Rapid detection of cytomegalovirus in bronchoalveolar lavage specimens by a monoclonal antibody method.

Cytomegalovirus (CMV), a common cause of pneumonia in immunocompromised subjects, is conventionally diagnosed in the laboratory by tube cell culture assays or by detection of characteristic inclusions in histologic sections. Of 160 immunocompromised patients, CMV infection was diagnosed in 19 subjects by bronchoalveolar lavage (BAL), using a monoclonal antibody directed against an early nuclear antigen of the virus. Cytospin preparations from BAL and MRC-5 cell cultures inoculated with the BAL specimens yielded positive results for 6 (31.6%) and 18 (94%) of the 19 subjects, respectively, within hours of the bronchoscopic procedure, whereas conventional tube cell cultures were positive for 11 of the 19 subjects (57.9%) only after an average of 9.3 days. The monoclonal antibody method permitted easy and rapid detection of CMV in BAL specimens.     

Identification of Acanthamoeba in bronchoalveolar lavage specimens.

Acanthamoeba species infect humans occasionally and act as opportunistic pathogens in immunocompromised individuals. This study demonstrates the application of cytocentrifugation as an aid to identification of Acanthamoebae. In addition, certain staining procedures clearly optimized visualization of characteristic amoebic features. This was demonstrated by adding amoebae from laboratory cultures to bronchoalveolar lavage specimens. In preparations stained by the Papanicolaou, trichrome, or hematoxylin-eosin (H&E) procedures, the discrete deeper staining nucleolus was the most distinctive feature. The vacuolated cytoplasm also aided in the identification of amoebae. These features were less apparent and often distorted following staining of Acanthamoeba species with the Hema III and Giemsa procedures.     

Epithelial cell atypia in bronchoalveolar lavage specimens from lung transplant recipients.

In lung transplant recipients, bronchoalveolar lavage (BAL) is mainly performed to detect infectious agents. However, in addition to microorganisms, epithelial cell atypia may be identified, and determination of its significance is necessary. Specimens obtained at BAL in lung and heart-lung transplant recipients (LTRs) between 1991 and 1998 were examined for the presence of significant cytologic atypia in epithelial cells. Ten cases in 9 patients were identified, and these composed the core of our study. These transplant BAL specimens were compared with 4 BAL specimens with carcinoma from non-transplant patients (NTPs). Fourteen cytologic parameters were evaluated, and clinical and biopsy correlation was made in each case. Significant overlap in cytologic features, including background cellularity, number of atypical cell clusters, number of cells in each cluster, size of cell clusters, contour of clusters, 3-dimensionality, tenacious intercytoplasmic connections, multinucleation, nuclear size, nuclear/cytoplasmic ratio, nuclear membrane irregularity, chromatin pattern, intranuclear inclusions, and nucleolar characteristics, was observed between atypical LTR cases and NTP carcinoma cases. Clinically, all LTR cases derived from nonneoplastic conditions including harvest injury (diffuse alveolar damage), acute cellular rejection, and infections. Our study results show that evaluation of cytologic features alone does not permit differentiation of atypical cells found in nonneoplastic conditions from those in malignant conditions. Clinical and histologic correlation and awareness of the range of atypia seen in posttransplant syndromes is important in correct interpretation of these cases.     

Optimal use of the cytocentrifuge for recovery and diagnosis of Pneumocystis carinii in bronchoalveolar lavage and sputum specimens.

To facilitate the diagnosis of Pneumocystis carinii from bronchoalveolar lavage and sputum specimens, we have defined conditions for optimal use of the cytocentrifuge for this purpose. Centrifugation in the cytocentrifuge at 1,200 rpm for 10 min yielded the best recovery of P. carinii. To reliably ensure complete absorption of the fluid specimen from the cytocentrifuge chamber, it was necessary to use two absorption filters simultaneously. Different methods of treating induced sputum with mucolytic agents to process sputum with the cytocentrifuge were tried. Results of these studies and our current method for treating sputa are discussed. Comparisons of slides prepared by traditional centrifugation and by cytocentrifuge processing showed the latter to be equally effective for detecting P. carinii. The most prominent advantage of the cytocentrifuge was the much smaller area to review and consequently the shortened time required to read the slides.     

Correlation between viral loads of cytomegalovirus in blood and bronchoalveolar lavage specimens from lung transplant recipients determined by histology and immunohistochemistry

Cytomegalovirus (CMV) is an important pathogen in lung transplant recipients. Early detection of CMV end-organ disease should help with treatment management. We determined the CMV viral load by hybrid capture in bronchoalveolar lavage (BAL) fluid samples from patients who had undergone lung transplantation. For 39 of these samples (from 25 patients), corresponding transbronchial biopsy samples were available for CMV immunohistochemistry (IHC). The CMV IHC results were interpreted and categorized as positive or negative, and the positive results were subcategorized as typical if cells with both significant nuclear enlargement or Cowdry A-type inclusions and positive staining were present or as atypical if definitive nuclear staining was seen but significant nuclear enlargement was not. Diagnostic CMV viral inclusions were reported in the anatomic diagnosis, based on hematoxylin-eosin staining alone, for three (8%) of the biopsy samples. CMV was detected by IHC in 13 (33%) samples (5 typical, 8 atypical). The median CMV viral load in BAL samples was 0 copies/ml for BAL samples from patients with IHC-negative biopsy samples; 47,678 copies/ml for BAL samples from patients with biopsy samples with positive, atypical staining; and 1,548,827 copies/ml for BAL samples from patients with biopsy samples with positive, typical staining (P < 0.001). Compared to routine pathology of biopsy samples, the use of IHC increased the diagnostic yield of CMV. Also, the CMV viral load in BAL fluid samples increased along with immunoreactivity from negative to positive, atypical staining to positive, typical staining. The CMV viral load determined with the end-organ sample, the BAL fluid sample, was higher than the corresponding viral load determined with blood. Both IHC and determination of the CMV viral load in BAL samples may be useful for the detection of individuals at risk for the development of fulminant invasive CMV disease.     

Detection of cytomegalovirus in bronchoalveolar lavage: a comparison of techniques.

Cytomegalovirus (CMV) is a common cause of lower respiratory tract infections in immunocompromised individuals. Bronchoalveolar lavage (BAL) is a noninvasive means to procure large numbers of bronchial and alveolar cells from the lung. To assess various methods of detecting CMV in the lavage specimen, 26 BAL specimens from 16 patients at high risk for CMV infection were evaluated. The methods and time required for analysis were the following: cytologic examination of Papanicolaou-stained membrane filters (1 h); viral cytopathic effects in tissue culture (days to weeks); spin amplification followed by staining with a monoclonal antibody for detection of CMV early nuclear antigen (18 h); and in situ hybridization (IH) with a biotinylated complementary DNA (cDNA) CMV probe (5 h). CMV was detected in 11 of 26 (42%) specimens by the early antigen assay, ten of 26 (38%) by in situ hybridization, five of 26 (19%) by tissue culture, and three of 26 (12%) by routine cytology. The absence of diagnostic CMV nuclear and/or cytoplasmic inclusions in many specimens positive by in situ hybridization and/or early antigen detection assay may be in part due to low levels of viral replication, insufficient for the development of diagnostic inclusions. These data show that techniques using in situ hybridization or fluorescent anti-CMV antibodies are rapid and are more sensitive for CMV identification than both cytomorphological examination and traditional tissue culture methods. Additional studies are required to determine the clinical significance of early CMV detection by in situ hybridization and early nuclear antigen detection assays.     

Rapid detection of cytomegalovirus in bronchoalveolar lavage specimens from marrow transplant patients: evaluation of a direct fluorescein-conjugated monoclonal antibody reagent

An FITC-conjugated monoclonal antibody reagent containing three CMV-specific monoclonal antibodies was evaluated for the rapid detection of CMV in bronchoalveolar lavage (BAL) cytospin preparations by direct IF (DFA). Eighty-six BAL samples from 72 marrow transplant patients were inoculated into both centrifugation and standard cell culture. CMV was detected in 49/86 (57%) BAL samples. DFA detected 37/46 (80%) samples which were positive in centrifugation culture. While DFA staining lacked the sensitivity (overall sensitivity 38/49, 78%) to replace either standard or centrifugation culture, the total laboratory time needed to complete the DFA was only 1.5 h and its concurrent use with centrifugation culture can provide rapid specific diagnosis of CMV pneumonia.     

Atypical cells in bronchoalveolar lavage specimens from bone marrow transplant recipients. A potential pitfall

Numerous nonneoplastic conditions of the lungs may result in atypical cells in bronchoalveolar lavage (BAL) specimens mimicking malignant neoplasms. Bone marrow transplant (BMT) recipients have many predisposing factors that would lead to atypical cells in BAL specimens, presenting diagnostic challenges. We reviewed BAL specimens from BMT recipients and correlated our findings with clinical information. During a 5.5-year period, 21 BMT recipients had atypical cells in 27 BAL specimens at Fairview-University Medical Center, Minneapolis, MN. The atypical cells had the cytologic features of squamous or glandular cells. The nuclear/cytoplasmic ratio, atypical cells per case, and background varied from case to case. Most of the patients had 1 or more of the clinical findings that would lead to atypia in BAL specimens: 13 had recent cytoreductive treatment, 9 had positive cultures, and 7 had graft-vs-host disease. There was substantial overlap between the reactive atypia and carcinoma. Clinical correlation was the most important factor in making accurate diagnosis.     

Comparative recovery of cytomegalovirus from saliva, mucolysed induced sputum, and bronchoalveolar lavage fluid from patients at risk for or with acquired immunodeficiency syndrome.

The recovery rates of cytomegalovirus from mucolysed induced sputum samples and bronchoalveolar lavage fluid obtained from individuals at risk for or with acquired immunodeficiency syndrome were compared. It was demonstrated that cytomegalovirus could be reliably recovered from mucolysed induced sputum, and such recovery was highly predictive of recovery from bronchoalveolar lavage samples obtained from the same individual.     

Large granular lymphocytes in bronchoalveolar lavage fluids from immunocompromised patients with cytomegalovirus pneumonitis

Natural killer (NK) cells activities had been demonstrated to be depressed in patients with fatal cytomegalovirus (CMV) pneumonitis. NK cells can be identified by morphologic features characteristic of large granular lymphocytes (LGLs). Bronchoalveolar lavage (BAL) cells from 16 immunocompromised patients with CMV pneumonitis were analyzed. Two different groups of patients could be distinguished depending on the course of the CMV pneumonitis: nine patients who recovered (Group A), seven patients with a fatal outcome (Group B). Except for the increase in polymorphonuclear cells (PMN) in Group B (12.4 +/- 11.6%), no significant difference in the macrophage or the total lymphocyte population was observed. A differential count excluding alveolar macrophages specified the percentage of LGLs from the total lymphocyte population. The LGLs in Group A (7.1 +/- 9.9%) were similar to those previously reported in normal lung. A significant increase in LGLs was observed in the BAL cells from patients of Group B (28.1 +/- 22%). The discrepancy between the high percentage of LGLs in patients with a fatal outcome and their expected protective effects is discussed.     

Analysis of bronchoalveolar lavage specimens from immunocompromised patients with a protocol applicable in the microbiology laboratory.

Several studies have concluded that bronchoalveolar lavage (BAL) is a useful technique for diagnosing pulmonary disease in immunocompromised patients, but implementation of a protocol for obtaining, processing, and analyzing BAL specimens in a clinical microbiology laboratory has not been reported. We determined the utility of a laboratory protocol by analyzing 100 BAL specimens from 94 immunocompromised patients. Each BAL specimen was cultured quantitatively for bacteria. A concentrate of each specimen was cultured for fungi, viruses, mycobacteria, and Legionella sp. Slides of the BAL concentrate were prepared by cytocentrifugation and stained by a number of histochemical and fluorescence techniques. Overall diagnostic yields of 81% for infections, 90% for hemorrhage, and 13% for neoplasms were obtained with the patients studied. BAL analysis was incapable of diagnosing drug- or radiation-induced pneumonitis or idiopathic interstitial pneumonitis. After evaluation of the protocol was completed, it was successfully implemented in two university-based clinical microbiology laboratories as a routine diagnostic service.     

Direct detection of cytomegalovirus from bronchoalveolar lavage samples by using a rapid in situ DNA hybridization assay.

An in situ DNA hybridization assay was compared with centrifugation culture for rapid detection of cytomegalovirus (CMV) from bronchoalveolar lavage (BAL) samples. Eighty BAL samples were inoculated into both centrifugation culture and standard culture. Cytospin preparations of the BAL samples were studied in a 75-min in situ DNA hybridization assay using the PathoGene CMV kit (Enzo Biochem, Inc., New York, N.Y.). Of the 80 samples, 39 (49%) were positive for CMV; 37 of 39 (95%) were positive by centrifugation culture, 34 of 39 (87%) were positive in standard culture, 24 of 39 (62%) were positive by in situ hybridization, and 20 of 39 (56%) were positive by histologic and/or immunofluorescence techniques. The in situ hybridization assay detected 23 of the 37 samples positive in centrifugation culture, for a sensitivity of 62% and a specificity of 98%. We conclude that the in situ hybridization assay is a specific and more rapid test than centrifugation culture and standard culture for diagnosis of CMV pulmonary infection. For the clinical laboratory, however, current hybridization methods are not sufficiently sensitive to replace centrifugation culture for detection of CMV in BAL specimens.     

Cloning of T lymphocytes from bronchoalveolar lavage fluid.

We have prepared T-cell clones from bronchoalveolar lavage fluid (BALF) from four healthy, nonsmoking persons and from four patients with allergic asthma. T cells were cloned by direct limiting dilution and with the use of a fluorescent activated cell sorter with an automated cell deposition unit. T-cell clones from the blood (PB) were prepared as well. The cloning efficiencies of T cells from BALF ranged from 3 to 40% and were lower than those obtained from PB T cells (18 to 72%). The cloning conditions generated CD4+ as well as CD8+ clones. The very late antigen-4, VLA-4, was more frequently expressed on CD4+ T-cell clones from BALF than from the blood (P < 0.05). CD8+ clones from BALF were more frequently VLA-1+ than those from blood (P < < 0.01). Mitogen- and monoclonal antibody-driven proliferation of CD4+ clones showed that BALF clones were well responsive to proliferation stimuli similar to those from the blood. Analysis of interleukin-4 production by 10 BALF and 10 PB clones showed large variations between individual CD4+ clones (BALF: range, < 100 to 700 pg/ml; PB: range, < 100 to 1,100 pg/ml), indicating the generation of different types of clones, which was also clear from analysis of interferon-gamma production. The analysis of properties of BALF T-cell clones and their regulation will improve insight into immunologic reactions in the lungs.     

Immunodetection of Pneumocystis carinii in bronchoalveolar lavage specimens compared with methenamine silver stain.

Immunodetection of Pneumocystis carinii, based on immunofluorescence and use of a monoclonal antibody specific for an antigen located within the cyst wall and detectable after trypsin digestion only, was compared with a methenamine silver stain in 553 bronchoalveolar lavage specimens from immunosuppressed patients. P. carinii was found by immunofluorescence in 72 (86%) and by silver stain in 68 (81%) of the total of 84 positive samples detected by either or both of these methods.     

HIV isolation from pulmonary cells derived from bronchoalveolar lavage.

In a study of 75 alveolar cell co-cultures from 55 HIV-seropositive subjects, p24 antigen production was identified by ELISA in 11 out of 26 (42%) of unseparated cell cultures, 15 out of 39 (38%) purified alveolar macrophage cultures and eight out of 10 purified alveolar lymphocyte samples. Positivity in unseparated cell cultures was associated with an alveolar lymphocytosis greater than 30%. Negative macrophage cultures were significantly more likely in the early stages of HIV infection with none positive when the subject had a peripheral CD4+ cell count greater than 300/microliters. Alveolar macrophage infection thus appears to increase with HIV disease progression.     

Quantification of cytomegalovirus in bronchoalveolar lavage fluid after allogeneic marrow transplantation by centrifugation culture.

A technique to quantify cytomegalovirus (CMV) by centrifugation culture of bronchoalveolar lavage fluid from marrow transplant recipients was developed. This technique was used to assess the CMV response to antiviral treatment and the relationship between viral load, asymptomatic excretion versus symptomatic infection, and prognosis. Relative to tube cell culture, centrifugation culture of bronchoalveolar lavage fluid was more sensitive than direct fluorescent-antibody staining. It was also a rapid, replicable method for detecting and measuring the amount of CMV. There was no significant difference between viral load at diagnosis and after 9 days of treatment with ganciclovir and intravenous immunoglobulin. Viral load was not predictive of outcome, and there was no difference in amount of virus between patients with asymptomatic CMV excretion and those with CMV pneumonia. The amount of CMV may not be as important as other factors (e.g., host immune response) in the pathogenesis of CMV pneumonia.     

Direct in situ hybridization for rapid detection of cytomegalovirus in bronchoalveolar lavage

Rapid detection of cytomegalovirus (CMV) from pulmonary specimens in immunosuppressed persons may provide an origin for pneumonia. In situ DNA hybridization has been effective for detection of CMV in otherwise nondiagnostic histologic material. Studies comparing bronchoalveolar lavage (BAL) with open-lung biopsy have shown the former to be superior in detecting most pulmonary pathogens affecting immunocompromised patients. Fifty consecutive BAL specimens were studied to compare direct in situ DNA hybridization, routine tissue culture, and conventional cytologic examination to assess the efficacy of the hybridization technic to rapidly detect CMV. Using tissue culture as the standard, a sensitivity of 90% (28 of 31) and specificity of 63% (12 of 19) were observed with the CMV probe. Discrepant results between the probe and tissue culture were present in ten cases. There were seven probe-positive, culture-negative cases, three of which had systemic CMV infection, including two patients with inclusions noted by conventional cytologic examination. Three probe-negative, culture-positive cases were found. In the authors' laboratory, the predictive value of a positive CMV probe is 80% (28 of 35). In contrast to the probe, conventional cytologic examination revealed CMV inclusions in only 23% (7 of 31) of the culture-positive cases. An average of 21 days was required for CMV cultures to become positive; probe results were available within 24 hours. The authors conclude direct in situ DNA hybridization is a useful rapid method for the detection of CMV in BAL specimens submitted for cytologic examination.     

PCR detection of Pneumocystis carinii in bronchoalveolar lavage specimens: analysis of sensitivity and specificity.

Although PCR detection of Pneumocystis carinii DNA has been described, little is known about the sensitivity or specificity of the assay in routine laboratory practice. We had the unique opportunity to use a bronchoalveolar lavage (BAL) specimen bank with samples for which the direct examination results for P. carinii were known. DNA purified from 129 selected specimens was amplified by using the primers described previously (A. E. Wakefield, F. J. Pixley, S. Banerji, K. Sinclair, R. F. Miller, E. R. Moton, and J. M. Hopkin, Mol. Biochem. Parasitol. 43:69-76, 1990). Of the 129 specimens, 37 were positive for P. carinii by direct examination. All 37 specimens were positive for P. carinii by PCR, yielding a 100% sensitivity and 100% negative predictive value for the assay. An additional 23 specimens were repeatedly positive for P. carinii by PCR but were not positive by direct examination. Review of the patient charts for these specimens with discordant results demonstrated that five of the patients were actually positive for P. carinii, as determined by either biopsy or examination of repeat or prior BAL specimens. A response to empiric therapy for P. carinii pneumonia was seen in an additional two patients. Of the remaining specimens, 8 produced no significant isolates other than P. carinii, while 12 contained culture-confirmed significant respiratory pathogens in addition to P. carinii (two fungal, nine bacterial, and one viral pathogen). Cytomegalovirus, which was of unknown significance, was isolated from 16 additional specimens. Overall, the specificity of the PCR assay was 79.3% compared to the results of direct examination. We hypothesized that the apparently poor specificity of the PCR assay was due to the increased sensitivity of the assay compared to that of direct examination. The sensitivity of the PCR assay was therefore assessed with BAL specimens containing P. carinii cysts. Serial dilutions of this preparation were evaluated by direct examination and PCR. PCR was found to be 100-fold more sensitive than direct examination, which detected one to two cysts per amplification. No false-positive results were detected in controls containing no DNA or by using target DNA from various fungal, viral, or bacterial respiratory pathogens. We conclude that PCR detection of P. carinii in BAL specimens is very sensitive and should be considered for patients whose specimens do not yield a diagnosis. The increased sensitivity of the PCR assay may help to identify those patients with low-titer infections who might benefit from directed antibiotic therapy for P. carinii and would otherwise be missed by direct examination alone.     

Clinical utility of bronchoalveolar lavage cytomegalovirus viral loads in the diagnosis of cytomegalovirus pneumonitis in infants

Cytomegalovirus (CMV) pneumonitis is a significant cause of morbidity and mortality of children in Africa. The current practice for diagnosing CMV pneumonitis in this setting is based on interpretation of clinical, laboratory, and radiological findings. There is a need for a sensitive and specific laboratory test to objectively distinguish between patients with CMV pneumonitis and those with CMV infection, and non‐CMV pneumonia. In this study, we compared plasma and non‐bronchoscopic bronchoalveolar lavage (NBBAL) CMV viral loads in patients with CMV pneumonitis and those with CMV infection and non‐CMV pneumonia. Receiver operator characteristic curve analysis was used to establish a threshold and assess utility of viral loads in the diagnosis of CMV pneumonitis. We assessed the urea dilution method, and expression of viral loads relative to the total amount of extracted nucleic acids in correcting for NBBAL dilution. CMV quantification in NBBAL specimens was more predictive of CMV pneumonitis than blood CMV quantification. The threshold of 4.03 log IU/ml in NBBAL specimens has good predictive value and can be used to guide management of infants with suspected CMV pneumonitis. Adjusting for dilution of NBBAL specimens by using the urea dilution method or by expressing the viral load relative to the total nucleic acids extracted did not provide additional analytical benefits. J. Med. Virol. 89:1080–1087, 2017 . © 2016 Wiley Periodicals, Inc.