Evaluation of the relationship between mast cell activation and postural orthostatic tachycardia syndrome in children and adolescents.

OBJECTIVE: Postural orthostatic tachycardia syndrome (POTS) is one of the orthostatic intolerance syndromes that are common in young adolescents and impair quality of life. POTS is a multi-systemic disease. Many mechanisms have been defined in POTS etiology, such as autonomic denervation, hypovolemia, hyperadrenergic stimulation, low condition, and hypervigilance. Recently, mast cell activation (MCA) has also been on the agenda in etiology. There are few studies in the literature on the relationship between MCA and POTS in adulthood. However, data on children and adolescents is limited. In light of this information, we aimed to evaluate the relationship between POTS and MCA by measuring serum tryptase levels, a specific marker for MCA. METHODS: This prospective study included patients who were admitted to Kocaeli University Faculty of Medicine Hospital Pediatric Cardiology outpatient clinic for syncope-presyncope between November 2018 and August 2019. Patients who underwent the TILT-table test were enrolled in the study. Patients with structural heart disease or chronic heart disease were not included in this study. Serum tryptase levels were obtained from all patients before the TILT-table test, and serum tryptase levels were re-studied after the test was terminated in patients with positive TILT-table tests for POTS. Patients diagnosed with POTS were classified as Group 1, and other patients were classified as Group 2. RESULTS: Twenty-eight of the 58 patients included in the study (mean: 14.4±2.0 years; 38 girls, 20 boys) were diagnosed with POTS. The remaining 30 patients were diagnosed with vasovagal syncope and included in Group 2. The increase in mean heart rate during the test was 38±6 beats/min and 47.05%±15.65% in patients with POTS. Basal serum tryptase levels were not different between groups (3.2±1.3 ng/ml and 3.84±1.78 ng/ml, respectively; p=0.129), while serum tryptase levels (both baseline and after 45-60 min of the TILT-table test) were higher in patients presenting with symptoms related to MCA compared to others. CONCLUSION: In the literature, MCA was considered to be one of the mechanisms leading to POTS. Although other mechanisms, such as neuropathic and hypovolemic POTS, may be active in the patients, the symptoms of MCA in these patients should be routinely questioned.

Retinal vessel density and choroidal flow changes in oligoarticular juvenile idiopathic arthritis with and without uveitis.

PURPOSE: This cross-sectional optical coherence tomography angiography (OCTA) study aimed to assess the macular and optic nerve head (ONH) vascular density, foveal avascular zone, and outer retina and choriocapillaris flow in oligoarticular juvenile idiopathic arthritis (oJIA). STUDY DESIGN: Prospective. METHODS: Twenty-two eyes of 22 oJIA patients with uveitis (oJIA-U), 20 eyes of 20 oJIA patients without uveitis (isolated oJIA), and 26 healthy volunteers of similar ages and sexes were investigated. The superficial capillary plexus (SCP) and deep capillary plexus (DCP), ONH, foveal avascular zone (FAZ) parameters, the flow area of the outer retina, and choriocapillaris were evaluated. RESULTS: Compared with the control group, both the oJIA-U group and isolated oJIA group showed significantly decreased vessel density of parafovea (p = 0.031 and p = 0.047, respectively) in DCP. Choriocapillaris flow area at 1 mm radius was significantly lower in the oJIA-U group compared to the control group (p = 0.001). Choriocapillaris flow area at 2- and 3-mm radius were significantly lower in the oJIA-U group compared to the control group (p < 0.001, for both) and isolated oJIA-U group compared to the control group (p = 0.008 and p = 0.001, respectively). The VD and thickness parameters of SCP and ONH, FAZ, and outer retina flow area were similar between the groups. CONCLUSIONS: oJIA patients with and without uveitis revealed a decreased vessel density in the deep parafoveal region and choriocapillaris flow. Our findings suggest that retinal choroidal microvascular changes could be evident in oJIA-U patients without posterior segment involvement as well as oJIA patients without uveitis.

Cardiac evaluation of patients with juvenile dermatomyositis.

BACKGROUND: The present study aims to evaluate possible cardiac involvement in juvenile dermatomyositis (JDM) patients by conventional methods and cardiac magnetic resonance imaging (MRI) along with a systematic review of the literature on cardiac features in JDM. METHODS: The study group consisted of JDM patients who underwent cardiac MRI. We conducted a systematic review of the published literature involving JDM patients with cardiac involvement. RESULTS: In the present study, although baseline cardiologic evaluations including electrocardiography and echocardiography were within normal limits, we showed late gadolinium enhancement on cardiac MRI in 3 of 11 JDM patients. In the literature review, we identified 25 articles related to cardiac involvement in JDM. However, none of them, except one case report, included cardiac MRI of JDM patients. CONCLUSION: Cardiac abnormalities have been reported among the less frequent findings in patients with JDM. Cardiovascular complications during the long-term disease course are a leading cause of morbidity and mortality in these patients. Early detection of cardiac involvement by cardiac MRI in patients with JDM and aggressive treatment of them may improve the clinical course of these patients. IMPACT: The myocardium in patients with JDM may be involved by inflammation. Myocardial involvement may be evaluated by using contrast-enhanced cardiac MRI. This is the first study evaluating cardiac involvement by cardiac MRI in JDM patients. MRI may show early cardiac involvement in patients whose baseline cardiologic evaluations are within normal limits. Early detection of cardiac involvement by cardiac MRI may improve the long-term prognosis of patients with JDM.

Is tear proteome profile a predictor of developing uveitis in ANA-positive patients with oligoarticular juvenile idiopathic arthritis?

PURPOSE: Although less than one-third of anti-nuclear antibody (ANA) positive patients with oJIA develop uveitis, ANA positivity is still the most well-known marker for assessing the risk of uveitis in oligoarticular JIA (oJIA). Therefore, novel biomarkers are needed to better assess the risk of developing uveitis. For this purpose, we performed a comparative tear proteome analysis of uveitis patients to reveal the identity of differentially regulated proteins. DESIGN: Tear samples were collected using the Schirmer strips in 7 oJIA and 7 oJIA patients with uveitis (oJIA-U). All oJIA-U patients had developed bilateral anterior uveitis and were inactive and topical treatment-free. METHODS: The nHPLC LC-MS/MS system was used for protein identification and label-free proteome comparisons. The PANTHER and STRING analyses were carried out using UniProt accession numbers of the identified proteins. RESULTS: Patient characteristics, e.g., age, gender, disease duration, and treatments were similar. For protein identification, three different databases were searched. Twenty-two, 147, and 258 database searches, respectively. Of these, 15 were common to all three proteome databases. Of these 15 proteins, 10 proteins were upregulated, and 2 were downregulated, based on the twofold regulation criteria. The upregulated proteins were, namely, cystatin-S, secretoglobin family 1D member, opiorphin prepropeptide, mammaglobin-B, lysozyme C, mesothelin, immunoglobulin kappa constant, extracellular glycoprotein lacritin, beta-2-microglobulin, and immunoglobulin J chain. The downregulated proteins were dermcidin and prolactin-inducible protein. Among the differentially regulated proteins, cystatin-S was the most regulated protein with an 18-fold upregulation ratio in tear samples from uveitis patients. CONCLUSION: Here, the identities and regulation ratios of several proteins were revealed when tear samples from uveitis patients were compared to patients without uveitis. These proteins are putative biomarkers for assessing uveitis risk and require further attention.

Evaluation of endothelial dysfunction in hypertensive children and adolescents.

BACKGROUND: Atherosclerotic changes can be attributed to early endothelial damage in individuals with hypertension. We aimed to explore the relationship between endothelial dysfunction and hypertension in newly diagnosed children without end-organ damage, considering carotid intima-media thickness (CIMT), flow-mediated dilatation (FMD), and functional capillaroscopy parameters. We also analyzed the differences between dipper and non-dipper patients. METHODS: In this cross-sectional study, 20 patients diagnosed with essential hypertension with no target organ damage, and 20 age and sex-matched healthy volunteers were enrolled. The patient group comprised newly diagnosed individuals not receiving antihypertensive treatment. Hypertensive patients were divided into two groups (dipper and non-dipper patients). The measurements of CIMT, brachial FMD, and functional capillaroscopy were performed before starting treatment. RESULTS: Among the patients, 11 were boys, and 9 were girls, with a median age of 16.0 (2.13) years. Of 20 hypertensive patients, 10 were dipper and 10 were non-dipper. Significant differences were observed between the hypertensive patients and controls in terms of CIMT (p = 0.04), brachial artery FMD (p = 0.02), and functional capillary density (p < 0.001). Hypertensive patients exhibited increased CIMT, reduced brachial artery FMD, and lower capillary density. However, there were no differences between dippers and non-dippers regarding age, sex, height SDS, weight SDS, CIMT SDS, brachial artery FMD, and capillary density. CONCLUSIONS: Understanding the vascular consequences associated with essential hypertension emphasizes the importance of early detection and management of hypertension. Herein, we have effectively highlighted significant endothelial changes through the analysis of three parameters in newly diagnosed children without apparent target organ damage.