Prevalence and diagnosis of allergic bronchopulmonary aspergillosis: a systematic review

Background: Allergic bronchopulmonary aspergillosis (ABPA), a chronic fungal allergic lung condition, is a common side effect of asthma or cystic fibrosis (CF). The majority of patients affected by Aspergillus species, notably Aspergillus fumigatus, experience allergic respiratory symptoms. Aspergillus-induced lung illness and maladaptive immune responses range from developing essential fungal asthma to severe asthma with fungal sensitization to ABPA. The estimated ABPA prevalence in CF patients varied from 3% to 25% in adults and 8% to 10% in children, for an overall prevalence of 8.9%. Aim: To evaluate the current literature on the prevalence and diagnosis of allergic ABPA. Methods: Studies related to our subject were explored using PubMed and Google Scholar databases. The keywords included were "Respiratory allergy, bronchopulmonary aspergillus, allergic bronchopulmonary aspergillosis, prevalence, and diagnosis" and were used in various combinations. The inclusion criteria were original studies that reported ABPA and full articles. Results: A total of 200 articles were obtained, but only 9 articles were eligible for the inclusion criteria. The detailed studies were conducted on 929 participants, 8 of them were cross-sectional studies, and only 1 was a prospective longitudinal study. Conclusion: Our study showed that ABPA has a moderate prevalence among patients with asthma and CF. No risk factors were found for ABPA other than the appearance of brownish sputum in children with ABPA. The clinical manifestations of ABPA were a late start, decreased blood immunoglobulin E levels, and frequent recurrences/ flares. Several diagnostic biomarkers were shown to be effective in the diagnosis of ABPA, including basophil CD203c upregulation and Thymus and activation-regulated chemokine.