Development of Aspergillosis in a cohort of non-neutropenic, non-transplant patients colonised by Aspergillus spp

José Barberán,Alberto Fernández-Villar,Juan-José Granizo,Cristina Salas,Eduardo Malmierca,Lorenzo Aguilar,María-José Giménez,Victoria Villena,Francisco-Javier García-Pérez

doi:10.1186/s12879-016-2143-5

Abstract

BackgroundA previous study explored factors discriminating colonization and true infection among non-transplant, non-neutropenic patients with repeated Aspergillus spp. isolation from lower respiratory samples. The present study explored the evolution of patients with Aspergillus colonization in that study to determine the percentage of cases progressing to aspergillosis and time to development.MethodsClinical records were retrospectively reviewed (for each patient from his end date in the past study) and data from all respiratory processes suffered by patients up to April 2015 were recorded. Comparisons of variables were performed between colonized patients that developed aspergillosis and those that did not. A Kaplan-Meier curve was used to describe time to development of aspergillosis in chronic obstructive pulmonary disease (COPD) patients for II-IV stages of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification.ResultsSixty seven colonized patients were followed, 12 of them (17.9%) developed aspergillosis. Diagnoses included six tracheobronchitis (4 invasive, 2 simple tracheobronchitis), four pulmonary disease (2 invasive pulmonary aspergillosis, 2 chronic pulmonary aspergillosis), one allergic bronchopulmonary aspergillosis and one pulmonary aspergilloma. Up to 47 (70.4%) of the study patients presented COPD. Among patients developing aspergillosis COPD was more frequent (100%) than among those that did not develop aspergillosis (35 out of 55; 63.6%) (p = 0.012), as well as GOLD IV patients were more frequent among COPD patients developing aspergillosis than among COPD patients that did not (50.0 vs. 26.1%, p = 0.046). Mean time to development of aspergillosis was 18.4 months (median: 8.5) with a wide range (1–58). Overtime, the percentage of patients developing aspergillosis was significantly higher among GOLD IV patients than among GOLD II-III patients (p = 0.032).ConclusionsThe high percentage of cases progressing to aspergillosis among colonized patients, especially among those with COPD (25.5%), stresses the importance of colonization as risk factor, and creates awareness of the possible change from colonization to invasive disease in GOLD IV patients.

Highlights

A previous study explored factors discriminating colonization and true infection among non-transplant, non-neutropenic patients with repeated Aspergillus spp. isolation from lower respiratory samples
One important finding was the high number of patients with probable/proven aspergillosis among patients with chronic obstructive pulmonary disease (COPD) [3], including GOLD (Global Initiative for Chronic Obstructive Lung Disease) Acute Physiologic and Chronic Health Evaluation (II) patients [4]
Nowadays, approximately 30–50% cases of invasive pulmonary aspergillosis are diagnosed in non-neutropenic patients [15], and pre-existing structural disease of the lungs such as COPD increases the risk for developing invasive pulmonary aspergillosis [16]

Summary

Introduction

A previous study explored factors discriminating colonization and true infection among non-transplant, non-neutropenic patients with repeated Aspergillus spp. isolation from lower respiratory samples. The present study explored the evolution of patients with Aspergillus colonization in that study to determine the percentage of cases progressing to aspergillosis and time to development. A previous study by our group explored implications of repeated isolation of Aspergillus spp. from lower respiratory samples in non-transplant, non-neutropenic patients in an attempt to identify factors helping in discriminating colonization and true infection [3]. The aim of the present follow-up study was to explore the evolution of colonized patients from the cohort identified in the previous study [3] to determine the percentage of cases progressing to aspergillosis and time to development The cohort of patients categorized as colonized in the previous study offered the opportunity to explore the possible progression and time to development of aspergillosis in non-transplant, non-neutropenic patients as previously explored for post-lung transplant patients [5] and patients with acute myeloid leukemia [6].

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Conclusion