Is there an overlap in immune response between allergic bronchopulmonary and chronic pulmonary aspergillosis?

Publication date: Available online 8 September 2018

Source: The Journal of Allergy and Clinical Immunology: In Practice

Author(s): Inderpaul Singh Sehgal, Hansraj Choudhary, Sahajal Dhooria, Ashutosh Nath Aggarwal, Mandeep Garg, Arunaloke Chakrabarti, Ritesh Agarwal

ABSTRACT

Background

Chronic pulmonary aspergillosis (CPA) and allergic bronchopulmonary aspergillosis (ABPA) are presumed to represent two distinct manifestations of Aspergillus species in the lung.

Objective

To investigate any possible overlap of the immunological tests used for diagnosing ABPA in proven cases of CPA.

Methods

In consecutive subjects with CPA, we calculated the proportion of subjects who tested positive for all the immunological investigations used to diagnose ABPA (A.fumigatus-specific IgE >0.35 kUA/L, total IgE ≥500 IU/mL and eosinophil count ≥500 cells/μL) or obligatory criteria (A.fumigatus-specific IgE >0.35 kUA/L and total IgE ≥500 IU/mL).

Results

269 subjects (53.5% males) of CPA with mean (SD) age of 44.3 (14.7) years were enrolled. The most common underlying disease was previously treated pulmonary tuberculosis (n=230, 85.5%). Ninety-three (34.6%) subjects had total IgE ≥500 IU/mL, while A.fumigatus-specific IgE >0.35 kUA/L was seen in 112 (41.6%) subjects. Thirteen (4.8%) subjects met all the immunological criteria for ABPA, while 59 (21.9%) subjects met the obligatory criteria. Subjects meeting the obligatory criteria had significantly higher eosinophil count (p=<0.0001), greater immediate cutaneous reactivity to Aspergillus antigen (CPA-others vs. obligatory criteria, 9.8±13.9 vs. 13.9±14.9 mm, p value=0.048), higher A.fumigatus-specific IgG (99.3±61.9 vs. 122±66.6 mgA/L, p=0.015) and greater number of fungal balls (0.9±0.7 [range, 0-3] vs. 1.1±0.9 [range, 0-4], p=0.026) compared to those without.

Conclusions

About 5% of subjects with CPA fulfilled all the immunological criteria used for diagnosing ABPA while 22% met the obligatory criteria for ABPA. Whether these patients would require a different management protocol requires further investigation.