OBJECTIVE: Vitamin B12 is involved in the production of adrenaline from noradrenaline. It is the cofactor involved in catecholamine degradation and plays a role in myelin synthesis. The current study aimed to investigate the association between vitamin B12 levels and postural orthostatic tachycardia syndrome (POTS) during adolescence when accelerated myelin synthesis increases the vitamin B12 need. METHODS: One hundred twenty-five patients (mean age 11.1 ± 2.3 years; 60% female) reporting short-term loss of consciousness and diagnosed with vasovagal syncope based on anamnesis with a normal distribution and 50 control subjects (mean age 10.94 ± 2.5 years, 62% female) were included in this study. Serum vitamin B12, folic acid, and ferritin levels were measured prospectively in addition to other tests. We defined vitamin B12 deficiency as a serum level <300 pg/mL.1–4 RESULTS: Vitamin B12 levels were significantly lower in the patient group compared with the control group (47.2% vs 18%, P < .001). In the patient group, children with the POTS pattern had significantly lower vitamin B12 levels compared with children without the POTS response (P = .03). CONCLUSIONS: Vitamin B12 deficiency in patients with POTS may lead to sympathetic nervous system baroreceptor dysfunction.

Objectives Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe condition resulting in excessive response of the immune system after SARS-CoV-2 infection. We report a single-center cohort of children with MIS-C, describing the spectrum of presentation, therapies, clinical course, and short-term outcomes. Methods This is a prospective observational study from to a tertiary pediatric rheumatology center including patients (aged 1 month to 21 years) diagnosed with MIS-C between April 2020-April 2021. Demographic, clinical, laboratory results and follow-up data were collected through the electronic patient record system and analyzed. Results A total of 67 patients with MIS-C were included in the study. Fever was detected in all patients; gastrointestinal system symptoms were found in 67.2% of the patients, rash in 38.8%, conjunctivitis in 31.3%, hypotension in 26.9% myocarditis, and/or pericarditis in 22.4%, respectively. Respiratory symptoms were only in five patients (7.5%). Kawasaki Disease like presentation was found 37.3% of the patients. The mean duration of hospitalization was 11.8 7.07 days. Fifty-seven patients (85%) received intravenous immunoglobulin (IVIG), 45 (67%) received corticosteroids, 17 (25.3%) received anakinra, and one (1.5%) received tocilizumab. Seven of the patients (10.4%) underwent therapeutic plasma exchange (TPE). In 21 (31.3%) patients, a pediatric intensive care unit (PICU) was required in a median of 2 days. The first finding to improve was fever, while the first parameter to decrease was ferritin (median 6.5 days (IQR, 4–11.2 days)). Sixty-five patients were discharged home with a median duration of hospital stay of 10 days (IQR, 7–15 days). Conclusion Patients with MIS-C may have severe cardiac findings and intensive care requirements in admission and hospital follow-up. The vast majority of these findings improve with effective treatment without any sequelae until discharge and in a short time in follow-up. Although the pathogenesis and treatment plan of the disease are partially elucidated, follow-up studies are needed in terms of long-term prognosis and relapse probabilities.

Although our results share some similarities with those of other reports, thrombocytosis was markedly increased in the severe group and served as the most predictive laboratory factor of clinical severity.

This study investigated the predictors of chronic valvular disease in children with rheumatic carditis. The short- to mid-term follow-up records of 88 patients (mean age, 10.68 ± 2.5 years) with chronic rheumatic heart disease were reviewed. The mean follow-up period was 2.95 ± 1.4 years. Valvular involvement completely improved for 24 of the patients (27%) during the follow-up period. The multivariate logistic regression analysis found initial left ventricular dilation to be a significant independent risk factor associated with the persistence of either valvular involvement or mitral regurgitation. Furthermore, persistence of mitral regurgitation was found to be strongly correlated with cardiac murmur at admission. No significant correlation was detected between age, gender, severity of valvular involvements at initial evaluation, and chronic valvular disease. The majority of patients with rheumatic carditis had normal left ventricular systolic function. However, a significant proportion of patients had left ventricular dilation, reported in the medical literature to be associated with the severity of valve involvement. This study found no relation between initial severity of valve involvements and chronic valvular disease. For this reason, increased left ventricular end-diastolic diameter may be secondary to myocardial involvement independent of valvular regurgitation. The findings in this study also suggest that subclinic carditis had a better outcome than clinically evident carditis.