ORIGINAL ARTICLE Is the mean platelet volume a predictive marker for the diagnosis of acute pyelonephritis in children? Mehmet Tekin • Capan Konca • Abdulgani Gulyuz • Fatih Uckardes • Mehmet Turgut Received: 11 September 2014 / Accepted: 24 October 2014 Ó Japanese Society of Nephrology 2014 Abstract Background Acute pyelonephritis (APN) can lead to renal scar formation, high blood pressure, and end-stage renal failure. Prompt and early diagnosis of APN is important for preventing future complications. Our goal was to study the mean platelet volume (MPV) as a pre- dictor of APN in children. Methods The records of 43 patients with APN and 51 patients with a lower urinary tract infection (UTI) were investigated prospectively. APN was confirmed using radioactive nuclide 99mTc-DMSA scanning. The white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), and MPV of both groups were measured and compared. Results The WBC count, MPV and ESR values, and the serum concentration of CRP were higher in the APN group than in the lower UTI group (p \ 0.05). In the children with APN, the optimal cut-off value for the MPV was 8.2 fl [area under the curve (AUC): 0.906], with sensitivity of 81.4 % and specificity of 86.3 %. The MPV was associated with APN (p = 0.001), and the sensitivity and specificity of the MPV for the diagnosis of APN were higher than those of the other inflammation markers. MPV [ 8.2 fl yielded an adjusted OR of 7.8 (95 % CI 3.3–18.4, p \ 0.001) for APN. MPV [ 8.2 fl was significantly associated with late renal scar formation (adjusted OR 5.7, 95 % CI 2.3–13.8, p \ 0.001). Conclusion The MPV is a fast and reliable measurement with considerable predictive value for the diagnosis of APN and renal scars, and its predictive capacity is better than that of CRP, ESR, and WBC values. Keywords Acute pyelonephritis Á Childhood Á Mean platelet volume Introduction Urinary tract infections (UTIs) are common bacterial infectious diseases in infants and children [1]. UTIs can occur as bladder infections (lower UTI) or can also involve the kidneys (acute pyelonephritis) [2, 3]. Differentiating between these diseases is particularly difficult in infants and children, but it is necessary because pyelonephritis can lead to renal scar formation, high blood pressure, and end-stage renal failure in later life [4]. The prevalence of renal scar- ring due to acute pyelonephritis (APN) is 26.5–49 % [5]. A dimercaptosuccinic acid (DMSA) scan is considered the gold standard in imaging to determine renal parenchy- mal involvement [6]. However, a DMSA scan is not available in all medical centers and exposes children to radioactive chemicals. Although clinical symptoms, such as fever, abdominal pain, flank pain, nausea, and anorexia, and inflammatory markers, including white blood cells (WBC), the erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), can determine the location of a UTI, these symptoms are not always reliable [7]. Therefore, a practical and prompt method that could assist clinicians in differen- tiating between upper and lower UTI is required. M. Tekin (&) Á C. Konca Á M. Turgut Department of Pediatrics, Adiyaman University School of Medicine, Kahta Street, 02000 Adiyaman, Turkey e-mail: drmehmettekin@hotmail.com A. Gulyuz Department of Pediatrics, Sevgi Hospital, Malatya, Turkey F. Uckardes Department of Statistics, Adiyaman University School of Medicine, Adiyaman, Turkey 123 Clin Exp Nephrol DOI 10.1007/s10157-014-1049-z