Diagnostic accuracy of Leucine-rich α-2 glycoprotein (LRG) as a urinary biomarker in pediatric appendicitis: a prospective observational pilot study from Eastern India

Abstract

Background Recently, several serum and urinary biomarkers have been investigated for diagnosis of acute appendicitis. Urinary biomarkers seem to be advantageous in children as it is non-invasive, painless, and easy to perform. Leucine-rich α-2-glycoprotein (LRG) is regarded as a reliable urinary biomarker for the diagnosis of pediatric appendicitis. A prospective observational pilot study was conducted in children presenting with abdominal pain. Assessment of pediatric appendicitis score (PAS), routine blood tests, and measurements of urinary LRG was done. The present study aimed to evaluate the diagnostic accuracy of urine LRG in appendicitis in Indian children and to assess the concentration of urine LRG at which it will guide the management. Results LRG had a receiver operating characteristic (ROC) area under the curve (AUC) of 0.586 (95% CI 0.407–0.766). There was no specific cut-off identified using Youden’s index. ROC analysis of the PAS score resulted in an AUC of 0.821 (95% CI 0.691–0.952). Using Youden’s index, the cut-off for PAS scoring was identified as 6.5 with the sensitivity of 80%, the specificity of 76.2%, positive predictive value 76.19%, negative predictive value as 80%, and diagnostic accuracy of 78%. Conclusions LRG could not show better diagnostic performance compared to routine blood tests and PAS scores. There was no specific cut-off value at which it will differentiate mesenteric adenitis and acute appendicitis and guide their management. With 78% diagnostic accuracy, PAS score (> 6) is still a better tool for the diagnosis of acute appendicitis. Trial registration Clinical Trials Registry Government of India, CTRI/2018/01/011182, Registered on: 08 Jan 2018.

Leucine-Rich Alpha-2-Glycoprotein as a non-invasive biomarker for pediatric acute appendicitis: a systematic review and meta-analysis

“…The risk of bias in relation to the selection of patients was considered low in 6 of the 8 studies [ 10 – 12 , 14 , 15 , 17 ], unclear in 1 of them [ 13 ] and high in the last one [ 16 ]. The risk of bias in relation to the index test was considered low in 6 of the studies [ 10 – 12 , 14 – 17 ] and unclear in two of them [ 13 , 16 ].…”

“…The risk of bias in relation to the selection of patients was considered low in 6 of the 8 studies [ 10 – 12 , 14 , 15 , 17 ], unclear in 1 of them [ 13 ] and high in the last one [ 16 ]. The risk of bias in relation to the index test was considered low in 6 of the studies [ 10 – 12 , 14 – 17 ] and unclear in two of them [ 13 , 16 ]. The risk of bias in relation to the reference standard was considered low in 7 of the studies [ 10 – 15 , 17 ] and high in one of them [ 16 ].…”

“…The risk of bias in relation to flow and timing was considered low in 7 of the studies [ 10 – 12 , 14 – 17 ] and unclear in one of them [ 13 ]. Regarding applicability concerns, the risk was estimated as low in all categories except for patient selection, for index test and for reference standard in 1 study [ 16 ]. The results of the QUADAS2 analysis are shown in Fig.…”

“…All studies were carried out between 2010 and 2021. One was from Latvia [ 17 ], 3 from the United States [ 10 – 12 ], 2 from Singapore [ 14 , 15 ], 1 from Sweden [ 13 ] and 1 from India [ 16 ]. All studies were prospective and involved only pediatric populations aged between 3 and 18 years.…”

“…In 7 of the 8 included studies [ 10 – 15 , 17 ], patients were recruited in the emergency department prior to diagnosis, and biological samples were obtained at the time of inclusion in the study. One study [ 16 ] included patients from both the emergency department and an outpatient department.…”