In beta-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 (U(NAG)) and beta2 microglobulin, in patients with thalassemia. The object of this study was to analyze renal tubular and glomerular function in pediatric patients with beta-thalassemia and to correlate the renal findings to iron overload. Thirty-seven patients with beta-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. U(NAG) and U(NAG) to creatinine ratio (U(NAG/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 beta- 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.

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 (99m)Tc-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 microg/l vs. 0.13, range 0.02-2.15 microg/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/mm(3) (range 10,200-26,900) and 14,600/mm(3) (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.

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.

In the absence of specific symptomatology in children, the early diagnosis of acute pyelonephritis (APN) is a challenge, particularly during infancy. In an attempt to differentiate APN from lower urinary tract infection (UTI), we evaluated the ability of power Doppler ultrasonography (PDU) to predict renal parenchymal involvement, as assessed by dimercaptosuccinic acid ((99m )Tc-DMSA) scintigraphy. The study comprised 62 patients, 46 girls and 16 boys, aged 2 weeks to 5 years, admitted to the pediatric department with febrile UTI. All children were examined by PDU and DMSA scintigraphy within the first 3 days of admission. In the group of 31 patients with one or more DMSA scan abnormalities, the PDU showed a matching perfusion defect in 27 (87%). Of 26 children with normal DMSA scintigraphy, the PDU evaluation was also normal in 24. The sensitivity and specificity of PDU for the detection of affected kidneys were 87% and 92.3%, and the positive predictive value and negative predictive value were 93.1% and 85.7%, respectively. These data indicate the PDU has a high sensitivity and specificity for differentiating APN from lower UTI and may be a useful and practical tool for the diagnosis of APN in infants and children.

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