OF FVIII FUNCTIONAL ACTIVITIES WITH QUANTITATIVE

Factor VIII Aurora: A Naturally Occurring Gain of Function FVIII Variant with Enhanced FIXa Affinity.

Data demonstrate that the prothrombotic phenotype of FVIII-R571S is driven by increased FIXa affinity, which enhances FVIIIa-FIXa complex assembly and function, providing a unifying explanation for the observed gain-of-function phenotype.

Activated Platelets Protect Factor VIIIa from Degradation by Activated Protein C and from Subunit Dissociation.

Data indicate that platelets support greater activity of FVIII than PLV through stabilization against dissociation of the A2 domain and protection from degradation by APC.

The Preparation of Chromatographically Purified Anti-Smallpox Immunoglobulin from Equine Blood Serum

The aim of the work was to obtain chromatographically purified anti-smallpox immunoglobulin from equine blood serum and evaluate its properties. Materials and methods . The horse blood serum containing antibodies to the vaccine virus, L-IVP strain, was used. Сhromatographic purification of serum was carried out on Akta Avant preparative chromatograph (GE HealthCare, Sweden), molecular parameter control at the stages of immunoglobulin production was conducted on the LC-20ad HPLC system (Shimadzu, Japan). The biological properties of immunoglobulin were evaluated in rabbits, white mice, and guinea pigs. The level of specific virus neutralizing antibodies was determined in the neutralization reaction on the chorionallantoic membrane (CAМ) of 12-day chicken embryos. Results and discussion . The technology for obtaining chromatographically purified anti-smallpox immunoglobulin from equine blood serum has been developed. At the initial stage, the immune blood serum of horses was purified by filtration through glass fiber cassette-type filters from fibrin sediment, residual quantity of lipids and lipoproteins, and then the immunoglobulin fraction was precipitated with a saturated solution of ammonium sulfate. At the next stage, ammonium salts, low molecular weight fractions, residual quantity of albumins and euglobulins were removed using ion exchange chromatographic purification. At the final stage, dimers, polymers, and aggregates of immunoglobulins were eliminated using gel filtration. The experimental series of immunoglobulin prepared using the developed technology is characterized by a high degree of purification. The monomer content in the finished product is at least 99 %, and the specific activity by titer of specific neutralizing antibodies – at least 1:16000.

Characterization of the Migration Profile of 36 Therapeutic Monoclonal Antibodies in Serum Protein Electrophoresis and Immunofixation.

BACKGROUND Therapeutic monoclonal antibodies (t-mAbs) are widely used in oncology, hematology, and immune-mediated diseases. Some t-mAbs are detectable by serum protein electrophoresis (SPEP) and immunofixation (IF), potentially mimicking monoclonal gammopathies. Despite widespread use, migration profiles of many t-mAbs remain incompletely described. METHODS Thirty-six t-mAbs were tested using Sebia Capillarys 3 (SPEP) and Hydrasis (IF) systems. Normal human sera, free of electrophoretic abnormalities, were spiked with each t-mAb at its reported maximum therapeutic concentration (Cmax). Electropherogram data were processed with a Python-based workflow for axis alignment, standardized profile overlay, and visualization. T-mAbs not detected at Cmax were assessed at 500 mg/L to determine their electrophoretic migration profiles. RESULTS No interference was observed below 110 mg/L. All t-mAbs tested above this threshold were detectable by SPEP and IF. Migration patterns were newly characterized for several t-mAbs, including bispecific and drug-conjugated antibodies, and confirmed for previously described agents. Overlay analysis enabled refined attribution of migration zones within alpha and beta regions. T-mAbs detectability was summarized in a consolidated table. A stepwise decision algorithm was developed to guide interpretation of suspected t-mAb-related interference. CONCLUSION This study expands knowledge of t-mAb interference with SPEP and IF and provides standardized electrophoretic profiles for established and emerging therapies. The summary table and decision algorithm offer practical tools for clinical laboratories, facilitating interpretation of electrophoretic patterns, supporting differentiation between t-mAb and monoclonal gammopathies, and highlighting the need for continued characterization of novel t-mAbs entering routine practice.

Isolation and Partial Purification of Procollagen-Lysine 5-Dioxygenase from a Patient with Coronary Artery Disease

This pilot case study describes the isolation and partial purification of the Procollagen-lysine 5-dioxygenase (PLOD) enzyme from the blood serum of a single 42-year-old male patient diagnosed with coronary artery disease using different techniques, starting with precipitation with ammonium sulfate, dialysis and ion exchange technique. The results showed the presence of two peaks for protein solution; the first peak I showed the highest activity of the enzyme in (18.33 U/ml) band (A), with the specific activity (4.47 U/mg), and the highest activity for peak II was in (6.7 U/ml) band (B). A single band was obtained when applying electrophoresis to the enzyme purified by ion exchange that was used for estimating the molecular weight of the PLOD enzyme, which is approximately equal to (85) kilodaltons.

REDUCED 8-FXIIa-INHIBITION CAPACITY IN HEPARINIZED PLASMA