Hypertension, asymmetric renal parenchymal defect, sterile urine, and high E. coli antibody titre

[Clinical course and scar development in operated vesico-renal reflux in a long-term study]

62 patients (14 boys, 48 girls) representing 85 refluxive renal units (Grade 2-4) were investigated after successful operation for the development of further urinary tract infections (UTI) and renal scars (RS). The mean follow-up was 9.3 years. With the exception of one boy, none of the male patients developed any UTI or new RS. A similar result was obtained for about 45% of the girls. These two groups of patients presented with high-grade reflux before surgery. The remaining female patients (about 55%), however, presenting with lower-grade reflux before surgical treatment, developed further UTI as well as new RS despite surgical correction of their reflux. Investigations on the capacity of uroepithelial cells (UEC) to suppress bacterial growth revealed a deficient antibacterial effect of UEC in these patients. Such an UEC defect has also been shown in patients with asymptomatic bacteriuria. In conclusion, different reasons seem to be responsible for recurrent UTI and the development of RS in patients with reflux.

Assessment of renal parenchymal thickness in normal children

The normal range of variation of the parenchymal thickness in well defined parts of the kidney was determined in children (0 to 15 years). The values were correlated with the distance between the superior surface of L1 and the inferior surface of L3. The ratio between the parenchymal thickness on the right side and the left side was also determined. The results are compiled in two nomograms.

Segmental "hypoplasia" of the kidney (Ask-Upmark)

Severe segmental renal atrophy with loss of parenchymal elements in small kidneys is commonly known as segmental hypoplasia. The scars are seen as cortical depressions overlying shrunken medullary pyramids and their dilated calyces, and are characterized histologically by colloid-filled tubular microcysts and a paucity or absence of glomeruli. This lesion has been identified in 17 patients, 11 female and 6 male, between 6 and 23 years of age. Eleven patients had hypertension, which developed in six while they were under observation. Thirteen had histories of urinary tract infection, and 16 had evidence of vesicoureteric reflux. Seven patients had impaired renal function (GFR less than 40 ml/minute/1.73 m2). Abnormal metanephric differentiation (dysplasia) in two specimens, one in association with posterior urethral valves, suggested an occasional intrauterine origin of the abnormality. Twelve patients had radiographic evidence of decreasing renal size over two to five years of observation, even after surgical correction of reflux, in four of them unaccompanied by infection. We conclude that segmental "hypoplasia" is an acquired lesion, although it sometimes has intrauterine origins, and that it is commonly associated with vesicoureteric reflux, even in the absence of demonstrable infection.

Use of nitroblue tetrazolium (NBT) test in the differentiation between pyelonephritis and cystitis

NBT tests were performed on blood from 37 patients with urinary tract infections caused by coliform bacteria. The level of infections was evaluated by the clinical signs, ESR, renal concentrating capacity and titre of antibodies against the strains of E. coli isolated in their urine. Elevated proportions of NBT-positive neutrophils were found in 11 of 14 patients with pyelonephritis and in 3 of 23 patients with cystitis or asymptomatic bacteriuria (ABU). The total number of NBT-positive neutrophils was 1000 or more per mm3 blood in 11 of 13 patients considered to have pyelonephritis, while it was 800 or less in all the patients investigated, evaluated as having cystitis or asymptomatic bacteriuria. The NBT test is recommended as an adjunct in the level diagnosis or urinary tract infections in children. The utility of the test in smouldering pyelonephritis is presently being investigated.