ABSTRACT
Declaration de liens d'interets: Les auteurs declarent ne pas avoir de liens d'interets. Copyright © 2022
ABSTRACT
Meprins are zinc metalloproteases that are membrane-bound and secreted from these membranes. Many of these enzymes are secreted from the cell membranes and some of them are attached to the cell membrane and act both extracellularly and intracellularly. They have a role in tissue differentiation and remodeling and the processing of physiologically active peptides and cytokines in adult tissues. The Meprin α enzyme was isolated and purified from the blood serum of COVID-19 patients using a variety of biotechniques, such as sedimentation with 65 percent ammonium sulphate, dialysis, and ion exchange chromatography, where one highly active main peak is separated by the DEAE-cellulose ion exchange method. The number of purifications was 16 times. Then, using Sephadex G-150 for gel filtration, it was found that there was one peak with strong activity for the Meprin α, which had gone through 30 purification cycles with a 55 percent recovery rate of the enzyme. Furthermore, the estimated molecular weight of Meprin α extracted and partially purified from blood serum (140560 Dalton) of one peak was determined using gel filtration chromatography (Sephadex G-150). The results show that the optimal conditions for the activity of the isolated and partially purified enzyme are a potassium phosphate buffer at a pH of (8), a reaction time of (15 minutes), and a temperature of (40°C) using a concentration of (0.48 mmol/L) of tetramethyl benzidine (TMB) substrate, The maximum velocity (Vmax) of Meprin α was 136.9 U/ml with an enzyme concentration of 150 ng/ml and Michaelis-Menten constant (Km) values of 0.133 mmol/L.
ABSTRACT
Background: The most common symptoms seen in COVID-19 patients are fever, fatigue, and dry cough, and dyspnea. Although there is comparatively few rising reports on the hematological sequelae. Hematological changes commonly described in patients with COVID-19, include reduced lymphocyte count and platelet count but normal white blood cell count. we present a case of pancytopenia and hypocellular marrow which is not a commonly known sequalae of COVID 19 infection. Aims: To describe a novel case of coronavirus disease 2019 (COVID- 19)-associated aplastic anemia in a patient known to have primary glomerulonephritis. Methods: we described a case report of hematological sequalae of a COVID 19 case including the clinical presentation, management, and response to therapy Results: A 25-year-old lady with a background of primary membranous glomerulonephritis with crescent formation required therapy with rituximab monoclonal anti CD20, presented with anemia, mucocutaneous bleeding. 25 days before her presentation she had subjective fever, cough, and dyspnea with radiological findings highly suspicious for COVID 19 and she tested positive for COVID-19 by PCR on nasopharyngeal swab. Isolation at home was recommended for her as she had mild-moderate COVID19 and her swab turned negative after 15 days of onset of the respiratory symptoms. she experienced pallor and muco-cutaneous bleeding in form of ecchymosis all over the body, wet purpura but the rest of her clinical examination was free, her CBC revealed hemoglobin: 6.9 g/dl;WBC: 2.67×103/mm3;platelets: 10×103/mm3. MCV 79 with reticulocytopenia, all immunological profiles as well as virology screening for HCV, HBV, HIV, CMV and EBV were negative. Bone marrow aspirate and biopsy revealed marked hypocellular marrow (cellularity 20%) with all bone marrow element were markedly depressed. Cyclosporine was prescribed for her as well as eltrombopag in the dose of 50 mg/day orally which titrated gradually according to platelet response to 100 mg/day PO with repeated irradiated packed RBCs and platelet transfusion during hospital stay. During her hospital stay her liver enzymes (AST & ALT) were elevated so doses of cyclosporine and eltrombopag were decreased till the normalization of her liver enzymes then reiterated again according to the hematological response. She is maintained on this protocol now for 2 months with minimal hematological response. she prepared now for HLA matching and hematopoietic stem cell transplantation. Summary/Conclusion: Further exploration of potential COVID-19- related hematological abnormalities is needed and requires extensive collaboration to collect large, organized data sets. The possibility of an immune-mediated process and its therapeutic implications also warrants greater study.
ABSTRACT
Background: Coronavirus disease 2019 (COVID-19) emerged as a small outbreak in Wuhan rapidly progressing into the deadliest pandemic since the Spanish flu of 1918. The disease was deemed trivial in children, until the reporting, few days ago, of an emerging pediatric multi-inflammatory syndrome mimicking Kawasaki disease (KD). Main body: This report reveals that coronaviridae were implicated in induction of several post-infectious vasculitides, namely, KD, AHEI, and HSP. This occurs in genetically susceptible individuals to vascular inflammation. Shared genetic susceptibilities between KD and CoV include genes encoding for CD 40, HLAB-15:03, and ACE. This leads to augmented inflammation with hypersecretion of cytokines especially IL-6. Conclusion(s): The revealed relationships between KD and CoV can help to predict the risk of KD in COVID-19 patients through screening levels of upregulated cytokines. It might also signify that classic treatment of KD with IVIG might need to be replaced with anti-cytokine therapy in COVID-19 patients. Copyright © 2020, The Author(s).