Serum alkaline phosphatase and γ-glutamyl transferase in acute pyelonephritis

Abstract

Background Elevated serum alkaline phosphatase (AP) and γ-glutamyl transferase (γ-GT) are commonly observed in patients with acute pyelonephritis. The goal of this study was to examine the clinical significance of elevated serum AP and γ-GT levels and to explore the mechanisms underlying these changes. Methods We examined serum AP and γ-GT levels in 438 patients with acute pyelonephritis. Urine AP/creatinine (Cr), urine γ-GT/Cr, fractional excretion of AP, and fractional excretion of γ-GT (FE γ-GT ) were evaluated in patients with elevated and normal serum levels. AP isoenzymes were also examined. Results We identified 77 patients (17.6%) with elevated serum AP and 134 patients (30.6%) with elevated serum γ-GT. Among them, both enzymes were elevated in 64 patients (14.6%). Older age, longer hospital stay, elevated baseline serum Cr, and complicated pyelonephritis were associated with increases in serum AP and γ-GT. Multivariate analysis showed that high serum AP levels were significantly correlated with renal impairment (odds ratio, 2.13; 95% confidence interval, 1.08–4.19; P = 0.029). FE γ-GT was significantly lower in patients with elevated serum enzyme levels. The liver fraction for AP isoenzyme profile did not increase in patients with elevated serum AP. Conclusion Our results demonstrated that elevated serum AP and γ-GT levels are associated with complicated pyelonephritis and renal impairment. Lower FE γ-GT levels in patients with elevated serum enzymes may be the result of decreased urinary excretion of these enzymes.

Alkaline Phosphatase Pathophysiology with Emphasis on the Seldom-Discussed Role of Defective Elimination in Unexplained Elevations of Serum ALP – A Case Report and Literature Review

“…Relatively minor elevations of ALP not clearly attributable to liver or bone disease are relatively common in healthy 22 and hospitalized subjects. 23 In hospitalized patients, such elevations were associated with renal failure, pyelonephritis, 24 congestive heart failure, and various malignancies. In patients with benign disease, the majority of the elevations normalized during a 3 month follow-up; most patients with persistent, appreciable ALP elevations had obvious severe medical problems and extensive evaluation for subtle causes of elevated ALP seldom was not required.…”

Kidney-based in vitro models for drug-induced toxicity testing

“…In AKIs, two subtypes of GST, α and π, are released from proximal and distal tubule, respectively, allowing to distinguish between the two segments when affected (Wang et al 2018). As GGT and ALP increase during damage in the brush border, elevated levels of these enzymes were associated with complicated pyelonephritis and renal impairment (Han et al 2019).…”