Delineating asthma according to inflammation phenotypes with a focus on paucigranulocytic asthma

Abstract

Asthma is characterized by chronic airway inflammation and airway hyper-responsiveness. However, the differences in pathophysiology and phenotypic symptomology make a diagnosis of “asthma” too broad hindering individualized treatment. Four asthmatic inflammatory phenotypes have been identified based on inflammatory cell profiles in sputum: eosinophilic, neutrophilic, paucigranulocytic, and mixed-granulocytic. Paucigranulocytic asthma may be one of the most common phenotypes in stable asthmatic patients, yet it remains much less studied than the other inflammatory phenotypes. Understanding of paucigranulocytic asthma in terms of phenotypic discrimination, distribution, stability, surrogate biomarkers, underlying pathophysiology, clinical characteristics, and current therapies is fragmented, which impedes clinical management of patients. This review brings together existing knowledge and ongoing research about asthma phenotypes, with a focus on paucigranulocytic asthma, in order to present a comprehensive picture that may clarify specific inflammatory phenotypes and thus improve clinical diagnoses and disease management.

Efficacy of Mepolizumab in the Treatment of Severe Asthma with a Mixed Granulocytic Pattern of Airway Inflammation (Case Report)

“…Тяжелая бронхиальная астма со смешанным гранулоцитарным паттерном воспаления характеризуется сочетанием в себе признаков как Т2-, так и не-Т2-эндотипов с одновременным выявлением нейтрофилеза и эозинофилии в образцах индуцированной мокроты или бронхоальвеолярной лаважной жидкости [1]. Распространенность данного варианта воспаления при астме по разным источникам составляет от 3 % (при уровне эозинофилов ≥3 % и нейтрофилов ≥76 % в индуцированной мокроте) до 22 % (при уровне эозинофилов ≥2 % и нейтрофилов ≥50 % в индуцированной мокроте) [2]. Наиболее часто смешанный гранулоцитарный паттерн воспаления при астме встречается у курящих пациентов, при коморбидной патологии, в частности, при сочетании бронхиальной астмы с хронической обструктивной болезнью легких (ХОБЛ) или бронхоэктазами [1].…”

“…Control of asthma, severity of shortness of breath and respiratory function (clinical observationNo. 2) …”

Asthma Inflammatory Phenotypes: How Can We Distinguish Them?

“…There is no agreement about the cut-off values of neutrophils and eosinophils that should be used for the definition of asthma inflammatory phenotypes. In the literature, eosinophilic asthma is defined with the range of eosinophils in the sputum from >1.01% to ≥4%, and neutrophilic asthma is defined with a sputum neutrophil percentage from >40 to ≥76% [9][10][11][12]. The evaluation of inflammatory phenotypes in individual patients, besides giving information about inflammatory cell components, may guide therapeutic decisions and the need for corticosteroid therapy [13,14].…”