WTO must ban harmful fisheries subsidies

[Figure: see text].

Anti-lymphocyte antibodies late in the course of pediatric renal transplantation

Beyond the immediate post-transplant period, physicians are often reluctant to use anti-lymphocyte preparations to treat episodes of acute renal functional deterioration attributable to acute rejection. This is due to the perception that such episodes are less likely to be reversible, and to concern regarding the potential adverse effects of anti-lymphocyte antibodies, including opportunistic infections, lymphoproliferative disorders, and the development of human anti-mouse antibodies. Records were reviewed for all 365 renal transplants performed in 267 patients at our center from 1971 to 1996. Anti-lymphocyte antibodies were used in an attempt to reverse 6 episodes of corticosteroid-resistant acute rejection in 5 children at a mean interval of 24.5 months following transplantation. The mean serum creatinine at initiation of therapy with the anti-lymphocyte agents was 2.9 mg/dl. Following treatment, the mean serum creatinine decreased to 1.3 mg/dl (P=0.03, Student's t-test). Two patients developed uncomplicated opportunistic infections after completion of anti-lymphocyte therapy; none have developed lymphoproliferative disorders or antibodies to OKT3. We conclude that in the correct clinical setting with corticosteroid-resistant acute rejection, the use of anti-lymphocyte antibodies should not be withheld solely on the basis of length of time since transplantation.

Predictive value of race in post-transplantation recurrence of focal segmental glomerulosclerosis in children

BACKGROUND

Focal segmental glomerulosclerosis (FSGS) is a leading cause of end-stage renal disease (ESRD) in children, and one of the most difficult to manage because of its high recurrence rate post-transplantation (Tx). Several predictive factors have been associated with disease recurrence (DR) although one in particular, the role of recipient race, has not been adequately evaluated. Herein we report our experience with DR in the post-Tx period in eight patients.

METHODS

Records were reviewed for all renal transplants performed at St Christopher's Hospital for Children from 1971 to 1997.

RESULTS

Twenty patients received 27 allografts for ESRD due to FSGS. Ten (37%) grafts went to African-American (AA) children, and 16 (59%) to those of Caucasian (C) origin. DR was observed in eight (30%) grafts after Tx. No differences were noted between the patients who developed DR and those who did not, with respect to age at diagnosis or time to ESRD. DR was observed in one (10%) of 10 grafts in AA, compared to seven (41%) of 17 grafts in the other (O) racial groups (P=0.19). At last follow-up, the only AA recipient with DR has maintained stable renal function, while three (43%) of seven in O have lost their grafts.

CONCLUSION

In conclusion, in our population post-Tx recurrence of FSGS occurred more frequently and represented a greater threat to graft survival in O recipients than in those of AA descent. Recipient race should therefore be taken into consideration during pre-Tx counselling of families of children with FSGS.

Pleural effusion complicating acute peritoneal dialysis in hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a leading cause of acute renal failure (ARF) in children, and one for which treatment with peritoneal dialysis (PD) is often necessary. Between January 1982 and December 1996, 176 children received PD for ARF at St. Christopher's Hospital for Children; 34 (19%) of whom had HUS. Of these 34, 7 (20%) developed pleural effusions (PE) while receiving PD, whereas none of the remaining 142 children with other causes of ARF did so. The mean age of the 7 affected children was 5.2 (range 0.4-17) years; none had heart failure or nephrotic syndrome, nor had any of them undergone thoracic surgery. PE were diagnosed by chest radiograph at an interval of 2 (range 1-3) days after starting PD. Thereafter, 4 (57%) patients were successfully maintained on a modified PD prescription; 2 others were converted to hemodialysis and 1 to continuous venovenous hemodiafiltration. Although PE are a known complication of PD, none of the patients so treated for non-HUS related ARF developed them. Whether they represent a purely mechanical complication of PD, or are in some way attributable to HUS itself, is not entirely clear. Regardless, when children with HUS require PD, physicians should monitor for the development of this potential complication to minimize the risk of serious respiratory compromise.

Calcineurin activity in children with renal transplants receiving cyclosporine

BACKGROUND

The major immunosuppressive effect of cyclosporine is through the inhibition of calcineurin, an enzyme important in the activation of T lymphocytes. In children, neither calcineurin activity nor its inhibition by cyclosporine (CsA) has been investigated.

METHODS

Calcineurin activity, was measured in stable pediatric renal transplant patients, with healthy children used as controls. Whole blood CsA concentrations were measured by monoclonal radioimmunoassay. Simultaneous calcineurin and CsA levels were measured before and 1, 2, 3.5, 5, and 12 hr after their routine morning CsA dose.

RESULTS

Calcineurin activity was approximately 50% inhibited at trough blood concentrations (148 microg/L); moreover, inhibition increased as CsA concentrations rose and declined as concentrations fell. Maximum calcineurin inhibition was about 70% at concentrations of about 431 microg/L. Linear regression analysis revealed a significant correlation between mean CsA blood concentration and the mean degree of inhibition of calcineurin activity (P=0.005, one-tailed).

CONCLUSION

We conclude that inhibition of calcineurin activity by CsA in pediatric renal transplant recipients correlates with CsA blood concentrations.

Response to the varicella vaccine in children with nephrotic syndrome

Varicella vaccine was administered to seven children with corticosteroid-sensitive nephrotic syndrome. Immunization was not associated with any significant reactions or with increased frequency of relapse. The antibody response was, however, variable and a second dose was necessary before seroconversion was achieved in four patients. The findings indicate that immunization with varicella vaccine is safe in children with nephrotic syndrome in remission, but that a two-dose vaccine schedule should be considered.

Comparison and validation of limited sampling equations for cyclosporine area-under-the-curve monitoring calculations in pediatric renal transplant recipients

Therapeutic monitoring of cyclosporine (CsA) by using area-under-the-concentration-time-curve (AUC) values in renal transplant recipients has been previously demonstrated to predict posttransplant clinical outcome. Two previous studies also reported that limited sampling equations could accurately determine the AUC of CsA using one to six blood concentration determinations in adults. The purpose of this study was to validate the accuracy of these equations in a pediatric population. In 18 pediatric patients who received renal allografts, three limited sampling equations, which used one, four, or five concentration time points, accurately estimated CsA AUC when compared with an actual 7- to 9-point curve. An equation that used a single concentration time point at 5 hours was unbiased and provided the best precision in calculating a 12-hour interval AUC. This equation had a mean absolute percentage error of 5.8% (95% confidence interval, 3.3 to 8.3). Equations using four or five concentration time points were found to provide estimates of AUC for a 24-hour interval AUC, with less than 10% error. These findings suggest that limited sampling models using as few as one to four concentration time points provide accurate estimations of CsA AUC in pediatric patients. The use of these limited sampling models provides the clinical advantage of lower blood sampling requirements and reduced costs associated with the monitoring of cyclosporine.

Intravenous immunoglobulin prophylaxis of cytomegalovirus infection in pediatric renal transplant recipients

Cytomegalovirus (CMV), the most significant infectious cause of morbidity following renal transplantation, may be a greater problem for children than for adults due to their relative lack of experience with this virus. Therefore, we prospectively gave Gammagard as prophylaxis to CMV-negative children who received CMV-positive allografts and compared the results to our experience with similar high-risk recipients transplanted prior to our use of intravenous immunoglobulin G (IvIgG). Symptomatic CMV disease developed in 17% of the IvIgG recipients as compared with 71% of the untreated patients (p = 0.01). The CMV infections that did occur in IvIgG recipients developed significantly later than in untreated children (median time of onset after transplantation 2.60 vs. 1.35 months; p < 0.05) and generally were less severe, although 1 IvIgG recipient died despite prophylaxis. IvIgG administration did not affect the frequency of rejection or graft or patient survival. We conclude that IvIgG administration to high-risk pediatric renal transplant recipients may protect against posttransplantation CMV disease and may lessen the severity of infections that do develop in patients who receive it.

Effective immunization against influenza in pediatric renal transplant recipients

Viral infections such as influenza are an important cause of morbidity following organ transplantation. We evaluated the immunogenicity of a commercially available influenza vaccine in pediatric renal transplant recipients in a two-phase, prospective study. In phase one, 47 transplant patients and seven control subjects with bronchopulmonary dysplasia received influenza vaccine. Sera were collected at the time of vaccination and 6 wk later. In phase two, sera from 18 transplant recipients and 47 healthy adults who had received the same vaccine were collected 6-12 months after vaccination. Antibody titers to the A/Taiwan/1/86 antigen were measured with hemagglutination inhibition assay in both phases of the study. Vaccine was well tolerated in all subjects. No vaccinated patient required hospitalization for complications of influenza infection. Vaccination did not increase the frequency of acute allograft rejection. In phase one, 43 patients (91%) and 5 controls (71%) either seroconverted (developed a fourfold or greater rise in titer), or developed post-vaccination titers > or = 1:160 (p = NS). Among the transplant recipients, non-seroconverters had a higher pre-vaccination geometric mean antibody titer (GMT) than those who seroconverted. Seroconversion developed independently of whether patients received double or triple immunosuppression. In phase two, post-vaccination GMT were similar for patients and control subjects at 11.5 and 8 months post-vaccination, respectively. In our study, influenza vaccination produced equivalent humoral immunity in transplant recipients and normal subjects. Routine influenza vaccination should be performed annually in this high-risk population.

Pharmacokinetics of cyclosporine after renal transplant in children

The pharmacokinetics of cyclosporine and the relationship between blood levels and average drug concentration were prospectively evaluated in 18 children 1 month after renal transplantation. All children had normal renal function and no hepatic or gastrointestinal dysfunction. Cyclosporine was administered after an overnight fast, and serial blood samples were drawn over a 24-hour period. Analysis of cyclosporine levels was performed by means of monoclonal radio immunoassay on whole blood. Children were divided into three age groups for comparison: 2-5 years, 5-10 years, and > 10 years. There were no differences between age groups in serum protein, serum lipids, or hemoglobin levels, or in the pharmacokinetic parameters of cyclosporine except as follows: significant differences were noted in cyclosporine dose based on body weight, apparent steady-state volume of distribution, and apparent blood clearance, with the youngest children (2-5) requiring higher doses, a relative greater distribution, and exhibiting more rapid drug clearance than those > 10 years of age. In addition, we observed diurnal variation in trough levels, with morning levels (0 hr) significantly higher than those obtained in the evening (12 hours after administration of cyclosporine). Trough levels demonstrated a fair correlation with area under the concentration-time curve (AUC) and average concentration (Cav), but an abbreviated kinetic profile using cyclosporine levels 1 and 3.5 hours after administration accurately predicted AUC.

Fusarium peritonitis in a child on peritoneal dialysis: case report and review of the literature

OBJECTIVE

To review various aspects of the management of peritonitis due to Fusarium, a soil mold which infrequently causes infections in humans.

DATA SOURCES

A case of Fusarium peritonitis in a child on chronic peritoneal dialysis (PD) is presented. The child developed Fusarium peritonitis 2 weeks after an episode of bacterial peritonitis. His Tenckhoff catheter was removed, and he was maintained on hemodialysis while receiving intravenous amphotericin. Following 2 weeks of treatment with amphotericin, he was successfully returned to PD. A literature review of all previously reported cases of Fusarium peritonitis was then conducted to determine features common to infections caused by Fusarium. Emphasis was also placed on unique characteristics of the organism that may affect patient management, as well as patient characteristics that may increase the risk for infection by Fusarium.

RESULTS

Fusarium may cause infection in immunosuppressed individuals, such as cancer patients or patients on chronic PD. The organism has a propensity to attach to foreign bodies such as intravascular and intraperitoneal catheters. Therefore, successful treatment of infections caused by Fusarium may require catheter removal in addition to systemic antifungal therapy.

CONCLUSIONS

This report presents the first known case of Fusarium peritonitis in a child. In view of the difficulties posed by this unusual organism, optimal therapy of Fusarium peritonitis should consist of immediate catheter removal and treatment with systemic antifungal drugs.

Natural history and etiology of hyperuricemia following pediatric renal transplantation

A retrospective review was conducted to determine the incidence, etiology, natural history and complications of hyperuricemia after pediatric renal transplantation. Of 81 active transplant recipients aged 10.1 +/- 4.8 (mean +/- SD) years being followed by St. Christopher's Hospital for Children, 57 (70%) were males and 59 (73%) Caucasian. Their immunosuppression consisted of azathioprine, cyclosporine A and prednisone. Mean serum uric acid concentrations peaked at 6 months post transplantation (6.2 +/- 2.6 mg/dl), when 39% of the patients had hyperuricemia and 60% were receiving diuretics, and decreased thereafter. At 30 months, 23% of the patients had hyperuricemia and 17% required diuretics. When we compared 42 normouricemic (group A) with 24 hyperuricemic (group B) patients at 18 months post transplantation, we found that patients in group B were older (11.6 +/- 4.2 vs. 8.6 +/- 5.2 years, P = 0.01), had worse renal function (77 +/- 25 vs. 96 +/- 36 ml/min per 1.73 m2, P = 0.03) and required diuretics more frequently (63% vs. 21%, P = 0.001), but had identical blood levels of cyclosporine A (82 +/- 28 vs. 84 +/- 35 ng/ml, P = 0.78). A family history of gout did not affect the prevalence of hyperuricemia after transplantation. Asymptomatic hyperuricemia is common following pediatric renal transplantation and is more likely attributable to reduced renal function and diuretic therapy than to the known hyperuricemic effect of cyclosporine A. Of these variables, only diuretic therapy is readily controllable and should be closely regulated following pediatric renal transplantation.

Peritoneal dialysis catheter infections in children after renal transplantation: choosing the time of removal

As a foreign body, the peritoneal dialysis (PD) catheter represents a potential source of infection, particularly for immunosuppressed renal transplant patients. A retrospective study was therefore undertaken to compare the risks and benefits of our policy of removing PD catheters at 3 months following renal transplant, which was established to allow for early re-initiation of dialysis. Between 1984 and 1990, 43 renal transplants were performed in 35 children who had been receiving maintenance PD. During the 1st month post transplantation, the PD catheter was used in 25 patients (58%) because of acute rejection or primary allograft non-function. Thirty-one patients were eventually discharged with functioning allografts and a PD catheter in place. Of them, 43% developed a catheter-related infection within the next 2 months, a period during which PD was not performed. Potential contributing factors included a history of catheter-related infection prior to transplantation, use of high-dose methylprednisolone to treat acute rejection, and the type of maintenance immunosuppression prescribed; conversely, the use of prophylactic antibiotics appeared to decrease this risk. This study established the potential need for the catheter during the first few weeks, but because of the infection risk of 43% by 3 months post transplantation, our protocol was revised to include catheter removal at the time of hospital discharge. From 1990 until the end of 1992, an additional 19 PD recipients underwent transplantation. In this group, catheters were used during the 1st month in 6 children (32%). Fifteen patients were discharged with a functioning allograft and only 1 patient returned to PD at 12 months post transplant. It is concluded that PD catheters represent an additional source of infection following transplantation and should be removed at the time of hospital discharge, after which the likelihood of use is low.

Growth of children following the initiation of dialysis: a comparison of three dialysis modalities

Maintenance dialysis usually serves as an interim treatment for children with end-stage renal disease (ESRD) until transplantation can take place. Some children, however, may require dialytic support for an extended period of time. Although dialysis improves some of the problems associated with growth failure in ESRD (acidosis, uremia, calcium, and phosphorus imbalance), many children continue to grow poorly. Therefore, three different dialysis modalities, continuous ambulatory peritoneal dialysis (CAPD), cycler/intermittent peritoneal dialysis (CPD), and hemodialysis (HD), were evaluated with regard to their effects on the growth of children initiating dialysis and remaining on that modality for 6-12 months. Growth was best for children undergoing CAPD when compared with the other two modalities with regard to the following growth parameters: incremental height standard deviation score for chronological age [-0.55 +/- 2.06 vs. -1.69 +/- 1.22 for CPD (P < 0.05) and -1.80 +/- 1.13 for HD (P < 0.05)]; incremental height standard deviation score for bone age [-1.68 +/- 1.71 vs. -2.45 +/- 1.43 for CPD (P = NS) and -2.03 +/- 1.28 for HD (P = NS)]; change in height standard deviation score during the dialysis period [0.00 +/- 0.67 vs. -0.15 +/- .29 for CPD (P = NS) and -0.23 +/- .23 for HD (P = NS)]. The reasons why growth appears to be best in children receiving CAPD may be related to its metabolic benefits: lower levels of uremia, as reflected by the blood urea nitrogen [50 +/- 12 vs. 69 +/- 16 mg/dl for CPD (P < 0.5) and 89 +/- 17 for HD (P < 0.05)], improved metabolic acidosis, as indicated by a higher serum bicarbonate concentration [24 +/- 2 mEq/l vs. 22 +/- 2 for CPD (P < 0.05) and 21 +/- 2 for HD (P < 0.05)]. In addition, children undergoing CAPD receive significant supplemental calories from the glucose absorbed during dialysis. CAPD, and possibly, other types of prolonged-dwell daily peritoneal dialysis appear to be most beneficial for growth, which may be of particular importance for the smaller child undergoing dialysis while awaiting transplantation.

Growth after conversion to alternate-day corticosteroids in children with renal transplants: a single-center study

During the 1980s all children with growth potential and stable/adequate renal function at 6-9 months after kidney transplantation underwent conversion to alternate-day corticosteroids in an attempt to maximize growth. Conversion was attempted in 79 of 160 children who received allografts during this decade and was considered successful if they remained on alternate-day prednisone for more than 1 year, with a calculated creatinine clearance of at least 75% of the pre-conversion baseline value. Conversion succeeded in 55 children but failed in 24. Growth was markedly improved among those successfully converted when compared with the failure group, as measured by standard deviation score for growth velocity based on chronological age (+0.94 +/- 1.58 vs. -0.86 +/- 1.53, P < 0.001) and bone age (+0.49 +/- 0.61 vs. -1.24 +/- 1.47, P < 0.001). The improved growth among the successfully converted patients is believed to have been related to the combined effects of lower corticosteroid dose (0.36 +/- 0.16 vs. 0.48 +/- 0.21 mg/kg per day, P < 0.02) and better renal function (calculated creatinine clearance 87 +/- 32 vs. 47 +/- 21 ml/min per 1.73 m2, P < 0.001) at 1 year post conversion. Two factors appeared to improve the likelihood of successful conversion: the use of cyclosporine and receiving a live-related rather than cadaver transplant. Cyclosporine was associated with improvement in the overall rate for successful conversion in all recipients, from 59% to 83% (P < 0.05). Recipients of allografts from live-related donors underwent successful conversion in 90% of cases compared with 58% receiving cadaver allografts (P < 0.05). (ABSTRACT TRUNCATED AT 250 WORDS)

Urinary tract infections in children with posterior urethral valves after kidney transplantation

The records of 14 boys with posterior urethral valves who had renal failure and subsequently underwent renal transplantation were reviewed to determine the postoperative incidence of urinary tract infection relative to that of 29 male transplant children without valves, who served as controls. There were no significant differences between the posterior urethral valve patients and controls with regard to age, donor source, immunosuppression, followup after transplantation or mean calculated creatinine clearance. Vesicoureteral reflux was found in 1 child with posterior urethral valves and 3 of the children in the control group (p not significant). A total of 15 urinary tract infections occurred in 5 children (36%) with posterior urethral valves, for a rate of 1 per 30 patient-months of followup, and 6 urinary tract infections occurred in 2 controls (7%), for a rate of 1 per 216 patient-months of followup (p < 0.05). However, only 1 of 26 controls (4%) without vesicoureteral reflux had urinary tract infection, for a rate 1 per 1,144 patient-months (p < 0.01). Conversely, the rate of urinary tract infections in controls with vesicoureteral reflux was similar to that of children with posterior urethral valves. Of the 5 children with posterior urethral valves 4 had the initial urinary tract infection within 2 months of transplantation and 10 of 15 episodes occurred within the first 4 months. Antimicrobial prophylaxis did not appear to decrease the rate of infection in children with posterior urethral valves. A history of posterior urethral valves increases the frequency of urinary tract infection after renal transplantation but the usefulness of antimicrobial prophylaxis and the relationship to long-term graft function remain to be determined. Urinary tract infection rarely develops in other transplanted boys without vesicoureteral reflux.

Cerebral infarct with recurrence of hemolytic-uremic syndrome in a child following renal transplantation

A white girl with a history of atypical hemolytic-uremic syndrome (HUS) and persistent microangiopathic anemia, and thrombocytopenia for 2 months after the initial presentation at age 7 months, received her first cadaveric renal transplant at age 3 years. During the first 2.5 days post transplant, she developed progressive thrombocytopenia and anemia followed by tonic-clonic seizures and loss of consciousness, secondary to a diffuse cerebral infarction of the left hemisphere. Renal histology showed evidence of glomerular microthrombi and microangiopathy. A large cerebral infarct, previously described in patients during their initial presentation with HUS, presented in our patient as part of the recurrence of the disease post renal transplantation.

Treatment of steroid-resistant post-transplant nephrotic syndrome with cyclophosphamide in a child with congenital nephrotic syndrome

A child with congenital nephrotic syndrome underwent renal transplantation, was treated for acute rejection, and then developed nephrotic syndrome and renal failure. He was felt to have minimal change disease on allograft biopsy, but failed to respond to therapy with corticosteroids. Cyclophosphamide was substituted for cyclosporine and rapidly induced a complete remission of his nephrotic syndrome. We feel that this case not only represents an important example of a useful therapeutic approach to the child with congenital nephrotic syndrome who develops nephrotic syndrome post transplantation, and also raises questions concerning the pathogenesis of congenital nephrotic syndrome.

Effect of recipient's race on pediatric renal allograft survival: a single-center study

One hundred twenty-seven children (83 males, 44 females, 86 white, 41 nonwhite; mean age 12.1 years) who received 160 renal transplants between 1980 and 1989 were retrospectively studied. Variables such as age, sex, primary diagnosis, type, HLA-DR mismatching, and repeated transplants were compared between races and found not to be significant. However, HLA-A and -B cadaveric-graft mismatching, which was equivalent between whites and nonwhites prior to 1985 (pre-cyclosporine A era), has significantly favored whites (49% with 0 to 2 HLA-A and -B mismatch vs 16% in nonwhites) since 1985 (P less than .05), and a significantly higher proportion of nonwhite patients (59%) were receiving medical assistance (P less than .0001). Graft survival was evaluated with significantly poorer results in nonwhites as compared to whites (P less than .05). Although no difference was found between white and nonwhite cadaveric-graft survival before 1985, nonwhites had significantly worse graft survival since 1985 (72% vs 59% for 1 year and 61% vs 24% for 3 years in whites and nonwhites, respectively; P less than .05). Subpopulations such as nonwhite adolescents, nonwhite females, nonwhites with repeated transplants, and all low socioeconomic patients were identified as high-risk children with poor long-term survival. It is concluded that secondary to poorer matching since 1985 there has been decreased graft survival in nonwhites despite cyclosporine A. Attempts to improve matching and attention to high-risk groups are needed for equivalent survival.

Response to measles-mumps-rubella vaccine in children on dialysis

Ten children receiving maintenance dialysis were immunized with the standard dose of measles-mumps-rubella vaccine between 15 and 33 months of age. Immune responses to vaccination were determined using commercially available enzyme-linked immunosorbent assays for measles, mumps, and rubella viruses. Eight children responded to measles vaccine, 5 to mumps vaccine, 8 to rubella vaccine, and only 3 children to all three vaccines, compared with a seroconversion rate of over 90% to all three vaccines in healthy children (P less than 0.0001). We contend that the relatively poor immunocompetence of our dialysis patients explains their less than optimal vaccine response and suggest that children vaccinated while undergoing dialysis be tested to confirm serological evidence of immunity.

Combined liver-kidney transplantation in a child with primary hyperoxaluria

A 3.5-year-old boy presented with end-stage renal disease and bilateral nephrocalcinosis. Renal biopsy demonstrated marked parenchymal calcium oxalate deposition and a diagnosis of primary hyperoxaluria (PH) was made. Following 2 years of hemodialysis he received two renal allografts which were lost at 7 and 11 months, respectively, due to biopsy-proven recurrent oxalosis. Combined liver-kidney transplantation was then performed, after which renal and hepatic function initially stabilized. The patient died on the 28th postoperative day, of infectious complications and progressive respiratory insufficiency. However, comparisons between the patterns of urinary oxalate excretion noted after the isolated renal and liver-kidney transplants indicated that, following the latter, successful biochemical correction of the enzyme defect responsible for type 1 PH had occurred.

Linear growth and anthropometric and nutritional measurements in children with mild to moderate renal insufficiency: a report of the Growth Failure in Children with Renal Diseases Study

During the control period of the Growth Failure in Children With Renal Diseases Study, investigators at 23 centers were able to observe and characterize growth and to make anthropometric and nutritional measurements in 82 children with mild to moderate renal insufficiency. As a multicenter, controlled clinical trial designed to study the relative efficacy of 1,25-dihydroxyvitamin D3 and dihydrotachysterol in the treatment of renal osteodystrophy, no prior vitamin D exposure and a creatinine clearance of 25 to 75 ml/min/1.73 m2 were criteria for entrance into the clinical trial. Ages ranged from 18 months to 11 years (mean 5.6 +/- 3.1 years), and distribution by age category was as follows: 38%, 1 to 3 years; 28%, 4 to 6 years; and 34%, 7 to 10 years. There was a 3:1 male/female ratio; 72% of the patients had congenital disease by the International Classification of Diseases (ninth revision). Mean creatinine clearance was 49.5 +/- 20 ml/min/1.73 m2. The C-terminal parathyroid hormone values (1121 +/- 1562 pg/ml) were well above 2 SD of the mean of a normal growing population of similar age. Parathyroid hormone values correlated with degree of renal insufficiency (r = -0.57) and with height by bone age but not with chronologic height or growth velocity. The bone age/height age ratio, a predictor of growth potential in normal children, was low for the entire series of patients (0.88 +/- 0.35) but failed to correlate with growth velocity and was negatively correlated with rising parathyroid hormone levels. Average values for height, weight, triceps skin fold, mid-arm muscle circumference, and body mass index were within 2 SD of the mean of the normal population, although measurements for the 1- to 3-year age group were significantly less than those of the older patients. Total energy intake averaged less than 86% of the recommended dietary allowances; total protein intake was more than 161% of the allowance. Nitrogen balance in 23 patients was positive and correlated most significantly with increasing energy intake (r = 0.6). Growth velocity, calculated from the interval gain during the month control period, averaged +0.3 SD, with the highest growth velocity z scores recorded for those with acquired disease. A growth velocity index, expressed as the slope of the regression between change in height SD and growth velocity z score, was used to describe the growth accomplished in the control period by age category.(ABSTRACT TRUNCATED AT 400 WORDS)

Safe conversion from cyclosporine to azathioprine with improved renal function in pediatric renal transplantation

Although cyclosporine has improved allograft survival in renal transplant patients, problems with drug toxicity remain, raising the question whether cyclosporine should be stopped at some point post-transplant. However, the relative safety of converting from cyclosporine to another immunosuppressive agent, or simply stopping cyclosporine remains an issue of debate and has not been evaluated in children. We have developed a protocol to convert children, who are 6 months post-transplant and have stable kidney function, from cyclosporine and prednisone to azathioprine and prednisone. Eleven children have undergone conversion because of suspected/potential nephrotoxicity or because of other difficulties with cyclosporine (expense, hirsutism). These children were compared with a control group of 12 children who met all criteria for conversion at 6 months but remained on cyclosporine. Allograft survival was similar in both groups but the children converted from cyclosporine experienced an improvement in renal function as measured by calculated creatinine clearance. There were no episodes of rejection for a period of 4 months post-conversion and all rejection episodes that developed subsequently occurred during or after the change from daily to alternate-day prednisone. We believe that conversion from cyclosporine to azathioprine can be accomplished safely in children with stable allograft function but long-term risks and benefits need further evaluation.

Predicting the response to cytotoxic therapy for childhood nephrotic syndrome: superiority of response to corticosteroid therapy over histopathologic patterns

To determine the utility of steroid response in classifying childhood nephrotic syndrome, we reviewed 119 biopsies in 92 children aged 1 to 16 years who had been followed for a mean of 7.2 years. Steroid responses were classified as steroid resistant, steroid dependent, and frequent relapser as defined by the International Study of Kidney Disease in Children. Biopsy specimens were classified as showing focal glomerulosclerosis (FSGS) in 39 children, as showing lipoid nephrosis in 28, and as questionable in another 25 with either focal global sclerosis, IgM nephropathy, or mesangial prominence and tubular changes. A strong agreement (p less than 0.01) was found between children whose FSGS was steroid resistant and children whose lipoid nephrosis resulted in frequent relapses. The length of the remission after therapy with chlorambucil or cyclophosphamide was determined in 84 children. A significantly shorter length of remission after cytotoxic drug therapy (p less than 0.05) was identified for patients with FSGS versus those with lipoid nephrosis; this difference became more significant for steroid-resistant patients in comparison with those who were steroid dependent or were frequent relapsers (p less than 0.005). Among all steroid-resistant patients, those with FSGS had shorter remissions than patients with other histologic changes (p less than 0.001). The data suggest that patterns of response to corticosteroid therapy correlate with the histologic abnormality. Thus steroid-sensitive patients need not undergo renal biopsy before receiving cytotoxic drugs. Steroid-resistant patients would benefit from a biopsy, because the findings tend to predict the outcome.

Vesicoureteral reflux and urinary tract infections in renal transplant recipients

Fifty-six children who received kidney transplants were evaluated for postoperative vesicoureteral reflux and frequency of urinary tract infection. Two methods of ureteral implantation were compared: a nonantireflux extravesicular ureteroneocystostomy and an antireflux intravesicular ureteroneocystostomy. Reflux was found in 79% of children who had the nonantireflux procedure vs 19% of children who had the antireflux procedure. This disparity was present regardless of sex and age. Infections occurred at a rate of one per 11 patient-months after the nonantireflux procedure vs one per 40 patient-months after the antireflux procedure. Regardless of surgical technique, the incidence of infection was higher in children with reflux. The potentially harmful effect of infection with reflux warrants concern. Because of the need to maximize allograft function for a longer time period, an antireflux procedure is recommended in all pediatric kidney transplants.

Urolithiasis in childhood

Urolithiasis occurs less frequently in children than it does in adults living in contemporary industrialized nations. However, renal calculi continue to be identified with greater frequency in certain children: those who live in some areas of North America (e.g., the Southeastern United States), in those with relatively common metabolic disorders such as idiopathic hypercalciuria or with congenital urinary tract malformations, and in patients who have remained immobilized for long periods. Evaluation of children with suspected urolithiasis should include a careful history and physical examination to identify associated symptoms and signs and factors known to predispose to calculus formation, appropriate radiographic and blood studies, and timed urine collections. Appropriate management varies with etiology but should include maintaining adequate fluid intake, and long-term monitoring of the activity of the stone disease.

Neurologic development of children with severe chronic renal failure from infancy

A literature review was conducted to summarize current understanding of the effects of severe chronic renal failure (CRF), when present from infancy, on neurologic development. Data were obtained from the results of 95 examinations performed in 85 patients, most of whom had been studied after 12 months of age, or following initiation of maintenance dialysis or successful transplantation. CRF was diagnosed at birth or during the neonatal period in 71.7% of these patients; serum creatinine concentrations or calculated clearances were greater than or equal to 2.0 mg/dl (177 mumol/l) or less than 15 ml/min per 1.73 m2, respectively, in 75.8%. Head circumferences were greater than 2 standard deviations below the mean for age in 33 of 51 (64.7%) patients. Developmental delay was identified in 63.2% of all cases, and in 29 of 48 (60.4%), 16 of 19 (84.2%), and 4 of 13 (30.7%) patients studied while receiving conservative management or maintenance dialysis, or following successful transplantation, respectively. Moderate to severe delays were commoner for gross motor and language development. No significant relationships could be identified between age or severity of CRF at diagnosis and either the prevalence or severity of developmental delay. Other factors that may have contributed to observed developmental delays are also discussed, including aluminum loading, hyperparathyroidism, undernutrition, and psychosocial problems. New data are presented and discussed, and recommendations for future studies provided.

The utility of renin profiling in childhood hypertension

Criteria to categorize children as having hypertension associated with high, low or normal PRA as determined by the technique of renin sodium indexing; or with PRA responsiveness which was normal, suppressed or excessive after acute volume depletion induced by a loop diuretic were established in 30 normotensive adolescents. Four hour upright PRA corrected for daily sodium excretion was elevated in 16% of 43 and 84% of 25 children with essential and renal related hypertension. Low PRA was found in 5 of 43 and 0 of 25 children. In 36 children with essential hypertension evaluated after acute volume depletion, 4 and 5 had hyper- and hypo- responsive PRA compared to the 30 normotensive children. The application of these two approaches enables the renin angiotensin system to be systematically categorized in hypertensive children.

Development of pneumatosis cystoides intestinalis following transperitoneal renal transplantation in a child

A 9 1/2-year-old female developed pneumatosis cystoides intestinalis (PCI) which was detected radiographically 4 1/2 months after transperitoneal cadaveric renal transplantation, during a period characterized by recurrent episodes of acute rejection. Radiographic evaluation was prompted by the development of cramping abdominal pain, distention, and tenderness localized to the region of the allograft, which occurred during one such episode. Pneumatosis was localized primarily to an area of colon that lay in direct contact with the allograft. Evaluation of the available clinical and roentgenographic evidence suggested that pneumatosis may have resulted from the development of a sympathetic inflammatory reaction within the bowel wall adjacent to the acutely inflamed allograft. Subsequent stabilization of renal function was associated with resolution of the pneumatosis over the ensuing 8 months without surgical intervention or additional medical therapy.

Severe hypertension in children with renal disease: treatment with minoxidil

Sixteen children with renal disease and severe hypertension refractory to other drugs were treated with minoxidil for periods of five days to 77 months. The maximum dose ranged from 0.05 to 1.88 mg/kg/d. With therapy, the mean BP decreased from 158/112 to 133/90. Thirteen children had an antihypertensive response. 2 had progressive rejection of transplanted kidneys, and 1 received a low dose and failed to respond. Complications were hypertrichosis in 14; fluid retention in 4, with congestive heart failure in 1; and decreased renal function in 2. Pericarditis, possibly related to minoxidil, occurred in one child. Minoxidil is a valuable antihypertensive drug in children but should be used with caution.

Acid-base changes and acetate metabolism during routine and high-efficiency hemodialysis in children

Changes in acid-base status and plasma acetate concentrations were studied in eight children during 11 hemodialysis sessions. During dialysis, the blood bicarbonate concentration fell (20.5 +/- 0.7 to 19.6 +/- 0.8 mEq/liter), the Pco2 fell (33.4 +/- 0.8 to 27.5 +/- 1.4 mm Hg), and the pH rose (7.42 +/- 0.01 to 7.48 +/- 0.02). During the hour after dialysis, the bicarbonate concentration rose to normal (23.4 +/- 0.7 mEq/liter), the PCO2 rose (32.8 +/- 0.8 mm Hg), and the pH remained unchanged. The half-life of plasma acetate, measured after dialysis, was 8.7 min. During five "high-efficiency" dialysis sessions (urea clearance, greater than 3.0 ml/min/kg), blood bicarbonate concentration fell 3.2 mEq/liter, PCO2 fell 8.7 mm Hg, and plasma acetate rose to 7.51 mmoles/liter, whereas during six "routine efficiency" dialysis sessions (urea clearance. 1.5 to 3.0 ml/min/kg), blood bicarbonate rose 1.0 mEq/liter, PCO2 fell 36 mm Hg, and plasma acetate rose to 3.52 mmoles/liter. At 1 hour after the end of dialysis, blood bicarbonate, PCO2, and plasma acetate concentrations were similar in the two groups. Clinical problems occurred more frequently in the high-efficiency group during dialysis although the difference was not significant. The data indicate that (1) dialysis with acetate buffer effectively corrects predialysis metabolic acidosis, (2) although children have a high rate of acetate metabolism, during high-efficiency dialysis this rate is exceeded by the influx of acetate, and acid-base abnormalities occur. These abnormalities are transient but may cause clinical problems.