Late Cytomegalovirus Disease Causes Ileal Perforation after Kidney trasplantation

Cytomegalovirus (CMV) is the single most common infection following kidney transplantation and despite prophylactic strategies and the development of new antiviral agents, it still remains a cause of considerable morbidity and mortality. Current literature suggests that CMV infection may trigger rejection. We report a case of late CMV disease in a preemptive seropositive recipient who did not receive CMV prophylaxis. Diarrhea and abdominal cramping persisted after the administration of mycophenolate mofetil (MMF) six months after transplantation and resulted in ileal perforation at eight months after transplantation. The boy recovered after six weeks of treatment with ganciclovir. MMF has been mooted as a risk factor for CMV infection since its introduction, and further investigations are required to confirm its role. More attention to infectious complications is necessary and serial monitoring of viral load is recommended when MMF is administered.

Renal and Renovascular Hypertension in Children

Hypertension is a major risk factor of atherosclerosis which results in cardiovascular disease, and remains a major health problem worldwide. While children are more likely to have secondary hypertension, recent studies support the theory that the prevalence of essential hypertension in children and adolescents is increasing with the global epidemic of childhood obesity, and close attention is needed. Evaluation of hypertension in the pediatric age group should be guided by the age at presentation, and renal diseases must be considered in every child with hypertension, because of the prevalence of renovascular and renal parenchymal disorders as the etiology in any age group. The majority of children with chronic kidney disease are hypertensive, and many have associated end organ damage. Thus, once hypertension has been confirmed, end organ care as well as pharmacologic therapy must be continued. In renovascular hypertension, as cure could be gained with surgical/endovascular intervention, accurate diagnosis is important and it is recommended that every suspected child should undergo angiography.

Genetics of kidney development: pathogenesis of renal anomalies / 소아과

Congenital anomalies of the kidney and urinary tract (CAKUT) account for more than 50% of abdominal masses found in neonates and involve about 0.5% of all pregnancies. CAKUT has a major role in renal failure, and increasing evidence suggests that certain abnormalities predispose to the development of hypertension and cardiovascular disease in adulthood. To understand the pathogenesis of human renal anomalies, understanding the development of kidney is important. Diverse anomalies of the kidney corresponding to defects at a particular stage of development have been documented recently; however, more research is required to understand the molecular networks underlying kidney development, and such an investigation will provide a clue to the therapeutic intervention for CAKUT.

The Role of MCP 1 and IL 6 on the Progress of Crescentic Glomerulonephritis / 대한신장학회지

PURPOSE: Growing data on the relationship between cytokine expression and the progression of renal diseases make these cytokines potential targets for therapeutic interventions. Weexamined the helper T1-cell- and macrophage-associated cytokines in anti-glomerular basement membrane (GBM) antibody-induced nephritis in mice and their temporal relationships with renal tissue fibrosis. METHODS: Kidneys were harvested on days 1, 3, 7, 11, and 16 after glomerulonephritis was induced with anti-GBM antibody. The progression of renal fibrosis was serially monitored to quantitate the accumulation of cortical extracellular matrix, and various cytokines were measured simultaneously. RESULTS: A single injection of anti-GBM antibody successfully produced severe crescentic glomerulonephritis. Proteinuria increased abruptly and both mesangial matrix expansion and interstitial fibrosis progressed rapidly. Cortical fibronectin and type III collagen increased continuously, reaching a peak on day 7, and the deposition of type III collagen followed the same pattern, in parallel with that of urinary transforming growth factor 1 (TGF-1) expression. Serial cytokine measurements revealed a sustained increase in interleukin (IL) 6 and monocyte chemoattractant protein 1 (MCP1) from day 3, but neither IL12, IL18, nor interferon changed significantly. Real-time polymerase chain reaction confirmed these features at the transcription level. CONCLUSION: MCP1 and IL6 correlated with the progression of renal fibrosis, with no increase in Th1- inducing cytokines. This confirms MCP1 and IL6 as attractive therapeutic targets for renal fibrosis in crescentic glomerulonephritis.

Intravenous Iron Supplementation in Korean Children on Chronic Dialysis

PURPOSE: Limited information is available on experiences of intravenous iron treatment in children. In this study, iron sucrose was administered intravenously to determine its effect, the factors predicting outcome, and safety in children on chronic dialysis. METHODS: Twenty-one children whose serum ferritin levels were less than 100 ng/mL or transferrin saturations (TSAT) were less than 20% were enrolled. In 12 children on peritoneal dialysis (PD), the drug was infused intravenously as 200 mg/m2 (< or =200 mg) at week 0, 2, 4, and 6. In 9 children on hemodialysis (HD), it was given intravenously as 8 weekly doses of 3 mg/kg (< or =100 mg) through week 0-7. RESULTS: After treatment, serum ferritin levels increased significantly in both groups, and TSAT rose significantly in PD group. However, hemoglobin level did not rise significantly in both groups. Children with baseline hemoglobin less than 10 g/dL or baseline TSAT less than 20% showed significantly higher rise of hemoglobin after intravenous iron treatment. To the contrary, those with higher baseline hemoglobin and TSAT levels displayed higher rise in serum ferritin after the treatment. Although no serious adverse event occurred, TSAT levels exceeding 50% were noted in 6 patients in PD group. CONCLUSION: This suggests that 3 mg/kg/week of intravenous iron sucrose can be used safely in children on chronic HD, but 200 mg/m2 every other week may incur excessive TSAT level in some patients on chronic PD.

Acute renal failure in pediatrics / 소아과

Acute renal failure is the generic term for an abrupt and sustained decrease in renal function resulting in retention of nitrogenous and non nitrogenous waste product. This may results in life threatening consequences including volume overload, hyperkalemia, and metabolic acidosis. Acute renal failure is both common and carries high mortality rate, but as it is often preventable, identification of patients at risk and and appropriate management are crucial. This review summarized the most recent information on definition, epidemiology, clinical causes and management of acute renal failure in pediatric patients.

1 year follow-up results of prenatally diagnosed unilateral hydronephrosis according to renal sonographic findings at 1 month of age / 소아과

PURPOSE: The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. METHODS: Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and Tc(99m)-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. RESULTS: Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD 30 mm, and the operation risk is higher as the APPD is increased. CONCLUSION: In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.

Follow-up of children with isolated microscopic hematuria detected in a mass school urine screening test / 소아과

PURPOSE: The isolated microscopic hematuria is the most common abnormality detected by school urinary screening, but there is no consensus about the range of investigations and long-term outcomes of isolated hematuria in children yet. This study aims to elucidate the prognosis of hematuria and the range of diagnostic studies by follow-up results. METHODS: Students with isolated hematuria who were referred to the Department of Pediatrics, Asan Medical Center from Aug. 1990 to Feb. 2004 were analysed retrospectively. Cases that presented Through significant proteinuria(>250 mg/day), other symptoms of nephritis or renal dysfunction (creatinine clearance <85 mL/min/1.73m2) were excluded. Follow-up was done every six months with checking urinalysis, serum creatinine, protein and albumin. When albuminuria was detected, 24 hour urine protein was checked. Renal biopsy was done when urine protein was over 500 mg/day. RESULTS: A total of 331 students were enrolled in this study. There were 157 males and 174 females. The mean age at presentation was 9.9+/-2.3 years(7-15 years) and mean follow-up period was 2.2+/-1.6 years(1-10 years). Seventy five(22.7 percent) patients showed the resolution of microscopic hematuria. The mean resolution period was 2.6+/-1.7 years(1-8 years). Eight(2.4 percent) patients developed significant proteinuria and renal biopsy was done in four of them. Two cases of mild IgA nephropathy and two of minimal change were detected. None of them developed hypertension. At the end of the follow-up, renal function had remained stable in all subsets of patients. CONCLUSION: The prognosis of isolated microscopic hematuria was good. This study suggests that invasive studies including renal biopsy are not necessary and a regular follow-up of urinalysis is enough for children with isolated microscopic hematuria.

Two Cases of Isolated Diffuse Mesangial Sclerosis with WT1 Mutations

Here we report two cases of isolated diffuse mesangial sclerosis (IDMS) with early onset end-stage renal failure. These female patients did not show abnormalities of the gonads or external genitalia. Direct sequencing of WT1 PCR products from genomic DNA identified WT1 mutations in exons 8 (366 Arg>His) and 9 (396 Asp>Tyr). These mutations have been reported previously in association with Denys-Drash syndrome (DDS) with early onset renal failure. Therefore we suggest that, at least in part, IDMS is a variant of DDS and that investigations for the WT1 mutations should be performed in IDMS patients. In cases with identified WT1 mutations, the same attention to tumor development should be required as in DDS patients, and karyotyping and serial abdominal ultrasonograms to evaluate the gonads and kidney are warranted.

A Clinical Study of Acute Poststreptococcal Glomerulonephritis in Children, from 1994 to 2003 / 소아과

PURPOSE: Acute poststreptococcal glomerulonephritis (APSGN) is a common form of glomerulonephritis in children. Most patients recover completely after the acute phase but a few patients have acute complications or progress to chronic renal disease. In recent years, the frequency of APSGN has been was decreasing but is still common in children. So we studied the clinical characteristics of APSGN from 1994 to 2003 and compared it with past studies. METHODS: We studied 105 patients who were diagnosed with APSGN in the Department of Pediatrics, Asan Medical Center between January 1994 and December 2003, with a retrospective chart review. RESULTS: The mean age was 8.5+/-2.6 years. The male to female ratio was 2: 1. Average annual incidence was 10.5+/-4.9 most patients (60.0 percent) occurred from October to January. Edema was seen in 82 cases (78.1 percent), gross hematuria in 70 cases (66.7 percent), hypertension in 50 cases (47.6 percent) and oliguria in 22 cases (20.9 percent). Microscopic hematuria was seen in 105 cases (100 percent), positive ASO in 99 cases (94.2 percent), proteinuria in 67 cases (63.8 percent) and azotemia in 38 cases (36.2 percent). Serum complement 3 (C3) level decreased in 96 cases and returned to normal within eight weeks in 70 patients (75.3 percent). Kidney biopsy was carried out in 22 cases. Most acute symptoms subsided within 2 weeks of onset. CONCLUSION: We concluded that there was no significant difference between clinical features of recent and past APSGN in children, and short term prognoses were excellent.

Parvovirus B19 Infection in Two Korean Pediatric Kidney Transplant Patients

Parvovirus B19(PV B19) is a nonenveloped single-stranded DNA virus that causes a wide variety of diseases ranging from benign childhood infection such as slapped-cheek rash(fifth disease) to life threatening diseases such as hydrops fetalis in fetuses or aplastic anemic crises in patients with hemolytic anemia. In immunocompromised hosts including organ transplant recipients, this infection can cause chronic anemia. Recently, the reports of cases of PV B19 infection have been increasing in transplant recipients and most reported cases of PV B19 infection-associated anemia in renal transplant recipients were successfully treated with intravenous immunoglobulin infusion. We experienced two cases of aplastic anemia caused by PV B19 infection in pediatric renal transplant recipients. The patients were an 8- year-old boy and 12-year-old boy who received allograft kidneys from their mothers. Anemia developed 2 weeks after transplantation and their serum was positive for PV B19 PCR. They were treated with 400 mg/kg of intravenous immunoglobulin(IVIG) for 5 consecutive days. In one of the case, anemia was corrected promptly after the first 5-day course of IVIG therapy but in the other, anemia persisted but responded to the second course of IVIG therapy. One year later, the patients have normal hematocrit levels and stable renal function. These are the first cases of PV B19 infection treated successfully with IVIG in pediatric renal transplant recipients in Korea.

Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy in Children

PURPOSE: Regional anticoagulation with trisodium citrate for continuous renal replacement therapy(CRRT) is an effective and safe method, with lower bleeding risk. However it is not widely used because of complex current protocols used to prevent anticipated metabolic derangements. We evaluated simplified regional anticoagulation protocols with ACD-A(R) solution and commercially available calcium-containing dialysis solution. METHODS: The medical records of twenty-eight patients who underwent CRRT were reviewed. Hemofilter life span according to the anticoagulation method used was compared, and laboratory findings at pre- and 48 hours post-CRRT initiation were compared in the citrate-based CRRT group. RESULTS: Of the twenty-eight patients, five patients underwent citrate-based CRRT. Hemofilter life span was 1.60+/-0.72 days, showing no significant differences with the hemofilter life span in the heparin based and LMWH based CRRT group. No patients experienced hemorrhagic complications. PT, aPTT, sodium, tCO2, iCa levels showed no difference in pre- and post-CRRT. Total calcium levels were increased. At the recommended postfilter iCa level, i.e., 0.25-0.39 mmol/L, all five patients needed increased amount of citrate infusion, and Ca infusion requirement was decreased. CONCLUSION: Simplified regional citrate anticoagulation with calcium-containing dialysate is an effective and safe method, and is not associated with increased hemofilter clotting. However, increased postfilter iCa level is recommended.

A Case of Renal Osteodystrophy with Severe Bone Deformity

With the advent of hemodialysis, the success of renal transplants in the 1960s and the wide use of continuous ambulatory peritoneal dialysis at the end of the 1970s, children with renal failure now enjoy an extended life span. As a result, several children experience renal osteodystrophy and growth retardation. Renal osteodystrophy is induced by phosphorus retention, hypocalcemia, low vitamin D levels and hyperparathyroidism. The pharmacologic interventions are used to prevent bone deformities and to normalize growth velocity. But surgical intervention is required sometimes when osteodystrophy is severe and poorly controlled. We report an eight-year-old boy with chronic renal failure who developed severe bone deformities and needed osteotomy.

Outcome of Continuous Renal Replacement Therapy in Children / 소아과

PURPOSE: There is growing use of continuous renal replacement therapy(CRRT) for pediatric patients, but reports about the use and outcome of CRRT in children is rare in Korea. We report our experiences of CRRT in critically ill pediatric patients. METHODS: We reviewed the medical records of 23 pediatric patients who underwent CRRT at Asan Medical Center between May 2001 and May 2004. We evaluated underlying diseases, clinical features, treatment courses, CRRT modalities and outcomes. RESULTS: Ages ranged from three days to 16 years with a median of five years. Patients weighed 2.4 to 63.9 kg(median 23.0 kg; 10 patients < or =20 kg). The underlying diseases were malignancy(nine cases), multiple organ dysfunction syndrome(five cases), hyperammonemia(four cases), acute renal failure associated with liver failure(three cases), dilated cardiomyopathy(one case) and congenital nephrotic syndrome(one case). Pediatric Risk of Mortality(PRISM) III score was 17.6+/-7.6 and the mean number of failing organs was 3.0+/-1.7. Duration of CRRT was one to 27 days(median:nine days). Eleven patients(47.8%) survived. Chronic renal failure developed in two cases, intracranial hemorrhage in one case, and chylothorax in one case among the survivors. PRISM III score and the number of vasopressor before the start of CRRT was significantly lower in the survivors(12.7+/-4.2 and 0.9+/-1.1) compared with nonsurvivors(22.1+/-7.8 and 2.4+/-1.4)(P<0.05). CONCLUSION: CRRT driven in venovenous mode is an effective and safe method of renal support for critically-ill infants and children to control fluid balance and metabolic derangement. Survival is affected by PRISM III score and the number of vasopressors at the initiation of CRRT.

Continuous Renal Replacement Therapy in Pediatrics / 소아과

Continous renal replacement therapy(CRRT) is becoming increasingly popular for the support of critically ill patients with acute renal failure, and the development of pump-driven volumetric-control CRRT machines with small extracorporeal volumes has lead to the widespread use of venovenous form of CRRT in pediatric field. Basic principles are diffusion and convection. CRRT is indicated in the hemodynamically unstable pediatric patients for hypervolemic anuric acute renal failure, electrolyte abnormalities, multiorgan failure, catabolic patients with increased nutritional needs and hyperammonemia, etc. To date, experiences are limited for pediatric CRRT, but current reports support that CRRT is feasible and useful in children and even infants, and the survival rate of the patients on CRRT is as same as adults. We describe the basic principles, equipments, methods and complications of CRRT, with special considerations on small children to meet the current need for CRRT.

A Case of Transient Pseudohypoaldosteronism Secondary to Ureteropelvic Junction Obstruction

We report a 2-month-old boy who presented with severe hyponatremia and hyperkalemia secondary to ureteropelvic junction(UPJ) obstruction. By prenatal ultrasonography at 19 weeks of gestation, severe hydronephrosis was found which was confirmed postnatally. Pyeloplasty was done on the 45th day of life, and fifteen days after pyeloplasty, non-bilious vomiting, decreased activity and dehydration developed. Severe hyponatremia and hyperkalemia were observed, as a result of elevated serum aldosterone and plasma renin activity. The anterior posterior pelvic diameter(APPD) and Society for Fetal Urology(SFU) grade measured showed no interval change before and after pyeloplasty. Pseudohypoaldosteronism was diagnosed, and 2M NaCl was administrated orally for 7 days. The electrolyte imbalance was corrected, and 8 weeks later, the elevated levels of aldosterone and plasma renin activity were normalized. The left hydronephrosis was improved at 5 months of age. We hereby report a transient pseudohypoaldosteronism secondary to UPJ obstruction with a review of the literature.

Three Cases of Hypercalcemia Due to Vitamin D Intoxication in Infancy / 소아과

Hypercalcemia in infancy is an uncommon disorder but has a potential of serious sequelae. Therefore, infants with hypercalcemia must be promptly investigated and need urgent management. We report three cases of infantile hypercalcemia caused by vitamin D intoxication, emphasizing diagnostic investigations and the course of treatment. The first and the second cases were thought to be vitamin D intoxication without doubt, and were presented with a low parathyoid hormone(PTH) level and increased 25-hydroxyvitamin D3(25(OH)D3). The third case, which was hypotonic and accompanied with chromosomal anomaly, showed relatively low PTH and elevated 25(OH)D3. The first and the third case presented with poor oral intake and a failure to thrive. The second case was asymptomatic and founded incidentally by routine laboratory tests during treatment of the underlying disease. The hypercalcemia of three patients improved after a change of the formula milk with short term medication, lowering serum calcium. Thus we suspect that infants with hypercalcemia have a vitamin D intoxication caused by formula milk. This report describes three cases of hypercalcemia in infancy induced by vitamin D intoxication, a with review of the literature.

Guideline in the Management of Antenatally Diagnosed Unilateral Hydronephrosis

PURPOSE: Neonatal hydronephrosis has been detected with increasing frequency with the widespread use of prenatal ultrasonography, but the consensus about its postnatal management has not yet been reached, especially about surgical intervention. We attempted to determine the guideline of follow-up study and surgical intervention of hydronephrosis by analyzing clinical outcomes of neonates with hydronephrosis. MATERIALS AND METHODS: Between 1994 and 2000, 128 hydronephrotic kidneys were postnatally confirmed. Cases associated with other urologic anomalies were excluded and 90 unilateral hydronephrotic kidneys with a minimum follow-up of 12 months were enrolled in this study. We classified the patients into 6 groups according to the anterior posterior pelvic diameter(APPD) at initial ultrasonography(USG) within 1 month after birth. Renal USG and Tc99m-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol, and pyeloplasty was performed when indicated according to our protocol. RESULTS: Most cases whose APPD were below 10 mm improved or resolved. Only few cases with APPD above 20 mm showed spontaneous improvement and most(88%) had undergone operation. Those with initial APPD within 10-19 mm showed variable outcomes. When the risk factors for irreversible renal functional deterioration were analyzed, the age at pyeloplasty and pre-operative functional deficit were significant. CONCLUSION: We concluded that in infants with initial APPD below 10 mm, consideration of surgery is not needed, and in those with initial APPD above 20 mm, early operation is recommended. Our set protocol based on initial USG is useful, but the cut-off value of relative renal function(RRF) for operation might be increased to 40% to improve post operative RRF.

A Case of Posttransplant Lymphoproliferative Disease Following Renal Transplantation in a Child

Posttransplant lymphoproliferative disease(PTLD) has emerged as a potential life-threatening complication of immunosuppressive therapy after organ transplantation. The occurrence of PTLD is usually associated with an Epstein-Barr virus(EBV) infection in patients who are treated by aggressive immunosuppressive therapy. PTLD is represented by diverse manifestations ranging from reactive lymphoid hyperplasia to high grade malignant lymphoma. This is a case report of a late PTLD in a child. The patient is a 14-year-old girl, who presented as malignant lymphoma 44 months after successful renal transplantation. There was no evidence of EBV infection. On bone marrow study, many neoplastic lymphoid cells were detected. Aggressive chemotherapy for PTLD had resulted in clinical remission. However the patient expired from uncontrolled sepsis and septic shock after 77 days.

Urinary Transforming Growth Factor-beta1 (TGF-beta1)/Creatinine Ratio and Its Clinical Implications in Childhood Acute Pyelonephritis / 대한신장학회잡지

BACKGROUND: Pyelonephritis is one of the major causes of chronic renal failure in children, and the transforming growth factor-beta1 (TGF-beta1) is a molecule with pivotal roles in fibrogenesis. This study was performed to investigate the alteration and clinical implications of urinary TGF-beta1/creatinine ratio in children with acute pyelonephritis. METHODS: Urine was collected from 67 normal children and 25 children with acute pyelonephritis. After routine urinalysis, urine TGF-beta1 was quantitated by ELISA method and creatinine was measured by alkaline picrate method. Urinary TGF-beta1/ creatinine ratios in children with pyelonephritis were compared with those of age-matched controls, and sequential changes of the ratios in pyelonephritic children were traced after antibiotic treatment. Correlation of urinary TGF-beta1/creatinine ratio with the degree of pyuria and renal scar was analyzed each. RESULTS: Neonates showed higher urinary TGF-beta1/creatinine ratios than older children. The ratio increased in acute pyelonephritis and gradually returned to the control level two days after antibiotic treatment. Urinary TGF-beta1/creatinine ratio in acute pyelonephritis was not correlated with the degree of pyuria and renal scar. CONCLUSION: The age should be considered in evaluation of urinary TGF-beta1/creatinine ratio in children. The ratio increases in acute pyelonephritis, and is independent of the degree of pyuria or renal scarring.