Distal renal tubular acidosis as a rare complication of vesicoureteral reflux in children: a case report and literature review.

Distal renal tubular acidosis (dRTA) is a clinical picture of hyperchloremic hypokalemic metabolic acidosis with a normal anion gap. It can be caused by a variety of conditions including obstructive uropathy such as vesicoureteral reflux (VUR). We report a rare case of dRTA secondary to VUR in a 4-year-old girl with a history of meningomyelocele, neurogenic bladder and recurrent urinary tract infections. She was admitted to the hospital with complaints of polydipsia, polyuria, and inability to gain weight for the last 1 year. She was on prophylactic antibiotic treatment with clean intermittent catheterization and anticholinergic drug. She had a history of subureteral injection of various agents and botulin toxin injection into the bladder. Her voiding cystourethrogram revealed grade 5 VUR in the left kidney, tortuosity in the left ureter, and the bladder had a dome-like appearance and was trabeculated. When all laboratory values of the patient since birth were examined, it was observed that urine pH was high despite hypokalemic hyperchloremic metabolic acidosis for the last year; these abnormalities became more severe in the last few months. In conclusion, the development of hypokalemia and nephrolithiasis/nephrocalcinosis along with metabolic acidosis in a patient diagnosed with VUR should be considered as an indicator of impaired tubular functions. Also, the possibility of an underlying VUR in the presence of recurrent urinary tract infection in a patient diagnosed with dRTA should not be ignored.

Allelic Variants of the Complement Genes in Acute Postinfectious Glomerulonephritis.

Acute postinfectious glomerulonephritis (APIGN) is one of the most common causes of acute glomerulonephritis in children. It may lead to inflammation and proliferation of glomerular tissue through immunologic mechanisms (Balasubramanian R, Paediatr Int Child Health 2017;37:240-247).

Spontaneous tendon or ligament ruptures in patients undergoing dialysis: First pediatric case report and literature review.

Spontaneous tendon or ligament ruptures are quite rare and mostly associated with chronic systemic diseases such as diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis, and chronic kidney disease (CKD). In this study, we present the first documented case of a spontaneous rupture of the medial patellofemoral ligament (MPFL) in a pediatric patient. The patient was undergoing long-term peritoneal dialysis (PD) and had a history of severe secondary hyperparathyroidism. Additionally, we discussed spontaneous tendon and ligament ruptures associated with CKD or dialysis through a comprehensive literature review. This case report highlights the importance of recognizing that spontaneous tendon or ligament injuries are not exclusive to adults; children with CKD can also be affected. Several factors including poor parathyroid hormone (PTH) and metabolic acidosis control, prolonged CKD duration and presence of malnutrition play role in the pathogenesis. Early diagnosis is crucial as it allows for timely surgical intervention and leads to a favorable functional recovery.

Comprehensive evaluation of patients with primary hyperoxaluria type 1: A nationwide study.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is characterized by increased endogenous oxalate production and deposition as calcium oxalate crystals. The main manifestations are nephrocalcinosis/nephrolithiasis, causing impaired kidney function. We aimed to evaluate the clinical characteristics and overall outcomes of paediatric PH1 patients in Turkey. METHODS: This is a nationwide, multicentre, retrospective study evaluating all available paediatric PH1 patients from 15 different paediatric nephrology centres in Turkey. Detailed patient data was collected which included demographic, clinical and laboratory features. Patients were classified according to their age and characteristics at presentation: patients presenting in the first year of life with nephrocalcinosis/nephrolithiasis (infantile oxalosis, Group 1), cases with recurrent nephrolithiasis diagnosed during childhood (childhood-onset PH1, Group 2), and asymptomatic children diagnosed with family screening (Group 3). RESULTS: Forty-eight patients had a mutation consistent with PH1. The most common mutation was c.971_972delTG (25%). Infantile oxalosis patients had more advanced chronic kidney disease (CKD) or kidney failure necessitating dialysis (76.9% vs. 45.5%). These patients had much worse clinical course and mortality rates seemed to be higher (23.1% vs. 13.6%). Patients with fatal outcomes were the ones with significant comorbidities, especially with cardiovascular involvement. Patients in Group 3 were followed with better outcomes, with no kidney failure or mortality. CONCLUSION: PH1 is not an isolated kidney disease but a systemic disease. Family screening helps to preserve kidney function and prevent systemic complications. Despite all efforts made with traditional treatment methods including transplantation, our results show devastating outcomes or mortality.

Comparison of echocardiographic aortic stiffness index measurements and pulse wave velocity measurements in obese and overweight children.

BACKGROUND: Aortic/arterial stiffness is a reliable, independent predictor and a risk factor for cardiovascular mortality. Arterial stiffness is assessed by pulse wave velocity and echocardiography. The purpose of this study is to analyse aortic/arterial stiffness in patients using echocardiographic and pulse wave velocity techniques. MATERIALS AND METHODS: The participants of this study consisted of 62 patients who presented to the Gazi University Pediatric Endocrinology and Pediatric Cardiology outpatient clinics, including 21 obese, 20 overweight, and 21 normal-weight patients. Echocardiography was performed on all patients, and echocardiographic measurements were compared to pulse wave velocity measurements. RESULTS: The mean (min-max) arterial strain measurements were 0.146 ± 0.0 (0.06-0.3) in the obese group and 0.106 ± 0.0 (0.05-0.18) in the overweight group. In comparison to the overweight group, the obese group had greater arterial strain measurements. The pulse wave velocity measurements in the obese and overweight groups were greater than those in the normal weight group (p > 0.05). Elastic modulus and aortic stiffness ß index values were shown to be positively correlated with pulse wave velocity measurements in the obese group (r = 0.56, r = 0.53, respectively; p = 0.008, p = 0.01, respectively). Systolic and diastolic blood pressure measurements were correlated with pulse wave velocity measurements in the obese group (r = 0.98, p = 0.0001, respectively). CONCLUSION: In our study, echocardiographic aortic measurements showing the vessel wall were correlated with pulse wave velocity measurements. Echocardiographic evaluation should be included in the routine follow-up of patients because pulse wave velocity measurement devices are not available in all centres, echocardiography is available in many centres, it is easily applicable, and it facilitates the follow-up of patients.

Rituximab use in paediatric nephrology practice in Türkiye: TRTX.

AIM: Rituximab (RTX) is a genetically engineered chimeric monoclonal antibody which binds directly to CD20 antigen and mediates inhibition of B cell development. Although RTX has been widely used in paediatric nephrology, there is no routine protocol for its use. In this study, paediatric nephrologists in Türkiye were asked to fill out a questionnaire to understand their practice in using RTX. This study aimed to determine common practices and clarify the uncertainties regarding the use of RTX in paediatric nephrology. METHODS: This was a nationwide, multicenter, retrospective cohort study based on data evaluating the use of RTX in paediatric nephrology practice. An online questionnaire was sent to all paediatric nephrology centers in Türkiye. The questionnaire forms included information about how many patients in total applied RTX treatment, for which indications they use RTX, and whether they made any preparations before using RTX. RESULTS: According to this survey on RTX use in Türkiye, paediatric nephrologists use it most commonly in SSNS and followed by SRNS, ABMR, SLE and AAV, respectively. Dosing was highly standard but there is significant heterogeneity in pre-exposure tests and patient monitoring in the clinical practice of RTX. Also, the rate of encountering RTX-related allergic and infectious side effects at least once during the professional experience of our physicians can be quite high. CONCLUSION: There is an increasing need for the preparation of a guideline on the indications for RTX use for each diagnosis, posology, and the practices to be performed before and after infusion.

A rare cause and an even rarer treatment of hypertension in a 5-year-old boy: Mid-aortic syndrome.

Renal artery stenosis is one of the common vascular diseases that cause hypertension in children. However, renal artery aneurysms and abdominal aortic aneurysms, which may be components of mid-aortic syndrome, are rarely associated with renal artery stenosis. Despite its rarity, early diagnosis and treatment are critical to prevent fatal complications. Currently, non-surgical invasive techniques are considered the first choice for treatment, but in some cases, surgery is inevitable. Here, we present a 5-year-old boy with a mid-aortic syndrome. The patient presented with a history of severe headache and epistaxis 5-6 times a day and was diagnosed with hypertension. A 9 × 9 mm saccular aneurysm on the anterior surface of the abdominal aorta at the level of the left renal artery ostium, and a 12 mm aneurysm in the left renal artery after a stenotic segment at the hilum level was detected in the doppler USG and contrast-enhanced imaging techniques. The patient was operated on electively. We used a PTFE patch to repair the abdominal aorta and, saphenous vein which was taken from his father to repair the renal artery. The patient recovered well and was discharged on the 18th day.

Could Dry Weight Be Estimated Using Changes in Blood Viscosity in Children on Chronic Hemodialysis?

Kidney failure patients on chronic hemodialysis are at risk for cardiovascular complications. Dry weight (DW), one of the dialysis parameters, should be optimized to reduce the complications caused by high blood pressure. By definition, DW is the lowest weight at which patients are clinically euvolemic, not hypotensive or hypertensive after dialysis, and do not require antihypertensives. In hemodialysis patients, DW is achieved by removing fluid from the body through ultrafiltration. Although it is usually determined by trial and error in clinical practice, more objective data are needed. Echocardiography to determine the inferior vena cava diameter and collapse index, bioimpedance analysis to quantify the fluid compartments of the body and blood volume monitoring are among the options. In addition, blood viscosity measurement may be a new method to determine DW.

LAMB2 gene: broad clinical spectrum in Pierson syndrome.

Pierson syndrome (PS) is a rare autosomal recessive disease, characterized by congenital nephrotic syndrome (CNS), and ocular and neurologic abnormalities. In affected cases, there is abnormal b-2 laminin which is compound of the several basement membranes caused by inherited mutations in the LAMB2 gene. Although patients have mutations in the same gene, the phenotype is highly variable. In this case series, the relationship between genotype and phenotype is emphasized, and information about the clinical follow-up of the patients is presented. Hereby, we report four pediatric cases with PS as a result of mutation in the LAMB2 gene. Clinical spectrum of LAMB2-associated disorders varies from mild-to-severe ocular, kidney, and neurologic involvement. Since genotype-phenotype correlation in PS has not been clearly demonstrated, we recommend that all patients with ophthalmic anomalies and glomerular proteinuria should be tested for LAMB2 mutations.

Arterial Stiffness and Ambulatory Blood Pressure Measurements in Children With Familial Mediterranean Fever.

Familial Mediterranean fever (FMF) is an autoinflammatory disease which may cause endothelial dysfunction and arterial stiffness. In this study, we evaluated patients with FMF in terms of arterial stiffness indicators and investigated whether there was any difference according to colchicine response. This is a single-center, prospective, case-control study conducted on pediatric patients with FMF. Patients were categorized into 2 groups: patients on colchicine monotherapy (group 1) and patients who used anti-interleukin-1 (IL-1) plus colchicine (group 2). Patient age, mutations in the MEFV gene, overall duration of treatments, and general characteristics of symptoms were recorded. Laboratory values in an attack-free period were noted. Pulse wave velocity (PWV) was measured in all patients. Erythrocyte sedimentation rate and C-reactive protein, nocturnal hypertension, and PWV were higher in group 2. Arterial stiffness develops due to subclinical inflammation in patients with FMF. It is more pronounced in colchicine-resistant patients.

Electrocardiographic measurements in children with pre-dialysis chronic kidney disease and undergoing kidney replacement therapy.

Cardiovascular diseases are the main causes of morbidity in children with chronic kidney disease (CKD). Electrocardiography (ECG) can provide important information about cardiac functions and parameters associated with sudden cardiac death. This study aims to evaluate the potentially dangerous changes in CKD and kidney replacement therapies by ECG and to determine the value of ECG in predicting cardiovascular outcome compared with echocardiography. 101 patients with CKD were divided into subgroups according to treatment modalities as pre-dialysis CKD, hemodialysis (HD), peritoneal dialysis (PD) and kidney transplantation (KTx). Differences in anthropometric measurements, laboratory results, blood pressures, ECG monitoring were compared within groups as well as with 40 healthy controls. Available echocardiographic findings were noted. In the patients, HD group had highest frequency of hypertension. ECG revealed prolonged QTc as more frequent (16.8% vs 0%, p = 0.006) and higher QTcD (56.7 ± 6.5 vs 39.9 ± 5.1 ms, p = 0.001) in the patients compared to controls, especially in dialysis patients, whereas lowest values were in KTx subgroup. Left ventricular (LV) hypertrophy (LVH) was more frequent (47.1%) in HD compared to other CKD subgroups in ECG (p = 0.052). Echocardiography also showed LV mass index as highest in HD and lowest in KTx (121.4 ± 55.7 vs 63.7 ± 18.3 g/m2, p = 0.000), with numerically highest LVH in HD (58.3%, p = 0.063).  Conclusion: ECG can be used to detect cardiovascular problems in patients with CKD, especially in HD. As ECG results were in line with echocardiography, patients with ECG abnormalities suggestive of LVH should be referred for echocardiographic assessment. What is Known: • Cardiovascular diseases such as coronary artery disease, congestive heart failure, arrhythmias and sudden cardiac death are major causes of morbidity and mortality in chronic kidney disease. • Electrocardiography has significant advantages in demonstrating cardiac functions in children because it is readily available, non-invasive and often non-experts can interpret the results. What is New: • The heart rate is higher, QTc is longer and QTcD is higher in dialysis patients and the prolonged QTc is more frequent in patients with underlying glomerular diseases. • Left ventricular hypertrophy is more common in HD patients and those with hypertension, hypercalcemia, anemia or glomerular etiology. The cardiovascular risky conditions are less frequent in the patients with kidney transplantation.

A Rare Isolated Kidney Cyst: Hydatid Cyst.

Hydatid disease is a parasitic disease caused by Echinococcus granulosus or Echinococcus multilocularis. It is still a serious public health problem in endemic regions such as the Mediterranean basin. Since the complaints caused by the cysts are non-specific and routine laboratory tests do not always yield positive results, diagnosis may be difficult. While liver involvement is present in 70% of cases, larvae escaping from the filtration of the liver cause pulmonary disease in 25% of cases. Although the prevalence of kidney involvement in all hydatid cysts is approximately 2-4%, and isolated kidney involvement is extremely rare at 1.9%. In this case report, we present an extremely rare pediatric case of isolated renal hydatid cyst, the diagnosis of which was somewhat delayed.

Isocitrate Dehydrogenase 1 and 2 Mutations in Pediatric Neuroblastoma Patients.

Objective: Neuroblastoma is one of the common tumors of childhood. The demonstration of new factors such as isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) mutations will be important in the diagnosis and treatment. IDH1 and IDH2 mutations have been found in many types of cancer, such as malignant gliomas, acute myeloid leukemias, chondrosarcoma, and thyroid carcinoma. This study aimed to investigate the presence of IDH1 or IDH2 mutations in patients with neuroblastoma and to determine whether these mutations were different in terms of age, clinical findings, and response to treatment. Methods: Biopsy specimens of 25 patients with pediatric neuroblastoma patients were evaluated for IDH mutations. The clinical and laboratory features of the patients with/without mutation were retrospectively analyzed from a hospital database. Results: A total of 25 patients for whom genetic analysis could be performed were included in the study (60% male, n=15). The mean age was 32.2±25.9 months (3 days-96 months). IDH1 mutation was detected in 8 (32%) and IDH2 mutations in 5 (20%) patients. These mutations showed no statistically significant relationship with age, tumor localization, laboratory results, stage, and prognosis. However, in the case of IDH mutation, patients were diagnosed at the advanced stage. Conclusions: This study demonstrated the relationship between neuroblastoma and IDH mutation for the first time. Because to the fact that the mutation is very heterogeneous, it would be appropriate to conduct a larger series of patients in terms of the impact of the clinical significance of each mutation on the diagnosis and prognosis.

Clinical Characteristics of Children With Acute Tubulointerstitial Nephritis: A Single-Center Experience.

OBJECTIVE: Acute tubulointerstitial nephritis (ATIN) is an infiltration of the kidney interstitium with inflammatory cells. Medications are most frequently blamed for the etiology. Patients may present with non-specific signs and symptoms. Therefore, the diagnosis of ATIN is often delayed. In this study, clinical characteristics, treatment protocols, and outcomes of children diagnosed with ATIN were presented. METHODS: This is a retrospective study based on the data of 18 patients diagnosed with ATIN between 2017 and 2022 at Gazi University. Patients were divided into two groups: steroid-treated (n=13) and non-steroid-treated (n=5). Clinical features and laboratory evaluations were compared between the groups. RESULTS: The mean age of the patients was 14.4±2.6 years, and the great majority were girls (88.9%, n=16). ATIN was mostly medication-related (n=17, 94.4%). Steroids were started in one-third of patients using non-steroidal anti-inflammatory drugs. Steroids were started in 45.4% of the patients with eosinophilia, 75% of those with pyuria, 66.6% of those with hematuria, and half of the patients with increased kidney echogenicity. The kidney functions returned to normal ranges in all patients. In steroid-treated patients, although recovery times for serum creatinine were longer (7.2±2.5 vs. 71.2±100.7 days), blood eosinophil count reached normal values more rapidly (5.4±2.3 vs. 3.1±1.0 days). CONCLUSION: ATIN can be associated with diverse clinical presentations. The first and most important step of treatment is to discontinue the medication responsible for the etiology. Steroid treatment improves eosinophilia more rapidly. However, randomized controlled studies are needed to determine further treatment steps and establish a more definite treatment protocol.