Dyslipidemia in children with chronic kidney disease-findings from the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study.

BACKGROUND: Dyslipidemia is an important and modifiable risk factor for CVD in children with CKD. METHODS: In a cross-sectional study of baseline serum lipid levels in a large prospective cohort study of children with stage 3-5 (predialysis) CKD, frequencies of abnormal lipid levels and types of dyslipidemia were analyzed in the entire cohort and in subpopulations defined by fasting status or by the presence of nephrotic range proteinuria. Associated clinical and laboratory characteristics were determined by multivariable linear regression analysis. RESULTS: A total of 681 patients aged 12.2 ± 3.3 years with a mean eGFR of 26.9 ± 11.6 ml/min/1.73 m2 were included. Kidney diagnosis was classified as CAKUT in 69%, glomerulopathy in 8.4%, and other disorders in 22.6% of patients. Nephrotic range proteinuria (defined by a urinary albumin/creatinine ratio > 1.1 g/g) was present in 26.9%. Dyslipidemia was found in 71.8%, and high triglyceride (TG) levels were the most common abnormality (54.7%). Fasting status (38.9%) had no effect on dyslipidemia status. Except for a significant increase in TG in more advanced CKD, lipid levels and frequencies of dyslipidemia were not significantly different between CKD stages. Hypertriglyceridemia was associated with younger age, lower eGFR, shorter duration of CKD, higher body mass index (BMI-SDS), lower serum albumin, and higher diastolic blood pressure. CONCLUSIONS: Dyslipidemia involving all lipid fractions, but mainly TG, is present in the majority of patients with CKD irrespective of CKD stage or fasting status and is significantly associated with other cardiovascular risk factors.

Variable phenotype and genotype of pediatric patients with HNF1B nephropathy.

AIMS: Hepatocyte nuclear factor 1ß (HNF1B) mutations are the most common monogenic cause of congenital anomalies of the kidney and urinary tract (CAKUT). We aimed to investigate clinical and genetic characteristics of patients with HNF1B nephropathy to expand its phenotypic and genetic spectrum. MATERIALS AND METHODS: This retrospective cohort study included 16 unrelated pediatric patients (6 females, 10 males) from 13 families with genetically confirmed HNF1B-related nephropathy. RESULTS: Abnormal prenatal kidney abnormalities were present in 13 patients (81.3%). The most common antenatal kidney abnormality was kidney cysts, which were observed in 8 patients (61.5%). Urinary system abnormalities (vesicoureteral reflux (VUR) and ureteropelvic junction obstruction (UPJO)) were present in 4 patients (25%). HNF1B analysis uncovered missense variants in 4 families (30.8%) as the most common genetic abnormality. In addition, 4 novel pathological variations have been defined. During follow-up, hypomagnesemia and hyperuricemia were observed in 7 (43.8%) and 5 patients (31.3%), respectively. None of the patients with a missense variant had hypomagnesemia. However, 7 out of 12 patients (58.3%) with a non-missense variant had hypomagnesemia (p = 0.09). None of the patients had an HNF1B score below 8, and the mean score was 15.3 ± 4.4. The mean follow-up period was 7.4 ± 5.0 years. While 100% of patients (n = 4) with missense variants were in various stages of CKD (CKD2: 2 patients, CKD3: 2 patients), 25% of those with non-missense variants had CKD (CKD2, 3, and 5; 1 patient, respectively) (p = 0.026). CONCLUSION: Patients with HNF1B-associated disease have concomitant urinary system abnormalities such as VUR or UPJO. Missense variants seem to be the most common pathological variations in HNF1B gene and have higher risk of CKD.

Very-early-onset Inflammatory Bowel Disease in an Infant with a Partial RIPK1 Deletion.

The monogenic causes of very-early-onset inflammatory bowel disease (VEO-IBD) have been defined by genetic studies, which were usually related to primary immunodeficiencies. Receptor-interacting serine/threonine-protein kinase-1 (RIPK1) protein is an important signalling molecule in inflammation and cell death pathways. Its deficiency may lead to various clinical features linked to immunodeficiency and/or inflammation, including IBD. Here, we discuss an infant with malnutrition, VEO-IBD, recurrent infections and polyathritis who has a homozygous partial deletion in RIPK1 gene.

Management of pediatric hemolytic uremic syndrome.

Classical clinical triad of hemolytic uremic syndrome (HUS) is microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury associated with endothelial cell injury. Several situations, including infections, medications, malignancies, and transplantation can trigger endothelial damage. On the HUS spectrum, atypical hemolytic uremic syndrome (aHUS) deserves special attention in pediatric patients, as it can cause endstage kidney disease and mortality. A dysfunction in the alternative complement pathway, either acquired or genetic, has been shown to be the main underlying cause. In the last decades, breathtaking advances have been made in understanding the pathophysiology of this rare disease, which has led to more efficient treatment. Recent studies have implicated genes in pathways beyond the alternative complement system, such as DGKE, TSEN2, and INF2 highlighting the importance of personalized management. Eculizumab has brought about dramatic improvements in the treatment of aHUS. Beyond eculizumab, there are many alternative therapeutics in the pipeline that target the complement system. Because of the rarity of aHUS, data from multiple patient registries are very important. The present report aimed to summarize the most important aspects of diagnosing and treating aHUS based on the Turkish national registry and the literature so as to improve clinical practice.

Adverse events of biological agents in pediatric rheumatologic diseases.

OBJECTIVES: To evaluate adverse events (AEs) in pediatric patients with rheumatologic diseases being treated with approved or off-label biologic agents (BAs). METHODS: This observational, retrospective, multicenter study was conducted from 2010 to 2022 in patients under 18 years of age with rheumatic diseases who were receiving interleukin-1 antibodies (Anti-IL1), interleukin-6 antibodies (Anti-IL6), and tumor necrosis factor alpha inhibitors (anti-TNF). Efficacy, AEs, and timing of AEs were collected from electronic medical records. RESULTS: Three hundred and fifteen BAs were prescribed to 237 patients. Fifty AEs occurred in 44 patients (18.6%). Anti-TNF exposure was present in 8 (72.2%) of 11 patients with latent tuberculosis (TB) and in all 7 patients with herpes infections. Four of 6 patients (66.7%) with recurrent upper respiratory tract infections and 7 of 8 patients (87.5%) with local skin reactions were on Anti-IL1. The cutoff value for latent TB development was determined as 23.5 months by ROC analysis (AUC: 0.684 ± 0.072, p = 0.038, 95% CI: 0.54-0.82). In patients who used BA for 23.5 months or more, the risk of latent TB was 5.94-fold (p = 0.024, 95% CI: 1.26-27.97). Drug rash with eosinophilia and systemic symptoms (DRESS) occurred in 2 patients on anakinra, and anaphylaxis occurred in 1 patient on anti-IL6. There were no cases of malignancy or death in any patient. CONCLUSION: The physician should be vigilant for latent TB in patients exposed to BA for more than 2 years. While local skin reactions are more prevalent in patients receiving anti-IL1, severe skin reactions such as DRESS may also occur.

Risk factors for recurrence in pediatric urinary stone disease.

BACKGROUND: Children's urinary system stones may develop from environmental, metabolic, anatomical, and other causes. Our objective is to determine the recurrence and prognosis, demographic, clinical, and etiological characteristics of children with urolithiasis. METHODS: Medical records of patients were evaluated retrospectively. Patients' demographic data and medical history, serum/urine biochemical and metabolic analysis, blood gas analysis, stone analysis, imaging findings, and medical/surgical treatments were recorded. RESULTS: The study included 364 patients (male 187). Median age at diagnosis was 2.83 (IQR 0.83-8.08) years. The most common complaints were urinary tract infection (23%) and urine discoloration (12%). Sixty-two percent had a family history of stone disease. At least one metabolic disorder was found in 120 (88%) of 137 patients having all metabolic analyses: hypercalciuria was found in 45%, hypocitraturia in 39%, and hyperoxaluria in 37%. Anatomical abnormalities were detected in 18% of patients. Of 58 stones analyzed, 65.5% were calcium and 20.6% were cystine stones. Stone recurrence rate was 15% (55/364). Older age (> 5 years), family history of stone disease, stone size (≥ 5 mm), and urinary system anatomical abnormalities were significantly associated with stone recurrence (p = 0.027, p = 0.031, p < 0.001, and p < 0.001, respectively). In adjusted logistic regression analysis, stone size ≥ 5 mm (OR 4.85, 95% CI 2.53-9.3), presence of urinary system anatomical abnormalities (OR 2.89, 95% CI 1.44-5.78), and family history of stone disease (OR 2.41, 95% CI 1.19-4.86) had increased recurrence rate. CONCLUSIONS: All children with urolithiasis should be evaluated for factors affecting stone recurrence. Children at higher risk of recurrence need to be followed carefully.

Nutcracker syndrome in pediatrics: initial findings and long-term follow-up results.

BACKGROUND: Nutcracker syndrome (NCS) describes a set of symptoms and signs resulting from compression of the left renal vein (LRV). There is a lack of knowledge about its natural course, diagnosis, and management, especially in children. Herein, we present our single-center experience with a large number of patients who have long-term follow-up results. METHODS: All patients with NCS diagnosed between January 2011 and March 2021 were included and their data were obtained retrospectively. RESULTS: A total of 123 NCS patients (85 females) were included. The median age at the time of diagnosis was 12 (IQR 10-14) years, and BMI percentiles were below 5% in 38% of the cases. At the time of diagnosis, two-thirds of the patients were asymptomatic. The most common laboratory finding was nephritic proteinuria (98%), followed by microscopic hematuria (16%). Signs of LRV compression were significantly more evident in upright position Doppler ultrasonography (DUS) examination. All patients have been followed conservatively; hematuria and/or proteinuria resolved in 43 of the 108 patients (40%) within 35.8 ± 25.8 months of follow-up. Control DUS was performed in 52 patients after a mean period of 39.1 ± 21.3 months. The median peak velocity and diameter ratios of the LRV in the upright position were found to be decreased significantly when compared to the initial assessment (p < 0.05). Normal DUS findings were noted in 13 patients at the final evaluation. CONCLUSIONS: In unexplained proteinuria and/or hematuria, NCS should be considered, especially in asthenic adolescents. Our results support conservative management in children as the first-line treatment approach.

Hospitalizations after Renal Transplantation in Children: Risk Factors, Causes, and Outcomes.

INTRODUCTION: The aims of this study were to evaluate the frequency and causes of hospitalizations in the posttransplant period of children, investigate the risk factors, and evaluate the relationship between hospitalizations and renal prognosis in the long term. METHODS: We retrospectively reviewed the files of pediatric renal transplant patients, followed at least 6 months after kidney transplantation, in our center. Clinical information including age at transplantation, gender, primary disease, donor type, immuno-suppressive medication, hospitalization dates, and indications (infections and non-infectious) during follow-up period and graft outcomes was recorded. RESULTS: A total of 74 children (46 males) were followed up for a median of 54 months. Among them, 69 patients (93.2%) were hospitalized 446 times. The most common cause of hospitalizations was infections (314 times, 70%). Urinary tract infections were the most important cause followed by upper respiratory tract infections. Forty (54%) patients were hospitalized 132 times (29.5%) for non-infectious reasons. The most common non-infectious reason was nonspecific graft dysfunction (19 patients, 30 times), followed by rejection (17 patients, 27 times). Younger age, use of induction therapy, and having congenital anomalies of kidney and urinary tract (CAKUT) were found to be risk factors for increased hospitalization rates (p < 0.05). The number of hospitalizations was found to be negatively affecting the final glomerular filtration rate of transplant recipients (p: 0.04, r: -0.023). CONCLUSION: Patients with CAKUT, who received induction therapy, and small children were hospitalized more frequently after transplantation. Strategies to prevent hospitalizations will achieve a better graft prognosis.

Long Term Follow-Up Of Patients With Nonrefluxing Hydronephrosis.

BACKGOUND: The aim of this study is to examine the long-term prognosis of children with ureteropelvic junction obstruction-like hydronephrosis (UPJO-like HN). PATIENTS AND METHODS: The files of children with hydronephrosis (HN) were analyzed retrospectively. Patients with vesicoureteral reflux (VUR) and other genitourinary anomalies were excluded. The final status of the HN, the need for surgery, and urinary tract infection (UTI) frequency were evaluated. RESULTS: The study included 219 patients with 302 renal units (RU) with HN. Surgery rate was higher in RUs with larger kidney size and parenchymal thinning (p:<0.001 for both). Hydronephrosis resolved in 113 (40.2%) RUs, improved in 66 (23.3%), unchanged in 100 (35.5%) and worsened in 4 (1.4%). The frequency of recovery and improvement was found to be less in RUs with severe HN, large kidney size, and thin parenchyma. The UTI frequency was higher in severe HN group (12.2% vs 30.6% p:<0.001). CONCLUSIONS: Children with mild HN had an excellent prognosis. Although the majority of the patients with high-grade HN had also a good prognosis, it seems important to closely follow up patients with severe HN, increased kidney size, and accompanying parenchymal thinning. Clinicians should be aware of the increased frequency of UTIs in children with severe HN.

Evaluation of Gastrointestinal System Complaints and Comorbidities in Pediatric Familial Mediterranean Fever Patients.

OBJECTIVE: Familial Mediterranean fever (FMF) is the most prevalent hereditary autoinflammatory disease among children. Abdominal pain and various gastrointestinal system (GIS) manifestations may arise directly from FMF or concomitantly with FMF. This study aimed to evaluate GIS complaints and findings other than classic peritonitis attacks in patients with FMF and to interpret concomitant GIS and hepatic disorders in these patients. METHODS: The medical and genetic findings of patients with FMF who attended our clinic between December 2011 and December 2021 were reviewed. Gastrointestinal system symptoms, liver function tests, abdominal images, and endoscopic and histopathological data were extracted from medical records. RESULTS: A total of 576 pediatric patients (female, 52.3%) diagnosed with FMF were included. Among them, almost one-fifth displayed GIS complaints, such as abdominal pain, defecation problems, and dyspepsia, distinct from typical FMF attacks. High serum aminotransferase levels were detected in 18.4% of the patients, with viral infections being the most common cause of moderate/severe hypertransaminasemia. In addition, during follow-up, 26.9% of them were referred to the pediatric gastroenterology department. At least 1 gastroenterological and hepatobiliary disorder was detected in 17.5% of the patients because of organic and functional GIS disorders or hepatobiliary disorders, such as gastroesophageal reflux disease, esophagitis, functional dyspepsia, and inflammatory bowel diseases. CONCLUSION: Various GIS and hepatic disorders can be encountered in children with FMF. The spectrum of these complaints and pathologies can range from frequently observed health problems to more severe diseases.

The outcomes of renin-angiotensin-aldosterone system inhibition and immunosuppressive therapy in children with X-linked Alport syndrome.

BACKGROUND: Alport syndrome (AS) is characterized by progressive kidney disease. There is increasing evidence that renin-angiotensin-aldosterone system (RAAS) inhibition delays chronic kidney disease (CKD) while the effectiveness of immunosuppressive (IS) therapy in AS is still uncertain. In this study, we aimed to analyze the outcomes of pediatric patients with X-linked AS (XLAS) who received RAAS inhibitors and IS therapy. METHODS: Seventy-four children with XLAS were included in this multicenter study. Demographic features, clinical and laboratory data, treatments, histopathological examinations, and genetic analyses were analyzed retrospectively. RESULTS: Among 74 children, 52 (70.2%) received RAAS inhibitors, 11 (14.9%) received RAAS inhibitors and IS, and 11 (14.9%) were followed up without treatment. During follow-up, glomerular filtration rate (GFR) decreased < 60 ml/min/1.73 m2 in 7 (9.5%) of 74 patients (M/F=6/1). In male patients with XLAS, kidney survival was not different between RAAS and RAAS+IS groups (p=0.42). The rate of progression to CKD was significantly higher in patients with nephrotic range proteinuria and nephrotic syndrome (NS), respectively (p=0.006, p=0.05). The median age at the onset of RAAS inhibitors was significantly higher in male patients who progressed to CKD (13.9 vs 8.1 years, p=0.003). CONCLUSIONS: RAAS inhibitors have beneficial effects on proteinuria and early initiation of therapy may delay the progression to CKD in children with XLAS. There was no significant difference between the RAAS and RAAS+IS groups in kidney survival. AS patients presenting with NS or nephrotic range proteinuria should be followed up more carefully considering the risk of early progression to CKD.

Exertional leg pain represents a severe disease phenotype in childhood familial Mediterranean fever.

OBJECTIVES: Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease. Recurrent fever, serositis, and arthritis are common findings of the disease. In addition, musculoskeletal complaints such as exertional leg pain can be overlooked, although they are common and affect patients' quality of life. The aim of this study was to evaluate the frequency of exertional leg pain in pediatric FMF patients and to analyze the association of this finding with other characteristics of FMF. METHODS: The files of FMF patients were retrospectively evaluated. The clinical characteristics and disease severity of the patients with exertional leg pain were compared with the patients without exertional leg pain. International severity scoring system for FMF (ISSF) and Mor severity score were used for assessment. RESULTS: The study included 541 FMF patients (287 females), 149 (27.5%) with exertional leg pain. The median colchicine dosage was significantly higher in patients with exertional leg pain (p = 0.02), arthritis (p = 0.001) and arthralgia (p˂0.001) were encountered more frequently in the attacks of these patients. The median disease severity scores calculated by both Mor severity scale and ISSF were significantly higher in patients with exertional leg pain compared to those without (p˂0.001). In the group of patients with exertional leg pain, the M694V mutation, either in one allele or in two alleles, was found to be significantly more common (p = 0.006 and p˂0.001, respectively). CONCLUSIONS: Exertional leg pain in pediatric FMF patients is the component of moderate-to-severe disease course, and this may be considerably associated with the presence of M694V mutation.

Childhood-Onset Sacroiliitis: Causes and Correlation Between Clinical Findings and Magnetic Resonance Imaging.

OBJECTIVE: The aims of this study were to describe disease associations of magnetic resonance imaging (MRI)-confirmed and clinically symptomatic sacroiliitis in pediatric patients with rheumatic diseases and to examine the relationship between patient characteristics and MRI findings of the sacroiliac joint (SIJ). METHODS: Demographic and clinical data were extracted from the electronic medical records of the patients with sacroiliitis followed in the last 5 years. Active inflammatory and structural damage lesions of the SIJ-MRI were examined by the modified Spondyloarthritis Research Consortium of Canada scoring system, and correlation analysis of these results with clinical characteristics was evaluated. RESULTS: A total of 46 symptomatic patients were found to have MRI-proven sacroiliitis of 3 different etiologies: juvenile idiopathic arthritis (JIA) (n = 17), familial Mediterranean fever (FMF) (n = 14), and chronic nonbacterial osteomyelitis (CNO) (n = 8). Seven patients, FMF and JIA (n = 6) and FMF and CNO (n = 1), had a co-diagnosis that might cause sacroiliitis. Although inflammation scores and structural damage lesions did not statistically differ between the groups, capsulitis and enthesitis on the MRI were more frequently detected in the CNO group. There was a negative correlation between symptom onset and inflammation scores of bone marrow edema. Disease composite scores and acute phase reactants were correlated with MRI inflammation scores. CONCLUSIONS: We demonstrated that JIA, FMF, and CNO were the major rheumatic causes of sacroiliitis in children originating from the Mediterranean region. Quantitative MRI scoring tools can be used to assess the inflammation and damage of the SIJ in rheumatic diseases, show discrepancies between them, and have an important correlation with various clinical and laboratory features.

Chronic inflammatory demyelinating polyradiculoneuropathy associated with Sjögren`s syndrome in a child.

BACKGROUND: Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a peripheral nervous system disease associated with polyautoimmunity. CASE: We report a previously healthy 13-year old boy who was referred to our outpatient clinic with gait disturbance and distal lower limb weakness that had been increasing for six months. The patient had decreased deep tendon reflexes in the upper extremities and absence in the lower extremities, reduced muscle strength in the distal and proximal lower extremities, muscle atrophy, drop foot, and normal pinprick sensations. The patient was diagnosed with CIDP as a result of clinical findings and electrophysiological studies. Autoimmune diseases and infectious agents were investigated in terms of triggering CIDP. Although there was no clinical sign other than polyneuropathy, he was also diagnosed with Sjögren`s syndrome due to positive antinuclear antibodies and antibodies against Ro52, and with autoimmune sialadenitis. After six months of monthly intravenous immunoglobulin and oral methylprednisolone treatments, the patient was able to dorsiflex his left foot and walk without support. CONCLUSIONS: To our knowledge, our case is the first pediatric case with the coexistence of Sjögren`s syndrome and CIDP. Therefore, we suggest investigating children with CIDP in terms of underlying autoimmune diseases such as Sjögren`s syndrome.

Antenatal Hyperechogenic Colon and Cystinuria.

A male newborn was investigated for history of antenatal hyperechogenic colon (HEC) detected at 32 weeks of gestation. In the first week of life, urinary ultrasonography showed nephrolithiasis. Urinary amino acid analysis expressed increased excretion of dibasic amino acids, and high urinary cystine levels were detected in both spot and 24-hour urine specimens. He was diagnosed as cystinuria, and genetic analysis of the patient revealed a heterozygous mutation in SLC7A9 gene. Antenatal presentation of cystinuria with HEC is rare and reported to be associated with a more severe disease course.

Alemtuzumab as a Successful Antirejection Therapy: Experience in a Pediatric Renal Transplant Patient.

Alemtuzumab is a monoclonal antibody against CD52 that is being increasingly used in renal transplantation as a lymphocyte-depleting agent. Data on alemtuzumab use in resistant rejection episodes are scarce, especially in children. Here, we present a 14-year-old renal transplant patient with acute cellular and humoral rejection who was treated with pulse steroids, plasmapheresis, and intravenous immunoglobulin with no success. He had 2 previous rejection episodes that were treated with antithymocyte globulin. In the third episode, alemtuzumab was given as a rescue therapy, and the patient benefited from the treatment. No complications were observed. Alemtuzumab can be a treatment option in pediatric patients with refractory rejection episodes.

What are the factors associated with the duration of remission of intra-articular corticosteroid injection in juvenile idiopathic arthritis?

INTRODUCTION: Intra-articular corticosteroid injection (IACI) is generally used in the management of juvenile idiopathic arthritis (JIA) to obtain rapid relief of active synovitis and functional recovery and to prevent the need for regular systemic therapy. The aim of this study was to investigate the outcome of IACI treatment and the factors associated with remission of synovitis. METHODS: The clinical records of JIA patients who received IACI between January 2014 and December 2020 in two pediatric rheumatology centers were reviewed. The procedure was evaluated in terms of efficacy, factors that may affect the duration of remission, procedural and drug-related complications. RESULTS: During the study period, 134 patients received 227 injections and 37 joints were injected more than once. One hundred and six (79%) patients had persistent oligoarticular disease. At the time of injection, all patients were receiving non-steroidal anti-inflammatory drugs, 74 patients were on methotrexate, and 14 patients were on biologics. The median duration of remission without exacerbation of synovitis treated with IACI was 15 (range 1-64) months. The inactivity rate was 81% at the 6th month after the injection. It has been shown that being less than 7 years old at disease onset and low initial CRP levels were correlated with a long remission period (p < 0.05). Despite the differences were not statistically significant, the duration of remission was longer in boys, in ANA positives, in HLA-B27 negatives, in patients with concurrent methotrexate treatment and in patients not receiving biologic therapy (p > 0.05). Only two patients (1.5%, 95% CI - 0.6 to 3.5) developed cutaneous hypopigmentation and subcutaneous atrophy as side effects of injection. CONCLUSION: Intra-articular corticosteroid injection was more effective especially in patients with low initial CRP levels and younger than 7 years of age. The duration of remission was longer in these patients. Key Points • Intra-articular corticosteroid injection is an effective method for controlling joint inflammation and achieving long-term remission without significant side effects. • Intra-articular corticosteroid injection can be preferred in all forms of juvenile idiopathic arthritis as primary therapy or to relieve the patient while waiting for the effect of systemic agents or to avoid increasing the dose of systemic drugs. • It can be recommended as a treatment option at any stage of the disease, especially in young patients and patients with low initial CRP values.

Erysipelas-Like Erythema: A Manifestation of Severe Disease Phenotype in Pediatric Patients with Familial Mediterranean Fever.

OBJECTIVE: Erysipelas-like erythema is the pathognomonic skin manifestation of familial Mediterranean fever although not frequently seen in the pediatric population. This study aims to describe the differences between patients presenting with and without erysipelas-like erythema and to examine the relation of erysipelas-like erythema with subclinical inflammation in a large pediatric cohort of familial Mediterranean fever patients. MATERIALS AND METHODS: This retrospective study from a single pediatric rheumatology referral center included familial Mediterranean fever patients with a follow-up for at least 6 months in the last 5 years. Patients were grouped according to the presence of erysipelas-like erythema and subclinical inflammation. RESULTS: Among 515 patients with familial Mediterranean fever, 35 patients (6.8%) were found to present with erysipelas-like erythema, and the earliest age for erysipelas-like erythema was 2.9 years. All erysipelas-like erythema lesions were defined on lower extremities with concurrent arthritis in 21 patients (60.0%). Compared to other patients in the cohort, patients presented with erysipelas-like erythema had significantly higher frequencies of acute arthritis, subclinical inflammation, and biallelic exon 10 mutations, and they used significantly higher doses of colchicine at the latest visits (all P ≤ .002). Patients with subclinical inflammation more frequently presented with erysipelas-like erythema compared to others without subclinical inflammation (21.7% vs. 2.9%, P < .001). CONCLUSION: Erysipelas-like erythema is an uncommon but important finding that can be a sign of severe disease course and subclinical inflammation in the pediatric population with familial Mediterranean fever.

The Characteristics of Pediatric Patients with Familial Mediterranean Fever Treated with Anti-Interleukin-1 Treatment.

OBJECTIVE: Interleukin-1 inhibitors are effective agents used in colchicine resistance or intoler- ance during the treatment of familial Mediterranean fever. This study aims to review the char- acteristics of patients treated with interleukin-1 inhibitors and their long-term follow-up in a large pediatric cohort of familial Mediterranean fever patients. MATERIALS AND METHODS: The study was conducted in a pediatric rheumatology reference cen- ter. The patients treated with interleukin-1 inhibitors for at least 6 months were included and compared to other patients with familial Mediterranean fever. Clinical and laboratory charac- teristics of the cohort were recorded. RESULTS: Among 542 patients with familial Mediterranean fever, 6.1% (n = 33) were treated with interleukin-1 inhibitors. Colchicine resistance was the reason in 82.8% and renal amyloidosis in 17.2% of the patients. Patients with interleukin-1 inhibitors had earlier disease onset and higher frequencies of acute arthritis, chest pain, and erysipelas-like erythema with pathogenic exon 10 mutations of the MEFV gene (all P < .04). All patients diagnosed with renal amyloidosis also received interleukin-1 inhibitors. Six patients were switched from anakinra to canakinumab or vice versa to control ongoing disease activity. Attack frequency was reduced in all patients. CONCLUSION: Interleukin-1 inhibitors are used in a relatively small number of pediatric patients with familial Mediterranean fever. Patients presenting with earlier disease onset, acute arthri- tis, chest pain, and erysipelas-like erythema and carrying pathogenic exon 10 mutations of the MEFV gene may show a higher need for interleukin-1 inhibitors. In pediatric familial Mediterranean fever patients who are resistant to colchicine, interleukin-1 inhibitors seem to be highly effective agents.