Harry Stark

Urinary tract infections in girls: the cost-effectiveness of currently recommended investigative routines

Abstract. Current recommendations for the universal investigation of urinary tract infection (UTI) in children by ultrasonography, voiding cystourethrography, and dimercaptosuccinic acid renal scan (and sometimes intravenous pyelography as well) are not based on any convincing evidence as to the necessity or effectiveness of such a routine. Over 8% of all girls will have a UTI during childhood. About 87 individuals in a million will develop end-stage renal disease (ESRD) by the age of 60 years, caused in about 9% by pyelonephritis (PN) or reflux nephropathy. From these statistics, the maximal risk of a first diagnosed UTI progressing to ESRD is approximately 1:10,000. The risk of developing hypertension following a first UTI in childhood, without eventual evolution to ESRD, appears to be very small. The cost of the widely recommended routine imaging procedures ranges from U.S.

Direct Measurement of TP/GFR: A Simple and Reliable Parameter of Renal Phosphate Handling

355 in Britain to U.S.

Renal tubular dysfunction following vascular accidents of the kidneys in the newborn period

1,090 in the United States. The minimal cost of preventing a single progression to ESRD by early diagnosis of underlying pathology - if this were possible in all cases - would range between U.S.

Effect of erythromycin on blood cyclosporine concentrations in kidney transplant patients.

5 million in Britain and U.S.

Value of Routine Electron Microscopy in the Differential Diagnosis of the Nephrotic Syndrome

15 million in the United States. Since in many instances progressive renal damage can not be prevented, the true cost is considerably higher. Lower UTI in girls is a very common and, in most cases, benign finding in primary-care practice. It is suggested that girls with afebrile UTI, presenting with lower urinary tract symptoms alone, need not undergo any imaging procedures, but should be followed with urine examinations and cultures at the time of febrile illness. The recommended investigative routines should be reserved for UTI in infants and in girls with fever or other symptoms suggesting PN, and for proven recurrent UTI. Such a regimen will allow a marked saving in terms of costs and in terms of unneccessary radiation, psychological stress to children, and stress, inconvenience, and time loss to parents. There is no evidence that this approach will compromise the course or final outcome of this very common condition.

Severe tubular resistance to aldosterone in a child with familial juvenile nephronophthisis

As the Walton-Bijvoet nomogram for estimating renal phosphate (P) threshold (TmP/GFR) is not applicable to children of all ages, we sought an alternative method for measuring renal handling of P. Recognizing that the nomogram represents an indirect correlation between TmP/GFR and TP/GFR under fasting conditions, we examined this directly in 26 children. An excellent correlation was found, expressed as TmP/GFR = (fasting TP/GFR X 1.1) -0.3 (r = 0.95). The regression line in adults, expressed as TmP/GFR = (fasting TP/GFR X 1.4) -0.9 (calculated from published studies) is markedly different at the higher values typical for children. Since no advantage could be seen in the use of a mathematically derived TmP, we investigated the direct use of measured TP/GFR (tubular P reabsorption per 100 ml glomerular filtrate) as a measure of renal P handling in clinical practice. No differences were found between morning fasting and nonfasting values. Measurements in 151 healthy subjects aged 3 days to 53 years established normal values in relation to age. The use of this parameter in patients is shown to accurately reflect defects and changes in renal P handling. We believe it to be the preferred parameter because it represents a directly measured physiologic function applicable to all age-groups.

Gaucher's disease and mesangiocapillary glomerulonephritis in childhood — a coincidence?

Two infants, each of whom had a renal vascular accident in the newborn period, developed rickets at 7 months of age. At age 8 and 12 months, respectively, active rickets, acidosis, and growth retardation were found. Investigation demonstrated multiple renal tubular dysfunctions, with only moderate reduction in the glomerular filtration rate. One infant had tubular proteinuria, glucosuria, hyperaminoaciduria, hyperphosphaturia, and defects in urinary concentrating and acidifying capacities. The second one had defects only of phosphate reabsorption and of the concentrating and acidifying mechanisms. A third infant had a thrombosis of the right renal vein on the second day of life. At age 17 months he had a constant, mild metabolic acidosis attributed to an isolated tubular “bicarbonate leak.” Urography demonstrated a dwarfed, but functioning, right kidney. It is suggested that some “idiopathic” tubular nephropathies, which present in early childhood, may be the result of undiagnosed renal vascular accidents of the newborn period.

Parameters for Evaluation and Correlation of Renal Phosphate Handling and of Parathyroid Function in Children

Patient 1. A 10-year-old boy with renal failure caused by dysgenesis of a congenital single kidney underwent cadaveric renal transplantation in 1984. Immunosuppression was achieved with prednisone and cyclosporine. Plasma concentrations of cyclosporine over the period of 3 years ranged between 70 and 130 ng/ml. Serum creatinine levels over the last months were 4.2 to 4.4 mg/dI (370 to 390 #tool/L). Thirty-six months after transplantation, interstitial pneumonia developed and the patient was given erythromycin in a dose of 40 mg/kg for 10 days. Over 14 days the plasma cyclosporine levels rose from 73 to 373 ng/ml and returned to a level of less than 30 ng/ml within 10 days after erythromycin was discontinued. At the same time, serum creatinine values rose from 4.4 mg/dl (520 t.~mol/L), returning to 4.2 mg/dl after the erythromycin was discontinued. Patient 2. A 10-year-old girl with renal failure secondary to Wegener granulomatosis underwent cadaveric renal transplantation in 1986. Immunosuppression was achieved with prednisone and cyclosporine. After the renal transplant, her serum creatinine levels ranged from 0.9 to 1.2 mg/dl (80 to 106 ~mol/L) and the plasma cyclosporine concentration from 30 to 45 ng/ml. Four months after transplantation, pneumonia developed and erythromycin, 50 mg/kg daily, and co-trimoxazole, 40/8 mg/kg daily, were prescribed. Five days later, facial edema and hypertension

Diffuse ultrastructural glomerular alterations in apparent 'focal' Schönlein-Henoch nephritis.

Routine electron microscopic examination of renal biopsies was performed in 37 nephrotic patients with primary glomerular lesions. These cases were classified according to the following pathological p

Ultrastructural Changes Suggestive of Focal Segmental Glomerulosclerosis in Atypical Minimal Change Nephrotic Syndrome

A 9.5-year-old girl, whose early symptoms were polyuria and growth retardation, is described. During the progression of her disease, hyperkalaemia developed out of proportion to the degree of renal insufficiency. Her fractional excretion of sodium increased from 3.3% to 35%, and her fractional excretion of potassium decreased from 55% to 22%. The plasma aldosterone level and plasma renin activity (PRA) were very high −290 ng/ml and 100 ng/dl per hour, respectively (normal range for this age 2.6–20.8 ng/ml and 1.2–2.7 ng/ml per hour, respectively). In an attempt to reduce these hormone levels, an acute and sustained saline load, captopril and peritoneal dialysis were used. Only the sustained saline load normalized the PRA, and only peritoneal dialysis sufficiently suppressed the plasma aldosterone level. Successful renal transplantation normalized both plasma aldosterone and PRA. This girl presents the unusual occurrence of pseudohypo-aldosteronism type I, during the course of familial juvenile nephronophthisis.