Evaluation of pediatric rheumatologists' approach to rituximab use: a questionnaire study.

Rituximab (RTX) is a chimeric monoclonal antibody that targets the CD20 antigen on B cells and is used in various autoimmune disorders. In this study, we aimed to measure the awareness of pediatric rheumatologists about the use of RTX through a survey. Between February and March 2023, a 42-question survey was sent via email to pediatric rheumatology specialists in Turkey. The participants were questioned for which diagnoses and system involvement they preferred to use RTX, which routine tests they performed, vaccination policy, and adverse events that occurred during or after infusion. Forty-one pediatric rheumatologists answered the survey. They prescribed RTX most frequently for systemic lupus erythematosus (87.8%) and ANCA-associated vasculitis (9.8%). Prior to the administration of RTX, 95% of clinicians checked renal and liver function tests, as well as immunoglobulin levels. The most frequently tested hepatitis markers before treatment were HBsAg and anti-HBs antibody (97.6%), while 85.4% of rheumatologists checked for anti-HCV. Clinicians (31.4%) reported that they postpone RTX infusion 2 weeks following an inactivated vaccine. Sixty-one percent of rheumatologists reported starting RTX treatment 1 month after live vaccines, while 26.8% waited 6 months. The most frequent adverse events were an allergic reaction during RTX infusion (65.9%), hypogammaglobulinemia (46.3%), and rash (36.6%). In the event of hypogammaglobulinemia after RTX treatment, physicians reported that they frequently (58.5%) continued RTX after intravenous immunoglobulin administration. CONCLUSIONS: RTX has become a common treatment option in pediatric rheumatology in recent years. Treatment management may vary between clinician such as vaccination and routine tests. WHAT IS KNOWN: • During the course of rituximab therapy, clinicians should be attentive to specific considerations in pre-treatment, during administration, and in post-treatment patient monitoring. WHAT IS NEW: • There are differences in practice among clinicians in the management of RTX therapy. These practice disparities have the potential to impact the optimal course of treatment. • This study highlights that standardized guidelines are needed for RTX treatment in pediatric rheumatology, particularly for vaccination policies and routine tests.

Differences and similarities of multisystem inflammatory syndrome in children, Kawasaki disease and macrophage activating syndrome due to systemic juvenile idiopathic arthritis: a comparative study.

To compare the clinical and laboratory findings of multisystem inflammatory syndrome in children (MIS-C), patients with Kawasaki disease (KD) and with macrophage activating syndrome due to systemic juvenile idiopathic arthritis (sJIA-MAS) on real-life data. Patients diagnosed with MIS-C, KD, and sJIA-MAS from 12 different centers in Turkey who were followed for at least 6 months were included in the study. Demographic, clinical, and laboratory findings of all patients were analyzed. A total of 154 MIS-C, 59 KD, and 31 sJIA-MAS patients were included. The median age of patients with MIS-C were higher than those with KD while lower than those with sJIA-MAS (8.2, 3, 12 years, respectively). Myalgia (39.6%), cardiac (50.6%), gastrointestinal (72.7%), and neurological (22.1%) involvements were more common in patients with MIS-C compared to others. MIS-C patients had lower levels of lymphocyte (950 vs 1700 cells/µl) and thrombocyte (173,000 vs 355,000 cells/µl) counts and higher pro-BNP (1108 vs 55 pg/ml) levels than KD. Ferritin levels were higher in patients with MIS-C compared to patients with KD while they were lower than patients with sJIA-MAS (440, 170, 10,442 ng/ml, respectively). Patients with MIS-C had a shorter duration of hospitalization than sJIA-MAS (p = 0.02) while they required intensive care unit admission more frequently (55 vs 8 patients, p < 0.001). The median MAS/sJIA score of MIS-C patients was - 1.64 (- 5.23 to 9.68) and the median MAS/sJIA score of sJIA-MAS patients was -2.81 ([- 3.79] to [- 1.27]). MIS-C patients displayed certain differences in clinical and laboratory features when compared to KD and sJIA-MAS. Definition of the differences and similarities between MIS-C and the other intense inflammatory syndromes of childhood such as KD and MAS will help the clinicians while making timely diagnosis.

Case report: Thrombotic microangiopathy in pediatric multisystem inflammatory syndrome associated with COVID-19: a case series.

Introduction: This report provides insight into three distinct pediatric cases exhibiting a nexus between multisystem inflammatory syndrome in children (MIS-C) and thrombotic microangiopathy (TMA) triggered by COVID-19. The aim is to underscore the range of clinical presentations and the essentiality of early interventions. Case presentations: This report presents three cases aged 10 months, 7 years, and 3 years with persistent fever, diarrhea, nausea, and vomiting. The first case, a 10-month-old girl, demonstrated acute kidney injury (AKI) and microangiopathic hemolytic anemia (MAHA) following a COVID-19 infection. Despite initial negative SARS-CoV-2 RT-PCR results, her condition escalated rapidly, presenting increased levels of LDH (peaking at 4,200 U/L) and requiring renal replacement therapy (RRT) to manage deteriorating renal function. Interventions with eculizumab and anakinra led to marked improvements, with a stable follow-up of 13 months post-hospitalization. The second case involved a 7-year-old girl who developed symptoms of MIS-C, hemolytic uremic syndrome (HUS), and posterior reversible encephalopathy syndrome (PRES) post-exposure to COVID-19, evidenced by heightened LDH levels (3,522 U/L at peak). After a precarious period of deteriorating kidney function and exacerbated hypertension, she responded positively to treatments, inclusive of IVIG, steroid therapies, and eculizumab, with a favorable 6-month follow-up showcasing stable laboratory results. The third case discusses a 3-year-old boy, without any medical history, manifesting HUS symptoms and COVID-19 infection. He exhibited increased LDH levels (peaking at 3,946 U/L) alongside elevated creatinine, marking renal impairment. He responded well to hemodialysis, IVIG, and steroid therapy, showcasing substantial recovery by the 19th day of hospitalization, which marked his discharge with a tapering steroid regimen. Conclusion: This case series underscores that MIS-C-associated TMA is a significant complication in pediatric COVID-19. Our findings illuminate the potential for treatment success but simultaneously emphasize the need for a more comprehensive understanding of the underlying pathophysiology.

Outcome of posterior urethral valve in 64 children: a single center's 22-year experience.

BACKGROUND: Posterior urethral valve (PUV) is the most serious form of congenital anomalies of kidney and urinary tract (CAKUT) in boys with significant risk of progression to chronic kidney disease (CKD). We present our long-term results in children with PUV. METHODS: Retrospective chart review of 113 children with PUV followed within the years of 1996-2018 was performed. Clinical, laboratory and epidemiologic parameters were analyzed for their impact on renal outcome. RESULTS: The median age of diagnosis was 1.00 month (1.00-132.00) and the median follow-up period was 70 months (60.00-216.00). Antenatal diagnosis was present in 33 patients (51.5%) mainly with bilateral hydronephrosis and oligohydramnios. The most common postnatal presentation was recurrent urinary tract infection (UTI) in 14 cases (21.9%) and incontinence in three cases (4.7%). Vesicoureteral-reflux (VUR) was present in 31 cases (48.4%). All patients had surgery and urinary diversion was needed in 18 (28.2%). Varying stages of chronic kidney disease (CKD) developed in 23 cases (35.9%) and rise in serum creatinine was especially prominent after the 4th year of follow-up. Of 23 CKD patients, seven (10.9%) were in ESRD and on dialysis. Mortality occurred in one (1.5%) patient. Hypertension, proteinuria and high initial serum creatinine (>1.28 mg/dL) were statistically significant risk factors for CKD, as expected. Surprisingly VUR and UTI did not show such a significant impact on CKD development. Antenatal detection was with significantly less risk for CKD. CONCLUSIONS: Our results confirm that PUV has a considerable risk for CKD development. Antenatal diagnosis, management of proteinuria and hypertension may modify this progression. But already injured kidneys still have a potential risk. The need for further research to evaluate the impact of any intervention on long term renal outcome is obvious.