Interlaboratory variation for NT-proBNP among Swedish laboratories in an external quality program 2011-2021

Reference intervals for high sensitivity cardiac troponin I and N-terminal pro-B-type natriuretic peptide in children and adolescents on the Siemens Atellica

OBJECTIVES

The cardiac biomarkers high sensitivity cardiac troponin I (hs-cTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are utilised in paediatric healthcare for the diagnosis and prognostic assessment of many conditions including myocarditis, congenital heart disease, multisystem inflammatory syndrome in children (MIS-C) and heart failure. However, the standardised age-related reference intervals, 99th percentile cut-offs and clinical guidelines are not available, making the interpretation of these biomarkers challenging. This study aimed to generate normative data in a paediatric cohort for the Siemens Atellica® IM 1300 analyser.

METHODS

Residual plasma samples were collected from children aged up to 17 years attending primary care and out-patient settings and with no apparent evidence of cardiac dysfunction, renal dysfunction or other confounders. Reference intervals were generated using the 2.5th-97.5th percentiles, and 99th percentile cut-offs determined according to CLSI EP28-A3c.

RESULTS

Statistical analysis revealed that partitioning was not required for gender for either biomarker. The reference interval for hs-cTnI for children aged one month to 16 years (n=292, 146 females and 146 males) was <14 ng/L with a 99th percentile cut-off of 19 ng/L. The reference interval for NT-proBNP for children aged one month up to one year was <714 ng/L (n=14) and for children aged 1-16 years (n=339) was <295 ng/L.

CONCLUSIONS

This is the first paediatric reference interval data generated on the Siemens Atellica® solution. These reference intervals and 99th percentiles will inform clinical decisions in the paediatric cardiology setting.

N-terminal pro-brain natriuretic peptide is a biomarker for cardiovascular damage in systemic lupus erythematous: a cross-sectional study

OBJECTIVES

Prediction models based on traditional risk factors underestimate cardiovascular (CV) risk in systemic lupus erythematosus (SLE). In a large sample of unselected SLE patients, we investigated cross-sectional associations of NT-proBNP with cardiovascular damage (CVD).

METHODS

Serum NT-proBNP was measured in SLE patients enrolled in the MUHC Lupus Clinic registry. Serum was collected between March 2022 and April 2023 at annual research visits. The primary outcome was CVD identified on the SLICC Damage Index. Factors associated with CVD and NT-proBNP levels were determined.

RESULTS

Overall, 270 SLE patients [female 91%, median age 50.7 (first quartile to third quartile: 39.6-62.1) years] were analysed for the primary outcome. Among them, 33 (12%) had CVD. The ROC curve for NT-proBNP demonstrated strong associations with CVD (AUC 0.78, 95% CI 0.69-0.87) with a threshold of 133 pg/ml providing the best discrimination for those with/without CVD. Hypertension (OR 3.3, 95% CI 1.2-9.0), dyslipidaemia (OR 3.6, 95% CI 1.3-9.6) and NT-proBNP >133 pg/ml (OR 7.0, 95% CI, 2.6-19.1) were associated with CVD in the multivariable logistic regression model. Increased NT-proBNP levels were associated with age (OR 4.2, 95% CI 2.2-8.3), ever smoking (OR 1.9, 95% CI 1.0-3.5), reduced eGFR (4.1, 95% CI 1.3-13.1), prior pericarditis/pleuritis (OR 2.5, 95% CI 1.4-4.5) and aPL antibodies (OR 2.6, 95% CI 1.4-4.9).

CONCLUSION

NT-proBNP is a biomarker for CV damage in SLE. The novel associations of NT-proBNP levels with prior pericarditis/pleuritis and aPL antibodies suggest new avenues for research to better understand what drives CV risk in SLE.

From volume to value: a watershed moment for the clinical laboratory

The clinical laboratory is often evaluated for the volume of testing. However, it is undeniable that laboratory tests affect clinical decision-making and are included in many clinical guidelines, meaning their contribution to determining clinical outcomes. Therefore, the clinical laboratory professional has the task of enhancing laboratory tests by optimizing the request and reporting phase and addressing patient outcomes. This opinion paper, presenting practical examples of managing value-based health care in the clinical laboratory context, underlines the need to shift towards value-based management to optimize outcome-based health care.