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IgG2 as an independent risk factor for mortality in patients with community-acquired pneumonia
Mari C de la Torre1, Elisabet Palomera2, Mateu Serra-Prat2
1Unidad Medicina Intensiva, Hospital de Mataró, Barcelona, Spain.
Background:
Mortality in patients with community-acquired pneumonia (CAP) remains high despite improvements in treatment.
Objective:
To determine immunoglobulin levels in patients with CAP and impact on disease severity and mortality.
Methodology:
Observational study. Hospitalized patients with CAP were followed up for 30 days. Levels of immunoglobulin G (IgG) and subclasses, immunoglobulin A (IgA) and immunoglobulin M (IgM) were measured in serum within 24 hours of CAP diagnosis.
Results:
Three hundred sixty-two patients with CAP were enrolled -172 ward-treated and 190 intensive care unit-treated. Intensive care unit-treated patients had significantly lower values of IgG1, IgG2, IgG3 subclasses, and IgA than ward-treated patients. Thirty-eight patients died before 30 days. Levels of IgG2 were significantly lower in non-survivors than survivors (P=.004) and IgG2 <301 mg/dL was associated with poorer survival according to both the bivariate (hazard ratio 4.47; P<.001) and multivariate (HR 3.48; P=.003) analyses.
Conclusions:
Patients with CAP with IgG2 levels <301 mg/dL had a poorer prognosis and a higher risk of death. Our study suggests the usefulness of IgG2 to predict CAP evolution and to provide support measures or additional treatment.
Insights
Low immunoglobulin G2 (IgG2) levels in community-acquired pneumonia (CAP) patients indicate a poorer prognosis and increased mortality risk. Measuring IgG2 may help predict CAP severity and guide treatment strategies.
Area of Science:
- Immunology
- Infectious Diseases
- Critical Care Medicine
Background:
- Community-acquired pneumonia (CAP) continues to have high mortality rates despite advances in medical treatment.
- Understanding host immune factors is crucial for improving outcomes in CAP patients.
Purpose of the Study:
- To investigate immunoglobulin (Ig) levels, including IgG subclasses, IgA, and IgM, in patients diagnosed with CAP.
- To assess the correlation between specific immunoglobulin levels and the severity of CAP and patient mortality.
Main Methods:
- An observational study was conducted involving 362 hospitalized CAP patients, followed for 30 days.
- Serum samples were collected within 24 hours of diagnosis to measure IgG, IgG subclasses (IgG1, IgG2, IgG3), IgA, and IgM.
- Patients were stratified into ward-treated and intensive care unit (ICU)-treated groups.
Main Results:
- ICU-treated patients exhibited significantly lower levels of IgG1, IgG2, IgG3, and IgA compared to ward-treated patients.
- Thirty-eight patients (10.5%) died within the 30-day follow-up period.
- Lower IgG2 levels (<301 mg/dL) were significantly associated with increased mortality in both bivariate and multivariate analyses (HR 4.47 and 3.48, respectively).
Conclusions:
- Patients with CAP and IgG2 levels below 301 mg/dL face a poorer prognosis and a higher risk of death.
- Serum IgG2 levels show potential utility in predicting CAP progression and guiding supportive or additional therapeutic interventions.
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