspicion of infection. Guidelines to promote consistency in the approach to the evaluation of lung infiltrates may improve clinical care of patients.

Minimally Invasive Diagnostic Strategy in Immunocompromised Patients with Pulmonary Infiltrates

Acute respiratory failure (ARF) is the main reason for ICU admission in patients with haematological malignancies. High mortality rates of up to 50% are reported in this situation, and mortality is highest when mechanical ventilation is needed. Rapid and accurate diagnostic methods are needed in these vulnerable patients to ensure the prompt initiation of effective treatment. However, the broad array of possible cause of ARF raises diagnostic challenges. In this review, we discuss the DIRECT strategy, which identifies the most plausible diagnosis in each patient based on the type of immune deficiency and clinical presentation. We will focus on non-invasive laboratory tests developed in recent years, discussing their sensitivity and specificity. We also discuss the usefulness in cancer patients with specific organ dysfunctions of biomarkers introduced over the past few years.

The clinical importance of bronchoalveolar lavage in allogeneic SCT patients with pneumonia

Patients who undergo allogeneic hematopoietic SCT (HSCT) are prone to pulmonary infections. Between 1998 and 2004, a total of 450 patients underwent HSCT at Karolinska University Hospital, Huddinge. Pneumonia was diagnosed in 167 patients (37%), including 42 children. Bronchoalveolar lavage (BAL) was performed on 68 occasions in 57 patients (six children). In 110 patients (36 children) with pneumonia, BAL was not performed. BAL contributed to the diagnosis in 43 cases (63%) and to relevant findings in 53 cases: bacteria (n=13, 24%), viruses (n=28, 53%) and fungi (n=12, 23%). In 25 cases BAL was negative. In 15 of these cases, BAL was performed >or=4 days after chest X-ray, and in four cases not in the same segment as the infiltrations. The median time between radiographic findings and positive BAL was 2 (0-15) days, and a negative BAL 6 (1-30) days (P<0.001). Antimicrobial treatment was administered to 79% patients with positive findings, and to 92% with negative findings at the time of BAL. No serious complications due to the procedure were reported. BAL resulted in a changed treatment in 32/68 (47%) episodes of pneumonia. To conclude, BAL is a safe and useful diagnostic procedure that should be performed early after the onset of pneumonia following allogeneic HSCT.

[Diagnostic strategy for acute respiratory failure in patients with haematological malignancy]

INTRODUCTION

About 15% of patients with haematological malignancy develop acute respiratory failure (ARF), necessitating admission to intensive care where their mortality is of the order of 50%.

STATE OF THE ART

The prognosis of these patients is not determined by the pathological characteristics of the malignancy but by the cause of the acute respiratory failure. In effect, the need to resort to mechanical ventilation in the presence of dysfunction of other organs dominates the prognosis. Even if the use of non-invasive ventilation in these patients has reduced the need for intubation and reduced the mortality, its prolonged use in the most severely affected patients prevents the optimal diagnostic and therapeutic management.

PERSPECTIVES

Fibreoptic bronchoscopy with broncho-alveolar lavage (BAL) is considered the cornerstone of aetiological diagnosis but its diagnostic effectiveness is poor, at best 50%, and this has led to increasing interest in high resolution CT scanning and regularly reawakens a transitory enthusiasm for surgical lung biopsy. Furthermore, in hypoxaemic patients, fibreoptic bronchoscopy with BAL may be the origin of the resort to mechanical ventilation, and thus increased mortality. The place of recently developed non-invasive tools is under evaluation. In effect, though the individual performance of diagnostic molecular techniques on sputum, blood, urine or naso- pharyngeal secretions has been established, the combination of these tools as an alternative to BAL has not yet been reported.

CONCLUSION

This review deals with acute respiratory failure in patients with haematological malignancy. It includes a review of the recent literature and considers the current controversies, in particular the risk-benefit balance of fibreoptic bronchoscopy with BAL in severely hypoxaemic patients.

Diagnostic strategy in cancer patients with acute respiratory failure

OBJECTIVE

Nearly 15% of cancer patients experience acute respiratory failure (ARF) requiring admission to the intensive care unit, where their mortality is about 50%. This review focuses on ARF in cancer patients. The most recent literature is reviewed, and emphasis is placed on current controversies, most notably the risk/benefit ratio of fiberoptic bronchoscopy and BAL in patients with severe hypoxemia.

BACKGROUND

Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is the cornerstone of the causal diagnosis. However, the low diagnostic yield of about 50%, related to the widespread use of broad-spectrum antimicrobial therapy in cancer patients, has generated interest in high-resolution computed tomography (HRCT) and primary surgical lung biopsy. In patients with hypoxemia, bronchoscopy and BAL may trigger a need for invasive mechanical ventilation, thus considerably decreasing the chances of survival.

DISCUSSION

The place for recently developed, effective, noninvasive diagnostic tools (tests on sputum, blood, urine, and nasopharyngeal aspirates) needs to be determined. The prognosis is not markedly influenced by cancer characteristics; it is determined chiefly by the cause of ARF, need for mechanical ventilation, and presence of other organ failures. Although noninvasive ventilation reduces the need for endotracheal intubation and diminishes mortality rate, its prolonged use in patients with severe disease may preclude optimal diagnostic and therapeutic management. The appropriateness of switching to endotracheal mechanical ventilation in patients who fail noninvasive ventilation warrants evaluation.

CONCLUSION

This review discusses risks and benefits from invasive and non invasive diagnostic and therapeutic strategies in critically ill cancer patients with acute respiratory failure. Avenues for research are also suggested in order to improve survival in these very high risk patients.

Pulmonary complications following hematopoietic stem cell transplantation: diagnostic approaches

Pulmonary complications are a significant cause of morbidity and mortality in hematopoietic stem cell transplant recipients. Pulmonary infiltrates in such patients pose a major challenge for clinicians because of the wide differential diagnosis of infectious and noninfectious conditions. It is rare for the diagnosis to be made by chest radiograph, and commonly these patients will need further invasive and noninvasive studies to confirm the etiology of the pulmonary infiltrates. This review describes the role of the different diagnostic tools available to reach a diagnosis in a timely manner in this patient population.

Natural history of pulmonary complications in children after bone marrow transplantation

We sought, in children after bone marrow transplantation (BMT), (1) to determine the natural history and incidence of pulmonary complications, (2) to evaluate the diagnostic yield of fiberoptic bronchoscopy and bronchoalveolar lavage (BAL); and (3) to determine the effect of bronchoscopy with lavage on patient outcome. The study design was a retrospective review in a tertiary care university hospital of all children undergoing BMT over a 5-year period. Patients were separated into 2 study groups: children with and without pulmonary complications. Pulmonary complications were defined as new or persistent pulmonary infiltrates on chest radiograph or chest computed tomography scan, respiratory symptoms, hypoxemia, or hemoptysis. Three hundred sixty-three pediatric patients underwent BMT between January 1, 1995, and December 31, 1999. Ninety patients (25%) developed pulmonary complications and were evaluated with bronchoscopy and BAL. Patients with pulmonary complications had a higher mortality (65% versus 44%; P < .01). The median posttransplantation survival for children with pulmonary complications was 258 days, compared with 1572 days in patients without pulmonary complications. The incidence of pulmonary complications was increased in patients with allogeneic BMT (P < .01). The time-dependent onset of severe (grade III to IV) graft-versus-host disease increased the relative risk of pulmonary complications by 2.0 (95% confidence interval, 1.1-3.7; P = .02). Pulmonary complications increased the time-dependent relative risk of mortality by 3.5 (95% confidence interval, 2.5-4.8). The diagnostic yield of bronchoscopy with lavage was 46% in patients undergoing BAL. Diagnostic bronchoscopy did not enhance either 30- or 100-day survival. Pathogen identification did not decrease mortality (P = .45). Pulmonary complications occur in 25% of children undergoing BMT and increase the risk of death in the first year after BMT. Although pathogen identification does not confer a survival advantage, rigorous, prospective screening may allow for earlier identification of pathogens and thereby provide a benefit to this uniquely vulnerable population.

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods

PURPOSE

To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia.

PATIENTS AND METHODS

Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed.

RESULTS

Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%).

CONCLUSION

The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Flexible bronchoscopy in the diagnosis of pulmonary infiltrates following autologous peripheral stem cell transplantation for advanced breast cancer

Flexible bronchoscopy is an important tool in the diagnosis of pulmonary complications following bone marrow transplantation. However, the value of this procedure in autologous peripheral stem cell transplant (APSCT) recipients with pulmonary complications is not well defined. We retrospectively evaluated the diagnostic yield of 27 consecutive bronchoscopies done on 23 APSCT recipients following high-dose chemotherapy for breast cancer. FB resulted in a positive diagnosis in 16 cases (59%). Broncheoalveolar lavage (BAL) was performed on all patients, and transbronchial biopsies (TBB) were carried out in 14. TBB were diagnostic in 10 (71%), with pulmonary drug toxicity as the most common finding (n = 8), followed by metastatic breast cancer (n = 2). BAL was diagnostic in six (22%): bacterial pneumonia (n = 3), aspergillosis (n = 2), Pneumocystis carinii pneumonia (n = 1) and Influenza B (n = 1). The procedure was well tolerated with no major complications except a small pneumothorax in one patient that did not require chest tube insertion. In conclusion, flexible bronchoscopy is a useful tool in the evaluation of pulmonary complications following APSCT for breast cancer. TBB can be done safely with relatively high diagnostic yield. Pulmonary drug toxicity is the most common pathological finding.

Fiberoptic bronchoscopy in allogeneic bone marrow transplantation: findings in the era of serum cytomegalovirus antigen surveillance

STUDY OBJECTIVES

Pulmonary complications occur in half of allogeneic bone marrow transplantation (BMT) patients. The incidence of these complications has been reduced by prophylaxis against Pneumocystis carinii pneumonia, preemptive therapy in patients at high risk for cytomegalovirus (CMV) reactivation, and, more recently, screening for serum CMV antigen. Since fiberoptic bronchoscopy (FOB) has historically been the primary diagnostic test to evaluate BMT patients with pulmonary disease, a review was performed to determine the impact, if any, that current prophylaxis and screening policies may have had on FOB utility.

DESIGN

The records of 174 adult patients undergoing BMT between January 1997 and December 1999 were reviewed to determine the diagnostic yield of FOB and the frequency by which FOB altered management.

RESULTS

Sixty-one patients underwent 76 bronchoscopies. FOB was diagnostic in 32 patients (42.1% of cases) and directly changed management in 24 patients (31.6% of cases). Half of these changes included the withdrawal of an antimicrobial agent. The most common findings were infection (32 cases) and diffuse alveolar hemorrhage (6 cases). CMV was the most prevalent infection identified, but FOB resulted in the addition of antiviral therapy to only two patients. P carinii pneumonia was not diagnosed in any patient studied.

CONCLUSIONS

These data suggest a changing spectrum of pulmonary disease in BMT patients. FOB has limited impact on the diagnoses of CMV disease or P carinii pneumonia with current prophylaxis and screening strategies. It may be useful in identifying other infectious etiologies and in eliminating unnecessary antimicrobials.

Use of first line bronchoalveolar lavage in the immunosuppressed oncology patient

Immunosuppressed oncology patients who develop pulmonary infiltrates during treatment have a mortality rate of the order of 55-90%. Early diagnosis and treatment is associated with increased survival. At present, diagnosis relies on invasive sampling of the respiratory tract using fibre-optic bronchoscopy. We have looked at a 30-month period, from June 1997 to December 1999, where 25 bronchoscopies were performed on patients from the Lymphoma and BMT units at The Royal Marsden Hospital for the further investigation of pulmonary infiltrates. Nine bronchoscopies (36%) yielded a positive result and seven (28%) led to a change in management. Analysis of the data showed that neither a positive result nor a change in management had any impact on overall survival. After reviewing the background literature on the investigation of pulmonary infiltrates in this group and discussion of the respective merits and limitations, we propose a management flowchart, with high-resolution computed tomography (HRCT) as the test arm in a future randomised trial of these patients.

Utility of fiberoptic bronchoscopy in neutropenic patients admitted to the intensive care unit with pulmonary infiltrates

OBJECTIVE

To analyze the impact of fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) on guiding the treatment and intensive care unit (ICU) clinical outcome in neutropenic patients with pulmonary infiltrates admitted to the ICU.

DESIGN

Prospective collection of data.

SETTING

Medical ICU in a teaching hospital.

PATIENTS

During a 6-yr period, we analyzed the results of 93 fiberoptic bronchoscopies plus BALs performed in 93 consecutive neutropenic ICU patients. We separated the patients into two groups according to the cause of neutropenia (high-dose chemotherapy [n = 41] or stem cell transplantation [SCT; n = 52]).

RESULTS

Of the 93 BALs, 53 were performed to evaluate diffuse infiltrates and 42 were performed on mechanically ventilated patients. Forty-nine percent of BALs (46 patients) were diagnostic, with a significantly better yield in ICU patients with high-dose chemotherapy-induced neutropenia (26 of 41 BALs). The number of cases of proven infectious pneumonia was significantly higher in this group of ICU neutropenic patients. In patients who underwent SCT, diffuse infiltrates were statistically correlated with a negative result of BAL. Twenty-six patients who underwent diagnostic BALs changed therapy. Sixteen complications (17%) occurred with only two intubations. The overall mortality rate in the ICU and the mortality rate in mechanically ventilated neutropenic patients were 71% and 93%, respectively. In neutropenic patients who underwent SCT, the mortality rate was statistically higher in patients in whom no diagnosis was established. Patients who had a diagnostic BAL that changed therapy did not have an increased probability of survival compared with patients who had a BAL that did not change therapy.

CONCLUSIONS

The use of routine diagnostic BAL in ICU neutropenic patients with pulmonary infiltrates is difficult to establish, even if BAL is helpful in the management of these critically ill patients. BAL in our ICU neutropenic patient population had an acceptable overall diagnostic yield (49%), which was higher in ICU patients with chemotherapy-induced neutropenia. Nevertheless, in the ICU, if BAL had a low complication rate, it had infrequently led to changed treatment and was not associated with improved patient survival.

Bronchoalveolar lavage in the diagnosis of pulmonary complications of bone marrow transplant patients

Bronchoalveolar lavage (BAL) has proved valuable in the diagnosis of pulmonary complications in immunosuppressed patients. We evaluated the diagnostic yield of BAL in pulmonary complications in bone marrow transplantation (BMT) recipients. We reviewed sequentially the records of 89 patients during an 18-month period. BAL was diagnostic in 42 patients (47%). The most common pulmonary complication diagnosed by BAL was diffuse alveolar hemorrhage (n = 15); followed by bacterial pneumonia (n = 10), respiratory syncytial virus (n = 8), aspergillosis (n = 6), Pneumocystis carinii pneumonia (n = 5), cytomegalovirus (CMV) (n = 4), and others (n = 4). The final diagnoses in the BAL non-diagnostic group were: bacterial pneumonia (n = 6), CMV (n = 6), idiopathic pneumonia syndrome (n = 5), cancer recurrence (n = 4), cardiogenic pulmonary edema (n = 4), and others (n = 9). We conclude that BAL is a useful diagnostic tool in BMT-related pulmonary complications.

Bronchoscopic evaluation of pulmonary infiltrates following bone marrow transplantation

STUDY OBJECTIVE

To determine the impact of fiberoptic bronchoscopy (FOB), including quantitative bacterial cultures obtained by BAL and protected specimen brushing on therapeutic decisions and outcome in bone marrow transplant (BMT) patients.

DESIGN

Retrospective review of all BMT patients undergoing FOB during a 4-year period.

SETTING

A tertiary care university hospital.

RESULTS

Three hundred five patients underwent BMT; 71 (23%) had FOB to assess pulmonary infiltrates. Allogeneic BMT recipients underwent FOB 3.37 times more often than autologous recipients (p < 0.001). Pathogens were identified in 31 (46%) patients undergoing FOB; bacteria were most commonly isolated although 86% of patients had received broad-spectrum empiric antibiotics. Therapy was changed in 20 (65%) patients when a microorganism was identified and in 9 (22%) with nondiagnostic results (p = 0.0026), but isolation of a presumed pathogen had no apparent effect on survival. There were 19 (27%) FOB complications, including bleeding in 8 (11%) patients and death in 2 (3%). Major complications were associated with prolonged prothrombin time (p = 0.006) and were more common (36% vs 14%; p < 0.05) in patients who had protected specimen brushing vs BAL alone. Mortality at 40 months in BMT patients not requiring FOB was 33% compared with 61% mortality in those undergoing FOB (p < 0.001); mortality was 96% in patients with respiratory failure requiring mechanical ventilation.

CONCLUSION

FOB is diagnostically useful in the evaluation of some BMT patients with pulmonary complications and often influences therapy, although no impact on survival was clearly demonstrated. FOB should be performed only after benefits of the procedure are weighed carefully against its increased risk in this select population.

Diagnostic value of protected BAL in diagnosing pulmonary infections in immunocompromised patients

STUDY OBJECTIVES

To assess the diagnostic utility of protected BAL (P-BAL) in respiratory infections in immunocompromised patients and to examine whether P-BAL alone could substitute the combined use of protected specimen brush (PSB) and BAL in such patients.

PATIENTS AND STUDY DESIGN

Thirty-seven immunocompromised patients who underwent PSB, P-BAL, and BAL simultaneously for the diagnosis or exclusion of bacterial or nonbacterial opportunistic respiratory infections were studied prospectively. The P-BAL was performed through the inner catheter of a telescoping plugged catheter with 60 mL of saline solution.

MAIN RESULTS

Thirteen (35%) cases of bacterial pneumonia were diagnosed. PSB obtained seven true-positive (TP) results, P-BAL obtained nine, and BAL obtained eight TP. Results of the three techniques were positive and concordant in 6 of the 13 cases. PSB remained free of contamination from oropharyngeal flora in all cases, P-BAL was contaminated twice, and BAL was contaminated in four cases. Opportunistic respiratory infections were diagnosed in 19 patients. P-BAL results were identical to those with BAL in all cases: 18 TP and 1 false-negative. The average volume of P-BAL fluid retrieved was 19 mL, sufficient for all microbiologic and cytologic processings. P-BAL was more time-consuming than both PSB and BAL procedures and was technically more complex.

CONCLUSION

P-BAL alone can substitute the combined use of both PSB and BAL in immunocompromised patients and attains a higher sensitivity than PSB in diagnosing bacterial pneumonia. The combined strategy continues to be a good choice, but due to the high incidence of bacterial pneumonia in these patients, a highly efficient diagnostic procedure is required not only for nonbacterial opportunistic respiratory infections but also for bacterial pneumonia.

Open lung biopsy provides a higher and more specific diagnostic yield compared to broncho-alveolar lavage in immunocompromised patients. Fungal Study Group

In order to examine the feasibility and safety of undertaking a larger prospective study to compare the diagnostic yield from concurrent open lung biopsy (OLB) and bronchoalveolar lavage (BAL) in febrile neutropenic patients with pulmonary infiltrates and the impact of such knowledge on clinical outcome, a pilot exploratory study was performed. 13 immunocompromised patients (mainly with haematological malignancy or bone marrow transplantation recipients) were investigated. At least one diagnostic finding in 12 of 13 patients was provided by OLB compared to 4 of 13 patients by BAL. BAL provided 7 specific diagnoses (pneumocystis 1, fungal infection 3, bacterial pneumonia 1, pulmonary haemorrhage 2) whilst OLB provided 12 specific diagnosis (CMV 2, pneumocystis 3, fungal infection 1, bacterial pneumonia 1, pulmonary haemorrhage 4, pulmonary embolism 1). Five patients with nonspecific interstitial/alveolar inflammation were diagnosed only by OLB. The concordance that the exact same specific diagnoses present in the OLB were found in the BAL was zero. There were 2 minor complications (1 wound infection by OLB, 1 moderate haemorrhage by BAL). Mortality at 28 days was 8 of 13 patients which in no case was related to either procedure. We suggest that OLB is a safe procedure in such patients, provides superior and more complete diagnostic information compared to BAL and a larger controlled study to investigate the impact of early OLB on the outcome of these patients appears to be justified.

Update on pediatric flexible bronchoscopy

Technological advances in flexible bronchoscopy have expanded the clinician's ability to diagnose and treat pulmonary disease in children. During the neonatal period, flexible bronchoscopy has contributed to the understanding of the incidence and factors responsible for acquired airway lesions. The ability to selectively collect lower airway secretions has contributed to the care of immunocompromised patients with new pulmonary infiltrates. New therapies may use the flexible bronchoscope to specifically target lower airway tissues of interest. Because of the breadth of both current and future applications, most pediatricians will require a working familiarity with the benefits of flexible bronchoscopy in their patients.

Investigation and management of pulmonary infiltrates following bone marrow transplantation: an eight year review

BACKGROUND

Although pulmonary infiltrates are common in bone marrow transplant recipients and add significantly to the morbidity and mortality of this group of patients, there is uncertainty as to the most appropriate investigation and a lack of information on the effects of investigations on management and outcome.

METHODS

All bone marrow transplant recipients from one institution referred for respiratory investigation between 1982 and 1990 were reviewed.

RESULTS

Of 204 bone marrow transplant recipients 27 developed pulmonary infiltrates which failed to respond to broad spectrum antibiotics. All were examined by bronchoscopy and bronchoalveolar lavage. A specific diagnosis was made in 20 cases, 17 with an infective cause and three with a non-infective aetiology. In 17 of the 27 episodes these investigations led to a positive change in treatment, but in only five did these changes result in patient survival beyond one month. Eighteen of the 20 deaths were due to progressive respiratory failure of an infective aetiology in 14 and non-infective in four.

CONCLUSIONS

Bronchoscopy and bronchoalveolar lavage are effective in establishing a diagnosis, but the impact on overall survival is disappointingly poor.

The detection of Aspergillus spp. by the polymerase chain reaction and its evaluation in bronchoalveolar lavage fluid

Invasive pulmonary aspergillosis (IPA) is an important cause of mortality and morbidity in the immunocompromised host. However, the diagnosis of this condition may be difficult, and it is sometimes missed because of the lack of sensitivity of available tests. Therefore, we used polymerase chain reaction (PCR)-based amplification of fragments of genes-encoding alkaline proteases from Aspergillus fumigatus and A. flavus to detect these organisms in bronchoalveolar lavage fluid specimens. The predicted size of the product (747 base pairs) after amplification of A. fumigatus was larger than that for A. flavus (690 base pairs). The reaction was highly sensitive (after amplification of 500 fg of A. fumigatus DNA, product could be detected by Southern analysis), and it was specific for A. fumigatus and A. flavus. Bronchoalveolar lavage fluid from four immunosuppressed patients with proved or probable IPA was positive by this assay (sensitivity, 100%); in addition, the sample from one patient with possible IPA was PCR-positive. Only one specimen from 18 immunosuppressed patients with no evidence of IPA was PCR-positive (specificity, 94.4%). Five of 28 bronchoalveolar lavage samples from nonimmunosuppressed patients were PCR-positive, probably representing colonization of the respiratory tract. PCR-based detection may prove useful in the diagnosis of IPA.

Complications of fiberoptic bronchoscopy in thrombocytopenic patients

STUDY OBJECTIVE

To determine the risk of epistaxis and pulmonary hemorrhage due to fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) in the presence of thrombocytopenia.

DESIGN

Prospective study of all patients undergoing FOB with BAL with a 4.9-mm-diameter bronchoscope after bone marrow transplantation (BMT) during a 6-month period.

SETTING

A single BMT center.

PATIENTS

Forty-seven BMT recipients undergoing 66 FOB with BAL. Thrombocytopenia (platelets < 100,000/ml) was present in 58 (88 percent). Platelets were < 50,000/ml in 44 (67 percent) and < 20,000/ml in 13 (20 percent). In the thrombocytopenic patients, FOB with BAL was transnasal in 37 (64 percent), transoral in 5 (9 percent), and via endotracheal tube in 16 (28 percent).

INTERVENTIONS

Fiberoptic bronchoscopy with BAL using a bronchoscope (Pentax FB-15H) (4.9-mm diameter). In one case, a pediatric bronchoscope (Pentax FB-10H; 3.5-mm diameter) was used in a 7-year-old patient.

MEASUREMENTS AND RESULTS

The BAL was diagnostic in 22 of 47 patients studied (47 percent). Complications occurred in 7 of 58 (12 percent) thrombocytopenic patients (epistaxis and/or hemoptysis, 4; bradycardia, 2; bronchospasm, 1) of which all but 1 were minor and self-limiting. One life-threatening complication of severe epistaxis occurred during a transoral FOB in a patient with prior epistaxis (platelet count, 18,000/ml). One of 8 (13 percent) nonthrombocytopenic patients had hemoptysis. No patient had worsening fever or oxygenation at 4 h and no patient displayed worsening radiographic infiltrates suggestive of pulmonary hemorrhage attributable to the BAL at 24 h.

CONCLUSIONS

We conclude that transnasal FOB in thrombocytopenic patients was safe, being associated with minor airway bleeding in 3 of 37 patients (8 percent). In conclusion, FOB with BAL, even via the transnasal route, may be performed with relative safety despite the presence of significant thrombocytopenia.

Can lung function measurements be used to predict which patients will be at risk of developing interstitial pneumonitis after bone marrow transplantation?

BACKGROUND

Lung function often deteriorates after bone marrow transplantation for haematological malignancies. Whether pulmonary function measurements are useful for monitoring patients' progress after transplantation and for alerting clinicians to the development of pneumonitis is uncertain.

METHODS

Serial pulmonary function measurements were made in 39 patients with a haematological malignancy, and the values from 18 recipients of T cell depleted allogeneic (n = 17) or autologous (n = 1) bone marrow transplants who developed interstitial pneumonitis were compared retrospectively with values from 21 recipients of allogeneic (n = 17) or autologous (n = 4) transplants who did not develop pneumonitis. Lung function was measured at the onset of a further 18 episodes of pneumonitis.

RESULTS

Measurements made before transplantation showed no difference in forced expiratory volume in one second (FEV1), transfer factor for carbon monoxide (TLCO), or total lung capacity between the two groups, but the forced vital capacity (FVC) was slightly higher in those who developed pneumonitis (mean (SD)% predicted 104 (12)) than in those who did not (93 (17%)). Six weeks and three months after transplantation all pulmonary function measurements had fallen slightly in both groups but TLCO had fallen considerably more in those who later developed pneumonitis, being 71% (SD 11%) and 77% (7%) of pretransplant values in patients who later developed pneumonitis compared with 109% (38%) and 96% (26%) in those who did not. All lung function measurements were significantly lower at the onset of pneumonitis than three months after transplantation, even in patients with no abnormal signs and a normal chest radiograph.

CONCLUSIONS

Serial measurements of gas transfer before and after bone marrow transplantation may be useful for predicting which patients will be at risk of developing pneumonitis and may help to diagnose pneumonitis in breathless patients with no abnormal signs.

Bronchoscopy with bronchoalveolar lavage in the evaluation of pulmonary complications of bone marrow transplantation in children

Pulmonary complications are a frequent cause of morbidity and mortality following bone marrow transplantation. We examined the results of flexible bronchoscopy (FB) and bronchoalveolar lavage (BAL) in 27 pediatric bone marrow transplant (BMT) recipients with 29 episodes of pulmonary complications. Bone marrow transplant was performed for a variety of malignancies and hematologic disorders. Median age of BMT was 10.3 years (range, 1.7-17.6 years). Median time of FB following BMT was 60 days (range, 11-1,026 days). Routine cytologic and culture techniques were utilized to detect malignant cells, viruses, fungi, bacteria, and protozoa. Positive results were found in 15 (52%) with cytomegalovirus (CMV), the most common positive finding. In 14 (48%) episodes the results were negative. Fourteen patients had follow-up autopsy or open lung biopsy (OLB). Based on autopsy/OLB results, there were two false negatives and no false positives, giving a diagnostic sensitivity of 75% and specificity of 100%. There was one possible complication of FB and BAL. Survival of both positive and negative patients was poor, only seven patients being alive 90 days post-FB with BAL. We conclude that FB with BAL is a safe and accurate procedure for the diagnosis of pulmonary complications of BMT.

Experience with fibreoptic bronchoscopy in the diagnosis of pulmonary shadows in renal transplant recipients over a 12-year period

Despite improvements in immunosuppressive therapy, pulmonary infections remain an important cause of morbidity and mortality in renal transplant recipients. Over a 12-year period (1 January 1977 to 31 December 1988) we prospectively assessed the value of fibreoptic bronchoscopy in diagnosing radiographic pulmonary shadows in this group of patients. Forty-eight bronchoscopies were performed on 46 patients. A definitive diagnosis was established in 28/48 (58%) procedures (and was partially definitive for one of two organisms ultimately identified in another). The procedure failed in 19/48 (40%), although in 15 of these, the radiographic shadows resolved on antibiotics (9) or spontaneously (3) or autopsy revealed acute pneumonia (3). In four instances a specific diagnosis was made by alternative means. Clinically useful information which led to changes in management was obtained in 17/48 (35%) procedures and bronchoscopy was thought to have favourably influenced survival in 16/48 (33%). Fibreoptic bronchoscopy is in our experience a safe (only one pneumothorax and no significant haemorrhage) and useful technique in evaluating pulmonary shadows in renal transplant recipients.

Pulmonary cell populations in recipients of bone marrow transplants with interstitial pneumonitis

The immunological basis of the inflammatory response in the lungs of patients with pneumonitis after bone marrow transplantation has been investigated by means of bronchoalveolar lavage. Ten episodes of pneumonitis associated with cytomegalovirus and nine episodes due to various other infectious and non-infectious causes were investigated in 16 patients (three patients had two episodes of pneumonitis). Total lavage cell counts and differential cell counts were determined and compared with results from normal control subjects. In most patients with pneumonitis the total cell yield was greater than normal (mean 6.8 (SD 6.0) x 10(5) cells/ml; normal 1-2 x 10(5) cells/ml). The percentage distribution of these cells was 71.9 (17) macrophage like cells, 24.1 (15.8) lymphocytes, 5.0 (5.0) polymorphonuclear cells, and 0.7 (1.0) eosinophils. None of the patients had peripheral lymphocytosis despite the increased number of lymphocytes in the lavage fluid. Further analysis of the lymphocyte population using monoclonal antibodies with immunocytochemical techniques showed that B cells were generally present in normal proportions, whereas the proportion of cells expressing T lymphocyte markers (CD2+, CD5+, CD8) were reduced in nine out of 19 cases. In 10 of the 19 episodes there were substantial numbers of cells expressing none of the B or T cell antigens studied ("null" cells). These abnormalities bore no relation to survival. The total cell yield, the proportion and number of lymphocytes, and the proportion and number of T cells in the bronchoalveolar lavage fluid were all lower in the group with cytomegalovirus infections than in those with pneumonitis from other causes. These results suggest that the pneumonitis in recipients of bone marrow transplants is associated with a local immune response despite the fact that the individuals are otherwise immunosuppressed.

Is the measurement of virus-specific antibody in the lungs of transplant recipients with cytomegalovirus pneumonitis of diagnostic or prognostic value?

We have investigated 12 transplant recipients (nine bone marrow transplants, three renal) with 15 episodes of pneumonitis caused by cytomegalovirus (CMV) and ten patients (eight bone marrow transplant recipients, two renal transplant recipients) with 12 episodes of interstitial pneumonitis in whom no CMV was detected, to determine whether levels of CMV-specific IgG in the lung are diagnostic of infection. We have also assessed whether a vigorous specific local antibody response is important for survival. CMV-specific IgG and herpes simplex (HSV)-specific IgG were measured in bronchoalveolar lavage (BAL) fluid and serum using albumin to correct for simple diffusion from serum into the lung. We have found evidence for local production or facilitated transport of CMV-specific IgG in ten patients with CMV pneumonitis but also in six patients with pneumonitis where no CMV was detected. Similar results were found for HSV-specific IgG although only one patient had a demonstrable HSV infection. There was a tendency for those patients producing large amounts of immunoglobulin in the lung to survive compared with those who died, but there were wide variations between patients in each group. The local humoral immune response in transplant patients with pneumonitis was not specific to the infecting agent and is most probably the result of polyclonal B cell activation or facilitated transport of IgG from serum to lung secretions. Measurement of CMV-specific IgG response in the lung should not, therefore, be used for diagnostic or prognostic purposes.

Humoral immune responses within the lung of bone marrow transplant recipients studied by bronchoalveolar lavage

We investigated 20 bone marrow transplant recipients with pneumonitis using bronchoalveolar lavage (BAL) to assess the humoral immune response in the lung. We measured the levels of total IgG, IgM and IgA in bronchoalveolar lavage fluid and serum, and albumin measurements were used to correct for simple diffusion of immunoglobulins from serum into the lung. We found evidence for the local production of immunoglobulins G, M and A in 15 patients. This was independent of the cause of the pneumonitis. We also found that, although seven patients who recovered from their pulmonary problem had evidence of considerable local production of immunoglobulin, eight patients who died were also producing immunoglobulins in the lung. Death due to pneumonitis in BMT recipients cannot, therefore, be ascribed to a failure of the local humoral immune response.