Adolescence-onset atypical hemolytic uremic syndrome: is it different from infant-onset?

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is a rare, mostly complement-mediated thrombotic microangiopathy. The majority of patients are infants. In contrast to infantile-onset aHUS, the clinical and genetic characteristics of adolescence-onset aHUS have not been sufficiently addressed to date.

METHODS

A total of 28 patients (21 girls, 7 boys) who were diagnosed as aHUS between the ages of ≥10 years and <18 years were included in this study. All available data in the Turkish Pediatric aHUS registry were collected and analyzed.

RESULTS

The mean age at diagnosis was 12.8±2.3 years. Extra-renal involvement was noted in 13 patients (46.4%); neurological involvement was the most common (32%). A total of 21 patients (75%) required kidney replacement therapy. Five patients (17.8%) received only plasma therapy and 23 (82%) of the patients received eculizumab. Hematologic remission and renal remission were achieved in 25 (89.3%) and 17 (60.7%) of the patients, respectively. Compared with the infantile-onset aHUS patients, adolescent patients had a lower complete remission rate during the first episode (p = 0.002). Genetic analyses were performed in all and a genetic variant was detected in 39.3% of the patients. The mean follow-up duration was 4.9±2.6 years. At the last visit, adolescent patients had lower eGFR levels (p = 0.03) and higher rates of chronic kidney disease stage 5 when compared to infantile-onset aHUS patients (p = 0.04).

CONCLUSIONS

Adolescence-onset aHUS is a rare disease but tends to cause more permanent renal dysfunction than infantile-onset aHUS. These results may modify the management approaches in these patients.

Complement gene mutations in children with C3 glomerulopathy: do they affect the response to mycophenolate mofetil?

BACKGROUND

C3 glomerulopathy (C3G) is a complement-mediated disease. Although genetic studies are not required for diagnosis, they are valuable for treatment planning and prognosis prediction. The aim of this study is to investigate the clinical phenotypes, kidney survival, and response to mycophenolate mofetil (MMF) treatment in pediatric C3G patients with and without mutations in complement-related genes.

METHODS

Sixty pediatric C3G patients were included, divided into two groups based on complement-related gene mutations. Demographic and clinical-pathological findings, treatment modalities, and outcome data were compared, and Kaplan-Meier analysis was performed for kidney survival.

RESULTS

Out of the 60 patients, 17 had mutations. The most common mutation was in the CFH gene (47%). The mean age at diagnosis was higher in the group with mutation (12.9 ± 3.6 vs. 11.2 ± 4.1 years, p = 0.039). While the patients without mutation most frequently presented with nephritic syndrome (44.2%), the mutation group was most likely to have asymptomatic urinary abnormalities (47.1%, p = 0.043). Serum parameters and histopathological characteristics were similar, but hypoalbuminemia was more common in patients without mutation. During 45-month follow-up,10 patients progressed to chronic kidney disease stage 5 (CKD5), with 4 having genetic mutation. The time to develop CKD5 was longer in the mutation group but not significant. MMF treatment had no effect on progression in either group.

CONCLUSIONS

This study is the largest pediatric C3G study examining the relationship between genotype and phenotype. We showed that the mutation group often presented with asymptomatic urinary abnormalities, was diagnosed relatively late but was not different from the without mutation group in terms of MMF treatment response and kidney survival.

Characteristics and predictors of chronic kidney disease in children with myelomeningocele: a nationwide cohort study

BACKGROUND

Myelomeningocele (MMC) is highly prevalent in developing countries, and MMC-related neurogenic bladder is an important cause of childhood chronic kidney disease (CKD). This nationwide study aimed to evaluate demographic and clinical features of pediatric patients with MMC in Turkey and risk factors associated with CKD stage 5.

METHODS

Data from children aged 0-19 years old, living with MMC in 2022, were retrospectively collected from 27 pediatric nephrology centers. Patients > 1 year of age without pre-existing kidney abnormalities were divided into five groups according to eGFR; CKD stages 1-5. Patients on dialysis, kidney transplant recipients, and those with eGFR < 15 ml/min/1.73 m2 but not on kidney replacement therapy at time of study constituted the CKD stage 5 group.

RESULTS

A total of 911 (57.8% female) patients were enrolled, most of whom were expectantly managed. Stages 1-4 CKD were found in 34.3%, 4.2%, 4.1%, and 2.4%, respectively. CKD stage 5 was observed in 5.3% of patients at median 13 years old (range 2-18 years). Current age, age at first abnormal DMSA scan, moderate-to-severe trabeculated bladder on US and/or VCUG, and VUR history were independent risk factors for development of CKD stage 5 (OR 0.752; 95%; CI 0.658-0.859; p < 0.001; OR 1.187; 95% CI 1.031-1.367; p = 0.017; OR 10.031; 95% CI 2.210-45.544; p = 0.003; OR 2.722; 95% CI 1.215-6.102; p = 0.015, respectively). Only eight CKD stage 5 patients underwent surgery related to a hostile bladder between 1 and 15 years old.

CONCLUSION

MMC-related CKD is common in childhood in Turkey. A proactive approach to neurogenic bladder management and early protective surgery in selected cases where conservative treatment has failed should be implemented to prevent progressive kidney failure in the pediatric MMC population in our country.

Low C3 in a 4-month-old baby: is it a problem?

A 4-month-old male baby was admitted because his father and uncles had chronic kidney disease. His father was diagnosed with membranoproliferative glomerulonephritis at the age of 5, underwent a kidney transplant at the age of 22, and lost the graft due to recurrence of the disease. In contrast, the young uncle was diagnosed with C3 glomerulopathy and mycophenolate mofetil and eculizumab were initiated early. It was remarkable that our patient had normal kidney function and urine analyses but low serum C3 level (0.56 g/L; N, 0.9-1.8 g/L). In the disease-associated clinical exome analysis, a heterozygous change in the CFH gene was found. The same mutation was found homozygous in the uncle. In genetically inherited diseases, findings may occur sequentially; early screening of at-risk individuals contributes to kidney survival.

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.

Therapeutic apheresis: is it safe in children with kidney disease?

BACKGROUND

Therapeutic apheresis (TA) is already used to treat various diseases in the field of nephrology. The aim of this study was to evaluate the frequency and types of complications that occur during TA in children with kidney disease.

METHODS

Records of children (≤ 18 years) who underwent TA between 2007 and 2022 were retrospectively reviewed. Children with missing data and those with a diagnosis of nonnephrological disease were excluded.

RESULTS

A total of 1214 TA sessions, including 1147 therapeutic plasma exchange (TPE) sessions and 67 immunoadsorption (IA) sessions, were performed on the 108 patients enrolled in the study. Forty-seven percent of the patients were male, and the mean age was 12.22 ± 4.47 years. Posttransplant antibody-mediated rejection (64.8%) and hemolytic uremic syndrome (14.8%) were the most common diagnoses indicating TA. Overall, 17 different complications occurred in 58 sessions (4.8%), and 53 sessions (4.6%) were not completed because of these complications. The distribution of complications among the patients was as follows: 41.4% had technical complications, 25.9% had allergic complications, and 32.7% had others. The most common technical complication was insufficient flow (37.5%). The incidence of complications was greater in patients aged 3-6 years than in patients in the other age groups (p = 0.031). The primary disease, type of vascular access, and rate of fresh frozen plasma/albumin use were similar between patients with and without complications (p values of 0.359 and 0.125 and 0.118, respectively).

CONCLUSIONS

Our study showed that complications occurred in only 4.8% of TA sessions. The most common complication was technical problems.

Treatment of BK Polyomavirus-Associated Nephropathy in Paediatric Kidney Transplant Recipients: Leflunomide Versus Cidofovir

OBJECTIVES

BK polyomavirus-associated nephropathy is a clinicopathological entity that negatively affects graft function in kidney transplant recipients. We compared the efficacy of leflunomide and cidofovir to treat BK polyomavirus-associated nephropathy in pediatric kidney transplant recipients.

MATERIALS AND METHODS

Medical records of pediatric recipients with BK viremia for the period 2004 through 2019 were reviewed retrospectively, and patients diagnosed with BK polyomavirusassociated nephro-pathy were included in the study. A serum BK virus level above 104 copies/mL was accepted as BK viremia. We defined BK polyomavirusassociated nephropathy as detection of BK virus SV40 antigen on immunochemistry staining of renal graft tissue accompanied by signs of tubulointerstitial nephritis or elevated serum creatinine in addition to BK viremia.

RESULTS

Of 304 kidney transplant recipients, 53 had persistent BK viremia; 36 of these patients (61.1% male) were included in the study with the diagnosis of BK polyomavirus-associated nephropathy. Twelve patients (33.3%) received cidofovir, and 14 (38.8%) received leflunomide. Results were similar between the cidofovir and leflunomide groups for serum creatinine level at last follow-up (0.91 ± 0.29 vs 0.94 ± 0.37 mg/dL, respectively; P = .843) and graft failure rate (8.3% vs 14.2%, respectively; P = .632). Graft failure was observed in 8.3% of patients with BK polyomavirus-associated nephropathy.

CONCLUSIONS

Leflunomide and cidofovir showed similar efficacy for treatment of BK polyomavirus-associated nephropathy.

Comparison of EULAR/PRINTO/PReS Ankara 2008 and 2022 ACR/EULAR Classification Criteria for Granulomatosis with Polyangiitis in Children

OBJECTIVE

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated vasculitis. The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR)-endorsed classification criteria for GPA was derived using data only from adult patients. We aimed to assess the performance of the ACR/EULAR classification criteria for GPA in pediatric patients and compare it with the EULAR/Pediatric Rheumatology International Trials Organization (PRINTO)/Pediatric Rheumatology European Society (PReS)-endorsed Ankara 2008 criteria for GPA.

METHODS

Retrospective data of pediatric patients with GPA in 20 centers from 9 countries were evaluated. The diagnosis of GPA was made according to the expert opinion. The sensitivity, specificity, positive predictive value, and negative predictive value of the criteria sets were evaluated.

RESULTS

The study included 77 patients with GPA and 108 controls (immunoglobulin A vasculitis (n = 44), Takayasu's arteritis (n = 20), microscopic polyangiitis (n = 16), polyarteritis nodosa (n = 14), Behçet's disease (n = 12), eosinophilic granulomatosis with polyangiitis (n = 1), and Cogan's syndrome (n = 1)) with a median age of 17.8 and 15.2 years, respectively. Of patients with GPA, constitutional symptoms (85.7%) and ear-nose-throat involvement (79.2%) were the most common presentations. In the GPA group, 73 patients fulfilled the Ankara 2008 criteria and 69 the ACR/EULAR classification criteria. Sensitivities of the Ankara 2008 criteria and the ACR/EULAR classification criteria were 94.8% and 89.6%, while specificities were 95.3% and 96.3%, respectively. No significant difference was found between sensitivities and specificities of both classification criteria (p= 0.229 and p= 0.733, respectively).

CONCLUSION

In children, both the ACR/EULAR and EULAR/PRINTO/PReS Ankara 2008 classification criteria for GPA perform well and similarly.

Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus: A multicenter study

INTRODUCTION

Neuropsychiatric (NP) involvement is a restricted area in juvenile-onset systemic lupus erythematosus (jSLE).

AIM

To investigate the prevalence, demographic and clinical features, and outcomes of the neurological involvement in the Turkish jSLE population.

METHODS

This study was based upon 24 referral centers' SLE cohorts, multicenter and multidisciplinary network in Turkey. Patient data were collected by a case report form which was standardized for NP definitions according to American Collage of Rheumatology (ACR). Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) neuropsychiatric part was used to determine NP damage. Variables were evaluated Ward's hierarchical clustering analyses, univariate, and multivariate logistic regression analyses.

RESULTS

A hundred forty-nine of 1107 jSLE patients had NP involvement (13.5%). The most common NPSLE findings were headache (50.3%), seizure (38.3%), and acute confusional state (33.6%). Five clusters were identified with all clinical and laboratory findings. The first two clusters involved neuropathies, demyelinating diseases, aseptic meningitis, and movement disorder. Cluster 3 involved headache, activity markers and other SLE involvements. Idiopathic intracranial hypertension, cerebrovascular disease, cognitive dysfunction, psychiatric disorders and SLE antibodies were in the fourth, and acute confusional state was in the fifth cluster. In multivariate analysis, APA positivity; OR: 2.820, (%95CI: 1.002-7.939), P: 0,050, plasmapheresis; OR: 13.804 (%95CI: 2.785-68.432), P: 0,001, SLEDAI scores; OR: 1.115 (%95CI: (1.049-1.186), P: 0,001 were associated with increased risk for neurologic sequelae.

CONCLUSION

We detected the prevalence of juvenile NPSLE manifestations in Turkey. We have identified five clusters that may shed light pathogenesis, treatment and prognosis of NP involvements. We also determined risk factors of neurological sequelae. Our study showed that new definitions NP involvements and sequelae for childhood period are needed.

A rare complication of Behçet's disease in a 12-year-old girl: a large intracardiac thrombosis

Behcet's disease is a multi-systemic inflammatory disease with a clinical spectrum as a triple complex of recurrent oral, genital ulcers, and uveitis. Cardiac involvement in patients with Behcet's disease is extremely rare and often associated with poor prognosis. Behcet's disease should be considered in the differential diagnosis of right ventricular mass especially in young adults, even there is no typical clinical features of Behcet's disease. In this case, a 12-year-old girl who admitted with chest pain and haemoptysis and then was diagnosed with intracardiac thrombus related to Behcet's disease during follow-up was described.

POS1221 EFFECT OF COVID-19 ON CHILDREN WITH RHEUMATIC DISEASE

Background

Pediatric patients with a diagnosis of rheumatic disease are at increased risk for infectious diseases due to immune dysregulation arising fromthe disease itself, as well as immunoregulatory or immunosuppressive drugs they use. However, there are studies reporting that COVID-19 disease has a moderate course in children with rheumatic disease.

Objectives

This study aims to determine the seroprevalence of SARS-CoV-2 in children with rheumatic disease during the COVID-19 pandemic, to evaluate the effects of immunosuppressive drugs and biological agents on seroprevalence of COVID.

Methods

Between September 2020 and September 2021, patients aged 2-18 years with a diagnosis of and with a follow-up period of more than 6 months were included in the study. Patients were selected by “simple random sampling” method.

Anti-SARS-CoV-2 antibodies (IgG and IgA) against the S1 domain of the SARS-CoV-2 spike protein were investigated with a micro ELISA kit.

Results

170 patients, 92 (54.1%) girls, with a mean age of 12.16±4.18 years, were included. The median age at diagnosis was 7.59 (IQR 4.33-11.30) years, and the median follow-up time after diagnosis was 3.24 (IQR 1.87-5.99) years. Primary disease distribution was presented on Figure 1. The co-morbid diseases as obesity, hypertension and chronic kidney disease was present in 4.7%, 9.4% and 5.3% of patients, respectively. The distribution of medications was as follows; colchicine 101 patients (59.4%), Disease Modifying Anti-Rheumatism Drugs 49 (28.8%), steroid 25 (14.7%), and biological agents 28 (16.5%).

Figure 1.

Distribution of patients according to primary rheumatologic diagnosis

Anti-SARS-CoV-2 Ig G antibody was positive in 40 (23.5%) of the patients. Demographic characteristics and treatment-related variables were similar between SARS-CoV-2 IgG seropositive and seronegative patients (Table 1).

Table 1.

Characteristics of patients who are seropositive and seronegative for anti-SARS-CoV-2 Ig G

VariableAnti-SARS-CoV-2 IgG negative patients (n=130)Anti-SARS-CoV-2 IgG positive patients (n=40)pAge (years)11.96±4.1912.80±4.140.528Sex (%)Female67 (%72.8)25 (%27.2)0.150Median age at diagnosis (years)7.56±4.038.69±4.750.195Median follow-up time after diagnosis (years)4.39±3.274.11±3.190.891Diagnosis (%) FMF and other autoinflammatory disease62 (%78.5)17 (%21.5)0.166 Juvenile idiopathic arthritis39 (%78.0)11 (%22.0) SLE ve other autoantibody related diseases16 (%80.0)4 (%20.0) Behçet’s disease8 (%66.7)4 (%33.3) Vasculitis5 (%55.6)4 (%44.4)MEFV mutation Homozygous30 (%75.0)10 (%25.0)0.991 Heterozygous33 (%76.7)10 (%23.3) No mutation36 (%75.0)12 (%25.0)Presence of colchicine usageYes76 (%75.2)25 (%24.8)0.396No54 (%78.2)15 (%21.7)Median colchicine dose (mg/day)1.09±0.441.13±0.420.842Presence of DMARD usageYes37 (%75.5)12 (%24.5)0.499No93 (%76.9)28 (%23.1)Presence of steroid usageYes17 (%68.0)8 (%32.0)0.202No113 (%77.9)32 (%22.1)Median steroid dose (mg/day)10.50±8.9114.71±11.950.333Presence of biological agent usageYes21 (%75.0)7(%25.0)0.505No109 (%76.8)33(%23.2)

Thirty-eight (22.4%) of the patients had close contact with an individual diagnosed with COVID-19. Thirty two (18.9%) patients underwent PCR testing for SARS-CoV-2; only 4 (2.4%) had positive. Of these 32 patients, 28.1% were positive for IgG. IgG seropositivity was observed in 3 (75.0%) of 4 patients with PCR positivity.

Conclusion

We found the SARS-CoV-2 seroprevalence of 23.5% in children with a diagnosis of rheumatic disease. It seems that primary rheumatological diagnosis does not affect COVID seropositivity in children.

Disclosure of Interests

None declared

AB1530-HPR INVESTIGATION OF FUNCTIONAL MUSCLE PERFORMANCE AND STRENGTH AND BALANCE IN CHILDREN WITH FAMILIAL MEDITERRANEAN FEVER: A COMPARATIVE PRELIMINARY STUDY

Background

Familial Mediterranean fever (FMF) is a hereditary, systemic autoinflammatory disease characterized by recurrent fever, peritonitis, pleuritis, arthritis, or erysipelas-like skin (1). Colchicine treatment is frequently used in Familial Mediterranean Fever (2). Nausea, vomiting, abdominal pain and diarrhea are the most common side effects of colchicine, neuropathy and muscle damage can also be observed (2). Musculoskeletal features are common in children with FMF (3). Arthritis, arthralgia, myalgia and erysipelas-like erythema symptoms can be frequently observed in those patients whose disease onset age is younger than 18 years (4). Decreased functional performance and Quadriceps muscle strength were observed in children with FMF compared to healthy children. (5). It has been reported that the decrease in muscle strength and functional capacity is also associated with the quality of life in children. (5). In the light of all this information, although there is muscle weakness in children, it is thought that endurance, balance and functionality may decrease. There has been no study in the literature examining whole body muscle strength, endurance, balance and functionality in these children.

Objectives

The aim of the study was to assess muscle strenght, endurance, balance and functionality in children with FMF and comparison with healthy children matched the same age and gender.

Methods

12 children with FMF and 12 healthy children between the ages of 7-17 were included in the study. 10 Meter Walk Test (10MWT) was used to evaluate walking speed in meters per second over a short duration; The 1 Minute Walking Test (1MWT) was used to evaluate functional capacity; Time Up and Go (TUG) was used to evaluate of functional mobility and dynamic balance; Functional Reach Test (FRT) was used evaluate dynamic balance; Muscle Power Sprint Test (MPST) was used to evaluate functional muscle strength and muscle performance short-term muscle strength; 10x5 Spring Test was used to evaulate agility; 30s Repetition Maximum Test was used to evaluate functional muscle strength; Vertical Jump Test used to evaluate explosive strength of the lower extremity; Standing Long Jump Test was used to evaluate muscular endurance of the upper body and the functional muscle strength of the lower extremities; Hand Dynamometer was used to evaluate general muscle strength.

Results

When the groups were compared, a significant difference was found in favor of healthy children in the 10MWT, 1-minute walking test, TUG, FUT, 30 s Repetition Maximum Test (p:0.00- 0.04).

Conclusion

According to the results of the study, children with FMF have low functional muscle performance and strength and balance compared with healthly children. There is a need for studies in which there are more children with FMF and assessmnet of muscle function. Therefore, in which we present the preliminary results, the functional muscle performance and strength and balance children with FMF should be routinely assessed and treatment and rehabilitation programs should be arranged according to these findings.

References

[1]Ben-Chetrit, E, Levy M. Familial Mediterranean fever. Lancet, 1998; 351: 659-64.

[2]Cocco G, Chu DC, Pandolfi S. Colchicine in clinical medicine. A guide for internists. Eur J Intern Med, 2010; 21: 503-508.

[3]Kunt SŞ, Aydin F, Çakar N, Özdel S, Yalçinkaya F, Özçakar ZB. The effect of genotype on musculoskeletal complaints in patients with familial Mediterranean fever. Postgraduate Medicine, 2020; 132(2): 220-224

[4]Tunca M, Akar S, Onen F, Ozdogan H, Kasapçopur Ö, Yalcinkaya F, et al. Familial Mediterranean fever (FMF) in Turkey: results of a nationwide multicenter study. Medicine (Baltimore), 2005; 84:1–11.

[5]Alayli G, Durmus D, Ozkaya O, Sen HE, Nalcacioglu H, Bilgici A, et al. Functional capacity, strength, and quality of life in children and youth with familial Mediterranean fever. Pediatr Phys Ther, 2014; 26: 347–52.

Disclosure of Interests

None declared

Could plasma based therapies still be considered in selected cases with atypical hemolytic uremic syndrome?

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) occurs due to defective regulation of the alternative complement pathway (ACP) on vascular endothelial cells. Plasma based therapy (PT) was the mainstay of the treatment for aHUS for many years until the introduction of therapies targeting blockage of the complement system. The aim of this study was to evaluate patients with aHUS who had been treated with plasma based therapies alone.

METHODS

The outcomes of seven genetically confirmed aHUS patients (2 girls, 5 males) were evaluated by means of clinical presentation, response to plasma therapy, course of the disease during the follow-up period and last status.

RESULTS

The median age of the patients at admission was 6.7 years (IQR 0.7-7.8). Three patients received plasma exchange therapy and the other four patients were treated with plasma infusions. One patient was lost to follow-up after one year; the median duration of follow-up for other patients was 3.7 years (IQR 2.7-6.5). During the follow up, two patients from our historical records when complement blocking therapies had not been in clinical use yet in Turkey, underwent kidney transplantation. One transplant patient experienced an acute rejection episode without graft loss. The remaining five patients had a glomerular filtration rate of more than 90 ml/min./1.73 m < sup > 2 < /sup > at the last visit.

CONCLUSION

Although we had a relatively small patient population, our findings indicate that PT might still be considered in selected patients particularly in countries where complement blocking therapies are difficult to reach due to their unavailability or costs that are not covered by the health care systems.

Clinical features of children with chronic non-bacterial osteomyelitis: A multicenter retrospective case series from Turkey

Objectives

This study aims to evaluate demographic, clinical, and radiological characteristics of Turkish children with chronic non-bacterial osteomyelitis.

Patients and methods

Between January 2008 and December 2018, a total of 28 patients (10 males, 18 females; median age: 12.5 years; range, 4.5 to 21 years) who were diagnosed with chronic non-bacterial osteomyelitis in three pediatric rheumatology centers were retrospectively analyzed. The demographic, clinical, and laboratory findings of the patients were recorded.

Results

The median age at the time of diagnosis was 10.2 years. The median time from symptom onset to diagnosis was 6.5 months. The median follow-up was 18.5 months. The most frequent symptom at onset was arthralgia (75.0%). The most frequently involved bone was the femur (67.9%). Eight (63.6%) of 12 patients had at least one Mediterranean fever gene (MEFV) mutation, indicating a significantly higher prevalence than the Turkish population (14.8%). Five of these patients fulfilled the diagnostic criteria for familial Mediterranean fever (FMF). All patients received non-steroidal anti-inflammatory drugs. Other drugs were methotrexate (46.4%), sulfasalazine (39%), corticosteroids (25%), anti-tumor necrosis factor (anti-TNF) agents (32%), pamidronate (25%), and colchicine (21.4%). Six of eight patients with MEFV mutations were administered with colchicine, and all of them responded to treatment.

Conclusion

Clinical evolution and imaging investigations should be carefully performed to prevent any delay in the diagnosis of patients with chronic non-bacterial osteomyelitis. Based on our study results, FMF coexistence is worth investigating in patients with chronic non-bacterial osteomyelitis, particularly in the Turkish population.

A Nationwide Retrospective Study in Turkish Children With Nephrocalcinosis

BACKGROUND

Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors and follow-up results of patients with NC in Turkey.

MATERIALS AND METHODS

Patients diagnosed with NC in the Pediatric Nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010?2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details and presence of NC after one year follow-up were recorded retrospectively.

RESULTS

The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44±47.25 (0.5?208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease.

CONCLUSION

The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one year follow-up. It may resolve particularly in patients with no underlying systemic disease.

Transplantation in pediatric aHUS within the era of eculizumab therapy

aHUS is caused by the over-activation and dysregulation of the alternative complement pathway. Data regarding outcomes of pediatric aHUS patients after kidney transplantation are still very scarce. Accordingly, the aim of this study was to describe the clinical findings and outcomes of pediatric aHUS patients after renal transplantation. This is a retrospective, multicenter study including 12 patients from the national registry system. Among the 12 patients, eight had received prophylactic eculizumab and none of those patients (except one) had experienced aHUS recurrence during a median follow-up period of 58.5 (min-max, 4-94) months. Although eculizumab had been started on the day before transplantation in one of them, aHUS recurrence occurred during the transplantation procedure. Eculizumab had been stopped in only one patient who had no complement gene mutation after 35 months of therapy, and recurrence had not been observed during the 19 months of follow-up. In three patients, maintenance doses had been spaced out without any recurrence. One additional patient with anti-CFH antibody received only two doses of eculizumab for transplantation and had been followed for 46 months without aHUS recurrence. The remaining three patients had not received anti-C5 therapy and none of those patients experienced aHUS recurrence during a median follow-up period of 21 (min-max, 9-42) months. Prophylactic eculizumab is a safe and effective treatment for the prevention of aHUS recurrence. Eculizumab interval prolongation, discontinuation, and transplantation without eculizumab prophylaxis can be tried in selected patients with close follow-up.

Predictors of poor kidney outcome in children with C3 glomerulopathy

BACKGROUND

C3 glomerulopathy (C3G) is characterized by heterogeneous clinical presentation, outcome, and predominant C3 accumulation in glomeruli without significant IgG. There is scarce outcome data regarding childhood C3G. We describe clinical and pathological features, treatment and outcomes, and risk factors for progression to chronic kidney disease stage 5 (CKD5) in the largest pediatric series with biopsy-proven C3G.

METHODS

Sixty pediatric patients with C3G from 21 referral centers in Turkey were included in this retrospective study. Patients were categorized according to CKD stage at last visit as CKD5 or non-CKD5. Demographic data, clinicopathologic findings, treatment, and outcome data were compared and possible risk factors for CKD5 progression determined using Cox proportional hazards model.

RESULTS

Mean age at diagnosis was 10.6 ± 3.0 years and follow-up time 48.3 ± 36.3 months. Almost half the patients had gross hematuria and hypertension at diagnosis. Nephritic-nephrotic syndrome was the commonest presenting feature (41.6%) and 1/5 of patients presented with nephrotic syndrome. Membranoproliferative glomerulonephritis was the leading injury pattern, while 40 patients had only C3 staining. Patients with DDD had significantly lower baseline serum albumin compared with C3GN. Eighteen patients received eculizumab. Clinical remission was achieved in 68.3%. At last follow-up, 10 patients (16.6%) developed CKD5: they had lower baseline eGFR and albumin and higher frequency of nephrotic syndrome and dialysis requirement than non-CKD5 patients. Lower serum albumin and eGFR at diagnosis were independent predictors for CKD5 development.

CONCLUSIONS

Children with C3G who have impaired kidney function and hypoalbuminemia at diagnosis should be carefully monitored for risk of progression to CKD5. Graphical abstract.

Evaluation of non-infectious complications of peritoneal dialysis in children: a multicenter study

BACKGROUND

Peritoneal dialysis (PD) is the most common kidney replacement therapy in children. Complications associated with PD affect treatment success and sustainability. The aim of this study was to investigate the frequency of PD-related non-infectious complications and the predisposing factors.

METHODS

Retrospective data from 11 centers in Turkey between 1998 and 2018 was collected. Non-infectious complications of peritoneal dialysis (NICPD), except metabolic ones, in pediatric patients with regular follow-up of at least 3 months were evaluated.

RESULTS

A total of 275 patients were included. The median age at onset of PD and median duration of PD were 9.1 (IQR, 2.5-13.2) and 7.6 (IQR, 2.8-11.9) years, respectively. A total of 159 (57.8%) patients encountered 302 NICPD within the observation period of 862 patient-years. The most common NIPCD was catheter dysfunction (n = 71, 23.5%). At least one catheter revision was performed in 77 patients (28.0%). Longer PD duration and presence of swan neck tunnel were associated with the development of NICPD (OR 1.191; 95% CI 1.079-1.315, p = 0.001 and OR 1.580; 95% CI 0.660-0.883, p = 0.048, respectively). Peritoneal dialysis was discontinued in 145 patients; 46 of whom (16.7%) switched to hemodialysis. The frequency of patients who were transferred to hemodialysis due to NICPD was 15.2%.

CONCLUSIONS

Peritoneal dialysis-related non-infectious complications may lead to discontinuation of therapy. Presence of swan neck tunnel and long duration of PD increased the rate of NICPD. Careful monitoring of patients is necessary to ensure that PD treatment can be maintained safely.

Viral seroprevalence in pediatric kidney transplant recipients

AIM

Viral infections commonly affect kidney transplant recipients and may lead to graft failure and death. The aim of this study was to evaluate the antibody seroprevalence against viral agents in kidney transplant recipients.

MATERIAL AND METHODS

The records of children who underwent kidney transplantation between 2008 and 2018 in Akdeniz University Faculty of Medicine were retrospectively reviewed. Epstein-Barr virus, cytomegalovirus, hepatitis A virus, hepatitis B virus, varicella, measles, rubella and mumps serologies evaluated before transplantation, were recorded. The clinical characteristics of seronegative and seropositive patients were compared, and factors that affected seropositivity were investigated.

RESULTS

The study included 253 children with a mean age of 16.7±6.23 years. The mean age at transplantation was 11.4±5.01 years. The seropositivity rates for vaccine-preventable viral infections varied: hepatitis B 89.7%, hepatitis A 60.5%, measles 78.7%, rubella 88.1%, mumps 61.2%, and varicella 71.9%. Cytomegalovirus seropositivity was 92.1% and Epstein-Barr virus seropositivity was 82.2%. Hepatitis B antibody positivity was 91.8% in patients undergoing hemodialysis, 94.5% in patients undergoing peritoneal dialysis, and 84.9% in pre-emptive transplantation patients (p=0.037). The mean age at transplantation was higher in patients with seropositivity for both cytomegalovirus and Epstein-Barr virus compared with seronegative patients (p<0.001 for both). The mean age at transplantation and diagnosis of glomerular disease was found to be effective for varicella seropositivity in multivariate regression analysis (OR 0.860, 95% CI: 0.808-0.915, p<0.001 and OR 2.502, 95% CI: 1.321-4.739, p=0.005, respectively).

CONCLUSION

It is important to screen patients with chronic kidney disease in terms of vaccine-preventable diseases to identify risky groups of patients and to immunize these patients before end-stage kidney disease develops.

Orthostatic proteinuria: an overestimated phenomenon?

BACKGROUND

Although orthostatic proteinuria (OP) is the most common cause of childhood proteinuria, excluding transient proteinuria, data regarding prevalence and long-term prognosis are limited. We aimed to determine prevalence of OP in healthy schoolchildren evaluating relationships with age, gender and body mass index, and determine follow-up.

METHODS

A total of 1701 healthy children aged 6-15 years were selected using a population-based, stratified, cluster-sampling method; and random urine samples were taken. For proteinuria ≥ 1+ in first urine samples, second and third random samples were taken at least 2 weeks apart to exclude transient proteinuria. For continuing proteinuria after third samples, first morning urine samples were collected. Cases where proteinuria was not detected in first morning urine samples were diagnosed as OP.

RESULTS

Sixty-four of 1701 children (3.7%) had proteinuria on first random urine samples. After second and third urine samples, proteinuria persisted in only 16 (0.94%). OP was detected in 11 (0.65%). Prevalence of OP tended to decrease with increasing BMI, though not statistically significant. All 7 cases with OP who were re-evaluated later, had no proteinuria 3 years after diagnosis.

CONCLUSIONS

Prevalence of OP in our study was lower than the literature. At least three random urine samples should be taken to exclude transient proteinuria in an asymptomatic child/adolescent before making a diagnosis of OP using first morning urine samples. OP is a benign condition and resolves spontaneously in most cases. Underweight children had a tendency for OP compared with overweight and obese children; however, further studies with larger number of patients are needed.

Early or Late Transplantation in Congenital Nephrotic Syndrome: Which is Effective for Optimal Growth?

Congenital nephrotic syndrome (CNS) is a genetic disease that is present in the antenatal period or during the first 3 months of life. In this study, we aimed to compare growth parameters of patients with CNS who received kidney transplants and either (1) had a normal glomerular filtration rate (GFR) at the time of transplant or (2) chronic kidney disease (CKD) at the time of transplant. Patients with a diagnosis of CNS who had a minimum follow-up period of 6 months were evaluated retrospectively. Children at stages 4 or 5 CKD or patients receiving dialysis during the pretransplant period were defined as group 1; patients with normal GFR at the time of transplantation were classified as group 2. Short stature and low weight were defined as less than -2 standard deviation scores (SDS) for height and weight according to their age. A total of 17 patients were included in the study. Thirteen of 17 patients had NPHS1 gene mutations. Group 1 and group 2 consisted of 8 and 9 patients, respectively. Mean height SDS and mean weight SDS in group 2 were higher than group 1 in the pretransplant period (-4.34 ± 1.74 vs -2.84 ± 1.56; P = .011 and -3.54 ± 0.93 vs -1.83 ± 1.13; P = .008). In the post-transplant period, the significant difference in height SDS continued in favor of group 2 (-3.16 ± 1.11 vs -1.16 ± 0.87; P = .002). The short stature rate was 83% in group 1 and 72% in group 2 in the pretransplant period (P = .62), and 83% in group 1 and 27% in group 2 in the post-transplant period (P = .02). Early renal transplantation seems to be effective for optimal height gain in children with CNS.

Semen analysis in adolescents with familial Mediterranean fever

BACKGROUND

Little is known about sperm health in male patients with familial Mediterranean fever (FMF). In this study, the authors aimed to search the frequency of sperm abnormalities of adolescent boys with FMF and also to investigate whether disease activity or colchicine treatment have negative effects on sperm parameters.

METHOD

The male adolescents older than 14 years with a diagnosis of FMF were investigated retrospectively. Tel Hashomer and pediatric FMF clinical criteria were used for diagnosis of FMF. Patients who had semen analysis were included in the study.

RESULT

Mean age at the diagnosis was 11.13 ± 3.82 years, and mean age at the study was 14.50 ± 0.70 years. The mean sperm concentration was found as 66.26 ± 41.02 million/ml (N > 15 million/ml), the mean total sperm count 113.42 ± 132.39 million (N > 39 million), and the mean sperm motility 51.78 ± 23.70% (N > 40%). Only 8 of 19 (42.1%) patients had normal sperm parameters. Sperm concentration was reduced in two cases, total sperm count was reduced in four patients, and motility was reduced in nine cases. The presence of FMF attacks under treatment was found to be a risk factor for decreased motility in the study group by multivariate regression analysis (odds ratio 0.076, [95% confidence interval 0.005-0.648], P = 0.031). Erythrocyte sedimentation rate at the time of diagnosis was high in patients with low sperm counts compared with those with normal sperm counts (56.00 ± 8.51 vs 24.35 ± 6.32, P: 0.03). Mean colchicine dose at the time of sperm analysis was higher in patients with low sperm motility than that with normal sperm motility (1.72 ± 0.18 vs 1.25 ± 0.08, P: 0.02).

CONCLUSION

Sperm abnormalities of male patients with FMF is not infrequent, and it is linked to both inflammation due to uncontrolled disease and colchicine therapy.

Clinical and histopathological prognostic factors affecting the renal outcomes in childhood ANCA-associated vasculitis

OBJECTIVE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are very rare in childhood with an increased risk of morbidity and mortality. We aimed to evaluate renal prognostic factors in childhood AAV from the perspective of ANCA serotype, histopathological classification, and five-factor score (FFS).

METHODS

Pediatric AAV patients from 11 referral centers in Turkey had been included to the study. The demographics, clinical findings, AAV subtypes, outcomes, and FFS were evaluated retrospectively. Kidney biopsies were classified histopathologically.

RESULTS

Totally, 39 patients were enrolled in the study. Among all patients, 74.4% had renal involvement, 56.4% ear-throat-nose involvement, and 51.3% had musculoskeletal involvement. Proteinase 3 (PR3)-ANCA was positive in 48.7%, and myeloperoxidase (MPO)-ANCA was positive in 30.8%. 69.2% of patients had impaired renal function, and 28.2% had progressed to end-stage renal disease (ESRD) during the follow-up. At the time of diagnosis, FFS was ≥ 2 in 53.8%. The most common histopathologic classifications were as follows: crescentic type in 40.7% and sclerotic type in 25.9%. Gastrointestinal and renal involvement, MPO-ANCA positivity, serum creatinine levels, and impaired renal function during the follow-up were significantly higher in patients with FFS ≥ 2, compared to patients with FFS < 2. Patients with FFS ≥ 2 had more common crescentic, mixed and sclerotic histopathologic findings in biopsies. By logistic regression analysis forward method, the strongest single-risk factor among all the parameters was the initial level of creatinine in patients with ESRD, compared to the other patients (p = 0,007).

CONCLUSIONS

Evaluation of the FFS, ANCA serology, and the creatinine levels may help to predict renal prognosis.

Delayed diagnosis of primary vesicoureteral reflux in children with recurrent urinary tract infections: Diagnostic approach and renal outcomes

OBJECTIVE

In this study, we aimed to assess renal outcomes of delayed diagnosis of dilating primary vesicoureteral reflux (VUR) following recurrent febrile urinary tract infections (fUTIs) and its diagnostic imaging procedures.

MATERIAL AND METHODS

The medical records of patients who underwent ultrasonography (US), non- acute dimercaptosuccinic acid (Tc-99mDMSA) scintigraphy and voiding cystourethrography (VCUG), and who were older than 2 years at the time of VUR diagnosis were retrospectively reviewed.

RESULTS

A total of 32 children (female, n=27: 84.4%) with a mean age of 7.67±3.34 years at the time of diagnosis of VUR were included in the study. Grade III, IV, V VUR were found in 22%, 69%, and 9% of the patients, respectively. At the time of VUR diagnosis, abnormal US findings were detected in 75% of the cases. Tc-99mDMSA detected abnormalities in 83.9% (7 with a single scar, 7 with multiple lesions, 12 with reduced kidney function) of the patients. Estimated glomerular filtration rate of 3 patients with bilateral grade IV VUR was <75 mL/min/1.73 m². In 5 patients (16%), VUR could not be predicted by US+DMSA scintigraphy (Grade IV VUR in 3 and Grade III in 2 cases ). The sensitivity in predicting VUR was 75.00% (95% CI: 56.60-88.54) and 83.87% (95% CI: 66.27-94.55), respectively, for US alone and combined US+DMSA.

CONCLUSION

VCUG should be performed routinely in addition to US and non-acute DMSA in all children referred with recurrent fUTIs. Awareness of childhood UTI in public and healthcare personnels should be increased in order to refer these patients at a early stage to pediatric urology and nephrology units.

Febrile seizures in children with familial Mediterranean fever: Coincidence or association?

BACKGROUND

Familial Mediterranean fever (FMF) is an inherited disease characterized by recurrent bouts of fever and polyserositis and caused by MEditerranean FeVer gene (MEFV) mutations. Given the febrile characteristics of the disease one would expect higher frequency of febrile seizure in this group of pediatric patients.

OBJECTIVES

To evaluate the frequency of febrile seizure and related factors in patients with FMF.

METHODS

The children with the diagnosis of FMF were enrolled in the study. Information including clinical features, type of mutation and the history of febrile seizure were all noted.

RESULTS

A total of 97 patients, 43 (44.3%) girls with a median age of 7.93 ± 4.05 years (2-16) and a median follow-up period of 20.65 ± 24.33 months (6-135) were included in the study. The frequency of febrile seizure in children with FMF was found as 13.4%, which is higher than the general population [p = 0.04, OR: 2.9 (95% CI: 1.0-8.5)]. The allele frequency of exon 2 mutations in MEFV genes was higher in the patients with febrile seizure (p = 0.03). Frequency of FMF related clinical findings (fever, abdominal pain, arthralgia/myalgia, arthritis, chest pain and erysipelas-like erythema) was similar between the two groups. However, frequency of headache was higher in the patients with febrile seizure (p = 0.014).

CONCLUSION

The frequency of febrile seizure in children with FMF was found to be higher than the general population. Although this finding may be related to high fever during FMF attacks in individuals with genetic propensity of febrile seizure, it may also be a neurologic complication of FMF.

Association between vitamin D deficiency and disease activity in juvenile idiopathic arthritis

Vitamin D has been shown to have immunomodulatory and anti-inflammatory properties in addition to its well-established role in the maintenance of mineral homeostasis and bone health. The aims of this study were to evaluate vitamin D status in patients with juvenile idiopathic arthritis (JIA), and also to examine whether there is an association between serum levels of 25-hydroxyvitamin D [25(OH)D] and disease activity in JIA. Children with JIA who had an outpatient visit between March and April 2011 were evaluated retrospectively. Clinical and laboratory findings and vitamin D levels were evaluated. Disease activity was calculated using JADAS-27. Serum vitamin D levels were measured using high-performance liquid chromatography (HPLC). A total of 47 patients, 29 (61.7%) of them girls, with a mean age of 9.3±3.9 years and a median follow-up period of 28 months, were included in the study. The mean serum vitamin D level of all patients was 17.7±11.6 ng/ml. Vitamin D insufficiency (serum vitamin D: 15-20 ng/ml) and deficiency (serum vitamin D level <15 ng/ml) were found in 9 (19.1%) and 25 patients (53.2%), respectively. The vitamin D level was <20 ng/ml in 72.3% of the children. Only 13 patients (27.7%) were found to have adequate vitamin D levels (>20 ng/ml). There was a significant negative correlation between vitamin D levels and disease activity (p=0.01, r=-0,37). The mean JADAS-27 score was significantly higher in patients with 25(OH)D levels <15 ng/ml than in patients with 25(OH)D levels >15 ng/ml (p = 0.003). We suggest that vitamin D deficiency may be a possible modifiable risk factor affecting disease activity in JIA.

Circulating endothelial cells in pediatric renal transplant recipients

BACKGROUND

An increase in the number of circulating endothelial cells (CEC) indicates endothelial damage and the risk of cardiovascular disease. The aim of our study was to investigate the association of CEC with various clinical parameters in pediatric renal transplant recipients.

METHODS

CEC, defined as CD45(-)CD146(+), were enumerated by flow cytometry from the peripheral blood of 50 pediatric renal transplant recipients and 20 healthy controls. Clinical parameters, including renal function tests, fasting blood glucose, serum cholesterol and triglyceride, cyclosporine A (CsA) (trough and 2nd-hour) and tacrolimus (tac) trough blood levels and their association with CEC numbers were analyzed.

RESULTS

CEC numbers of patients were higher than those of controls (respectively, 128 ± 89 cells/ml (42-468 cells/ml), 82 ± 33 cells/ml (32-137 cells/ml), p = 0.024). There was a statistically significant negative correlation between CEC numbers and glomerular filtration rate (GFR) (r = -0.300, p = 0.012). There was also a statistically positive association between CEC numbers and transplant duration as well as cyclosporine trough level (respectively, r = 0.397, p = 0.004, r = 0.714, p = 0.004). CEC numbers in patients on tac and CsA were similar (p = 0.716).

CONCLUSIONS

Our results demonstrate that renal transplant recipients with high CsA trough blood level, longer transplant duration, and lower GFR, are at greater risk of developing endothelial damage.

Frequency of mtDNA A1555G and A7445G mutations among children with prelingual deafness in Turkey

Considerable differences on the frequencies of the mitochondrial 12S rRNA A1555G and tRNA(Ser(UCN)) A7445G mutations have been reported in different populations. Our screening of 168 patients coming from independent Turkish families with prelingual sensorineural non-syndromic deafness revealed three deaf children with A1555G (1.8%) but no examples of A7445G. One proband with the mitochondrial A1555G mutation has also evidence for right parietal infarct on a brain imaging study, for which common thrombotic mutations were found to be negative.

CONCLUSION

This study shows that the mitochondrial A1555G mutation is among the significant causes of prelingual non-syndromic deafness in the Turkish population.