Vladislav Smolkin

Procalcitonin as a marker of acute pyelonephritis in infants and children

Abstract In the absence of specific symptomatology in children, the early diagnosis of acute pyelonephritis is a challenge, particularly during infancy. In an attempt to differentiate acute pyelonephritis from lower urinary tract infection (UTI), we measured serum procalcitonin (PCT) levels and compared these with other commonly used inflammatory markers. We evaluated the ability of serum PCT levels to predict renal involvement, as assessed by dimercaptosuccinic acid (DMSA) scintigraphy. Serum C-reactive protein (CRP), leukocyte counts, and PCT levels were measured in 64 children admitted for suspected UTI. Renal parenchymal involvement was assessed by 99mTc-DMSA scintigraphy in the first 7 days after admission. In acute pyelonephritis, the median PCT level was significantly higher than in the lower UTI group (3.41, range 0.36–12.4 μg/l vs. 0.13, range 0.02–2.15 μg/l, P<0.0001). In these two groups, respectively, median CRP levels were 120 (range 62–249 mg/l) and 74.5 (range 14.5–235 mg/l, P=0.012) and leukocyte counts were 15,910/mm3 (range 10,200–26,900) and 14,600/mm3 (range 8,190–26,470, P=0.34). For the prediction of acute pyelonephritis, the sensitivity and specificity of PCT were 94.1% and 89.7%, respectively; CRP had a sensitivity of 100%, but a specificity of 18.5%. We conclude that serum PCT may be an accurate marker for early diagnosis of acute pyelonephritis.

Association of Procalcitonin With Acute Pyelonephritis and Renal Scars in Pediatric UTI

BACKGROUND AND OBJECTIVE: Urinary tract infections (UTIs) are common childhood bacterial infections that may involve renal parenchymal infection (acute pyelonephritis [APN]) followed by late scarring. Prompt, high-quality diagnosis of APN and later identification of children with scarring are important for preventing future complications. Examination via dimercaptosuccinic acid scanning is the current clinical gold standard but is not routinely performed. A more accessible assay could therefore prove useful. Our goal was to study procalcitonin as a predictor for both APN and scarring in children with UTI. METHODS: A systematic review and meta-analysis of individual patient data were performed; all data were gathered from children with UTIs who had undergone both procalcitonin measurement and dimercaptosuccinic acid scanning. RESULTS: A total of 1011 patients (APN in 60.6%, late scarring in 25.7%) were included from 18 studies. Procalcitonin as a continuous, class, and binary variable was associated with APN and scarring (P < .001) and demonstrated a significantly higher (P < .05) area under the receiver operating characteristic curve than either C-reactive protein or white blood cell count for both pathologies. Procalcitonin ≥0.5 ng/mL yielded an adjusted odds ratio of 7.9 (95% confidence interval [CI]: 5.8–10.9) with 71% sensitivity (95% CI: 67–74) and 72% specificity (95% CI: 67–76) for APN. Procalcitonin ≥0.5 ng/mL was significantly associated with late scarring (adjusted odds ratio: 3.4 [95% CI: 2.1–5.7]) with 79% sensitivity (95% CI: 71–85) and 50% specificity (95% CI: 45–54). CONCLUSIONS: Procalcitonin was a more robust predictor compared with C-reactive protein or white blood cell count for selectively identifying children who had APN during the early stages of UTI, as well as those with late scarring.

Procalcitonin is a Predictor for High-Grade Vesicoureteral Reflux in Children: Meta-Analysis of Individual Patient Data

OBJECTIVE To assess the predictive value of procalcitonin, a serum inflammatory marker, in the identification of children with first urinary tract infection (UTI) who might have high-grade (≥3) vesicoureteral reflux (VUR). STUDY DESIGN We conducted a meta-analysis of individual data, including all series of children aged 1 month to 4 years with a first UTI, a procalcitonin (PCT) level measurement, cystograms, and an early dimercaptosuccinic acid scan. RESULTS Of the 152 relevant identified articles, 12 studies representing 526 patients (10% with VUR ≥3) were included. PCT level was associated with VUR ≥3 as a continuous (P = .001), and as a binary variable, with a 0.5 ng/mL preferred threshold (adjusted OR, 2.5; 95% CI, 1.1 to 5.4). The sensitivity of PCT ≥0.5 ng/mL was 83% (95% CI, 71 to 91) with 43% specificity rate (95% CI, 38 to 47). In the subgroup of children with a positive results on dimercaptosuccinic acid scan, PCT ≥0.5 ng/mL was also associated with high-grade VUR (adjusted OR, 4.8; 95% CI, 1.3 to 17.6). CONCLUSIONS We confirmed that PCT is a sensitive and validated predictor strongly associated with VUR ≥3, regardless of the presence of early renal parenchymal involvement in children with a first UTI.

Renal function in children with β-thalassemia major and thalassemia intermedia

In β-thalassemia, profound anemia and severe hemosiderosis cause functional and physiological abnormalities in various organ systems. In recent years, there have been few published studies demonstrating proteinuria, aminoaciduria, low urine osmolality, and excess secretion of the tubular damage markers, such as urinary N-acetyl-D-glucosaminidase (UNAG) and β2 microglobulin, in patients with thalassemia. The object of this study was to analyze renal tubular and glomerular function in pediatric patients with β-thalassemia and to correlate the renal findings to iron overload. Thirty-seven patients with β-thalassemia major and 11 with thalassemia intermedia were studied. Twelve children without iron metabolism disorders or renal diseases served as a control group. No difference in blood urea nitrogen (BUN), serum creatinine, creatinine clearance, electrolytes, fractional excretion of sodium and potassium, and tubular phosphorus reabsorption was found. Serum uric acid was equal in the two groups, but its urine excretion was significantly higher in the thalassemic group. UNAG and UNAG to creatinine ratio (UNAG/CR) were elevated in all patients with thalassemia compared with the control group (p < 0.001) and were directly correlated to the amount of transfused iron but not to actual ferritin level. We found that renal tubular function is impaired in children with β- thalassemia major and intermedia. It is not known whether these functional abnormalities would have any long-term effects on the patients. Further studies are needed, and means of preventing these disturbances should be sought.

Power Doppler sonography versus Tc-99m DMSA scintigraphy for diagnosing acute pyelonephritis in children: are these two methods comparable?

Purpose This study assessed the role of renal power Doppler ultrasonography (PDU) to identify acute pyelonephritis (APN) and to determine whether PDU can replace Tc-99m DMSA renal scintigraphy in the diagnosis of APN in children. Methods A prospective study was conducted in 40 infants and young children (78 kidneys were evaluated) with a mean age of 25.9 months (range, 1 to 68 months) who were hospitalized with a first episode of high fever and bacteruria, possibly APN. All children were examined by PDU and Tc-99m DMSA within the first 3 days after admission. Patients with congenital abnormalities, hydronephrosis, and urinary reflux were excluded. Results Twenty-seven of the 78 kidneys appeared abnormal on Tc-99m DMSA, and 20 of them were abnormal on PDU. Fifty-one of 78 kidneys were normal on Tc-99m DMSA, and 3 of 51 appeared diseased on PDU. The accuracy of PDU was 87%, sensitivity was 74%, and specificity was 94%. The positive predictive and negative predictive values were both 87%. When considering the numbers of lesions in 27 kidneys with positive Tc-99m DMSA studies (38 lesions), PDU did not disclose 16 lesions (false-negative results). Thus, the sensitivity of PDU for diagnosing lesions of APN decreased to 58%. Conclusions A positive PDU finding should obviate the use of Tc-99m DMSA in patients thought to have possible APN. However, because of a large number of false-negative results (26%) and underestimation of the number of pyelonephritic lesions (low sensitivity of 58%), PDU cannot replace Tc-99m DMSA in the diagnosis of APN in children.

Prediction of moderate and high grade vesicoureteral reflux after a first febrile urinary tract infection in children: construction and internal validation of a clinical decision rule.

PURPOSE Urinary tract infection leads to a diagnosis of moderate or high grade (III or higher) vesicoureteral reflux in approximately 15% of children. Predicting reflux grade III or higher would make it possible to restrict cystography to high risk cases. We aimed to derive a clinical decision rule to predict vesicoureteral reflux grade III or higher in children with a first febrile urinary tract infection. MATERIALS AND METHODS We conducted a secondary analysis of prospective series including all children with a first febrile urinary tract infection from the 8 European participating university hospitals. RESULTS A total of 494 patients (197 boys, reflux grade III or higher in 11%) were included. Procalcitonin and ureteral dilatation on ultrasound were significantly associated with reflux grade III or higher and then combined into a prediction model with an ROC AUC of 0.75 (95% CI 0.69-0.81). Given the prespecified constraint of achieving at least 85% sensitivity, our model led to the clinical decision rule, for children with a first febrile urinary tract infection cystography should be performed in cases with ureteral dilatation and serum procalcitonin level 0.17 ng/ml or higher, or without ureteral dilatation (ie ureter not visible) when serum procalcitonin level is 0.63 ng/ml or higher. The rule had 86% sensitivity (95% CI 74-93) with 47% specificity (95% CI 42-51). Internal cross-validation produced 86% sensitivity (95% CI 79-93) and 43% specificity (95% CI 39-47). CONCLUSIONS A clinical decision rule was derived to enable a selective approach to cystography in children with urinary tract infection. The rule predicts high grade vesicoureteral reflux with approximately 85% sensitivity and avoids half of the cystograms that do not find reflux grade III or higher. Further validation is needed before its widespread use.

Chronic recurrent multifocal osteomyelitis in infancy: A case report

Ch hronic recurrent multifocal osteomyelitis (CRMO) is a rare disorder characterized by a chronic inflammatory musculoskeletal process that presents with lytic lesions of the multiple bones with pain and swelling of the affected areas. The disorder has a varying course with exacerbations and spontaneous remissions. The etiology of the disorder is unknown, but it is theorized that there is either an au-

Steroid responsive nephrotic syndrome associated with bilateral renal dysplasia.

Abstract Renal dysplasia is characterized by hypoplastic kidneys that contain elements of primitive tubules. Patients may develop end-stage renal failure early in life. Nephrotic syndrome is one of the most common renal diseases in childhood and may occur in association with renal dysplasia. We report a case of a child with bilateral dysplastic kidneys and steroid responsive nephrotic syndrome (SRNS). An association between renal dysplasia with chronic renal failure and SRNS has not previously been reported in the English literature.