Skeletal findings in the first 12 months following initiation of glucocorticoid therapy for pediatric nephrotic syndrome

Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point.

INTRODUCTION

Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome.

METHODS

VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry.

RESULTS

Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017).

CONCLUSIONS

The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.

Skeletal findings in children recently initiating glucocorticoids for the treatment of nephrotic syndrome

SUMMARY

Eighty children with nephrotic syndrome underwent lumbar spine densitometry and vertebral morphometry soon after glucocorticoid initiation. We found an inverse relationship between glucocorticoid exposure and spine areal bone mineral density (BMD) Z-score and a low rate of vertebral deformities (8%).

INTRODUCTION

Vertebral fractures are an under-recognized complication of childhood glucocorticoid-treated illnesses. Our goal was to study the relationships among glucocorticoid exposure, lumbar spine areal BMD (LS BMD), and vertebral shape in glucocorticoid-treated children with new-onset nephrotic syndrome.

METHODS

Lateral thoracolumbar spine radiography and LS BMD were performed in 80 children with nephrotic syndrome (median age 4.4 years; 46 boys) within the first 37 days of glucocorticoid therapy. Genant semiquantitative grading was used as the primary method for vertebral morphometry; the algorithm-based qualitative (ABQ) method was used for secondary vertebral deformity analysis.

RESULTS

Six of the 78 children with usable radiographs (8%; 95% confidence interval 4 to 16%) manifested a single Genant grade 1 deformity each. All deformities were mild anterior wedging (two at each of T6, T7, and T8). Four of the 78 children (5%; 95% confidence interval 2 to 13%) showed one ABQ sign of fracture each (loss of endplate parallelism; two children at T6 and two at T8). Two of the children with ABQ signs also had a Genant grade 1 deformity in the same vertebral body. None of the children with a Genant or ABQ deformity reported back pain. An inverse relationship was identified between LS BMD Z-score and glucocorticoid exposure.

CONCLUSIONS

Although we identified an inverse relationship between steroid exposure and LS BMD soon after glucocorticoid initiation for childhood nephrotic syndrome, there was only a low rate of vertebral deformities. The clinical significance of these findings requires further study.

Prevalent vertebral fractures among children initiating glucocorticoid therapy for the treatment of rheumatic disorders

OBJECTIVE

Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid therapy.

METHODS

Children were categorized as follows: juvenile dermatomyositis (n = 30), juvenile idiopathic arthritis (n = 28), systemic lupus erythematosus and related conditions (n = 26), systemic arthritis (n = 22), systemic vasculitis (n = 16), and other conditions (n = 12). Thoracolumbar spine radiograph and dual x-ray absorptiometry for lumbar spine (L-spine) areal bone mineral density (BMD) were performed within 30 days of glucocorticoid initiation. Genant semiquantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative glucocorticoid dose, underlying diagnosis, L-spine BMD Z score, and back pain were analyzed for association with vertebral fracture.

RESULTS

Thirteen vertebral fractures were noted in 9 children (7%). Of these, 6 patients had a single vertebral fracture and 3 had 2-3 fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (grade 2); the others were mild (grade 1). For the entire cohort, mean +/- SD L-spine BMD Z score was significantly different from zero (-0.55 +/- 1.2, P < 0.001) despite a mean height Z score that was similar to the healthy average (0.02 +/- 1.0, P = 0.825). Back pain was highly associated with increased odds for fracture (odds ratio 10.6 [95% confidence interval 2.1-53.8], P = 0.004).

CONCLUSION

In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged glucocorticoid exposure.

A prospective randomized trial comparing 2 diuresis renography techniques for evaluation of suspected upper urinary tract obstruction in children

PURPOSE

We compare the diagnostic impact of 2 diuresis renography techniques for evaluation of suspected upper urinary tract obstruction in children.

MATERIALS AND METHODS

A total of 72 children were randomly assigned to 1 of 2 standardized diuresis renography protocols. The protocols were identical, except for the time of furosemide (F) injection. In the F+20 scans furosemide was given 20 minutes after the 99mtechnetium pentetic acid radiopharmaceutical. With the modified F-15 scans furosemide was injected 15 minutes before renography. Hydration, bladder catheterization, urine output determination, radiopharmaceutical injection and scan acquisition were identical. Renography outcomes (obstructed, nonobstructed or equivocal) were analyzed for the investigated side(s) and for the contralateral side, which was used as a control in children with suspected unilateral obstruction. Chi-square test was used to compare the percentage of obstructed and nonobstructed scans of both protocols. Fisher's exact test was used to compare the nonobstructed scans and equivocal results of both protocols.

RESULTS

Of the 96 scans performed 8 were excluded because of technical problems. The remaining scans included 44 F+20 and 44 F-15. Of the 88 scans 10 were used to evaluate possible bilateral obstruction. A total of 48 boys and 24 girls were evaluated. Because 2 children had a solitary kidney each, the total number of renal units studied for outcome was 174. The F-15 scan showed 7 times more obstruction than the F+20 scan on the investigated side, and this difference was statistically significant. No obstruction was diagnosed on the contralateral side with either technique when used to investigate cases of suspected unilateral obstruction.

CONCLUSIONS

The timing of the furosemide injection (F-15 scan versus F+20) has a significant impact on the obstructive versus nonobstructive renography results when evaluating children with suspected upper urinary tract obstruction.

Displaced calcium as a sign of transitional cell carcinoma in analgesic nephropathy

Transitional cell carcinoma is associated with analgesic nephropathy. Detection of this neoplasm may be delayed because hematuria and colic are the usual symptoms in both conditions. Plain film findings of displacement of the renal calcifications occurring in analgesic nephropathy may be the first sign of transitional cell carcinoma.

Sonographic demonstration of a patent umbilical vein in portal vein tumor thrombosis

A patent umbilical vein is a well-known sonographic sign of portal hypertension. We here describe this finding in a patient with extensive tumor thrombosis of the portal vein and its branches.