Low Serum Alkaline Phosphatase Levels in Paediatric sepsis Correlate With Acute Kidney Injury: A Multicenter Retrospective Study

AIMS: To investigate the association between serum ALP levels and the development of AKI in paediatric patients with sepsis. METHODS: Retrospective screening of a computerized database of 4 Israeli regional hospitals for children (0-18 years) hospitalized between 1.01.2000-1.06.2024 with ICD-9 sepsis-related diagnoses (study group) and age- and sex-matched non-septic febrile patients (controls). Serum ALP levels were sex- and age-adjusted and described as standard deviation scores (SDS). RESULTS: Of 809 952 screened hospitalizations, 701 records comprised the study group. Their median (IQR) age was 17 (10-38) months, 53% were males. Nadir ALP-SDS was lower in the sepsis group compared to controls (-1.65 ± 1.11 vs. -0.97 ± 1.36, p < 0.001) and further lower in those with AKI, which occurred in 23% of the sepsis cohort (-1.95 ± 1.16 vs. -1.56 ± 1.09, p < 0.001). Hospital stay was longer in the AKI compared to non-AKI group [median (IQR): 7 (4, 12) vs. 4 (3, 5) days, p < 0.001]. Lower ALP-SDS was independently associated with AKI [OR (95% CI): 0.7 (0.6-0.8), p < 0.001], after controlling for CRP and leucocyte count. CONCLUSIONS: ALP was lower in sepsis patients compared to controls, and significantly lower in AKI vs. non-AKI group, suggesting it as an additional marker of infection severity.