Mycological Diagnosis of Invasive Pulmonary Aspergillosis Should Depend on Both the Underlying Condition and the Neutropenia Status of Patients with Hematologic Malignancies
Authors: Bergeron Anne , Porcher Raphaël , Sulahian Annie , de Bazelaire Cédrid , Chagnon Karine , Lacroix Claire , Raffoux Emmanuel , Isnard Françoise , Poirot Jean-Louis , Vekhoff Anne , Bouges-Michel Claire , Tazi Abdellatif , Ribaud Patricia 
Published: October 2019

Abstract 1243

Background.

Accurate identification of the causative organism in invasive pulmonary aspergillosis (IPA) is important for both epidemiological reasons and optimal management of patients (pts); therefore, it is now recommended. The most efficient strategy to isolate the fungus, however, is not well-established. The reported mycological yield of bronchoscopy, the most commonly used noninvasive approach, does not exceed 40–60%. In the context of IPA, we investigated whether a mycological diagnostic strategy could be optimized based on pt characteristics.

Methods.

We used a database of 57 pts with IPA enrolled between May 2005 and February 2007 in a prospective multicenter study primarily designed to determine the performance of several microbiological tools in predicting the outcome of IPA. The study protocol was approved by the ethics committee of Saint-Louis Hospital, and all pts provided informed consent. Statistical methods: Predictive factors of positive microbiological results (cytology and/or culture) were analyzed by Fisher's exact test and multiple regression models. Whenever necessary, groups of pts were compared by Fisher's exact test. Analyses were carried out using R version 2.6.2 statistical software (the R Foundation for Statistical Computing, Vienna, Austria).

Pt and IPA characteristics according to the underlying condition.

Results.

The presence of Aspergillus in respiratory samples was significantly more frequent in non-acute leukemia (AL) pts (83%) than in AL pts (25%) (p=0.0003), and in pts with ANC > 100/mm3 (p=0.0002). In a logistic regression model, these 2 factors appeared independent, with an adjusted OR of 7.27 (95% CI 1.42 to 37.3) for non-AL pts and an adjusted OR of 7.20 (95% CI 1.38 to 37.7) for ANC > 100/mm3. A positive mycological yield was detected in 95% of the non-AL pts with ANC > 100/mm3 vs. 23% of the AL pts with ANC < 100/mm3 (p=0.0002). A positive mycological result was also more frequent among pts with lung CT scan signs of invasive airway disease than among other patients (p=0.026). Furthermore, the CT scan findings were strongly associated with the underlying condition and ANC counts of the pt. In particular, invasive airway signs were significantly more frequent among non-AL pts (p=0.049), whereas angioinvasive disease was significantly more frequent among both AL pts (p=0.01) and patients with ANC < 100/mm3 (p=0.0001). Steroid therapy (yes/no and > or < 1 mg/kg) and previous anti-mold therapy had no significant effect on the results. Notably, a concomitant pulmonary infection was identified with bronchoscopy more frequently among non-AL pts (p=0.0009).

Conclusions.

We strongly recommend bronchoscopy for a specific diagnosis of aspergillosis among non-AL patients, particularly among allogeneic stem cell transplant recipients. Among AL pts with severe neutropenia, another diagnostic strategy should be considered.

Disclosures:

No relevant conflicts of interest to declare.