PROCALCITONIN AND D-DIMER: MARKERS FOR EARLY DIAGNOSIS OF ACUTE PYELONEPHRITIS IN CHILDREN WITH URINARY TRACT INFECTION AT TERTIARY CARE HOSPITAL

Urinary tract infection (UTI) is one of the most common bacterial infections in children that can      be associated with renal parenchymal injuries and late scars suggestive of Acute pyelonephritis (APN).

DMSA scan known as gold standard for detecting Acute Pyelonephritis has lot of limitations. It is expensive, not easily available, has risks for radiation exposure and failure to distinguish between old and new scars unless follow-up scan is done. Gold Standard for diagnosis of UTI is urine culture which is time consuming and yield contamination if sample is not taken properly.

The clinical diagnosis is also difficult, as both cystitis and acute pyelonephritis patients sometimes present with non-specific symptoms of UTI. Delay in diagnosis eventually leads to delay in treatment causing more damages to renal parenchyma; or outpatient abuse of unnecessary antibiotics which can lead to subsequent development of antibiotic resistance.

D-dimer and PCT level can be determined by venous blood samples that is generally available in all hospitals, therefore we sought to use them as an inflammatory marker in UTI for early diagnosis of Acute pyelonephritis.

PCT is a precursor of calcitonin, with negligible blood levels under normal circumstances which appears in blood in few hours after inflammation, that could determine early renal parenchymal injury and helps to diagnose and treat children in best time possible to prevent renal scar. A meta-analysis of 18 studies concluded that PCT>= 1.0ng/ml has highest diagnostic performance for differentiation of acute pyelonephritis from cystitis. Studies also showed that PCT can also predict UTI severity.

D-dimer is a fibrin degradation product which represents the activation of coagulation system which can increase in conditions involving inflammation. Studies have reported its significance as an inflammatory marker of UTI.