The initial search identified 2300 articles (Supplementary Table 1). After duplicate detection, 1985 records were removed (Fig. 1). After title and abstract screening, we assessed 36 full-text studies for eligibility (Supplementary Table 2). Finally, 28 studies, with 2300 individuals, published between 1998 and 2023, were included in the systematic review [21,22,23,24,25, 39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61].

The PRISMA 2020 flow chart

The baseline characteristics of the included studies are presented in Table 1. The mean age of the study participants was between 3.5 months (1.8) to 10.6 years (2.9). The main background of nine studies’ patients was the relation of VUR with kidney scarring [21,22,23, 25, 39, 42, 44, 45, 53] and in 20 studies the relation of UTI [49] and fUTI [43, 45, 46, 48, 50,51,52, 54, 55, 57,58,59,60,61] or APN [24, 40, 41, 47, 56], with or without VUR, with kidney scarring. In total, 811 individuals with VUR as the main background [21,22,23, 25, 39, 42, 44, 45, 53] and 1581 individuals with UTI (UTI, fUTI, and APN) [24, 40, 41, 43, 45,46,47,48,49,50,51,52, 54,55,56,57,58,59,60,61] were included in the systematic review. Over half of the eligible studies evaluated the predictive role of PCT on kidney scarring [40, 41, 43, 46,47,48,49, 51, 54,55,56,57,58,59, 61]. Three of the included studies were cross-sectional [39, 44, 53], 21 studies were prospective [21, 22, 24, 40,41,42,43, 45,46,47, 49,50,51, 54,55,56,57,58,59,60,61], and four were retrospective studies [