Vesicoureteral reflux and urodynamic dysfunction.

INTRODUCTION: The concept of vesicoureteral reflux (VUR) as a consequence of congenital anomaly of vesicoureteral junction has undergone changes owing to the finding that such children may have lower urinary tract dysfunction, which produces high intravesical pressure and consequently a predisposition for VUR. PATIENTS AND METHODS: The urodynamics was investigated by pressure-flow-EMG study in 132 children with VUR and 162 refluxing units. RESULTS: Only 33 (25.0%) patients had normal urodynamic finding. The most frequent pathological finding was overactive bladder (OAB), found in 59 (44.7%) children, followed by dysfunctional voiding (DV) in 25 (18.9%) children. Children with VUR grades I and II had a higher percentage of pathological urodynamic findings than children with VUR grades III and IV. OAB was more frequent in children under 5 years of age with unilateral and lower grade VUR. It was found equally in children with and without uroinfections. DV was more frequent in children older than 5 years, with bilateral VUR, higher grade VUR and uroinfections. CONCLUSIONS: Children with VUR have a high incidence of urodynamic disorders. The results of the study indicate the possible role of urodynamic dysfunction in the pathogenesis of VUR, especially mild one.

Idiopathic nephrotic syndrome in children: review of 282 Croatian cases.

Recent data suggests increased incidence of focal segmental glomerulosclerosis (FSGS) among children with idiopathic nephrotic syndrome (INS). To determine the causes and possible longitudinal changes in the etiology of INS, 282 Croatian children diagnosed with INS between 1990 and 2009 were evaluated. In total, 122 children were assessed as having minimal change nephrotic syndrome (MCNS) based on their initial presentation, laboratory findings and clinical course. Kidney biopsy was performed in the remaining 160 children. MCNS was present in 18.1% of all biopsies performed. Total incidence of MCNS (assessed + biopsy proven) was only 53.5%. In contrast, FSGS was found in 40.6% of all biopsies and accounted for 23.1% of all cases. Mesangial proliferative glomerulonephritis (MesPGN) was the third most common diagnosis, present in 26.9% of the biopsies, and accounted for 15.2% of all cases. There were no significant longitudinal differences in the incidence of different causes of INS. The overall response to steroids at presentation was 71.6%. A higher proportion of initial steroid responders among children with FSGS (43.1%) and MesPGN (67.4%) than previously reported was noted. A longitudinal tendency of increasing steroid resistance in FSGS and MesPGN groups was observed.

[Clinical and histopathological characteristics of biopsy-proven renal diseases in Croatia]. / Klinicke i patohistoloske karakteristike biopsijom dokazanih bubreznih bolesti djece u Hrvatskoj.

There is little data on the spectrum of renal diseases in children in Croatia. The Croatian Society for Pediatric Nephrology has established the Registry of Biopsy-Proven Renal Diseases in an attempt to address this issue nationwide. Here we report preliminary results of a retrospective analysis of clinical and histopathological data of 565 children aged < or =17 years presenting to 9 hospitals in Croatia from 1991 to 2004, in whom kidney biopsy was performed. The most common indication for renal biopsy was nephrotic syndrome (39.1%), followed by asymptomatic proteinuria/hematuria (22.0%) and acute nephritic syndrome (17.0%). All biopsies were analysed by light-, immunofluorescent and electron microscopy. The majority of children, 552 out of 565 (92.4%), had glomerulonephritis (GN). Tubulointerstitial nephritis was found in 16 (2.8%), congenital renal parenchyma anomalies in 14 (2.5%) and vascular disease in 11 (1.9%) cases. One (0.2%) child had sarcoidosis with nephrocalcinosis. The sample was non-diagnostic in 1 (0.2%) case. Among children with GN, primary GN accounted for 70.9%, secondary GN for 16.1% and hereditary GN for 13.0% cases. The most frequent primary GN forms were focal segmental glomerulosclerosis (FSGS) (24.6%), mesangial proliferative glomerulonephritis (MEPGN) (19.2%) and IgA nephropathy (18.1%). Acute GN in resolution was found in 11.1% and minimal changes GN in 6.8% of cases. Most children with secondary GN had nephritis of Henoch-Schönlein purpura (HSP) (54.7%) and nephritis of systemic lupus erythematosus (SLE) (40.5%), while among hereditary GN Alport syndrome was most common (80.9%). In the group of children with primary GN who presented with nephrotic syndrome, most common forms were FSGS (38.5%) and MEPGN (24.0%). Minimal changes GN accounted for only 10.9% of cases. IgA nephropathy, primary or related to HSP (20.0%), FSGS (16.1%), MEPGN (12.6%) and Alport syndrome (9.7%) were the most common biopsy-proven renal diseases in Croatian children. The analysis provided data on the frequency of histological renal lesions in children in Croatia. The higher frequency of FSGS and MEPGN among Croatian children in comparison with other countries deserves further evaluation.

The significance of ultrasonography in diagnosing and follow-up of cystic cystitis in children.

Cystic cystitis is a separate form of urinary bladder inflammation, detected by cystoscopy in children with recurrent urinary infections. Cystoscopy is an invasive method, so the aim of this investigation was to determine the ultrasonographic characteristics of cystic cystitis and to assess the reliability of ultrasound in relation to cystoscopy in diagnosing cystic cystitis. The study included 115 girls with repeated urinary infections. Cystoscopy and ultrasonography was performed in all. According to the cystoscopic finding the subjects were divided into 4 groups. Lateral and posterior urinary bladder wall thickness was measured during ultrasonography. A statistically significant difference was found between all 4 groups, the method demonstrated a high degree of sensitivity (0.97) and specificity (0.91). Percentile calculations were determined for wall thickness. Ultrasonography can replace endoscopy in diagnosis and follow-up of cystic cystitis in children, with at least 50% fullness of the urinary bladder as a prerequisite.

Analysis of calcium, oxalate, and citrate interaction in idiopathic calcium urolithiasis in children.

The majority of urinary stones in children are composed of calcium oxalate. To investigate the interaction between urinary calcium, oxalate, and citrate as major risk factors for calcium stones formation, their 24-h urinary excretion was determined in 30 children with urolithiasis and 15 normal healthy children. The cutoff points between children with urolithiasis and healthy children, accuracy, sensitivity, and specificity for each risk factor alone as well as for all three taken together were determined. OneR and J4.8 classifiers as parts of the larger data mining software Weka, based on machine learning algorithms, were used for the determination of the cutoff points for differentiation of the children. The decision tree based on J4.8 classifier analysis of all three risk factors together proved to be the best for differentiating stone formers from normal children. In comparison to the accuracy of the differentiation after calcium and oxalate of 80% and 75.6%, respectively, the decision tree showed an accuracy of 97.8%. Even when its stability was tested by the leave-one-out cross-validation procedure, the accuracy remained at a very acceptable percentage of 93.2% correctly classified patients. J4.8 classifier analysis gave a look inside urinary calcium, oxalate, and citrate interaction. Urinary calcium excretion was shown as the most informative in discrimination of the children with urolithiasis from healthy children. However, it was shown that oxalate and citrate excretions might influence the stone formation in a subpopulation of the stone formers. In patients with low urinary calcium, a major role in lithogenesis belongs to oxalate, in some of them alone and in others in conjunction with citrate. Decreased urinary citrate excretion in the presence of increased oxalate excretion may lead to stone formation.

[Renal biopsy in children with isolated microhematuria]. / Biopsija bubrega u djece s izoliranom mikrohematurijom.

UNLABELLED: Isolated microscopic hematuria (IMH) in children always raises the question whether, besides other examinations, there is a need of performing a renal biopsy. Many authors consider IMH to be a minor abnormality where pathologic glomerular changes are not likely to be found, however, general agreement has not yet been achieved. The aim of the study was to evaluate the contribution of renal biopsy to the diagnosis of the disease in IMH. PATIENTS AND METHODS: Renal biopsy was performed in 54 children with IMH (22 boys and 32 girls, mean age 8.2 and 8.5 years, respectively) in whom urologic abnormalities, hypercalciuria, systemic diseases, coagulopathy or overt family history of renal disease were excluded. The mean duration of IMH prior to biopsy was 2.8 years. Biopsy specimens were examined by light (LM), immunofluorescent (IF) and electron microscopy (EM). RESULTS: Glomerular abnormalities were found in 43 (79.6%) patients. On LM 18 patients had normal glomeruli (NG), 22 mesangial proliferative glomerulonephritis (MEPGN), 9 focal glomerulosclerosis (FGS), 3 focal glomerulonephritis (FGN) and 2 membranoproliferative glomerulonephritis (MPGN). IF revealed 2 cases of NG, 5 cases of MEPGN, and all 3 cases of FGN as IgA nephropathy. EM detected GBM changes consistent with Alport syndrome in 21 patients, 7 of them with NG, 9 with MEPGN and 5 with FGS on LM. Diffuse thinning of GBM was found in 10 children, 7 with NG and 3 with MEPGN on LM. In 5 cases subepithelial hump-like deposits, which were considered to be the sign of acute postinfectious glomerulonephritis in resolution, were found. One of 2 cases of MPGN showed to be type II (DDD). On follow-up, 6 of 21 children with changes consistent with Alport syndrome developed clinical signs of the syndrome. Further surveillance is needed to confirm the significance of EM findings in others. CONCLUSION: The authors concluded that in children with IMH renal biopsy is justified and should always be analyzed by light, immunofluorescent and electron microscopy.

[Cystic cystitis in children]. / Cisticni cistitis u djece.

Cystic cystitis is a common urinary bladder disease with a histologic picture of nodular lesions of the bladder mucosa. Intralesional lymphoid proliferation due to recurrent urinary tract infection play a major role in the occurrence of cystic cystitis. It is often found together with vesicoureteral reflux and other urinary tract anomalies and urodynamic disturbances. Examination of 116 children with cystic cystitis revealed it to be associated with urinary tract anomalies, especially vesicoureteral reflux. The average age at diagnosis is 7 years. The disease often needs longterm prophylaxis for urinary tract infections, and has favorable prognosis.