Diagnostic characteristics of serological tests for the detection of SARS-CoV-2 cases.

To study the diagnostic characteristics of test systems for detecting antibodies to SARS-Cov-2. We studied the diagnostic characteristics of two test systems for detecting antibodies to SARS-Cov-2, registered in the Russian Federation. The first test system is a kit for detecting total antibodies to SARS-Cov-2 using immunochemiluminescence analysis on the «Cobas e 411¼ analyzer («Roche Diagnostics¼, Germany). The second test system is a kit for detecting IgM and IgG to SARS-Cov-2 («Core Technology Co., Ltd¼, China) by immunochromatographic analysis. The biological material for the study was blood serum. We assessed: diagnostic sensitivity, diagnostic specificity, and predictive value of positive and negative results. In the test system for detecting total antibodies to SARS-CoV-2, using an IHLA, the diagnostic sensitivity and specificity were 100%; the predictive value of positive and negative results was 100%. In the test system for the detection of IgM and IgG to Sars-CoV-2, using IHA, diagnostic sensitivity for IgM and IgG were 100%; diagnostic specificity for IgM - 60%, for IgG - 72%; predictive value of a positive result for IgM - 60%, IgG - 68,18%; predictive value of negative results for IgM and IgG - 100%. The best diagnostic characteristics were found in the test system for the detection of total antibodies to SARS-Cov-2, which must be taken into account when deciding whether to purchase test systems for the detection of antibodies to SARS-Cov-2.

[Down's syndrome with congenital acute leukemia and congenital heart disease]. / Sluchai sindroma Dauna s vrozhdennym ostrym leikozom i vrozhdennym porokom serdtsa.

OBJECTIVE: To report a rare case of Down's syndrome with congenital acute leukemia and congenital heart disease. MATERIAL AND METHODS: We have retrospectively analyzed an electronic database of patients aged 0-17 years who underwent inpatient treatment of congenital heart disease at the Federal Center for Cardiovascular Surgery for the period from January 1, 2010 to December 31, 2018. Incidence of Down's syndrome in children with congenital heart defects was 5.36% of the total number of children with congenital heart defects. No gender differences were identified. The most common congenital heart defects were ventricular septal defect, atrioventricular septal defect, atrial septal defect, patent ductus arteriosus, tetralogy of Fallot. Down's syndrome and congenital heart disease were diagnosed prenatally in 33 out of 319 patients. A rare case of Down's syndrome combined with congenital heart disease and acute leukemia is described. Treatment outcome was unfavorable. CONCLUSION. S: Evere concomitant diseases in a child with Down's syndrome determine high postoperative morbidity and mortality. Prenatal diagnosis of Down's syndrome via screening of pregnant women for ultrasound and biochemical markers of this pathology is required.

[Improving the quality of hematological studies using sigmametry.]

The purpose - evaluated the quality of the implementation of hematology studies using sigmametry. Studies were perfomed at the Federal state budgetary establishment "Federal center cardiovascular surgery". The data were collected in the period for 2017 y. The following hematology parameters were monitored daily: white cells, red blood cell, platelet, hemoglobin. For conducting laboratory quality control we used certified three-level (Level 1 (low) , Level 2 (normal)and Level 3 (High)) control material "CBC-XE Hematology control" ("R and D Systems", USA). The study of blood hematology parameters was carried out on an automatic hematology analyzer "Sysmex XT- 2000i" and "Sysmex XT- 1800i" ("Sysmex Corporation", Japan). Sigmametry values were calculated the CV (coefficient of variation), the systematic error (Bias) and the total allowable analytical error (TE max). On the analyzer «Sysmex XT- 2000i¼ sigma values for platelet were between 3 and 4. For white blood cells, red blood cells, hemoglobin the value of the sigma was greater than 4. On the analyzer «Sysmex XT- 1800i¼ for platelet, white blood cells, red blood cells, hemoglobin the value of the sigma was greater than 4. Based on the results obtained, we drew conclusions on the choice of control material and the frequency of the internal laboratory quality control. The introduction of sigmametry in the daily activities of clinic laboratory will improve the quality of the determination of platelet, which requires further observation.

[The reference intervals of antithrombin III in population of the Astrakhanskaia oblast at application of automated coagulometers.]

The foreign and national professional societies of laboratory diagnostic recommend to every laboratory to develop own or substantiate available in literature reference intervals for every laboratory index. The reference interval of antithrombin III was established for adult population of the Astrakhanskaia oblast according available standards on automated coagulometers "ACL 9000" (Instrumentation Laboratory, USA) and "STA Compact" (Diagnostica Stago, France). The received data were compared with data present in instructions to reactive kits for detection of antithrombin III and reference literature. The reference interval AT III in adult population of the Astrakhanskaia oblast has no dependencies on gender and age and can be compared with reference intervals mentioned in instructions to reactive kits for detection of activity of AT III of firms producers Instrumentation Laboratory (USA) and Diagnostica Stago (France) in the reference literature. The reference intervals AT III mentioned in instructions to reactive kits produced by Instrumentation Laboratory (USA) and Diagnostica Stago (France) and in reference literature can be applied for interpretation of results of detection of activity of AT III by automated coagulometers "ACL 9000" (Instrumentation Laboratory, USA) and "STA Compact" (Diagnostica Stago, France) in adult population of the Astrakhanskaia oblast.