Clinical relevance of peripheral blood eosinophil count in allergic bronchopulmonary aspergillosis

Agarwal, Ritesh; Khan, Ajmal; Aggarwal, Ashutosh N.; Varma, Neelam; Garg, Mandeep; Saikia, Biman; Gupta, Dheeraj; Chakrabarti, Arunaloke

doi:10.1016/j.jiph.2011.08.006

« Previous Next »Journal of Infection and Public Health
Volume 4, Issue 5 , Pages 235-243, November 2011

Clinical relevance of peripheral blood eosinophil count in allergic bronchopulmonary aspergillosis

Ritesh Agarwal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012, India
- Corresponding author. Tel.: +91 172 2756825; fax: +91 172 2748215.
Ajmal Khan
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012, India
Ashutosh N. Aggarwal
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012, India
Neelam Varma
- Department of Hematology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Mandeep Garg
- Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Biman Saikia
- Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
Dheeraj Gupta
- Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Sector-12, Chandigarh 160012, India
Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Received 21 February 2011; received in revised form 17 August 2011; accepted 21 August 2011.

Summary

Background and aims

Currently, there is not a uniform consensus regarding the number of criteria or specific cut-off values for the variety of tests that are used to diagnose allergic bronchopulmonary aspergillosis (ABPA). Traditionally, an eosinophil count >1000cells/μl is considered an important criterion in the diagnosis of ABPA. The goal of this study was to delineate the significance of the peripheral blood eosinophil count in the diagnosis of ABPA, and the relationship between eosinophil counts and lung function and immunological and radiological parameters.

Methods

This study was a retrospective analysis of the data from ABPA patients who were managed in our chest clinic. Based on their eosinophil count, the patients were classified into the following three categories: <500, 500–1000 and >1000cells/μl. The spirometric, immunological and radiological characteristics were also assessed.

Results

We studied 108 males and 101 females with a combined mean (±SD) age of 34.1±12.5years. The median (IQR) eosinophil count at diagnosis was 850 (510–1541)cells/μl, and 60% of the patients had an eosinophil count of <1000cells/μl. We found no relationship between eosinophil count and lung function using spirometry and other immunological parameters. The median eosinophil count was higher in patients with an high resolution computed tomography (HRCT) chest finding of bronchiectasis (986 vs. 620, p<0.001) vs. those without and in patients with high-attenuation mucus (1200 vs. 800, p<0.001) compared to those without high-attenuation mucus.

Conclusions

A peripheral blood eosinophil count has limited utility in the diagnosis of ABPA, and there is no relationship between eosinophil count and lung function or other immunological parameters. The higher eosinophil count that we observed in patients with central bronchiectasis or high-attenuation mucus suggests that eosinophils are primary mediators of inflammatory activity in ABPA.

Keywords: Allergic bronchopulmonary aspergillosis (ABPA), Aspergillus fumigatus, Eosinophils