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

Value of rapid on-site evaluation combined with interventional pulmonology techniques in the diagnosis of pulmonary cryptococcosis

OBJECTIVES

The aim of this study is to evaluate the diagnostic value of rapid on-site evaluation (ROSE) combined with computed tomography-guided percutaneous needle biopsy (CT-PNB) or radial endobronchial ultrasound-guided transbronchial lung biopsy (EBUS-TBLB) for pulmonary cryptococcosis (PC).

METHODS

Clinical data of 33 patients diagnosed with PC at the Third Affiliated Hospital of Soochow University between February 2018 and June 2023 were retrospectively analysed. Patients were divided into the CT-PNB and EBUS-TBLB groups based on the intervention method, and the diagnostic positivity rate and incidence of complications were compared between the two groups.

RESULTS

Compared with the final diagnosis, the positive diagnostic rates of ROSE, histopathology and serum CrAg of all patients were 81.8% (27/33), 72.7% (24/33) and 63.6% (21/33), respectively. The average turnaround times of the three methods were 0.1 (0.1-0.2) h, 96.0 (48.0-120.0) h and 7.8 (4.5-13.6) h, respectively (P < 0.001). The coincidence rate between histopathology and ROSE was 84.8% with a kappa value of 0.574. The positive diagnostic rate for PC was significantly higher in the CT-PNB group than in the EBUS-TBLB group (92.9% vs. 57.9%), and the difference was statistically significant (P < 0.05). Combined with the ROSE results, the positive diagnostic rate in the EBUS-TBLB group increased to 84.2% (16/19).

CONCLUSION

ROSE has commendable accuracy and timeliness, and CT-PNB offers further advantages in this regard. ROSE enhances the diagnostic efficiency of EBUS-TBLB for PC and is safe and effective.

Pulmonary cryptococcosis: A review of pathobiology and clinical aspects

Pulmonary cryptococcosis is an important opportunistic invasive mycosis in immunocompromised patients, but it is also increasingly seen in immunocompetent patients. The main human pathogens are Cryptococcus neoformans and C. gattii, which have a worldwide distribution. In contrast to cryptococcal meningitis, pulmonary cryptococcosis is still underdiagnosed because of limitations in diagnostic tools. It can mimic lung cancer, pulmonary tuberculosis, bacterial pneumonia, and other pulmonary mycoses both clinically and radiologically. Pulmonary nodules are the most common radiological feature, but these are not specific to pulmonary cryptococcosis. The sensitivity of culture of respiratory samples for Cryptococcus is poor and a positive result may also reflect colonisation. Cryptococcal antigen (CrAg) with lateral flow device is a fast and sensitive test and widely used on serum and cerebrospinal fluid, but sera from patients with pulmonary cryptococcosis are rarely positive in the absence of disseminated disease. Detection of CrAg from respiratory specimens might assist the diagnosis of pulmonary cryptococcosis but there are very few data. Molecular detection techniques such as multiplex reverse transcription polymerase chain reaction (RT-PCR) could also provide better sensitivity but these still require validation for respiratory specimens. The first line of treatment for pulmonary cryptococcosis is fluconazole, or amphotericin B and flucytosine for those with central nervous system involvement. Pulmonary cryptococcosis worsens the prognosis of cryptococcal meningitis. In this review, we summarize the biological aspects of Cryptococcus and provide an update on the diagnosis and management of pulmonary cryptococcosis.

Solitary cavitary pulmonary nodule may be a common CT finding in AIDS-associated pulmonary cryptococcosis

BACKGROUND

Previous studies have demonstrated that the most common chest radiologic finding in acquired immune deficiency syndrome (AIDS)-associated pulmonary cryptococcosis (PC) is diffuse interstitial infiltrates. The aim of this study was to provide additional radiologic characterization of PC in AIDS patients.

METHODS

AIDS patients from the Second Affiliated Hospital of the Southeast University who were diagnosed with cryptococcosis between February 2009 and May 2012 and who had undergone chest computed tomography (CT) scans before or at the time of diagnosis were retrospectively analyzed.

RESULTS

Twelve patients met eligibility criteria. The median CD4 T-cell count was 23 cells/μl (range 2-79 cells/μl). Eleven patients had pulmonary abnormalities on imaging. Initial chest CT scans demonstrated solitary cavitary pulmonary nodules in 9 patients, pleural effusions in 2 patients, bilateral ground-glass opacities in 6 patients, patchy opacities in 1 patient, and bronchiectasis in 1 patient. Bilateral ground-glass opacities appeared to be associated with Pneumocystis pneumonia, while the presence of a pleural effusion was predictive of PC. Of the 9 solitary cavitary pulmonary nodules, 7 were PC and the other 2 were probable cases of PC. These nodules were predominantly in the peripheral lung and were either asymptomatic or caused only mild pulmonary symptoms.

CONCLUSIONS

Solitary cavitary pulmonary nodule may be a common CT finding in AIDS-associated PC. All AIDS patients with solitary cavitary pulmonary nodules on chest CT should be screened for Cryptococcus infection.

Retrospective analysis of 76 immunocompetent patients with primary pulmonary cryptococcosis

BACKGROUND

Pulmonary cryptococcosis typically occurs in immunocompromised patients, but it can also occur in immunocompetent patients. Our objective was to describe the clinical manifestations, diagnosis, and management of primary pulmonary cryptococcosis in immunocompetent patients.

METHODS

We retrospectively reviewed the clinical data of 76 patients with primary pulmonary cryptococcosis who were admitted to our hospital from 1995 to 2010.

RESULTS

Pulmonary cryptococcosis was pathologically proven in all patients. Mean patient age was 42.5 years and 55 patients (72%) were male. The major clinical manifestations were cough (47 pts, 62%), expectoration (29 pts, 38%), fever (16 pts, 21%), chest pain (15 pts, 20%), dyspnea (17 pts, 22%), and emaciation (10 pts, 13%). Eighteen patients (24%) were asymptomatic. Most patients were admitted due to shadows on chest X-rays. Lesions were more common in the lower lung (60 pts, 78.9%) than in the upper lung (25 pts, 32.9%). More lesions (28 pts, 37%) were characterized by patchy consolidations. Pulmonary cryptococcosis was confirmed histologically among all patients. Surgical removal of lesions or treatment with fluconazole and other antifungal agents for complete courses led to favorable outcomes for most patients.

CONCLUSIONS

Primary pulmonary cryptococcosis was found mainly in immunocompetent patients aged <50 years without preexisting lung disease. Shadow on the chest X-ray is the predominant feature. Treatment with a complete course of fluconazole and/or other antifungal agents can achieve favorable outcome.

Clinicopathologic and ultrastructural study of non-HIV-related primary pulmonary cryptococcosis in China: report of 43 cases

OBJECTIVE

To clarify the clinicopathologic and ultrastructural features of primary pulmonary cryptococcosis (PC).

METHODS

43 cases of PC were observed by light microscopy and histochemical staining, including mucicarmine (MC), Alcian blue (AB), periodic acid-Schiff (PAS), and Grocott methenamine-silver (GMS). Transmission electron microscopy (TEM) was performed on 11 fresh and 8 formalin-fixed specimens.

RESULTS

The detective rate of Cryptococcus neoformans (CN) by MC, AB, PAS, GMS staining, and TEM was 61.3% (19/31), 62.2% (23/37), 85.7% (30/35), 79.1% (34/43), and 89.5% (17/19), respectively. All CN detected by TEM had a capsule. Most of them possessed simple structure with undeveloped cellular organelles.

CONCLUSION

Electron microscopy has a high rate of detecting CN. A combination of histochemical staining and electron microscopy can make an accurate diagnosis of PC.