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001-es BibID:	BIBFORM054216
Első szerző:	Ajzner Éva (laboratóriumi szakorvos)
Cím:	Anti-factor V auto-antibody in the plasma and platelets of a patient with repeated gastrointestinal bleeding / É. Ajzner, I. Balogh, G. Haramura, Z. Boda, K. Kalmár, G. Pfliegler, B. Dahlbäck, L. Muszbek
Dátum:	2003
ISSN:	1538-7933
Megjegyzések:	Development of autoantibody against coagulation factor V (FV) is a rare clinical condition with hemorrhagic complications of varying severity. The aim of this study was to establish the pathomechanism of an acquired FV deficiency and characterize the FV inhibitor responsible for the clinical symptoms. A 78-year-old female was admitted to hospital with severe gastrointestinal bleeding. General clotting tests and determination of clotting factors were performed by standard methods. FV antigen and FV containing immune complexes were measured by ELISA. The FV molecule was investigated by Western blotting and by sequencing the f5 gene. The binding of patient's IgG to FV and activated FV (FVa) was demonstrated in an ELISA system and its effect on the procoagulant activity of FVa was tested in clotting tests and in a chromogenic prothrombinase assay. Localization of the epitope for the antibody was performed by blocking ELISA. FV activity was severely suppressed both in plasma and platelets. FV antigen levels were normal by ELISA using polyclonal anti-FV antibody or monoclonal antibody against the connecting region of FV, but depressed when HV1 monoclonal antibody against the C2 domain in the FV light-chain was used as capture antibody. The FV molecule was found intact. An IgG reacting with both FV and FVa was present in the patient's plasma and its binding to FV was inhibited by HV1 antibody. FV-containing immune complexes were detected in the patient's plasma and platelet lysate. The patient's IgG inhibited the procoagulant function of FVa. An anti-FV IgG was present in the patient's plasma and platelets. The autoantibody reacted with an epitope in the C2 domain of FV light chain and neutralized the procoagulant function of FVa.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of thrombosis and haemostasis. - 1 : 5 (2003), p. 943-949. -
További szerzők:	Balogh István (1972-) (molekuláris biológus, genetikus) Haramura Gizella (1957-) (vezető analitikus) Boda Zoltán (1947-) (belgyógyász, haematologus, klinikai onkológus) Kalmár Kálmán Pfliegler György (1949-) (belgyógyász, hematológus, labor szakorvos) Dahlbäck, Björn Muszbek László (1942-) (haematológus, kutató orvos)
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM043326
035-os BibID:	PMID:16867987
Első szerző:	Preston, Roger J. S.
Cím:	Multifunctional specificity of the protein C/activated protein C Gla domain / Roger J. S. Preston, Eva Ajzner, Cristina Razzari, Stalo Karageorgi, Sonia Dua, Björn Dahlbäck, David A. Lane
Dátum:	2006
ISSN:	0021-9258 1083-351X
Megjegyzések:	Activated protein C (APC) has potent anticoagulant and anti-inflammatory properties that are mediated in part by its interactions with its cofactor protein S and the endothelial cell protein C receptor (EPCR). The protein C/APC Gla domain is implicated in both interactions. We sought to identify how the protein C Gla domain enables specific protein-protein interactions in addition to its conserved role in phospholipid binding. The human prothrombin Gla domain, which cannot bind EPCR or support protein S cofactor activity, has 22/45 residues that are not shared with the human protein C Gla domain. We hypothesized that the unique protein C/APC Gla domain residues were responsible for mediating the specific interactions. To assess this, we generated 13 recombinant protein C/APC variants incorporating the prothrombin residue substitutions. Despite anticoagulant activity similar to wild-type APC in the absence of protein S, APC variants APC(PT33-39) (N33S/V34S/D35T/D36A/L38D/A39V) and APC(PT36/38/39) (D36A/L38D/A39V) were not stimulated by protein S, whereas APC(PT35/36) (D35T/D36A) exhibited reduced protein S sensitivity. Moreover, PC(PT8/10) (L8V/H10K) displayed negligible EPCR affinity, despite normal binding to anionic phospholipid vesicles and factor Va proteolysis in the presence and absence of protein S. A single residue variant, PC(PT8), also failed to bind EPCR. Factor VIIa, which also possesses Leu-8, bound soluble EPCR with similar affinity to wild-type protein C, collectively confirming Leu-8 as the critical residue for EPCR recognition. These results reveal the specific Gla domain residues responsible for mediating protein C/APC molecular recognition with both its cofactor and receptor and further illustrate the multifunctional potential of Gla domains.
Tárgyszavak:	Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Journal of Biological Chemistry. - 281 : 39 (2006), p. 28850-28857. -
További szerzők:	Ajzner Éva (1968-) (laboratóriumi szakorvos) Razzari, Cristina Karageorgi, Stalo Dua, Sonia Dahlbäck, Björn Lane, David A.
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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