Double negative alpha beta T cells in pediatric hemophagocytic syndromes

Introduction: Autoimmune lymphoproliferative syndrome (ALPS) and hemophagocytic lymphohistiocytosis (HLH) share clinical and laboratory features including lymphadenopathy, splenomegaly, and pancytopenia. We sought to measure αβ double negative T cells (αβ DNT) in a group of patients with established diagnosis of HLH in relation to disease activity and severity.Methods: We conducted a follow-up, controlled study that comprised 25 patients with HLH and 25 healthy matched controls. Patients were subjected to clinical evaluation and flowcytometric measurement of αβ DNT Cells at presentation and 9 weeks after start of HLH induction treatment.Results: In 17 (68%) patients, infection was the trigger of HLH while the cause was malignancy in three (12%), and rheumatological disorders in two patients (8%). At enrollment, 15 patients (60%) had αβ DNT cells levels [median (IQR): 1.71 (1.25-2.12)] that were significantly higher than the control values [median (IQR): 0.7 (0.4-0.8)] (p<0.001). The αβ DNT counts of patients were also higher at enrollment as compared to values at the end of week 9 [median (IQR): 0.76 (0.45-1.17)]; p=0.018. Survivors (n=8) and non-survivors (n=17) had comparable levels of αβ DNT cells at enrollment (p=0.861). αβ DNT cell count correlated positively with ALT (p=0.019) and negatively with CD4/CD8 ratios (p=0.023).Conclusion: Elevated αβ DNT cell counts might be related to the HLH process and this implies that mild elevation can exist in HLH and are not specific to ALPS. Wider scale studies with longer periods of follow up are needed to validate the results and properly outline the correlation between both medical conditions.Keywords: Hemophagocytic lymphohistiocytosis, Double negative T cells, mortality, ALP

Circulating dendritic cells in pediatric patients with nephrotic syndrome

Background: Dendritic cells (DCs) represent one of the most extensively studied topics in immunology, because of their central role in the induction and regulation of adaptive immunity, and because of their therapeutic potential for manipulating immune responses. Objectives: To evaluate circulating DC levels in pediatric patients with idiopathic nephrotic syndrome (NS) and its relation to disease activity in these patients. Methods: Fifteen nephrotic patients in relapse (proteinuria>40mg/m2/hour, hypoalbuminemia, and edema) before initiating steroid therapy (Group I), and another15 nephrotic patients in remission after withdrawal of steroid therapy (Group II) were compared to 15 age- and sex- matched healthy children. Besides clinical evaluation and routine laboratory investigations of nephrotic syndrome, circulating DCs were measured by flowcytometry. Results: Circulating DC count was lower in nephrotic patients in both proteinuria and remission groups [(48.89±13.52) and (64.64±7.69) X106/liter respectively] than in the control group (78.54±9.8) X106/liter with highly significant statistical difference (p < 0.001), and lower in proteinuria group than the remission group with highly significant statistical difference (p < 0.001). There was a positive correlation between DC count and serum albumin (moderate association) (p=0.002) and a negative correlation between DC count and urine protein /creatinine ratio (strong association) (p=0.001). Conclusion: Nephrotic syndrome was associated with decreased number of circulating DCs and the decrease was more apparent in patients with active disease. The positive correlation between DC counts and total protein, and serum albumin, and the negative correlation between DC count and urine protein/creatinine ratio point to the link between the decrease in DC count and the severity of the disease process.Keywords: Denderitic cells, nephrotic syndrome, immune deficiencyEgypt J Pediatr Allergy Immunol 2011;9(1):41-4

A Rare Association Between Leukocyte Adhesion Deficiency Type I and Psoriasis in Humans

The β2 integrins are expressed exclusively on leukocytes and participate in many immune and inflammatory processes. This subfamily comprises four heterodimeric glycoproteins with a common β-subunit, designated β2 (CD18). Spontaneous mutations of the CD18 gene result in leukocyte adhesion deficiency type I (LAD-I). Low level of CD18 expression has also been implicated in the pathogenesis of psoriasis. We here describe a child with recurrent skin infections without pus formation, persistent gingivitis and periodontitis. His blood counts showed persistent leukocytosis (neutrophilia). CD11b expression was defective on neutrophils, while that of CD18 was normal. So, our patient represents a mild variant of LAD-I with possible dysfunctional CD18. Moreover, he developed psoriasis with reduced CD18 expression on CD4+ T-cells. Psoriasiform dermatitis has been described before in association with LAD-I, however, clinically and histologically confirmed psoriasis in association with LAD-I has been described only in CD18 hypomorphic mice. Therefore, our patient represents the first clinically and histopathologically documented association between LAD-I and psoriasis in humans. It lends support to the role of β2 integrins in the etiopathogenesis of psoriasis

A Novel Polyester Varnish Nanocomposites for Electrical Machines with Improved Thermal and Dielectric Properties Using Functionalized TiO2 Nanoparticles

Funding Information: This paper is based upon work supported by the Science, Technology, and Innovation Funding Authority (STIFA), Egypt, under a grant (31292). Publisher Copyright: © 2023 by the authors.Recently, there has been a growing interest in polymer insulating materials that incorporate nanoscale inorganic additives, as they have shown significantly improved dielectric, thermal, and mechanical properties, making them highly suitable for application in high-voltage insulating materials for electrical machines. This study aims to improve the dielectric and thermal properties of a commercial polyester varnish by incorporating different concentrations of titanium dioxide nanoparticles (TiO2) with proper surface functionalization. Permafil 9637 dipping varnish is the varnish used for this investigation, and vinyl silane is the coupling agent used in the surface functionalization of TiO2 nanoparticles. First, nanoparticles are characterized through Fourier transform infrared spectroscopy to validate the success of their surface functionalization. Then, varnish nanocomposites are characterized through field emission scanning electron microscopy to validate the dispersion and morphology of nanoparticles within the varnish matrix. Following characterization, varnish nanocomposites are evaluated for thermal and dielectric properties. Regarding thermal properties, the thermal conductivity of the prepared nanocomposites is assessed. Regarding dielectric properties, both permittivity and dielectric losses are evaluated over a wide frequency range, starting from 20 Hz up to 2 MHz. Moreover, the AC breakdown voltage is measured for varnish nanocomposites, and the obtained data are incorporated into a finite element method to obtain the dielectric breakdown strength. Finally, the physical mechanisms behind the obtained results are discussed, considering the role of nanoparticle loading and surface functionalization.Peer reviewe