The hematopoietic stem cell number in the peripheral blood of pediatric recipients correlates with the outcome after living donor liver transplantation.

It has been proposed that circulating HSCs play a role in graft survival after liver transplantation. The aim was to analyze the relationship between the number of HSCs before and after LDLT and liver function, immune biomarkers, and clinical outcomes in pediatric patients. We studied 15 pairs of adult healthy liver donors and pediatric recipients with ESLD. The CD34/CD45+ cell number was measured in the blood via flow cytometry, and plasma levels of immune biomarkers - via ELISA. CD34/CD45+ cell number in the recipients decreased within the first week after LDLT. The cell number before LDLT was negatively correlated with the plasma levels of CRP and the development of graft dysfunction in the early post-transplant period. After LDLT, the CD34/CD45+ cell number was positively correlated with the pretransplant plasma level of sCD40L, a T-cell activation marker. In adult liver donors, the cell number did not change within the first week after liver resection and was lower than in pediatric recipients. The results suggest that in pediatric recipients, the HSC number may be associated with graft function and could be regarded as a potential predictor of the clinical outcome after LDLT.

High Incidence of Clonal CD8+ T-cell Proliferation in Non-malignant Conditions May Reduce the Significance of T-cell Clonality Assay for Differential Diagnosis in Oncohematology.

Polymerase chain reaction (PCR) analysis of rearranged T-cell receptor (TCR) genes is a valuable diagnostic tool for differential diagnosis of T-cell large granular lymphocytic (T-LGL) leukemia and reactive lymphocytosis. Age-related narrowing of T-cells repertoire and expansion of immune or autoimmune clones may lead to false-positive results. The objective of this study was to evaluate the specificity and positive predictive value of PCR-based clonality assessment for a differential diagnostics of T-LGL leukemia. Rearrangements of TCRG and TCRB genes using the BIOMED-2 protocol were assessed in healthy individuals including the elderly (n = 62) and patients with rheumatic diseases (n = 14), transitory reactive CD8+ lymphocytosis (n = 17), and T-LGL leukemia (n = 42). Monoclonal TCRG/TCRB rearrangements in blood were identified in 11.3%/4.8% (7/3 of 62) of healthy individuals; 21.4%/14.3% (3/2 of 14) of patients with rheumatic diseases, and 17.6%/11.8% (3/2 of 17) of patients with reactive lymphocytosis. Immunomagnetic selection of lymphocytes in healthy individuals (31 of 33) revealed that clonal T-cells belong to CD8+ and CD57+ population. No clonal Vß-Jß TCRB rearrangements were found in the control group, only Dß-Jß TCRB and TCRG. Given the high detectability (96.7%) of Vß-Jß TCRB monoclonal rearrangements in patients with αß-T-LGL leukemia, this marker had the greatest specificity and positive predictive value (100%; 99.2%). The presence of clonal CD8+CD57+ cells in blood is common for healthy individuals and patients with reactive conditions and may not associate with any malignancy. Different specificity of TCRG/ Dß-Jß TRB/ Vß-Jß TCRB PCR reactions should be taken into account for T-cell clonality data interpretation.

Terahertz metamaterials and systems based on rolled-up 3D elements: designs, technological approaches, and properties.

Electromagnetic metamaterials opened the way to extraordinary manipulation of radiation. Terahertz (THz) and optical metamaterials are usually fabricated by traditional planar-patterning approaches, while the majority of practical applications require metamaterials with 3D resonators. Making arrays of precise 3D micro- and nanoresonators is still a challenging problem. Here we present a versatile set of approaches to fabrication of metamaterials with 3D resonators rolled-up from strained films, demonstrate novel THz metamaterials/systems, and show giant polarization rotation by several chiral metamaterials/systems. The polarization spectra of chiral metamaterials on semiconductor substrates exhibit ultrasharp quasiperiodic peaks. Application of 3D printing allowed assembling more complex systems, including the bianisotropic system with optimal microhelices, which showed an extreme polarization azimuth rotation of 85° with drop by 150° at a frequency shift of 0.4%. We refer the quasiperiodic peaks in the polarization spectra of metamaterial systems to the interplay of different resonances, including peculiar chiral waveguide resonance. Formed metamaterials cannot be made by any other presently available technology. All steps of presented fabrication approaches are parallel, IC-compatible and allow mass fabrication with scaling of rolled-up resonators up to visible frequencies. We anticipate that the rolled-up meta-atoms will be ideal building blocks for future generations of commercial metamaterials, devices and systems on their basis.

An inter-laboratory comparison of PNH clone detection by high-sensitivity flow cytometry in a Russian cohort.

OBJECTIVES: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder characterized by partial or absolute deficiency of glycophosphatidyl-inositol (GPI) anchor-linked surface proteins on blood cells. A lack of precise diagnostic standards for flow cytometry has hampered useful comparisons of data between laboratories. We report data from the first study evaluating the reproducibility of high-sensitivity flow cytometry for PNH in Russia. METHODS: PNH clone sizes were determined at diagnosis in PNH patients at a central laboratory and compared with follow-up measurements in six laboratories across the country. Analyses in each laboratory were performed according to recommendations from the International Clinical Cytometry Society (ICCS) and the more recent 'practical guidelines'. Follow-up measurements were compared with each other and with the values determined at diagnosis. RESULTS: PNH clone size measurements were determined in seven diagnosed PNH patients (five females, two males: mean age 37 years); five had a history of aplastic anemia and three (one with and two without aplastic anemia) had severe hemolytic PNH and elevated plasma lactate dehydrogenase. PNH clone sizes at diagnosis were low in patients with less severe clinical symptoms (0.41-9.7% of granulocytes) and high in patients with severe symptoms (58-99%). There were only minimal differences in the follow-up clone size measurement for each patient between the six laboratories, particularly in those with high values at diagnosis. CONCLUSIONS: The ICCS-recommended high-sensitivity flow cytometry protocol was effective for detecting major and minor PNH clones in Russian PNH patients, and showed high reproducibility between laboratories.