Comparative evaluation of galactomannan optical density indices and culture results in bronchoscopic specimens obtained from neutropenic and non‐neutropenic patients

Abstract

Aspergillus infections are major causes of morbidity and mortality among immunocompromised patients. This study was designed to investigate the galactomannan assay optical density (OD) indices relative to the culture results in bronchoscopic samples obtained from neutropenic and non-neutropenic patients. Galactomannan OD indices from 1427 samples from 2005 to 2012, which were sent from 839 patients and were composed of bronchial lavage (BL = 727) and bronchoalveolar lavage fluids (BAL = 700), were retrospectively analysed. The recovery rates of Aspergillus species from these specimens were 9.4% from the combined patient group and 13.3% from the neutropenic group. Aspergillus fumigatus complex was the most frequently isolated species. The mean and median OD indices of the positive and negative culture samples are approximately 5 and 1, respectively, and 91% of all culture-positive samples have ≥1 OD index value. The receiver-operating characteristics curve analysis demonstrated that the feasibility of the Aspergillus galactomannan assay and Aspergillus galactomannan test has superior accuracy in BAL compared to BL fluids, and the test is not affected by the immune status of the patient. We suggest that the Aspergillus galactomannan test, which uses bronchoscopic material, leads to an earlier diagnosis and if the OD index is found ≥1, fungal growth can be expected.

First determination of azole resistance in Aspergillus fumigatus strains carrying the TR34/L98H mutations in Turkey

“…Acquired resistance during clinical course wasn't seen. The coexistence of resistant and susceptible strains in most of the patients, is consistent with the literature and supports current knowledge concerning the probability of coexistence with both resistant and susceptible strains in a patient [15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

“…The clinical signs and symptoms, computerized tomography findings (cavite-consolidation, multiple nodule, halo) and serum and/or bronchoalveolar lavage galactomannan (GM indices>0,5 for serum in two consecutive specimens; GM indices>1 for BAL specimens) positivity were evaluated in order to decide the clinical significance of A. fumigatus growth [25,26].…”

Diagnosis of Invasive Fungal Diseases in Hematological Malignancies: A Critical Review of Evidence and Turkish Expert Opinion (TEO-2)

“…However, it is recommended in meta-analyses that the cutoff index value be taken as 1.5 in patients with hematological malignancies and 1 in mixed patient populations [ 45 , 46 ]. A study comparing culture and GM in BAL fluid samples emphasized that growth might be expected when the optical index is >1, and a correlation with clinical studies was also demonstrated [ 50 ].…”

“…While the use of antifungal drugs active in molds leads to an apparent decrease in sensitivity, no significant difference could be found related to Aspergillus spp. Furthermore, there is no difference in the sensitivity of BAL GM in patients with or without neutropenia [ 45 , 50 ]. Similar to serum GM testing, the use of semi-synthetic β-lactam antibiotics may lead to false positive results [ 45 ].…”

Development of a Real-Time Polymerase Chain Reaction Method for the Identification of Candida Species

“…Günümüzde antifungal duyarlılık test sonuçlarının yorumlanmasının, türe özgü direnç sınır değerleri ile yapılıyor olması, tür tanımlamasının önemli oluşunun bir diğer nedenidir. Günümüzde mayaların tanımlanmasında en sık uygulanan yöntem-ler; mikroskopi, kültür ve serolojik testlerdir [18][19][20] . Ancak, invazif Candida enfeksiyonunun semptomları özgül olmadığından, uygulanmakta olan geleneksel tanı yöntemlerinin duyarlılık ve özgüllükleri düşüktür ve bu yöntemler hızlı sonuç vermemektedir 21 .…”