Introduction: Asthma is a heterogeneous inflammatory disease with varying phenotypes and endotypes. Early-onset asthma (EOA) and late-onset asthma (LOA) may differ significantly in their clinical characteristics and underlying pathophysiology. Recent research has identified distinct eosinophil subtypes, namely inflammatory eosinophils (iEOS) and resident eosinophils (rEOS), which are believed to contribute differently to the disease process. However, data on distribution and role of blood iEOS and rEOS are currently lacking in EOA and LOA. This study aims to measure blood eosinophil subtypes in EOA and LOA patients, correlating them with clinical and functional outcomes to provide insights into the mechanisms driving these asthma phenotypes. Methods: A cohort of asthmatic patients, categorized into early-onset (EOA, onset < 12 years old, n=17) and late-onset (LOA, onset > 40 years old, n=22), was recruited at the Pneumology Unit, Padua University Hospital, along with a control group of healthy individuals (HC, n=15). Patients underwent comprehensive clinical evaluation, complete functional assessment (FeNO, spirometry, DLCO), and measurement of blood eosinophil count, total and specific IgE. Peripheral blood samples were obtained from all participants. Flow cytometry () was employed to differentiate and quantify eosinophil subtypes: iEOS (Siglec8+CD16-CD62Llow) and rEOS (Siglec8+CD16-CD62Lhigh). The distinct subsets of eosinophils were correlated with clinical and functional scores. Results: Subjects with EOA had a higher percentage of iEOS than healthy controls (iEOS in EOA 6.97±5.38% vs HC 4.54±4.43%, p=0.04). Subjects with LOA also had a higher percentage of inflammatory eosinophils than healthy controls (iEOS in LOA 7.24±6.02% vs HC, p=0.038). Interestingly, iEOS levels did not differ between subjects with EOA and LOA. Similar results were obtained when data were expressed as mean fluorescence intensity (MFI) instead of percentages. Regarding interleukin-5 receptor, no significant differences were found between subjects with EOA, LOA and healthy controls. Regarding the expression of CCR3, we observed that subjects with early-onset asthma had higher expression of CCR3 in inflammatory eosinophils than healthy controls (p value 0.0162) when the data are expressed as fluorescence intensity. The percentage of inflammatory eosinophils correlated significantly with FEV1/FVC and MEF50 values; there was no evidence of correlation between iEOS with the remaining functional parameters analyzed (FEV1, TLC, RV/TLC, DLCO) and with FeNO. The iEOS were not correlated with asthma control, as measured by ACT score, with the number of exacerbations, with the number of OCS cycles in the previous year, and with SNOT-22. There were no differences in iEOS levels between subjects in GINA treatment phases 4 and 5 (n=26) compared to those in steps 1-3 (n=13). Conclusions: Eosinophils subpopulations (iEOS and rEOS) do not differ significantly between patients with early- and late-onset asthma. Subjects with EOA and LOA have higher levels of iEOS than healthy controls. Among asthma patients, iEOS levels correlate significantly with FEV1/FVC and MEF50 values, but do not correlate with other clinical and functional parameters reflecting disease activity. Further studies are required to evaluate their role as biomarkers for asthma.
Introduzione: L'asma è una malattia infiammatoria eterogenea con diversi fenotipi ed endotipi. L'asma ad esordio precoce (EOA) e l'asma ad esordio tardivo (LOA) possono differire significativamente nelle loro caratteristiche cliniche e nella patogenesi sottostante. Recenti ricerche hanno identificato due sottotipi di eosinofili, ovvero gli eosinofili infiammatori (iEOS) e gli eosinofili residenti (rEOS), che si ritiene contribuiscano in modo diverso al processo patologico. Tuttavia, attualmente mancano dati sulla distribuzione e sul ruolo degli iEOS e dei rEOS nel sangue nell'EOA e nella LOA. Questo studio si propone di misurare i sottotipi di eosinofili nel sangue in pazienti con EOA e LOA, correlandoli con il quadro clinico e funzionale per fornire approfondimenti sui meccanismi che guidano questi fenotipi di asma. Metodi: Presso l'Unità di Pneumologia dell'Azienda Ospedaliera Universitaria di Padova è stata reclutata una coorte di pazienti asmatici, classificati in early-onset (EOA, esordio < 12 anni, n=17) e late-onset (LOA, esordio > 40 anni, n=22), insieme a un gruppo di controllo di soggetti sani (HC, n=15). I pazienti sono stati sottoposti ad una completa valutazione clinica e funzionale (FeNO, spirometria, DLCO) e alla misurazione della conta degli eosinofili nel sangue e delle IgE totali e specifiche. Da tutti i partecipanti sono stati ottenuti campioni di sangue periferico. La citometria a flusso è stata impiegata per differenziare e quantificare i sottotipi di eosinofili: iEOS (Siglec8+CD16-CD62Llow) e rEOS (Siglec8+CD16-CD62Lhigh). Le distinte sottopopolazioni di eosinofili sono state correlate a punteggi clinici e funzionali. Risultati: I soggetti con EOA presentano una percentuale maggiore di iEOS rispetto ai controlli sani (iEOS in EOA 6,97 ± 5,38% vs HC 4,54±4,43%, p=0,04). Anche i soggetti con LOA presentano una maggior percentuale di eosinofili infiammatori rispetto ai controlli sani (iEOS in LOA 7,24±6,02% vs HC, p=0,038). È interessante notare che i livelli di iEOS non differiscono tra i soggetti affetti da EOA e LOA. Risultati simili sono stati ottenuti quando i dati sono stati espressi come intensità media di fluorescenza (MFI) anziché come percentuali. Per quanto riguarda il recettore dell’interleuchina 5, non si sono riscontrate differenze significative fra i soggetti con EOA, LOA e i controlli sani. Per quanto riguarda l’espressione di CCR3, abbiamo osservato che i soggetti affetti da early-onset asma avevano una maggiore espressione di CCR3 negli eosinofili infiammatori rispetto ai controlli sani (p value 0,0162) quando i dati sono espressi come intensità di fluorescenza. La percentuale di eosinofili infiammatori correla significativamente con i valori di FEV1/FVC e MEF50; non vi è stata evidenza di correlazione fra gli iEOS con i restanti parametri funzionali analizzati (FEV1, TLC, RV/TLC, DLCO) e con il FeNO. Gli iEOS non erano correlati con il controllo dell'asma, misurato dal punteggio ACT, col numero di esacerbazioni, col numero di cicli di OCS nell'anno precedente e con lo SNOT-22. Non ci sono state differenze nei livelli di iEOS tra i soggetti nelle fasi di trattamento GINA 4 e 5 (n=26) rispetto a quelli nelle fasi 1-3 (n=13). Conclusioni: Le sottopopolazioni di eosinofili (iEOS e rEOS) non differiscono in modo significativo tra i pazienti con asma ad esordio precoce e tardivo. I soggetti con EOA e LOA presentano livelli di iEOS più elevati rispetto ai controlli sani. Tra i pazienti asmatici, i livelli di iEOS si correlano significativamente con i valori di FEV1/FVC e MEF50, ma non sono correlati ad altri parametri clinici e funzionali che riflettono l'attività della malattia. Ulteriori studi sono necessari per approfondire il loro ruolo come biomarcatore nell’asma bronchiale. Parole chiave: eosinofili infiammatori, eosinofili residenti, fenotipi asma, asma ad insorgenza precoce, asma ad insorgenza tardiva
Eosinofili residenti e infiammatori nell'asma ad insorgenza precoce e tardiva
RASTELLI, ANDREA
2022/2023
Abstract
Introduction: Asthma is a heterogeneous inflammatory disease with varying phenotypes and endotypes. Early-onset asthma (EOA) and late-onset asthma (LOA) may differ significantly in their clinical characteristics and underlying pathophysiology. Recent research has identified distinct eosinophil subtypes, namely inflammatory eosinophils (iEOS) and resident eosinophils (rEOS), which are believed to contribute differently to the disease process. However, data on distribution and role of blood iEOS and rEOS are currently lacking in EOA and LOA. This study aims to measure blood eosinophil subtypes in EOA and LOA patients, correlating them with clinical and functional outcomes to provide insights into the mechanisms driving these asthma phenotypes. Methods: A cohort of asthmatic patients, categorized into early-onset (EOA, onset < 12 years old, n=17) and late-onset (LOA, onset > 40 years old, n=22), was recruited at the Pneumology Unit, Padua University Hospital, along with a control group of healthy individuals (HC, n=15). Patients underwent comprehensive clinical evaluation, complete functional assessment (FeNO, spirometry, DLCO), and measurement of blood eosinophil count, total and specific IgE. Peripheral blood samples were obtained from all participants. Flow cytometry () was employed to differentiate and quantify eosinophil subtypes: iEOS (Siglec8+CD16-CD62Llow) and rEOS (Siglec8+CD16-CD62Lhigh). The distinct subsets of eosinophils were correlated with clinical and functional scores. Results: Subjects with EOA had a higher percentage of iEOS than healthy controls (iEOS in EOA 6.97±5.38% vs HC 4.54±4.43%, p=0.04). Subjects with LOA also had a higher percentage of inflammatory eosinophils than healthy controls (iEOS in LOA 7.24±6.02% vs HC, p=0.038). Interestingly, iEOS levels did not differ between subjects with EOA and LOA. Similar results were obtained when data were expressed as mean fluorescence intensity (MFI) instead of percentages. Regarding interleukin-5 receptor, no significant differences were found between subjects with EOA, LOA and healthy controls. Regarding the expression of CCR3, we observed that subjects with early-onset asthma had higher expression of CCR3 in inflammatory eosinophils than healthy controls (p value 0.0162) when the data are expressed as fluorescence intensity. The percentage of inflammatory eosinophils correlated significantly with FEV1/FVC and MEF50 values; there was no evidence of correlation between iEOS with the remaining functional parameters analyzed (FEV1, TLC, RV/TLC, DLCO) and with FeNO. The iEOS were not correlated with asthma control, as measured by ACT score, with the number of exacerbations, with the number of OCS cycles in the previous year, and with SNOT-22. There were no differences in iEOS levels between subjects in GINA treatment phases 4 and 5 (n=26) compared to those in steps 1-3 (n=13). Conclusions: Eosinophils subpopulations (iEOS and rEOS) do not differ significantly between patients with early- and late-onset asthma. Subjects with EOA and LOA have higher levels of iEOS than healthy controls. Among asthma patients, iEOS levels correlate significantly with FEV1/FVC and MEF50 values, but do not correlate with other clinical and functional parameters reflecting disease activity. Further studies are required to evaluate their role as biomarkers for asthma.File | Dimensione | Formato | |
---|---|---|---|
TESI ANDREA.pdf
accesso riservato
Dimensione
4.77 MB
Formato
Adobe PDF
|
4.77 MB | Adobe PDF |
The text of this website © Università degli studi di Padova. Full Text are published under a non-exclusive license. Metadata are under a CC0 License
https://hdl.handle.net/20.500.12608/81355