A protocol for a systematic review and meta-analysis of the diagnostic accuracy of mid-regional pro-adrenomedullin in predicting invasive bacterial infection in children

BACKGROUND

The early recognition of invasive bacterial infections (IBI) in children can be difficult. Clinically it is often challenging to differentiate between the early stages of an IBI and a benign self-limiting viral infection. These challenges mandate a cautious approach resulting in the overuse of antimicrobial drugs with resultant antimicrobial resistance. Due to these challenges, there is growing research into the role of biomarkers for the early identification of children with IBI. Earlier and more accurate diagnoses may lead to improved clinical outcomes for children and reduced antimicrobial resistance. Mid-regional pro-adrenomedullin (MR-proADM) is a biomarker that has been shown to be elevated in patients with IBI. The aim of this systematic review is to determine the diagnostic accuracy of MR-proADM at identifying children with IBI.

METHODS

To identify relevant studies we will search MEDLINE, Embase, Web of Science and Scopus from 1980 to the present day for all human clinical trials involving children that report the test accuracy of MR-proADM. We will include case-control studies, cohort studies and randomised control trials reported in any language. In addition, we will hand-search reference lists and grey literature including conference abstracts and web searches. Two reviewers will independently screen study titles and abstracts for eligibility followed by full-text assessment and data extraction including population, setting, timing and use of index test and reference standard used. Methodological quality will be assessed, by two authors, according to the revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2), any discrepancies will be resolved by a third author. The following test characteristics will be extracted into 2 × 2 tables for all included studies: true positives, false positives, true negatives and false negatives. Study-specific estimates of sensitivity and specificity with 95% confidence intervals will be displayed in forest plots.

DISCUSSION

This review will report the normal ranges for MR-proADM in health and the diagnostic accuracy of MR-proADM at identifying children with IBI. The review will help to define where in the diagnostic pathway MR-proADM could be useful including potential as a point-of-care test for children at first presentation with IBI.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018096295.

Mid-regional pro-adrenomedullin and ST2 in heart failure: Contributions to diagnosis and prognosis

Heart failure has a high prevalence in developed countries. It is a frequent cause of hospital admission and has an important impact on morbidity, mortality and healthcare costs. Biomarkers have been widely studied in heart failure, as they improve diagnosis and prognostic assessment. Natriuretic peptides are already a part of daily clinical practice but several other biomarkers are being studied. This review focuses on mid-regional pro-adrenomedullin (MR-proADM) and ST2. Neither of these biomarkers is useful in the diagnosis of acute heart failure. However, both have considerable short- and long-term prognostic value in patients with acute and with stable chronic heart failure. The utility of these two biomarkers in guiding heart failure treatment is yet to be established. ST2 appears to have some advantages compared to MR-proADM, because it is more closely associated with ventricular remodeling and fibrosis.

Association of metabolic complications with plasma mid-regional pro-adrenomedullin level in stable kidney transplant recipients

BACKGROUND

Recently, increased plasma mid-regional pro-adrenomedullin (MR-proADM) concentrations have been demonstrated in patients with chronic renal failure. In this study, we attempted to identify significant clinical factors associated with MR-proADM concentration in stable kidney transplant recipients.

METHODS

Forty-seven Japanese kidney transplant recipients who underwent transplantation >180days prior to the study were analyzed. To facilitate comparability of anti-hypertensive regimens across recipients taking different drugs, we calculated the treatment intensity score of anti-hypertensive drugs in each recipient. Morning blood samples were collected and plasma MR-proADM concentrations were measured using an enzyme immunoassay.

RESULTS

Multiple regression analysis identified treatment intensity score for anti-hypertensive drugs, serum albumin, creatinine clearance and use of lipid-lowering agents as significant independent factors associated with plasma MR-proADM concentration. Adjusted coefficient of determination for this model was 0.46.

CONCLUSION

Apart from indicating lowered renal function, plasma MR-proADM concentration may be a useful biomarker for metabolic disorders, especially hypertension and hyperlipidemia, in stable kidney transplant patients.

Mid-regional pro-adrenomedullin in the early evaluation of acute chest pain patients

BACKGROUND

The purpose of this study was to investigate the utility of mid-regional pro-adrenomedullin (MR-proADM) in the early diagnosis and risk stratification of patients with acute chest pain in comparison with established and novel biomarkers and risk scores.

METHODS

In this prospective, observational, international, multi-center trial (APACE), MR-proADM was determined in 1179 unselected patients with acute chest pain. Patients were followed for 24 months.

RESULTS

MR-proADM concentrations at presentation were higher in patients with AMI (median: 0.78 nmol/l, IQR 0.60-1.13) than in patients with other diagnoses (0.64 nmol/l, IQR 0.49-0.86 nmol/l; p<0.001). The diagnostic accuracy of MR-proADM for AMI as quantified by the area under the receiver operating characteristic curve (AUC) was 0.66. Adding MR-proADM to hs-cTnT could not improve its diagnostic accuracy for AMI (p=0.431). Seventy-six percent of all deaths occurred in the fourth quartile of MR-proADM (>0.90 nmol/l). Adding MR-proADM to the TIMI-score (AUC 0.87) predicted 1-year mortality more accurately than the TIMI-score alone (AUC 0.82; p<0.001). Net reclassification improvement (TIMI vs. additionally MR-proADM) amounted to 0.137 (p=0.012). MR-proADM had higher prognostic accuracy as compared to hs-cTnT in patients with AMI (p=0.015) and in those without AMI (p=0.003). MR-proADM at presentation was tantamount to GRACE score and BNP as to its prognostic accuracy for mortality. The AUC for the prediction of cardiovascular events amounted to 0.63.

CONCLUSIONS

While MR-proADM does not have clinical utility in the early diagnosis of AMI or predicting cardiovascular events in patients with acute chest pain, it may provide prognostic value for all-cause mortality.