Presentation of pediatric Henoch-Schönlein purpura nephritis changes with age and renal histology depends on biopsy timing

BACKGROUND

This study correlates the clinical presentation of Henoch-Schönlein purpura nephritis (HSPN) with findings on initial renal biopsy.

METHODS

Data from 202 pediatric patients enrolled in the HSPN registry of the German Society of Pediatric Nephrology reported by 26 centers between 2008 and 2014 were analyzed. All biopsy reports were re-evaluated for the presence of cellular crescents or chronic pathological lesions (fibrous crescents, glomerular sclerosis, tubular atrophy >5%, and interstitial fibrosis >5%).

RESULTS

Patients with HSPN with cellular glomerular crescents were biopsied earlier after onset of nephritis (median 24 vs 36 days, p = 0.04) than those without, whereas patients with chronic lesions were biopsied later (57 vs 19 days, p < 0.001) and were older (10.3 vs 8.6 years, p = 0.01) than those without. Patients biopsied more than 30 days after the onset of HSPN had significantly more chronic lesions (52 vs 22%, p < 0.001), lower eGFR (88 vs 102 ml/min/1.73m², p = 0.01), but lower proteinuria (2.3 vs 4.5 g/g, p < 0.0001) than patients biopsied earlier. Children above 10 years of age had lower proteinuria (1.98 vs 4.58 g/g, p < 0.001), lower eGFR (86 vs 101 ml/min/1.73m², p = 0.002) and were biopsied significantly later after onset of nephritis (44 vs 22 days, p < 0.001) showing more chronic lesions (45 vs 30%, p = 0.03). Proteinuria and renal function at presentation decreased with age.

CONCLUSIONS

In summary, we find an age-dependent presentation of HSPN with a more insidious onset of non-nephrotic proteinuria, impaired renal function, longer delay to biopsy, and more chronic histopathological lesions in children above the age of 10 years. Thus, HSPN presents more like Immunoglobulin A (IgA) nephritis in older than in younger children.

Predicting the response to growth hormone treatment in short children with chronic kidney disease

CONTEXT

Short stature in children with chronic kidney disease (CKD) is due to various underlying congenital or acquired renal disorders resulting in variable impairment of renal function and variable response to GH treatment.

OBJECTIVE

It was the aim to develop a mathematical model that allows the prediction of the individual growth response and to identify nonresponders.

DESIGN

Data from 208 prepubertal children on conservative or dialysis treatment in a large pharmaco-epidemiological survey, the KIGS (Pfizer International Growth Database), were used for the model and data from 67 similar CKD patients registered at the Dutch Growth Research Foundation for validation.

RESULTS

Annualized height velocity (centimeters per year) during the first year of GH treatment was best predicted by age at start, weight sd score, underlying renal disorder (hereditary kidney disorder), glomerular filtration rate (at baseline), and GH dosage. Using these parameters, the final model explained 37% of the overall variability of growth response. Standard error of the estimates was 1.6 cm. Age was the most important predictor of growth response (20.3% of variability) followed by weight sd score at start, and 27.2% of the variability of the second-year response could be predicted by the first-year response and glomerular filtration rate. Nonresponders of the validation group could be correctly identified.

CONCLUSION

Based on simple clinical variables, a robust prediction model was developed that provides realistic expectations of individual growth response to GH in short children with CKD. The model will help in identifying nonresponders and to tailor treatment strategies.

Growth hormone treatment in short children with chronic kidney disease

Growth hormone (GH) has been used for treatment of impaired growth in children with chronic kidney disease (CKD) for nearly 17 years. Controlled and open-label studies have shown that GH is highly effective in improving growth velocity and adult height. The growth response is negatively correlated with age and height at start and time spent on dialysis treatment; it is positively correlated with dose and duration of treatment and the primary renal disease (renal hypodysplasia). In children with renal transplants, corticosteroid treatment is an additional factor negatively influencing spontaneous growth rates. However, GH treatment is able to compensate corticosteroid-induced growth failure. GH treatment improved final height by 0.5-1.7 standard deviation score (SDS) in various studies, whereas the control group lost about 0.5 SDS in comparable time intervals. These variable results are explained in part by the factors mentioned above. The adverse events are comparable to those in non-CKD children treated with GH.

CONCLUSION

GH treatment is safe and highly effective in improving growth and final height of short children with all stages of CKD. The highest treatment success is obtained if treatment is started at an early age and with relatively well-preserved residual renal function and continued until final height.

Factors predicting the near-final height in growth hormone-treated children and adolescents with chronic kidney disease

CONTEXT

GH therapy is an accepted measure to increase adult height in young prepubertal patients suffering from growth failure related to chronic kidney disease (CKD). The impact of GH therapy on final height (FH) in CKD patients of pubertal age is unclear.

OBJECTIVE

This study set out to analyze near-FH in a cohort of GH-treated CKD patients.

DESIGN, SETTINGS, AND PATIENTS

Of 240 evaluable patients in the Pfizer International Growth Database (KIGS) with CKD, 39% were prepubertal and 61% were pubertal at baseline; 45% were on conservative treatment for CKD, 28% were on dialysis, and 27% were in the period after renal transplantation.

MAIN OUTCOME MEASURES

Near-FH, relation to pubertal stage, and factors predictive of growth response were the main outcome measures.

RESULTS

Mean height sd scores increased continuously during GH treatment until near-FH by 1.2 and 1.6 in boys and girls, respectively. Mean near-FH differed significantly from prepubertal patients showing severely delayed puberty (-3.6), late pubertal patients (-2.9), early pubertal patients (-2.2), and prepubertal patients with normal onset of puberty (-2.0). The initial degree of stunting, degree of bone age retardation, duration of GH therapy, time spent on conservative treatment/dialysis, pubertal delay (>2 sd), gender, and age at start of GH treatment were significant predictors of growth response to GH therapy, explaining between 33 and 61% of the overall variability.

CONCLUSIONS

Long-term GH therapy of CKD patients in prepubertal and pubertal age results in an increased adult height, but response is diminished in patients on dialysis and/or with severely delayed puberty.

Growth impairment shows an age-dependent pattern in boys with chronic kidney disease

The impact of chronological age on longitudinal body growth from early childhood through adolescence using detailed anthropometric methods has not yet been studied in children with chronic kidney disease (CKD). We have evaluated growth failure by measuring four components of linear growth: body height (HT), sitting height (SHT), arm length (AL) and leg length (LL). Data were prospectively collected for up to 7 years on 190 boys (3-21 years old) with congenital or hereditary CKD (all had developed at least stage 2 CKD by the age of 10 years). Patients showed the most severe growth failure in early childhood, followed by an acceleration in growth in pre-puberty, a slowing-down of growth at puberty, as expected, and thereafter a late speeding-up of growth until early adulthood. This pattern was observed irrespective of the degree of CKD and different treatment modalities, such as conservative treatment, recombinant human growth hormone (rhGH) therapy or transplantation. LL showed the most dynamic growth changes of all the parameters evaluated and emerged as the best indicator of statural growth in children with CKD. A specific age-dependent pattern of physical growth was identified in pediatric male CKD patients. This growth pattern should be considered in the evaluation of individual growth and the assessment of treatment efficacy such as rhGH therapy.

Body growth after combined liver-kidney transplantation in children with primary hyperoxaluria type 1

BACKGROUND

Children with primary hyperoxaluria type 1 (PH1) often develop severe growth failure, which is related to metabolic and endocrine consequences of chronic renal failure, and/or oxalate deposition in bone and cartilage. Combined liver and kidney transplantation (LKT) corrects the underlying metabolic defect and restores renal function in these children.

METHODS

We therefore analyzed longitudinal growth of 24 children with PH1 who underwent LKT at nine European centers. Mean age at LKT was 8.9 years, and mean duration of follow-up was 5.7 years.

RESULTS

After LKT mean standardized height tended to increase from -1.79 SD to -1.47 SD until last observation. Mean adult height amounted to 167 cm and 158 cm in boys and girls, respectively. At last observation, seven out of 24 patients were stunted. Within the whole study population, the degree of catch-up growth after LKT was positively associated with degree of stunting at the time of LKT and negatively associated with prednisolone dosage explaining together 39% of the overall variability.

CONCLUSIONS

Combined LKT does not induce true catch-up growth in the majority of children with PH1. Due to the preexisting growth retardation at the time of LKT, one third of patients end up with a reduced final height.

Arterial and cardiac disease in young adults with childhood-onset end-stage renal disease—impact of calcium and vitamin D therapy

BACKGROUND

Studies in patients with childhood-onset end-stage renal disease (ESRD) provide a diagnostic window to the evolution of cardiovascular disease (CVD) in this population. Hyperphosphataemia and renal osteodystrophy are particularly difficult to treat in paediatric patients, but there is only limited information regarding the effect of calcium-containing phosphate binders and vitamin D preparations on the development of CVD in the young.

METHODS

We studied 40 adult patients (mean age 23.6 years) who developed ESRD at the age of 11.5 +/- 4 years and 40 matched healthy control subjects. Nine patients were on dialysis and 31 had a functioning kidney transplant. Measurements included intima-media thickness (IMT) of the common carotid artery, electron beam computed tomography (EBCT) for the detection of coronary artery calcifications (CAC), echocardiography and post-ischaemic arterial blood flow by venous occlusion plethysmography. Patient characteristics, atherosclerotic risk factors and a complete account of prescribed medications were analysed for correlations with arterial and cardiac changes.

RESULTS

The IMT was not significantly different in patients and controls; four patients (10%) had coronary calcifications on EBCT. Twenty-five patients (62.5%) had left ventricular hypertrophy. Patients had a 40% reduction of post-ischaemic arterial flow. Morphological alterations of the heart and arteries were significantly correlated with the duration of ESRD and dialysis time, and with the cumulative intake of calcium-containing phosphate binders and active vitamin D preparations. Functional changes (vascular reactivity) were correlated with duration of ESRD and non-traditional risk factors.

CONCLUSIONS

Young adults with ESRD since childhood have systemic CVD characterized by a decrease in arterial elasticity, the occurrence of CAC and changes in left ventricular morphology. Treatment with calcium-containing phosphate binders and active vitamin D preparations is independently associated in a dose-dependent manner with surrogate markers for CVD.

Systemic cardiovascular disease in uremic rats induced by 1,25(OH)2D3

OBJECTIVE

Vitamin D may contribute to cardiovascular disease in the absence of hypercalcemia in patients with chronic kidney disease.

METHODS

We investigated the effects of long-term (6-week) treatment with 1,25(OH)2D3, at a non-hypercalcemic dosage (0.25 microg/kg per day per orally) in 5/6 nephrectomized rats: (i) vehicle-treated, sham-operated rats; (ii) 1,25(OH)2D3-treated, sham-operated rats; (iii) vehicle-treated, 5/6 nephrectomized rats; and (iv) 1,25(OH)2D3-treated, 5/6 nephrectomized rats.

RESULTS

Creatinine clearance after 6 weeks was significantly lower and parathyroid hormone levels were significantly higher in 1,25(OH)2D3-treated uremic rats, compared with uremic controls (P < 0.01). Serum calcium levels, as well as the calcium-phosphorus product, did not differ between both groups. Mean systolic blood pressure in 1,25(OH)2D3-treated animals was significantly increased, compared with vehicle (each P < 0.01). In addition, 1,25(OH)2D3-treated uremic animals showed left ventricular hypertrophy. Diffuse aortic calcification involving the intima and media layer occurred in 1,25(OH)2D3-treated uremic animals, but not in other groups. The mean aortic wall area and lumen area were increased two-fold in 1,25(OH)2D3-treated uremic animals compared with vehicle (P < 0.01), whereas the wall/lumen ratio remained unchanged, indicating fusiform aneurysm formation.

CONCLUSIONS

Hypertension, left ventricular hypertrophy, aortic calcification, and aneurysm, without hypercalcemia, occurred in 1,25(OH)2D3-treated, 5/6 nephrectomized rats. These data indicate a permissive effect of uremia for cardiovascular damage induced by non-hypercalcemic doses of 1,25(OH)2D3.

Effect of renal transplantation in childhood on longitudinal growth and adult height

BACKGROUND

Severe growth failure is frequently observed in children suffering from end-stage renal disease (ESRD).

METHODS

We analyzed the effect of renal transplantation (RTx) on longitudinal growth and final height in 37 children (19 girls) with ESRD with a mean follow-up of 8.5 years. The mean age at RTx was 11.3 years.

RESULTS

In children transplanted before start of puberty, mean height velocity increased significantly from 4.9 to 8.0 cm/year (P < 0.01), resulting in an increase in standardized height of 0.6 SD within two years post RTx. Although peak height velocity during puberty was significantly increased compared with healthy children, total pubertal height gain was reduced by 20% because of its shortened duration. Mean standardized height significantly increased from the time of RTx until final height by 1.3 SD and 0.7 SD in children transplanted before and after start of puberty, respectively. Mean adult height (boys 170 cm; girls 151 cm) was normal (> -2 SD) in 68% of patients. Change in standardized height from RTx until adult height was associated with initial degree of stunting and glomerular filtration rate (GFR; cumulative r2 0.49). Total pubertal height gain was associated with the age at start of puberty, GFR, and age at RTx (cumulative r2 0.57).

CONCLUSION

RTx in children with ESRD induces moderate catch-up growth during the prepubertal growth period. However, final height is reduced in about one third of patients due to the reduced pubertal height gain and preexisting height deficit at the time of RTx.

Effects of growth hormone treatment on body proportions and final height among small children with X-linked hypophosphatemic rickets

BACKGROUND

X-linked hypophosphatemic rickets (XLH) is characterized by rickets, disproportionate short stature, and impaired renal phosphate reabsorption and vitamin D metabolism. Despite oral phosphate and vitamin D treatment, most children with XLH demonstrate reduced adult height.

OBJECTIVE

To determine the beneficial effects of recombinant human growth hormone (rhGH) therapy on body proportions and adult height among patients with XLH.

METHODS

Three initially prepubertal short children (age, 9.4-12.9 years) with XLH were treated with rhGH for 3.1 to 6.3 years until adult height was attained.

RESULTS

rhGH treatment led to sustained increases in standardized height for all children. The median adult height was 0.9 SD (range: 0.5-1.3 SD) greater than that at the initiation of rhGH treatment and exceeded the predicted adult height by 6.2 cm (range: 5.3-9.8 cm). However, longitudinal growth of the trunk was stimulated more than leg growth. During rhGH treatment, the standardized sitting height increased by 1.6 SD (range: 1.1-2.7 SD), compared with baseline values. In contrast, the median subischial leg length did not change consistently (median change: 0.3 SD; range: -0.1 to 0.6 SD).

CONCLUSION

The increase in final height after rhGH treatment is of potential benefit for children with XLH. However, the exaggeration of disproportionate truncal growth observed for our prepubertal patients is a potential negative effect of treatment and should be confirmed with additional studies.

Effect of growth hormone treatment on the adult height of children with chronic renal failure. German Study Group for Growth Hormone Treatment in Chronic Renal Failure

BACKGROUND

Growth hormone treatment stimulates growth in short children with chronic renal failure. However, the extent to which this therapy increases final adult height is not known.

METHODS

We followed 38 initially prepubertal children with chronic renal failure treated with growth hormone for a mean of 5.3 years until they reached their final adult height. The mean (+/-SD) age at the start of treatment was 10.4+/-2.2 years, the mean bone age was 7.1+/-2.3 years, and the mean height was 3.1+/-1.2 SD below normal. Fifty matched children with chronic renal failure who were not treated with growth hormone served as controls.

RESULTS

The children treated with growth hormone had sustained catch-up growth, whereas the control children had progressive growth failure. The mean final height of the growth hormone-treated children was 165 cm for boys and 156 cm for girls. The mean final adult height of the growth hormone-treated children was 1.6+/-1.2 SD below normal, which was 1.4 SD above their standardized height at base line (P< 0.001). In contrast, the final height of the untreated children (2.1+/-1.2 SD below normal) was 0.6 SD below their standardized height at base line (P<0.001). Although prepubertal bone maturation was accelerated in growth hormone-treated children, treatment was not associated with a shortening of the pubertal growth spurt. The total height gain was positively associated with the initial target-height deficit and the duration of growth hormone therapy and was negatively associated with the percentage of the observation period spent receiving dialysis treatment.

CONCLUSIONS

Long-term growth hormone treatment of children with chronic renal failure induces persistent catch-up growth, and the majority of patients achieve normal adult height.

Factors predictive of the short- and long-term efficacy of growth hormone treatment in prepubertal children with chronic renal failure. The German Study Group for Growth Hormone Treatment in Chronic Renal Failure

To evaluate the growth-stimulating effects of short- and long-term treatment with recombinant human growth hormone (rhGH) in growth-retarded children with chronic renal failure (CRF), 103 prepubertal children with CRF on conservative treatment (n = 74) or dialysis (n = 29) were treated with rhGH for up to 5 yr. rhGH treatment persistently increased standardized height (+ 1.6 SD scores) and predicted adult height (+7.7 cm, Tanner method) during the first 3 treatment years (P < 0.001 versus baseline), followed by percentile parallel growth during continued treatment. Both standardized height and predicted adult height were significantly more increased in conservatively treated than in dialyzed children (P < 0.001). Age, GFR, target height, and prestudy growth rate were identified as independent predictors of the response to rhGH treatment during the first and second treatment year. GFR and target height were positively correlated with the change in height SD score and the change in absolute or age-standardized height velocity. Age affected the growth response depending on which outcome measure was used: Although the first-year change in height SD score was inversely correlated with age, the change in absolute height velocity was independent of age, and the change in standardized height velocity was positively correlated with age. The growth response during the first treatment year positively predicted the long-term response. In conclusion, the short- and long-term growth response to rhGH treatment in prepubertal growth-retarded children with CRF is significantly affected by age, GFR, target height, and the pretreatment growth rate. Therefore, rhGH should be preferably started at a young age, and early in the course of CRF.

Metabolic effects of long-term growth hormone treatment in prepubertal children with chronic renal failure and after kidney transplantation. The German Study Group for Growth Hormone Treatment in Chronic Renal Failure

To evaluate the metabolic effects of long-term treatment with recombinant human (rh) GH in short children with chronic renal failure (CRF), annual oral glucose tolerance tests (oGTT) during rhGH therapy for up to 5 y in 53 prepubertal children with CRF on conservative treatment, dialysis, and after renal transplantation were compared with that of 12 age-matched children treated with rhGH for idiopathic short stature. At the start of rhGH treatment, fasting values of glucose, insulin, glycosylated Hb A (HbA1C), triglycerides, cholesterol, glucose, and insulin responses during oGTT were significantly elevated in all patient groups compared with control subjects (p < 0.001). In the total population, fasting and 2-h postprandial glucose concentrations were inversely correlated with GFR and positively with age and methylprednisolone dosage in transplanted patients. Fasting insulin levels were positively correlated with body mass index and inversely with GFR. RhGH treatment was not associated with a change in fasting or stimulated glucose concentrations in any treatment group throughout the observation period. In contrast, serum insulin levels increased during the first treatment year in all groups, resulting in a more marked elevation of integrated insulin levels in transplant (1402 +/- 179 pM) and dialysis (1025 +/- 114 pM) patients compared with conservatively treated patients (829 +/- 94 pM), and control subjects (719 +/- 89 pM) (p < 0.01). Hyperinsulinemia persisted in all treatment groups for up to 5 y of follow-up. In conclusion, age, renal function, and obesity are the major independent predictors of glucose tolerance in children with CRF. Long-term rhGH treatment does not affect glucose tolerance, but aggravates the preexisting hyperinsulinemia in children with end-stage renal disease. In concert with the dyslipidemia of uremia, the rhGH-promoted hyperinsulinemia may contribute to the long-term risk for premature atherosclerosis in patients with childhood onset CRF.

Effect of growth hormone treatment on pubertal growth in a boy with cystinosis and growth failure after renal transplantation

Recombinant human growth hormone (rhGH) has proven effective in improving growth in short prepubertal children with chronic renal failure (CRF) before and after renal transplantation. However, its effect in pubertal patients is still doubtful. We report the case of a boy with nephropathic cystinosis and persistent growth failure despite successful renal transplantation who was treated with rhGH (30 i.u./m2 body surface area/week sc) from early puberty up to final height.

Short dialyzed children respond less to growth hormone than patients prior to dialysis. German Study Group for Growth Hormone Treatment in Chronic Renal Failure

Recombinant human growth hormone (rhGH) is a new treatment modality for short children with chronic renal failure (CRF) prior to and during dialysis. It is difficult to analyze whether dialysis patients respond less to rhGH than children with CRF on conservative treatment because they are older and often in a pubertal age range. One hundred and eight patients were treated with 28-30 IU rhGH/kg per week for at least 1 year. We analyzed the growth response to rhGH in 56 prepubertal patients aged less than 10 years at the start of rhGH treatment; 38 children with a mean age of 6.5 +/- 2.4 years were on conservative treatment (CT) and 18 patients with a mean age of 6.5 +/- 2 years on dialysis treatment (D). Mean height velocity was 4.9 +/- 2.3 cm/year in children on CT and 4.6 +/- 1.8 cm/year in children on D. During the 1st treatment year, height velocity was 9.5 +/- 3.8 cm/year in CT patients and 7.3 +/- 1.3 cm/year in D patients (P < 0.05). The change in height was +1.1 +/- 0.8 standard deviation (SD) in CT patients and +0.5 +/- 0.4 SD in D patients (P < 0.005). During the 2nd treatment year, the change in height was again greater in CT patients (0.5 +/- 0.4 SD vs. 0.2 +/- 0.4 SD; P < 0.05). The difference in height velocity and change in height standard deviation score was also significant when a subgroup of patients was matched for sex, age, height. Height velocity and the change in height velocity during rhGH treatment were not correlated with residual renal function, the degree of anemia, or metabolic acidosis. We conclude that short children on D respond less to rhGH than short children on CT, indicating a greater insensitivity to rhGH during D treatment.