{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T04:09:13Z","timestamp":1787630953455,"version":"build-2736575974"},"reference-count":30,"publisher":"Oxford University Press (OUP)","issue":"5","license":[{"start":{"date-parts":[[2021,5,10]],"date-time":"2021-05-10T00:00:00Z","timestamp":1620604800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2022,5,10]]},"abstract":"<jats:title>Summary<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Immunoglobulin G (IgG) subclass 2 deficiency is the most frequent IgG subclass deficiency identified in patients with bronchiectasis, but its clinical significance is not known.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Aim<\/jats:title>\n                    <jats:p>To analyse if bronchiectasis patients with isolated IgG2 deficiency at risk of recurrent exacerbations and\/or hospitalization? Do patients with IgG2 deficiency have worse disease progression?<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design and Methods<\/jats:title>\n                    <jats:p>This is a retrospective study (2015\u201320) exploring independent risk factors for recurrent exacerbations (3 or more per year) and\/or hospitalization with bronchiectasis exacerbations using multivariable models using binary logistic regression. There was no patient with IgG deficiency, IgG 1, 3 or 4 deficiency, or IgA or IgM deficiency included. In this model, the authors included: serum IgG2 level; lung function; body mass index; MRC breathlessness scale; age; sex; number of bronchiectatic lobes; bacterial colonization; comorbidities; and the use of long-term immunosuppressant drugs or antibiotics for more than 28\u2009days. Analysing 2-year longitudinal data, one-way ANOVA and Mann\u2013Whitney U-test were used to compare bronchiectasis severity between patients with different IgG2 levels.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Serum IgG2 levels (&amp;lt;2.68\u2009g\/l, 2.68\u20133.53 g\/l and 3.54\u20134.45 g\/l); hospital admission in the preceding 2 years; bacterial colonization with potentially pathogenic organisms and asthma were independent predictors for three or more bronchiectasis exacerbations. Those with low IgG2 levels (&amp;lt;2.68 g\/l and 2.68\u20133.53 g\/l), had worsening progression of their bronchiectasis, using the Bronchiectasis Severity Index, over 1 year compared with those who were IgG2 replete (&amp;gt;4.45\u2009g\/l) (P\u2009=\u20090.003, 0.013).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>Reduced IgG2 levels were an independent predictor for bronchiectasis exacerbations and have increased disease progression.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/qjmed\/hcab129","type":"journal-article","created":{"date-parts":[[2021,5,6]],"date-time":"2021-05-06T08:04:46Z","timestamp":1620288286000},"page":"292-297","source":"Crossref","is-referenced-by-count":16,"title":["Isolated IgG2 deficiency is an independent risk factor for exacerbations in bronchiectasis"],"prefix":"10.1093","volume":"115","author":[{"given":"Y","family":"Zhang","sequence":"first","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Clarke","sequence":"additional","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"},{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K H","family":"Regan","sequence":"additional","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"},{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Campbell","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S","family":"Donaldson","sequence":"additional","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"},{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"Crowe","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A G","family":"Rossi","sequence":"additional","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A T","family":"Hill","sequence":"additional","affiliation":[{"name":"The Centre for Inflammation Research at the University of Edinburgh, Queen\u2019s Medical Research Institute, Edinburgh BioQuarter, Edinburgh EH16 4TJ, UK"},{"name":"Department of Respiratory Medicine, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2021,5,10]]},"reference":[{"key":"2022051008153885100_hcab129-B1","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1136\/thoraxjnl-2012-201983","article-title":"British thoracic society National bronchiectasis audit 2010 and 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