Bronchoalveolar Lavage In the Diagnosis of Bronchiolo-Alveolar Carcinoma. A Case Report

Bronchiolo-alveolar carcinoma is usually localized to the terminal bronchioles and alveoli, and may present on chest X-ray as interstitial pulmonary disease with diffuse reticulonodular infiltrates. The cytological diagnosis is often difficult to obtain. This case demonstrates that bronchoalveolar lavage can be useful in the diagnostic evaluation of this type of malignancy, in conjunction with transbronchial lung biopsy.     

Cytology of Bronchoalveolar Lavage In Some Rare Pulmonary Disorders: Pulmonary Alveolar Proteinosis and Amiodarone Pulmonary Toxicity

Cytological patterns of bronchoalveolar lavage (BAL) in pulmonary alveolar proteinosis (PAP) and amiodarone pulmonary toxicity (APT) are presented together with light and electron microscopy (EM). the differential cell count of BAL in both diseases is similar in that alveolar macrophages predominate. However, the cytology of PAP is characterized by scanty macrophages and alveolar epithelial cells in abundant periodic acid-Schiff (PAS)-positive extracellular material. the gross appearance of the BAL fluid is therefore opaque. In contrast, the cytology of APT is characterized by foamy alveolar macrophages with numerous lamellar bodies in their cytoplasm, and the BAL fluid is clear.     

Increase in T-Cells Bearing CD25 in Bronchoalveolar Lavage Fluid from HAM/TSP Patients and HTLV-I Carriers

To determine the immunologic characteristics of T-cells in local pulmonary lesions of human T-cell lymphotropic virus type I (HTLV-I) carriers, we investigated lymphocyte surface markers in peripheral blood and bronchoalveolar lavage fluid (BALF) of 38 HTLV-I carriers, 8 HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, 44 HTLV-I seronegative patients with pulmonary diseases and 7 healthy volunteers using two-color flow cytometric analysis. In peripheral blood, activated T-cells, CD4+HLA-DR +, CD8 + HLA-DR + and CD3 + CD25 +, and CD4+CD29+ cells increased significantly in carriers and HAM/TSP patients compared with healthy volunteers and seronegative patients. In BALF, T-cells, especially CD25+ cells, increased significantly in carriers and HAM/TSP patients, compared with healthy volunteers and seronegative patients. These findings indicated that T-cells in the lungs, as well as in peripheral blood, are activated in carriers and HAM/TSP patients. Interestingly, there was dissociation between expression of CD3 + CD25+ cells in BALF and peripheral blood from these patients. These results suggest that T-cells activated probably by HTLV-I accumulate in the lungs in some carriers and HAM/TSP patients, and HTLV-I may be involved in the immunologic dysfunction in the lungs of these patients. However, we did not find any correlation between the degree of clinical features and the elevation of CD3 + CD25+ cells in BALF, or its characteristic features on chest roentgenograms.     

The Cytological Diagnosis of Pneumocystis Carinii By Fluorescence Microscopy of Papanicolaou Stained Bronchoalveolar Lavage Specimens

In a retrospective and prospective analysis fluorescence microscopy of Papanicolaou stained bronchoalveolar lavage specimens has been applied to the diagnosis of Pneumocystis carinii (PC) in routine cytology. The pneumocysts presented as circular structures of 5 microns in diameter and of brilliant green-yellow fluorescence surrounding two mirror image reniform structures. Fluorescent inclusions of 1-3 microns diameter within the alveolar macrophages could be identified as remnants of pneumocysts by a follow-up of all steps of degradation ending in very small irregular granules. By applying both criteria, i.e. pneumocysts with reniform bodies and degradation inclusions within macrophages, Pneumocystis carinii pneumonitis (PCP) could be detected in 100% of cases. Transbronchial biopsy permitted the correct diagnosis in only 65.2% of cases. Retrospective analysis of slides is possible after a long period as no significant loss of fluorescence occurs after 4 years. Thus fluorescence microscopy permits the diagnosis of Pneumocystis carinii without any additional staining or loss of time.     

Trace and Major Elements Status in Bronchoalveolar Lavage Fluid in Dogs with or without Bronchopneumonia

The aim of this study was to investigate the relationships between the bronchopneumonia and mean concentrations of those trace elements in bronchoalveolar lavage fluid (BALF). Twenty-nine dogs were included this study (17 healthy dogs and 12 dogs with respiratory disease). Each BALF sample had been obtained during bronchoscope examination by use of a standardized method. The concentrations of Al, Br, Ca, Cu, Fe, K, Ni, P, Si, Sr and Zn in BALF were measured by the particle-induced X-ray emission method. We found no relationship between the bronchopneumonia and the levels of elements in the BALF, except Ca, P and Zn. The dogs with respiratory disease were found to have a large amount of Ca and Zn, and a high Ca/P and Zn/Cu ratios in BALF compared to those without respiratory disease.     

The Diagnosis of Pneumocystis Carinii Pneumonia By Cytologic Evaluation of Papanicolaou and Leishman-Stained Bronchoalveolar Specimens In Patients With the Acquired Immunodeficiency Syndrome

The presence of foamy alveolar casts or flocculent material in Papanicolaou and Leishman-stained smears of bronchoalveolar lavage (BAL) fluid is said to be indicative of infection with Pneumocystis carinii. We have investigated the sensitivity and specificity of this method of diagnosing pneumocystis pneumonia in patients with the acquired immunodeficiency syndrome (AIDS). Patients (n= 114) with diffuse lung infiltrates were submitted to fibreoptic broncoscopy and BAL. Seventy of them were patients with AIDS. the other 44 individuals were not infected by the human immunodeficiency virus (HIV). Pneumocystis carinii organisms were identified on Grocott's methenamine silver (GMS)-stained BAL smears in 30 patients with AIDS. Flocculent material was present in the Papanicolaou and Leishman-stained smears from all of these cases. Conversely, P. carinii were not seen on GMS-stained smears in the remaining 84 individuals with or without AIDS. No flocculent material was observed in Papanicolaou or Leishman-stained smears in these 84 patients. We concluded that the presence of flocculent material in Papanicolaou or Leishman-stained smears of BAL fluid is indicative of P. carinii pneumonia in patients with AIDS. La présence de cylindres alvéolaires spumeux ou de matériel floculé dans les étalements de liquide de lavage bronchoalvéolaire (LBA) colorés selon Papanicolaou ou Leishman est considérée comme symptomatique d'une infection par Pneumocystis carinii. Nous avons étudié la sensibilité et la spécificité de cette méthode de diagnostic de l'infection par Pneumocystis carinii chez des patients atteints de syndrome de déficience immunitaire acquise (SIDA). Cent quatorze malades avec des infiltrats pulmonaires diffus ont subi une fibroscopie bronchique et un lavage broncho-alvéolaire. Soixante dix d'entre eux edtaient atteints de SIDA, 44 n'étaient pas infectés par le Virus de l'Immunodéficience Humaine (VIH). Le Pneumocystis carinii a été identifiié par la coloration de Grocott chez 30 patients atteints de SIDA. Chez ces patients, la présence d'un matériel floculé est constante sur les étalements colorés au Papanicolaou et au Leishman. A l'inverse, Pneumocystis carinii n'a pas été retrouvé chez les 84 autres malades, atteints ou non du SIDA et les étalements de LBA ne contenaient pas de matériel floculé. En conclusion, la présence de matériel floculé dans les étalements de LBA colorés selon Papanicolaou ou Leishmanest associée à une pneumpathie àPneumocystis carinii chez les patients atteints de SIDA. Sensitivität und Spezifität des Nachweises schaumiger oder flockiger Alveolarausgüsse bei Pneumocystis carinii wurden in 114 Fällen diffuser Lungeninfiltrate untersucht. 70 Patienten waren an AIDS erkrankt, 44 weitere waren HIV-negative. In 30 der AIDS-Fälle wurde P. carinii mit der Grocott'schen Färbung nachgewiesen. Die typischen Eiweißniederschläge waren in all diesen Fällen nachweisbar. Umgekehrt ergab die Grocottfärbung in 84 Fällen mit oder ohne AIDS ein negatives Ergebnis. In all diesen Fällen war kein Eiweißniederschlag nachweisbar. Daraus ergibt sich, daß die Eiweißniederschläge in Präparaten, die nach Papanicolaou oder Leishman gefärbt wurden, kennziechned sind für die P. carinii Pneumonie.     

快速检测支气管肺泡灌洗液T细胞的研究

目的建立一种简便、快速检测支气管肺泡灌洗液（ＢＡＬＦ）中Ｔ淋巴细胞总数的方法。方法用改良的α－醋酸萘酯酶（ＡＮＡＥ）染色法鉴别和计数ＢＡＬＦ中Ｔ淋巴细胞。用本法共检测２２７例大鼠ＢＡＬＦ,并采用两样本均数比较的ｔ检验分析３批动物实验的测定结果。结果大鼠ＢＡＬＦ细胞涂片ＡＮＡＥ染色效果满意,Ｔ淋巴细胞容易鉴别。测得１１０只正常大鼠ＢＡＬＦ中Ｔ淋巴细胞比值的正常值为（６９．３６±１１．４７）％。各个实验组与相应对照组比较,ＢＡＬＦ中Ｔ淋巴细胞比值均出现不同程度的变化。结论本方法简便易行,能准确地显示ＢＡＬＦ中Ｔ淋巴细胞数值的变化。本研究是国内首次报道,为实验和临床研究肺局部细胞免疫状况提供了一种简便的方法及其应用的实验依据。     

Usefulness of Cellular Analysis of Bronchoalveolar Lavage Fluid for Predicting the Etiology of Pneumonia in Critically Ill Patients

Background

The usefulness of bronchoalveolar lavage (BAL) fluid cellular analysis in pneumonia has not been adequately evaluated. This study investigated the ability of cellular analysis of BAL fluid to differentially diagnose bacterial pneumonia from viral pneumonia in adult patients who are admitted to intensive care unit.

Methods

BAL fluid cellular analysis was evaluated in 47 adult patients who underwent bronchoscopic BAL following less than 24 hours of antimicrobial agent exposure. The abilities of BAL fluid total white blood cell (WBC) counts and differential cell counts to differentiate between bacterial and viral pneumonia were evaluated using receiver operating characteristic (ROC) curve analysis.

Results

Bacterial pneumonia (n = 24) and viral pneumonia (n = 23) were frequently associated with neutrophilic pleocytosis in BAL fluid. BAL fluid median total WBC count (2,815/µL vs. 300/µL, P<0.001) and percentage of neutrophils (80.5% vs. 54.0%, P = 0.02) were significantly higher in the bacterial pneumonia group than in the viral pneumonia group. In ROC curve analysis, BAL fluid total WBC count showed the best discrimination, with an area under the curve of 0.855 (95% CI, 0.750–0.960). BAL fluid total WBC count ≥510/µL had a sensitivity of 83.3%, specificity of 78.3%, positive likelihood ratio (PLR) of 3.83, and negative likelihood ratio (NLR) of 0.21. When analyzed in combination with serum procalcitonin or C-reactive protein, sensitivity was 95.8%, specificity was 95.7%, PLR was 8.63, and NLR was 0.07. BAL fluid total WBC count ≥510/µL was an independent predictor of bacterial pneumonia with an adjusted odds ratio of 13.5 in multiple logistic regression analysis.

Conclusions

Cellular analysis of BAL fluid can aid early differential diagnosis of bacterial pneumonia from viral pneumonia in critically ill patients.     

炎症因子在大叶性肺炎患儿支气管肺泡灌洗液及血清中的表达及临床意义

目的:探讨炎症因子在大叶性肺炎患儿支气管肺泡灌洗液及血清中的表达水平及其临床意义。方法:收集2014年6月至2016年6月我院儿科收治的79例大叶性肺炎患儿为病例组,按照临床肺部感染评分(CPIS)分为重度组(n=46)和轻度组(n=33),于同期随机选取30例健康儿童为对照组,采用双抗体夹心酶联免疫吸附法(ELISA)检测各组支气管肺泡灌洗液及血清炎症因子如白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、白细胞介素-17(IL-17)、肿瘤坏死因子(TNF-α)以及高迁移率族蛋白B1(HMGB1)表达水平。结果:重度组、轻度组血清IL-6、IL-8、IL-17、TNF-α及HMGB1水平高于对照组,重度组血清IL-6、IL-8、IL-17、TNF-α及HMGB1水平高于轻度组,差异有统计学意义(P0.05)。病例组患儿支气管肺泡灌洗液IL-6、IL-8、IL-17、TNF-α及HMGB1水平高于血清,差异有统计学意义(P0.05)。重度组、轻度组支气管肺泡灌洗液IL-6、IL-8、IL-17、TNF-α及HMGB1水平高于血清,差异有统计学意义(P0.05),重度组支气管肺泡灌洗液、血清IL-6、IL-8、IL-17、TNF-α及HMGB1水平分别高于轻度组,差异有统计学意义(P0.05)。经Spearman积矩相关分析,支气管肺泡灌洗液与血清中IL-6、IL-8、IL-17、TNF-α及HMGB1水平分别呈正相关关系(r=0.711、0.695、0.752、0.793、0.728,P0.05)。结论:炎症因子在大叶性肺炎患儿支气管肺泡灌洗液及血清中呈高表达,并与大叶性肺炎病情严重程度密切相关,联合检测有助于早期评估病情。     

Analysis of Trace Elements in Bronchoalveolar Lavage of Patients with Diffuse Lung Diseases

Airborne trace elements are implicated in the etio-pathogenesis of a large number of pulmonary diseases. The aim of this study was to evaluate the reliability and effectiveness of direct determination of Cd, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn concentrations in bronchoalveolar lavage (BAL) samples from patients with sarcoidosis, idiopathic pulmonary fibrosis, and Langerhans cell histiocytosis and healthy (smoking and non-smoking) controls. A total of 44 individuals were recruited among sarcoidosis, idiopathic pulmonary fibrosis, and Langerhans cell histiocytosis patients and healthy (smoking and non-smoking) controls. Average Mn concentrations in BAL from patients were 45% lower than in controls (p < 0.01) and remarkable decreases in average concentrations of Cr, Ni and Zn were also found in BAL from patients with idiopathic pulmonary fibrosis and Langerhans cell histiocytosis. As these diseases are characterized by the enhanced activation of certain immunomodulatory cells and by generation of free radicals, the depressed Mn, Zn, Cr and Ni concentrations in BAL from patients may be due to oxidative stress. These preliminary results indicate that assessment of the elemental composition of BAL is a promising approach to study the pathogenesis of diffuse lung diseases and Langerhans cell histiocytosis.     

Investigating the Link between Alpha-1 Antitrypsin and Human Neutrophil Elastase in Bronchoalveolar Lavage Fluid of COVID-19 Patients

Neutrophils play a pathogenic role in COVID-19 by releasing Neutrophils Extracellular Traps (NETs) or human neutrophil elastase (HNE). Given that HNE is inhibited by α1-antitrypsin (AAT), we aimed to assess the content of HNE, α1-antitrypsin (AAT) and HNE–AAT complexes (the AAT/HNE balance) in 33 bronchoalveolar lavage fluid (BALf) samples from COVID-19 patients. These samples were submitted for Gel-Electrophoresis, Western Blot and ELISA, and proteins (bound to AAT or HNE) were identified by Liquid Chromatography-Mass Spectrometry. NETs’ release was analyzed by confocal microscopy. Both HNE and AAT were clearly detectable in BALf at high levels. Contrary to what was previously observed in other settings, the formation of HNE–AAT complex was not detected in COVID-19. Rather, HNE was found to be bound to acute phase proteins, histones and C3. Due to the relevant role of NETs, we assessed the ability of free AAT to bind to histones. While confirming this binding, AAT was not able to inhibit NET formation. In conclusion, despite the finding of a high burden of free and bound HNE, the lack of the HNE–AAT inhibitory complex in COVID-19 BALf demonstrates that AAT is not able to block HNE activity. Furthermore, while binding to histones, AAT does not prevent NET formation nor their noxious activity.     

Bronchoalveolar lavage in an immunosuppressed rabbit model of invasive pulmonary aspergillosis

A rabbit model of invasive aspergillosis has been used to investigate the pathogenesis of Aspergillus infection in the immunosuppressed host. The animals received hydrocortisone daily and a single dose of cyclophosphamide 2 days prior to intratracheal instillation of conidia from Aspergillus fumigatus. Bronchoalveolar lavage (BAL) was performed in 3 infected and 2 control saline treated animals sacrificed on days 1, 2, 4, 7 and 10 following inoculation. Infective load within the lung was quantified using an assay for chitin which is an important component of fungal cell walls (in particular the hyphal cell wall) and is not present in vertebrate tissue. The total BAL white cell count did not discriminate between infected and saline treated animals and Aspergillus was cultured from one lavage specimen only. Infected animals developed a marked neutrophil alveolitis by day 2 in contrast to a near total absence of neutrophils in the lavages of the control animals. Phagocytosis of conidia by alveolar macrophages was prominent but did not prevent progressive infection as confirmed by measurement of lung chitin. This pattern of cellular response within the alveolar airspace reflects the complex nature of the response to Aspergillus infection in the immunosuppressed host.     

Analysis of Cellular Response and Gamma Interferon Synthesis in Bronchoalveolar Lavage Fluid and Lung Homogenate of Mice Infected with Pneumocystis carinii

The cellular and cytokine responses in the lungs of mice infected with Pneumocystis carinii were examined on both lung homogenates and bronchoalveolar lavage (BAL) fluids. In the lungs of infected mice, the number of P. carinii cysts rapidly decreased by day 7, then started to increase with a peak on day 14, and thereafter decreased gradually. When the presence of P. carinii was examined at the DNA level by dot blot hybridization, a similar clearance curve was obtained, and the organisms were shown to be completely eliminated on day 28. In the late phase of infection, leukocytes, mainly lymphocytes, increased in number when analyzed on lung homogenates, while no significant increase of inflammatory cells was observed in BAL fluids. An accumulation of both CD4⁺ and CD8⁺ T cells and an increase of activated T cells expressing IL-2Rα were observed in lung homogenates of the infected mice. In addition, a considerable amount of IFN-γ was detected in lung homogenates, but not in BAL fluids. These data indicate that lung homogenates are more suitable than BAL fluids for the analysis of cellular and cytokine responses in the lungs of mice infected with P. carinii. To define the involvement of IFN-γ in host defense against P. carinii, the effect of this cytokine on the killing activity of macrophages against P. carinii was examined in vitro. IFN-γ was found to augment this activity by increasing nitric oxide synthesis of the macrophages. Thus, it is suggested that IFN-γ plays an important role in the protection of mice from P. carinii infection.     

支气管镜下肺泡灌洗对难治性肺炎患者炎症介质和肺功能的影响

目的:探讨支气管镜下肺泡灌洗对难治性肺炎患者炎症介质和肺功能的影响。方法:选择2013年1月~2015年12月在我院进行诊治的难治性肺炎患者100例,随机分为两组。对照组采取常规的临床治疗,观察组在常规治疗基础上采用支气管镜联合支气管肺泡灌洗治疗。观察两组的治疗效果以及对患者炎症介质和肺功能的影响。结果:观察组的有效率为90.00%(45/50),明显高于对照组的76.00%(38/50)(P0.05)。治疗后,两组肺泡灌洗液中的内毒素、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)和脂质过氧化物(LPO)水平均较治疗前明显降低(P0.05),且观察组降低的更为明显(P0.05);两组的肺功能均较治疗前明显改善(P0.05),且观察组改善的更为明显(P0.05)。结论:支气管镜下肺泡灌洗对难治性肺炎患者具有较好的治疗效果,可以有效降低炎症介质水平,并改善患者肺功能。     

Proteomic Profiling of Bronchoalveolar Lavage Fluid in Critically Ill Patients with Ventilator-Associated Pneumonia

Rationale

Ventilator-associated pneumonia (VAP) is a common complication in patients with acute lung injury (ALI) and can lead to increased morbidity and mortality. Identifying protein profiles specific to VAP in bronchoalveolar lavage fluid (BALF) may aid in earlier diagnosis, elucidate mechanisms of disease, and identify putative targets for therapeutic intervention.

Methods

BALF was obtained from 5 normal subjects and 30 ALI patients: 14 with VAP (VAP⁺) and 16 without VAP (VAP^–). Each sample underwent shotgun proteomic analysis based on tandem mass spectrometry. Differentially expressed proteins between the groups were identified using statistical methods based on spectral counting. Mechanisms of disease were explored using functional annotation and protein interaction network analysis. Supervised classification algorithms were implemented to discover a proteomic classifier for identifying critically ill patients with VAP.

Results

ALI patients had distinct BALF proteomic profiles compared to normal controls. Within the ALI group, we identified 76 differentially expressed proteins between VAP⁺ and VAP^–. Functional analysis of these proteins suggested activation of pro-inflammatory pathways during VAP. We identified and validated a limited proteomic signature that discriminated VAP⁺ from VAP^– patients comprised of three proteins: S100A8, lactotransferrin (LTF), and actinin 1 (ACTN1).

Conclusions

Combining proteomic with computational analyses is a powerful approach to study the BALF proteome during lung injury and development of VAP. This integrative methodology is a promising strategy to differentiate clinically relevant subsets of ALI patients, including those suffering from VAP.     

肺泡灌洗技术对重症支原体肺炎患儿血清炎症因子及肺功能的影响

目的:探讨支气管肺泡灌洗液(Bronchoalveolar Lavage Fluid,BALF)技术应用于儿科重症支原体肺炎(Severe Mycoplasma Pneumoniae Pneumonia,SMPP)对患儿的血清炎症因子表达影响及肺功能的变化,旨在为临床上SMPP的诊治提供科学参考。方法:回顾性选取我院收治的SMPP患儿83例,按照治疗方式不同,分为两组,对照组41例,静滴阿奇霉素,研究组42例,采用静滴阿奇霉素3-5天行BALF灌洗生理盐水+布地奈德治疗。于治疗7 d后对比两组治疗前后及组间肺功能和炎症指标的变化。结果:研究组IL-2、IL-6、IL-10表达水平均较对照组显著降低,差异有统计学差异(P0.05);研究组mPAP、PAWP、PVR均比对照组下降明显,差异有显著性意义(P0.05)。结论:BALF技术可明显改善患儿炎症因子表达,对促进患儿肺功能恢复正常有良好作用,适用于儿童SMPP的治疗。     

Bronchoalveolar fluid and plasma inflammatory biomarkers in contemporary ARDS patients

Purpose: Bronchoalveolar fluid (BALF) and plasma biomarkers are often endpoints in early phase randomized trials (RCTs) in acute respiratory distress syndrome (ARDS). With ARDS mortality decreasing, we analyzed baseline biomarkers in samples from contemporary ARDS patients participating in a prior RCT and compared these to historical controls.

Materials and methods: Ninety ARDS adult patients enrolled in the parent trial. BALF and blood were collected at baseline, day 4?±?1, and day 8?±?1. Interleukins-8/-6/-1β/-1 receptor antagonist/-10; granulocyte colony stimulating factor; monocyte chemotactic protein-1; tumour necrosis factor-α; surfactant protein-D; von Willebrand factor; leukotriene B₄; receptor for advanced glycosylation end products; soluble Fas ligand; and neutrophil counts were measured.

Results: Compared to historical measurements, our values were generally substantially lower, despite our participants being similar to historical controls. For example, our BALF IL-8 and plasma IL-6 were notably lower than in a 1999 RCT of low tidal volume ventilation and a 2007 biomarker study, respectively.

Conclusions: Baseline biomarker levels in current ARDS patients are substantially lower than 6–20?years before collection of these samples. These findings, whether from ICU care changes resulting in less inflammation or from variation in assay techniques over time, have important implications for design of future RCTs with biomarkers as endpoints.     

Analysis of Trace and Major Elements in Bronchoalveolar Lavage Fluid of Mycoplasma Bronchopneumonia in Calves

The aim of this study was to evaluate the reliability and effectiveness of direct determination of trace and major element concentrations in bronchoalveolar lavage fluid samples from Holstein calves with Mycoplasma bronchopneumonia (n = 21) and healthy controls (n = 20). The samples were obtained during bronchoscopy using a standard examination method. A total of 18 elements (aluminum, bromine, calcium, chlorine, chromium, copper, iron, potassium, magnesium, manganese, molybdenum, nickel, phosphorous, sulfur, silicon, strontium, titanium, and zinc) were detected by particle-induced X-ray emission. The average bromine, iron, potassium, magnesium, and phosphorous concentrations were higher in calves with bronchopneumonia than in controls (p < 0.05). They were found to have higher amounts of calcium and zinc, and a higher zinc–copper ratio than that in healthy calves (p < 0.001). Based on the receiver operating characteristics curves, we propose a diagnostic cutoff point for zinc–copper ratio for identification of Mycoplasma pneumonia of 8.676. Our results indicate that assessment of the elemental composition of broncholaveolar lavage fluid is a promising diagnostic tool for Mycoplasma bronchopneumonia.