A 13-year-old Indonesian boy who experienced successful living-related renal transplantation (LRRT) in 2017 (his 50-year-old father was his kidney donor) has been living with normal graft function. He underwent hemodialysis (HD) in 2014 after being diagnosed with end-stage renal disease (ESRD) secondary to bilateral renal hypoplasia. He was prepared for LRRT in March 2015; however, two months prior to the procedure he was infected with the hepatitis A virus (HAV). The HAV infection subsequently resolved, and LRRT preparations proceeded. Unfortunately, seven days prior to the scheduled LRRT procedure, there was a sudden significant rise in alanine transaminase (ALT) and aspartate aminotransferase (AST) levels, resulting in cancellation of the procedure. The rise in ALT and AST levels was later revealed to be caused by HCV seroconversion (). The patient was always hemodialyzed with a single-use dialyzer, and there was no history of blood transfusions or family history of viral hepatitis; however, there was an HCV outbreak in our pediatric dialysis unit in 2015.\nIn April 2015, his liver function markers rose (AST 498 U/L, ALT 816 U/L, Gamma-Glutamyltransferase (GGT) 170 U/L) and he was subsequently diagnosed with HCV infection (viral load 3.75 × 105 IU/mL, 5.57 log IU/mL of serum HCV RNA) (). HCV RNA genotype testing was conducted using hybridization probe (The Versant HCV Genotype 2.0 Assay (LiPA), Siemens), which revealed HCV genotype 1a. A 7.3-kPa liver stiffness was observed with transient elastography (fibroscan), which was categorized as F1-F2 (mild–moderate liver fibrosis) ().\nHe received interferon-based therapy with ribavirin post-HD once a week since September 2015. Six months after treatment initiation, the HCV was undetected and his liver function normalized. However, 10 months after treatment initiation, he had HCV virological breakthrough, suggested by HCV RNA of 1.28 × 104 IU/mL (4.11 Log IU/mL), leading to cessation of interferon therapy.\nPlans for LRRT were continued and HCV treatment was set up to be given a year post LRRT when stable renal graft function was achieved. In September 2017, LRRT was conducted. One year post-LRRT, graft function was normal; thus, treatment with DAAs for chronic HCV infection was commenced. Owing to a lack of evidence regarding treatment safety with DAAs in pediatrics, we arranged a thorough discussion with the Hospital Ethics Committee to obtain parental consent. In December 2018, he began receiving sofosbuvir/daclatasvir for 12 weeks. Evaluation immediately after (March 2019), at 12 weeks (June 2019), and at 24 weeks (October 2019) following treatment cessation showed no HCV recurrence (). Adverse effects, such as mild fever, fatigue, musculoskeletal pain, decreased appetite, itching and nasal congestion, were not found during treatment with DAAs.
A 15-year-old male with renal failure was referred to our center for dialysis treatment. Two weeks prior to referral, he was brought to an orthopedist for a suspected bone disorder characterized by worsening lumps on his left hand and ankle, which was noticed by his mother about 1 year before presentation. However, she had assumed that the swelling to his left hand was due to biting. In addition, swelling to his left ankle occurred after several leg strengthening exercises conducted by a physiotherapist. The orthopedist later recommended magnetic resonance imaging (MRI). On MRI preparation, the patient was found to have a high urea level and was thus referred to a pediatric nephrologist who subsequently initiated dialysis. His mother also claimed that the urine volume of her son had decreased within the last few weeks. On the second day of hospitalization, the swelling in his left ankle burst and thick masses containing blood, debris, and white crystalized materials were observed.\nThe patient was born to healthy non-consanguineous parents with no family history of HPRT deficiency (). At the age of 1 day, the patient developed stiffness in both hands. When he was 2 months old, he was diagnosed with severe psychomotor retardation and could only lie down. A pediatric neurologist diagnosed the patient with cerebral palsy at the age of 7 months based on computed tomography results showing cerebral atrophy. The patient has a habit of biting his lower lip, buccal mucosa, and left hand, which was evident since the age of 6 years, for which an occlusal bite guard was once used years before to protect his teeth. However, he refused to use it, which resulted in the extraction of some of his upper teeth. At present, he is unable to talk or communicate normally, but can express anger through agitating behavior. Moreover, his parents remarked about the occasional presence of orange sand-like sediments found in his diaper, which first occurred at the age of 3 years. However, a local pediatrician assumed that the patient was merely dehydrated and recommended increased water intake and intravenous fluid treatment, but neglected to measure his uric acid levels.\nOn a physical examination, deformities to the lower lip were noted (). A neurological examination revealed hypotonicity, dystonia, and clonus of all four extremities (). Single lump was seen on the antihelix of the earlobe (), along with multiple lumps on his extremities () and larger lumps similar to abscesses on his left hand and ankle (). He had scoliosis and flexion contracture of the hip, knee, and shoulder. He weighed 22 kg and was 140 cm tall (less than the third percentile of the Centers for Disease Control and Prevention, National Center for Health Statistics 2000 growth chart). The diuresis rate was 0.9 mL/kg/h. The laboratory workup results showed a hemoglobin level of 60 g/L (6.0 g/dL), serum uric acid level of 1608 µmol/L (27 mg/dL), urea level of 99.96 mmol/L (280 mg/dL), creatinine level of 671.8 µmol/L (7.59 mg/dL), and an estimated glomerular filtration rate of 7.6 mL/min/1.73 m2 (New Schwartz).\n24-h urine collection revealed a uric acid level of 1.1 mmol/24 h (186 mg/24 h) (with a total urine volume of 430 mL) and random urine uric acid to creatinine (UA/C) ratio of 2.7 (mg/mg). Electrolyte analysis indicated metabolic acidosis (bicarbonate level of 14.1 mmol/L), hyponatremia (sodium level of 129 mmol/L), hyperkalemia (potassium level of 7.14 mmol/L), and hyperphosphatemia (2.77 mmol/L). Other electrolytes were within normal limits.\nChest radiography showed thoracic scoliosis (). Arthrography or joint X-ray of the left hand and ankle showed revealed the presence of tissue masses (). After the lump on the left ankle burst, debridement and exploration sessions were performed in the left wrist and ankle, which revealed tophi of several joints (). Along with the debridement and exploration procedures, bone biopsy results confirmed juvenile gouty arthritis ().\nKidney ultrasonography revealed bilateral atrophic kidneys (left kidney: 5.4 × 2.9 cm; right kidney: 6.9 × 4.3 cm) with multiple stones in the right renal pelvis (). A diagnosis of LND was confirmed via genetic testing showing a homozygous deletion of exon 1 of the HPRT1 gene. The samples were sent to a foreign genetic laboratory and the results were obtained 1 month later. HPRT enzyme levels could not be measured in a timely fashion due to logistic challenges, such as unstable temperature for sample delivery and the inability to provide a short delivery time.\nHemodialysis was initiated, which was followed by regular hemodialysis within a week, but was switched to continuous ambulatory peritoneal dialysis to provide better long-term quality of life for the patient and his caregiver. The patient received a red blood cell transfusion, allopurinol treatment at a dose of 300 mg/day, a low-purine diet, and treatment for ESRD, which included subcutaneous erythropoietin (EPO) supplementation of 6000 U/week, oral calcitriol at a dose of 0.5 mcg daily, oral CaCO3 at 500 mg three times daily (with a meal), oral folic acid at 5 mg once daily, and one tablet of oral vitamin B complex daily. With treatment, serum uric acid levels decreased to 470 µmol/L (7.91 mg/dL) within 2 weeks. During a follow-up visit at 2 months after the tophi burst, the patient appeared to be more responsive when communicating with others. Moreover, the swelling to his ankle and wrist had significantly improved. The patient complied well to the treatment regimen and peritoneal dialysis caused no side effects. The results of a follow-up laboratory workup at the outpatient clinic were as follows: serum uric acid level of 336 µmol/L (5.65 mg/dL), serum urea level of 14.2 mmol/L (39.76 mg/dL), serum creatinine level of 323 µmol/L (3.65 mg/dL), and random urine UA/C ratio of 0.42 mg/mg. The parents were advised to undergo genetic consultation to identify if their daughters were carriers or if their other son also carried the mutation. The prognosis of the patient was poor because of the presence of ESRD accompanied with multiple irreversible abnormalities.