Empiric treatments impair the diagnostic yield of BAL in HIV-positive patients

What are the factors affecting the recovery rate of bronchoalveolar lavage fluid?

BACKGROUND

Bronchoalveolar lavage (BAL) is a useful examination for the evaluation of interstitial lung disease. A high BAL fluid (BALF) recovery rate is desirable because low recovery rates lead to inaccurate diagnoses and increased adverse events. Few studies have explored whether BALF recovery rates are influenced by clinical factors.

OBJECTIVES

This study aimed to identify the clinical parameters affecting the recovery rates of BALF and the extent of their effects.

METHOD

Data from patients who underwent BAL at the Chiba University Hospital between 2013 and 2019 were retrospectively reviewed. BAL was performed with three aliquots of 50-ml physiological saline. The potential association of the BALF recovery rate with clinical parameters such as age, sex, smoking status, underlying disease, bronchus used for the procedure and pulmonary function, was analysed.

RESULTS

Eight hundred twenty-six patients had undergone BAL. The average recovery rate was 52.4%. Factors affecting BALF recovery rates included male sex (odds ratio [OR]: 0.32, 95% confidence interval [CI]: 0.20-0.53, p < 0.001); age ≥ 65 years (OR: 0.50, 95% CI: 0.33-0.76, p < 0.001); use of the left bronchus (OR: 0.46, 95% CI: 0.30-0.71, p = 0.001) and bronchi other than the middle lobe bronchus or lingula (OR: 0.41, 95% CI: 0.25-0.65, p < 0.001); and forced expiratory volume in 1 s divided by forced vital capacity <80% (OR: 0.42, 95% CI: 0.40-1.00, p < 0.001).

CONCLUSION

Sex, age, bronchus used for the procedure and pulmonary function may be useful as pre-procedural predictors of BALF recovery rates.

Diagnosing Pneumocystis jirovecii pneumonia: A review of current methods and novel approaches

Pneumocystis jirovecii can cause life-threatening pneumonia in immunocompromised patients. Traditional diagnostic testing has relied on staining and direct visualization of the life-forms in bronchoalveolar lavage fluid. This method has proven insensitive, and invasive procedures may be needed to obtain adequate samples. Molecular methods of detection such as polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and antibody-antigen assays have been developed in an effort to solve these problems. These techniques are very sensitive and have the potential to detect Pneumocystis life-forms in noninvasive samples such as sputum, oral washes, nasopharyngeal aspirates, and serum. This review evaluates 100 studies that compare use of various diagnostic tests for Pneumocystis jirovecii pneumonia (PCP) in patient samples. Novel diagnostic methods have been widely used in the research setting but have faced barriers to clinical implementation including: interpretation of low fungal burdens, standardization of techniques, integration into resource-poor settings, poor understanding of the impact of host factors, geographic variations in the organism, heterogeneity of studies, and limited clinician recognition of PCP. Addressing these barriers will require identification of phenotypes that progress to PCP and diagnostic cut-offs for colonization, generation of life-form specific markers, comparison of commercial PCR assays, investigation of cost-effective point of care options, evaluation of host factors such as HIV status that may impact diagnosis, and identification of markers of genetic diversity that may be useful in diagnostic panels. Performing high-quality studies and educating physicians will be crucial to improve the rates of diagnosis of PCP and ultimately to improve patient outcomes.

Flexible Fiberoptic Bronchoscopy: Indications, Diagnostic Yield and Complications

Objective

Flexible fiberoptic bronchoscopy (FFB) has become an essential procedure for diagnosing and managing various respiratory conditions. We aimed to assess the main indications, diagnostic yield, and safety of FFB in our institute.

Methods

A total of 216 patients who underwent FFB between July 2009 and June 2012 at King Abdul-Aziz Medical City, Jeddah, Saudi Arabia, were reviewed retrospectively. Indications of the procedure, the diagnostic yield of variable respiratory diseases, and complications were reported.

Result

Out of 216 patients, 210 (97.2%) completed FFB. One hundred and ninety-eight (91.7%) bronchoscopies were for diagnostic purposes, and the remaining 12 (5.6%) were for therapeutic aim. The mean age of patients was 50 years ± 20 years and patients. Respiratory infection, malignancy, pulmonary infiltrate in febrile neutropenia (FN), and hemoptysis in order of frequency were the main indications. The overall diagnostic yield was 46%. Mycobacterium tuberculosis (MTB) was the most common indication (26.8%) and was identified in 37.7%, whereas pneumonia was confirmed in 46.3% of the patients. Malignancy was established in 35.3% of suspected cases, while eosinophilic pneumonia was diagnosed in 100%. The diagnostic yield in pulmonary infiltrates of human immunodeficiency viral (HIV) was 85.7%. Alveolar hemorrhage was the most common cause of hemoptysis. Out of therapeutic bronchoscopy, lung collapse was the main indication. There is no mortality and complications occurred in 1.5% of the cases.

Conclusion

MTB was the most common indication of FFB, followed by malignancy. It has a high diagnostic yield in eosinophilic pneumonia and pulmonary infiltrates in HIV patients. FFB is shown to be a safe modality for diagnostic and therapeutic purposes.   

Clinical utility of bronchoalveolar lavage and respiratory tract biopsies in diagnosis and management of suspected invasive respiratory fungal infections in children

BACKGROUND

Bronchoscopy with bronchoalveolar lavage (BAL) and respiratory tract biopsies are important tools for diagnosing fungal infections in children with cancer and hematopoietic stem cell transplant (HSCT) recipients. Our objective was to evaluate the impact of BAL and respiratory tract biopsies on the management of suspected fungal infections in oncology and HSCT patients.

PROCEDURE

We retrospectively reviewed the medical records of oncology and HSCT patients with possible, probable, or proven fungal infection of the respiratory tract and determined whether BAL or biopsy following computed tomography (CT) prompted a change in management.

RESULTS

Among 101 patients (0.5-29 years of age), 24 underwent a BAL and 31 had biopsies (27 lung and 4 sinus). The remaining 46 patients had CT scans only. Of these, there were radiographic findings suggestive of a fungal infection in 38 patients (83%). Thirty of these 38 patients (79%) had a change in management. BAL provided a diagnosis in 6 of 24 patients (25%). There was a change in management in 2 of the 6 (33%). Respiratory tract biopsy provided a diagnosis in 12 of 31 patients (39%). Biopsy results led to a change in management in 4 of the 12 patients (33%). Significant postoperative morbidity attributed to biopsy occurred in 3 of 31 patients (10%); 2 patients had pneumothorax requiring chest tube and intubation and a patient had prolonged intubation.

CONCLUSION

BAL and biopsy in children with an oncological diagnosis or those undergoing HSCT only infrequently lead to changes in management in the era of empiric therapy with broad-spectrum anti-fungal agents.

Serum and bal beta-D-glucan for the diagnosis of Pneumocystis pneumonia in HIV positive patients

BACKGROUND/PURPOSE

The diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-β -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi.

METHODS

We analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP.

RESULTS

The discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%,72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137).

CONCLUSION

The measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP.

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.

Laboratory diagnosis of pulmonary tuberculosis in TB and HIV endemic settings and the contribution of real time PCR for M. tuberculosis in bronchoalveolar lavage fluid

BACKGROUND

Tuberculosis (TB) in Africa is increasing because of the human immunodeficiency virus (HIV) epidemic, and in HIV/AIDS patients it presents atypically. Pulmonary tuberculosis (PTB) in Africa is mainly diagnosed clinically, by chest radiograph or by sputum smear for acid fast bacilli (AFB).

METHODS

We evaluated in 120 HIV-infected patients with chest infection the diagnostic accuracy of AFB smear of sputum and bronchoalveolar lavage (BAL) fluid, sputum Mycobacterium tuberculosis (MTB) culture, real-time PCR and MycoDot serological test, using MTB culture of BAL fluid as gold standard. We correlated PCR cycle threshold values (C(T)) to the culture results. Retrospectively, we evaluated the development of active TB in patients with positive PCR but negative culture.

RESULTS

Culture of BAL fluid identified 28 patients with PTB. Fifty-six patients could not produce adequate sputum. Sputum AFB smear and the serological test had sensitivities of 66.7% and 0%, respectively. PCR with C(T) 40 was positive in 73 patients, 27 of whom were also TB culture positive (96.4% sensitivity and 52.3% specificity of PCR). PCR with C(T) 32 had sensitivity of 85.7% and specificity of 90.9% to diagnose PTB in BAL. No patients with positive PCR but negative culture developed active TB during 18 months follow-up.

CONCLUSION

In these HIV-infected patients, AFB smear and serology had very low sensitivities. PCR of BAL with C(T) value 32 had improved specificity to diagnose active PTB. A prospective follow-up study is warranted in TB/HIV endemic settings, applying real time PCR to both sputum and BAL.

BAL neutrophils, serum procalcitonin, and C-reactive protein to predict bacterial infection in the immunocompromised host

BACKGROUND

Bacterial pulmonary infection is a common life-threatening complication in immunocompromised patients. The results of BAL cultures are not immediately available, and their microbiological yield might be limited by empiric antibiotic prescriptions. We evaluated clinical signs and symptoms, leukocyte counts, C-reactive protein (CRP) levels, procalcitonin levels, and BAL fluid neutrophil percentages as potential markers for bacterial infection in a cohort of immunocompromised patients with pulmonary complications.

METHODS

One hundred seven consecutive patients who had been referred for bronchoscopy due to suspected pulmonary infection were included in this study. Based on clinical, laboratory, radiologic, microbiological, and histologic results, patients were classified as having proven bacterial infection (n = 27), possible bacterial infection (n = 11), and no bacterial infection (n = 69).

RESULTS

Most common underlying conditions were hematologic malignancy (n = 62) and solid organ transplantation (n = 20). Clinical parameters were similar in patients with and without bacterial infection (difference was not significant). The percentage of BAL fluid neutrophils had the highest area under the curve (0.818; 95% confidence interval [CI], 0.700 to 0.935; p < 0.001), followed by absolute neutrophil counts (0.797; 95% CI, 0.678 to 0.916; p < 0.001), procalcitonin level (0.746; 95% CI, 0.602 to 0.889; p = 0.001), and CRP level (0.688; 95% CI, 0.555 to 0.821; p = 0.015) to predict proven bacterial infection (in opposition to no or possible bacterial infection) in the receiver operating characteristic analysis. Conversely, neither infiltrates (p = 0.123) nor leukocyte counts (p = 0.429) were useful in diagnosing bacterial infection. The percentage of BAL fluid neutrophils and procalcitonin level were independent predictors of bacterial infection in the multivariate regression.

CONCLUSIONS

Neutrophil percentage in BAL fluid, procalcitonin level, and CRP level might be potentially useful to differentiate bacterial infection from nonbacterial conditions in immunocompromised hosts with pulmonary complications.

O escarro induzido no diagnóstico das doenças pulmonares em pacientes positivos ao vírus da imunodeficiência humana

INTRODUÇÃO: O escarro induzido é utilizado para monitorar a inflamação de vias aéreas, porém seu papel como ferramenta diagnóstica de doenças pulmonares em pacientes imunocomprometidos ainda necessita de melhor definição. OBJETIVOS: Determinar o rendimento do escarro induzido no diagnóstico das doenças pulmonares em pacientes positivos ao virus da imunodeficiência humana (HIV). MÉTODO: No período de janeiro de 2001 a setembro de 2002, foram avaliados todos os pacientes com idade superior a 14 anos, infectados com o HIV, admitidos em Hospital de Referência. Foram incluídos aqueles indivíduos que apresentavam manifestações clínicas do aparelho respiratório há pelo menos 7 dias, associadas, ou não, a alterações radiológicas, bem como indivíduos assintomáticos do ponto de vista respiratório, com alterações no radiograma de tórax. Os pacientes foram submetidos à avaliação clínica, radiológica e laboratorial e realizaram a indução de escarro, seguida pela broncofibroscopia, lavado broncoalveolar e biópsia pulmonar transbrônquica. As amostras foram processadas para bacterioscopia pelo método de Gram e Ziehl-Neelsen, cultura quantitativa para bactérias, exame micológico direto, cultura para micobactérias e fungos, pesquisa de citomegalovírus e Pneumocystis jiroveci, bem como celularidade total e diferencial. RESULTADOS: 54 pacientes foram incluídos no estudo. A pesquisa de agente etiológico resultou negativa em 7 pacientes, sendo que nos casos restantes foram isolados 60 agentes. Dentre os agentes isolados, 46,7% foram P. jiroveci; 33,5% bactérias piogênicas e 16,7% Mycobacterium tuberculosis. O escarro induzido apresentou sensibilidade de 57,5%, especificidade de 42,9%, valor preditivo positivo de 87,1%, valor preditivo negativo de 13% e acurácia de 55,6%. CONCLUSÕES: Nesta população, a análise do escarro induzido é um procedimento simples, seguro e com bom rendimento diagnóstico.

Role of flexible bronchoscopy in immunocompromised patients with lung infiltrates

STUDY OBJECTIVE

To study the diagnostic role of flexible bronchoscopy (FB) in immunocompromised patients with pulmonary infiltrates.

DESIGN

Prospective, observational study.

SETTING

Tertiary care hospital.

PATIENTS

A total of 104 consecutive non-HIV-infected immunocompromised patients with lung infiltrates in whom FB was performed.

METHODS

The primary outcome measure was the diagnostic yield of FB, which was derived as the number of the diagnoses made using FB results divided by all final diagnoses. Final diagnoses were established using data from FB, surgical lung biopsy (SLB), and microbiology and serology testing, and by the clinical response to empiric therapy. We also studied the diagnostic yields of individual sampling procedures such as BAL, transbronchial biopsy (TBB), and protected-specimen brush (PSB) sampling.

RESULTS

Overall, 128 diagnoses were made in 104 patients. The overall diagnostic yield of FB was 56.2% (95% confidence interval [CI], 47 to 64%). FB provided at least one diagnosis in 53 of 104 patients (51%; 95% CI, 40 to 62%). FB was more likely to establish the diagnosis when the lung infiltrate was due to an infectious agent (81%; 95% CI, 67 to 90%) than to a noninfectious process (56%; 95% CI, 43 to 67%; p = 0.011). The diagnostic yields of BAL (38%; 95% CI, 30 to 47%) and TBB (38%; 95% CI, 27 to 51%) were similar (p = 0.94). The diagnostic yield of PSB sampling was lower (13%; 95% CI 6 to 24%; p = 0.001) than that of BAL. The combined diagnostic yield of BAL and TBB (70%; 95% CI, 57 to 80%) was higher than that of BAL alone (p < 0.001). Finally, the diagnostic yield of FB with PSB sampling, BAL, and TBB was similar to that of FB with BAL and TBB. The complication rate from FB was 21% (95% CI, 15 to 31%). Minor bleeding (13%) and pneumothorax (4%) were the most common complications.

CONCLUSIONS

FB has a high diagnostic yield in immunocompromised patients with pulmonary infiltrates. Based on our results, we recommend performing TBB in these patients, whenever possible.

[Identification of infectious agents in the lungs in autopsies of patients with acquired immunodeficiency syndrome]

Lung diseases are frequently observed in individuals infected with HIV. The aim of this study was to identify infectious agents in the lungs in the autopsied individuals with AIDS performed between march 1990 and july 2000 at the school of medicine (Uberaba- Brazil), using histochemical and immunohistochemical techniques. Analysis was made on lungs obtained from 40 individuals with AIDS. Infectious agents were observed in 34 (85%) cases of the 40 analyzed. Regarding fungis, Pneumocystis carinii was found in 8 (19.1%)cases; Cryptococcus sp in 4 (9.5%)cases, Histoplasma sp in 2 (4.8%)cases and Candida sp in 1 (2.4%)case. Association of Pneumocystis carinii, Citomegalovirus and Cryptococcus sp, was observed in one case, and in another, the association of CMV, and Toxoplasma gondii. There were 5 cases with Candida sp, CMV and Pneumocystis carinii associated with bacteria. In conclusion, this study shows that following bacterial agents fungi were the second most common infectious agents in post mortem examination of the lungs from patients with AIDS, being Pneumocystis carinii the most prevalent.

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.