| Title |
Serum IgG subclass levels and risk of exacerbations and hospitalizations in patients with COPD
|
|---|---|
| Published in |
Respiratory Research, February 2018
|
| DOI | 10.1186/s12931-018-0733-z |
| Pubmed ID | |
| Authors |
Fernando Sergio Leitao Filho, Seung Won Ra, Andre Mattman, Robert S. Schellenberg, Gerard J. Criner, Prescott G. Woodruff, Stephen C. Lazarus, Richard Albert, John E. Connett, Meilan K. Han, Fernando J. Martinez, Janice M. Leung, S. F. Paul Man, Shawn D. Aaron, Robert M. Reed, Don D. Sin, for the Canadian Respiratory Research Network (CRRN) |
| Abstract |
The literature is scarce regarding the prevalence and clinical impact of IgG subclass deficiency in COPD. We investigated the prevalence of IgG subclass deficiencies and their association with exacerbations and hospitalizations using subjects from two COPD cohorts. We measured IgG subclass levels using immunonephelometry in serum samples from participants enrolled in two previous COPD trials: Macrolide Azithromycin for Prevention of Exacerbations of COPD (MACRO; n = 976) and Simvastatin for the Prevention of Exacerbations in Moderate-to-Severe COPD (STATCOPE; n = 653). All samples were collected from clinically stable participants upon entry into both studies. IgG subclass deficiency was diagnosed when IgG subclass levels were below their respective lower limit of normal: IgG1 < 2.8 g/L; IgG2 < 1.15 g/L; IgG3 < 0.24 g/L; and IgG4 < 0.052 g/L. To investigate the impact of IgG subclass levels on time to first exacerbation or hospitalization, we log-transformed IgG levels and performed Cox regression models, with adjustments for confounders. One or more IgG subclass deficiencies were found in 173 (17.7%) and 133 (20.4%) participants in MACRO and STATCOPE, respectively. Lower IgG1 or IgG2 levels resulted in increased risk of exacerbations with adjusted hazard ratios (HR) of 1.30 (95% CI, 1.10-1.54, p < 0.01) and 1.19 (95% CI, 1.05-1.35, p < 0.01), respectively in the MACRO study, with STATCOPE yielding similar results. Reduced IgG1 or IgG2 levels were also associated with increased risk of hospitalizations: the adjusted HR for IgG1 and IgG2 was 1.52 (95% CI: 1.15-2.02, p < 0.01) and 1.33 (95% CI, 1.08-1.64, p < 0.01), respectively for the MACRO study; in STATCOPE, only IgG2 was an independent predictor of hospitalization. In our multivariate Cox models, IgG3 and IgG4 levels did not result in significant associations for both outcomes in either MACRO or STATCOPE cohorts. Approximately 1 in 5 COPD patients had one or more IgG subclass deficiencies. Reduced IgG subclass levels were independent risk factors for both COPD exacerbations (IgG1 and IgG2) and hospitalizations (IgG2) in two COPD cohorts. This study used serum samples from participants of the MACRO ( NCT00325897 ) and STATCOPE ( NCT01061671 ) trials. |
X Demographics
The data shown below were collected from the profiles of 11 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Canada | 3 | 27% |
| India | 1 | 9% |
| United States | 1 | 9% |
| Australia | 1 | 9% |
| United Kingdom | 1 | 9% |
| Unknown | 4 | 36% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 6 | 55% |
| Practitioners (doctors, other healthcare professionals) | 3 | 27% |
| Scientists | 2 | 18% |
Mendeley readers
The data shown below were compiled from readership statistics for 65 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 65 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 8 | 12% |
| Student > Bachelor | 8 | 12% |
| Researcher | 6 | 9% |
| Other | 5 | 8% |
| Student > Postgraduate | 5 | 8% |
| Other | 13 | 20% |
| Unknown | 20 | 31% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 24 | 37% |
| Biochemistry, Genetics and Molecular Biology | 5 | 8% |
| Agricultural and Biological Sciences | 5 | 8% |
| Nursing and Health Professions | 4 | 6% |
| Immunology and Microbiology | 4 | 6% |
| Other | 4 | 6% |
| Unknown | 19 | 29% |
Attention Score in Context
This research output has an Altmetric Attention Score of 7. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 12 March 2018.
All research outputs
#5,311,777
of 25,382,440 outputs
Outputs from Respiratory Research
#666
of 3,062 outputs
Outputs of similar age
#112,331
of 455,332 outputs
Outputs of similar age from Respiratory Research
#21
of 52 outputs
Altmetric has tracked 25,382,440 research outputs across all sources so far. Compared to these this one has done well and is in the 79th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 3,062 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 7.9. This one has done well, scoring higher than 78% of its peers.
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We're also able to compare this research output to 52 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 59% of its contemporaries.