ESPN 51th Annual Meeting

ESPN 2018


 
Urinary Alpha 1 Microglobulin, a potential biomarker for pyelonephritis
BONTE ALEXANDER 1 VAN HOLDER BENGT 1 MEESTERS KEVIN 1 VANDE WALLE JOHAN 1

1- DEPARTMENT OF PEDIATRIC NEPHROLOGY, GHENT UNIVERSITY HOSPITAL
 
Introduction:

In children, acute pyelonephritis (APN) is diagnosed by interpreting a urine culture in the context of clinical parameters, particularly fever. Yet, in case of an alternative febrile focus in children with a positive urine culture, it is difficult to differentiate pyelonephritis from lower UTI. Therefore, biomarkers could be useful. Urinary Alpha 1 microglobulin (A1M) is often measured in our clinic. In this study, we examined the diagnostic validity of urinary alpha-1-microglobulin (A1M) for APN in children.

Material and methods:

In this retrospective cohort study, we included all children in whom APN was suspected and both urinary A1M was measured and sufficient clinical information was available in the electronic medical files of our hospital, in a 5 years period. Patients were classified into 3 groups: ‘APN likely’, ‘APN possible’ and ‘APN unlikely’. Urinary A1M was compared between these groups, ROC curves were generated. ‘APN likely’ was used as reference group in al analyses, which were performed using SPSS for Windows.

Results:

Data of 91 children were available. A1M was significantly different between children with likely APN compared to children with unlikely APN (median: 14.8 versus 0 mg/l, p=0.001). Furthermore, A1M was significantly different between the groups APN likely and APN possible (median: 14.8 versus 0 mg/l, p=0.011). There is no significant difference between the groups APN unlikely and APN possible (median: 0 versus 0 mg / l, p=0.327). The AUC of the ROC curve was 0.864 (95% CI: 0.783 - 0.945, p=0.001). In our study population the optimal cut-off value is 5.35 mg/l, which has a sensitivity and specificity of 87.2% and 75.6%, respectively.

Conclusions:

A1M is a potential sensitive and specific biomarker for APN in children. Yet, further prospective validation is needed.