Cytokine responses, microbial aetiology and short-term outcome in community-acquired pneumonia

Abstract Background Disease severity and outcome in community-acquired pneumonia (CAP) depend on the host and on the challenge of the causal microorganism(s). We measured levels of immunoglobulins (Igs) and complement in 257 hospitalized adults with CAP and examined the association of low levels of Igs or complement to microbial etiology, disease severity, and short-term and long-term outcome. Methods Serum Igs were analyzed in blood samples obtained at admission and at 6 weeks postdischarge if admission levels were low. Serum complement deficiencies were screened with a total complement activity enzyme-linked immunosorbent assay (ELISA), with further analyzes performed if justified. Disease severity was assessed by the CURB-65 severity score. Short-term outcome was defined as a composite end point of intensive care unit (ICU) admission and 30-day mortality, and long-term outcome as 5-year all-cause mortality. Results At admission, 87 (34%) patients had low levels of at least 1 Ig, with low IgG2 as the most prevalent finding (55/21%). IgG levels were lower in bacterial than viral CAP (8.48 vs 9.97 g/L, P = .023), but low Igs were not associated with microbial etiology. Fifty-five (21%) patients had low lectin pathway activity, of which 33 (13%) were mannose-binding lectin (MBL) deficient. Low admission levels of any Ig or MBL were not associated with disease severity, short-term outcome, or long-term outcome. Excluding patients defined as immunocompromised from analysis did not substantially affect these results. Conclusion In hospitalized adults with CAP, low admission levels of Igs or complement were in general not associated with microbial etiology, disease severity, short-term outcome, or long-term outcome.

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Inflammatory biomarkers are associated with aetiology and predict outcomes in community-acquired pneumonia: results of a 5-year follow-up cohort study

ERJ Open Research ◽

10.1183/23120541.00014-2019 ◽

2019 ◽

Vol 5 (1) ◽

pp. 00014-2019 ◽

Cited By ~ 3

Author(s):

William W. Siljan ◽

Jan C. Holter ◽

Annika E. Michelsen ◽

Ståle H. Nymo ◽

Trine Lauritzen ◽

...

Keyword(s):

Hospital Admission ◽

Community Acquired Pneumonia ◽

C Reactive Protein ◽

Short Term ◽

Term Outcome ◽

Reactive Protein ◽

Short Term Outcome ◽

Bacterial Aetiology ◽

All Cause Mortality

BackgroundBiomarkers may facilitate clinical decisions in order to guide antimicrobial treatment and prediction of prognosis in community-acquired pneumonia (CAP). We measured serum C-reactive protein, procalcitonin (PCT) and calprotectin levels, and plasma pentraxin 3 (PTX3) and presepsin levels, along with whole-blood white cell counts, at three time-points, and examined their association with microbial aetiology and adverse clinical outcomes in CAP.MethodsBlood samples were obtained at hospital admission, clinical stabilisation and 6-week follow-up from 267 hospitalised adults with CAP. Adverse short-term outcome was defined as intensive care unit admission and 30-day mortality. Long-term outcome was evaluated as 5-year all-cause mortality.ResultsPeak levels of all biomarkers were seen at hospital admission. Increased admission levels of C-reactive protein, PCT and calprotectin were associated with bacterial aetiology of CAP, while increased admission levels of PCT, PTX3 and presepsin were associated with adverse short-term outcome. In univariate and multivariate regression models, white blood cells and calprotectin at 6-week follow-up were predictors of 5-year all-cause mortality.ConclusionsCalprotectin emerges as both a potential early marker of bacterial aetiology and a predictor for 5-year all-cause mortality in CAP, whereas PCT, PTX3 and presepsin may predict short-term outcome.

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