The prognostic value of serum procalcitonin in acute obstructive pyelonephritis

Abstract

Purpose: To evaluate the prognostic value of procalcitonin (PCT) in the occurrence of infectious complications in the management of acute obstructive pyelonephritis (AOP) compared with other biological parameters (leucocyte count, C-reactive protein [CRP]).

Methods: We conducted a retrospective study including patients who were treated for AOP and performed serum PCT tests in our center between January 1, 2017 and December 31, 2017. Upper urinary tract obstruction was confirmed by either ultrasound or CT urography. Clinical examinations and laboratory tests including leukocyte count, CRP, urine and blood cultures, and serum PCT measurements were performed in the emergency unit. Treatment included early renal decompression using indwelling ureteral stents or nephrostomy and empiric antibiotic therapy. The primary endpoint was occurrence of severe sepsis (SS), a composite criterion including urosepsis and/or septic shock and/or admission to the intensive care unit (ICU) and/or death.

Results: A total of 110 patients (median age: 61 years) were included, of whom 56.3% were female. SS occurred in 39 cases (35.4%). Multivariate regression analysis showed that serum PCT (OR 1.08; 95% CI 1.03-1.17; p = 0.01), CRP (OR 1.007; 95% CI 1.001-1.015; p = 0.03), and diabetes mellitus (OR 5.1; 95% CI 1.27-27.24; p = 0.04) were independent predictors for SS. Serum PCT was the biological marker associated with the highest accuracy to predict SS (ROC 0.912 (95% CI 0.861-0.962) and was superior to CRP (p < 0.001): the sensitivity and specificity of PCT to predict SS were 95% and 77%, respectively, with a serum PCT cutoff value of 1.12 µg/L.

Conclusions: PCT levels > 1.12 µg/L could help physicians to identify high-risk patients who could benefit from early and aggressive management in collaboration with intensive care specialists.

Keywords: Acute obstructive pyelonephritis; Leukocyte; Serum CRP; Serum procalcitonin; Urosepsis.