Diagnostic yield of bronchoscopy in histologically proven invasive pulmonary aspergillosis

Abstract

Summary:Invasive pulmonary aspergillosis (IPA) is a life-threatening infectious complication in neutropenic patients after high-dose chemotherapy or hematopoietic stem cell transplantation. Its diagnosis is mainly based on clinical symptoms, and radiological signs on thoracic CT scan. The value of bronchoscopy is controversial. We analyzed the diagnostic yield of bronchoscopy in 23 consecutive patients with histologically proven invasive pulmonary aspergillosis. In seven patients (30%) bronchoscopically obtained specimens were diagnostic for pulmonary fungal infection. Typical hyphae were detected by cytology in six patients and fungal cultures were positive in four cases. Patients with a positive bronchoscopic result presented more often with multiple changes on thoracic CT scan (71%; 5/7), but had received a lower median cumulative dose of amphotericine B (300 mg; 168-3010 mg) compared to patients with non-diagnostic bronchoscopy (25% multiple lesions (4/16); amphotericine dose 1100 mg, 260-2860 mg). The diagnostic yield of bronchoscopy was not associated with clinical symptoms or duration of neutropenia. Bronchoscopy allows the diagnosis of IPA in about one third of patients. Fungal cultures and cytological examination of intrabronchial specimens obtained during bronchoscopy have a high specificity, but its sensitivity is low. It is advisable to perform diagnostic bronchoscopy before starting antifungal therapy. Better diagnostic tools are urgently needed.

Impact of PCR-based diagnosis of invasive pulmonary aspergillosis on clinical outcome

“…3 The current approach in which clinical probability, fungal culture and cytology examination serve as guidelines for therapy is not satisfactory. 4,5 For this purpose, more rapid confirmation of aspergillus infection with non-culturebased testing may be more useful. Detection of ASP DNA in BAL fluid theoretically enables early diagnosis and early guided optimal therapy that is expected eventually to improve the outcome of IPA in high-risk patients.…”

“…1,2 Early diagnosis of IPA and administration of antifungal treatment is expected to improve outcome, but this goal is difficult to achieve as cultivation of the causative agent Aspergillus species (ASP) from respiratory secretions has poor sensitivity. [3][4][5][6][7] Deep tissue biopsy specimens are difficult to obtain in this setup because many affected patients have poor respiratory status in addition to coagulation defects. PCR-based ASP DNA detection in bronchoalveolar lavage (BAL) fluid theoretically enables earlier and more frequent diagnosis of IPA.…”

Retrospective utility of bronchoscopy after hematopoietic stem cell transplant

“…Although these guidelines considered the recovery of Aspergillus simply suggestive because of data at the time in non-transplant patients, 17 follow-up studies 18 and guidelines [19][20][21] in neutropenic patients suggest that recovery of Aspergillus on BAL has a low sensitivity but high specificity. We therefore considered any identified fungus at a level of more than a single colony as diagnostic but provide the proven, probable and possible categories according to international consensus guidelines.…”

Clinical and radiologic predictors of invasive pulmonary aspergillosis in cancer patients

“…Conversely, bronchial washing has been shown to yield a diagnosis in only 33% in patients with histologically proven IPA. 7 CT scan of the chest has been advocated for the early diagnosis of IPA. 8 However, the specificity of CT is controversial.…”