1/64. Acquired von Willebrand syndrome with inhibitors both to factor viii clotting activity and ristocetin-induced platelet aggregation.A case of acquired von Willebrand's syndrome (vWs) is described which appeared to be due to antibodies directed against factor viii clotting activity (FVIIIC), factor viii-related antigen (FVIIIRAg) and von willebrand factor. The antibodies directed against FVIIIRAg was demonstrated by the inhibitory effect of a platelet eluate on ristocetin-induced aggregation of normal platelets. This effect was not shown by the patient's platelet-poor plasma alone, nor could it be demonstrated in platelet eluates from 13 other patients who had antibodies to FVIIIC but in whom there was no evidence of an acquired vWs.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/64. An alloantibody recognizing the FVIII A1 domain in a patient with CRM reduced haemophilia A due to deletion of a large portion of the A1 domain dna sequence.We report the development of a FVIII inhibitor in a patient with severe, cross reacting material reduced (CRM(R)) haemophilia A. The level of factor viii antigen (FVIII:Ag) measured by ELISA using anti-C2 monoclonal and alloantibodies was 1.9 U/dl. This baseline FVIII:Ag level was increased to 8.3 U/dl after administration of DDAVP. The anti-FVIII inhibitor titer was 2.9 Bethesda U/ml. dna analysis showed a large deletion of the FVIII gene from exon 4 to 7, corresponding to amino acid residues 111-317 included within the A1 domain. The size of the gene deletion was approximately 28 kb. 5' and 3' breakpoints were identified by sequencing in intron 3 and intron 7, respectively. FVIII mRNA was detected in the patient's peripheral lymphocytes and the deletion spanning exon 4 to 7 was confirmed at the rna level. immunoprecipitation experiments using 125I labeled A1, A2 and light chain demonstrated that the inhibitor reacted only with the 54 kDa A1 domain. The inhibitor activity was more than 95% neutralized by A1 domain polypeptide. Our findings suggest a close relationship between the inhibitor epitope and the specific gene deletion with regard to the pathogenesis of the inhibitor in this patient.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/64. Combined factor viii and IX deficiency in a family.A family with combined deficiency of factor viii and factor ix is reported. family study showed that the father and his nephew had mild factor viii deficiency with normal von willebrand factor antigen and factor ix levels while his two sons had a reduced level of factor ix and normal factor viii levels. His wife was found to have marginally reduced factor ix levels, whereas his daughter had reduced or normal levels of both factors VIII and IX. dna analysis using the intra- and extragenic markers of factor viii and IX genes showed that mother is a carrier of haemophilia B and the daughter is a carrier for both haemophilia A and B. Thus, the combined deficiency observed was due to a chance association of two distinct genetic defects.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/64. factor viii levels during the course of acute hepatitis in a haemophiliac.A 51-year-old patient with haemophilia since childhood (usual factor viii level 14%) developed acute viral hepatitis type B two months after an operation which had been covered by cryoprecipitate. The course of the hepatitis following admission was severe with encephalopathy and ascites. Evidence of intravascular coagulation with an increased radioactive fibrinogen turnover was also present. The factor viii level measured by a one-stage clotting factor assay rose rapidly to 200% of normal and remained at this level for two weeks, and factor-VIII-related antigen as measured by electroimmunoassay also became greatly elevated (900% of normal). The possible mechanisms underlying those surprising changes are discussed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/64. First-time development of FVIII inhibitor in haemophilia patients during the postoperative period.Development of inhibitor to FVIII in haemophilia patients is well-known and is not uncommon. However, their development for the first time during the postoperative period has hardly been reported. In a developing country such as india, where resources are limited, development of such an eventuality may prove disastrous. However, as many of our patients are sparingly treated, therefore, even if they test negative for the inhibitor preoperatively, they may get the requisite FVIII antigenic stimulation during the preoperative and immediate postoperative period, leading to the development of inhibitors during this critical time of wound healing. We describe here six patients who developed such an inhibitor, from a group of 35 patients with haemophilia A who underwent various surgical procedures (19%). We stress that such an eventuality may not remain rare in developing countries as more patients of severe haemophilia undergo surgery and are therefore challenged for the first time in their life with large amounts of FVIII concentrate during their preoperative period.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/64. A novel splicing acceptor mutation of the factor viii gene producing skipping of exon 25.A gross deletion in the factor viii (FVIII) mRNA was determined by reverse transcriptase polymerase chain reaction (RT-PCR) for a patient with moderately severe hemophilia a. Sequencing of the RT-PCR product depicted a 177-bp deletion ranging from nucleotide (nt) 6724 to nt 6900 of FVIII cDNA, exactly corresponding to the whole exon 25. Further study of the genomic dna revealed the presence of a single base pair substitution (G >A) at position -1 of intron 24. The absolute consensus AG doublet of the intron 24 splicing acceptor changed to AA. In the novel splice site mutation, exon 24 was erroneously spliced to exon 26, skipping exon 25. The FVIII antigen level was normal despite the markedly reduced functional activity. Since exon 25 corresponds to part of the C2 domain, we speculate that for this patient the aberrant C2 domain markedly reduces binding affinity of FVIII protein to the phospholipid membrane, thus severely impairing the protein function.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/64. Combined deficiency of factor V and factor viii. A report of another case.A patient with combined factor V and factor viii deficiency is presented. The bleeding manifestations were: easy bruising, post-traumatic bleeding, bleeding after tooth extractions. The main laboratory feature was a prolonged partial thromboplastin time which was corrected by the addition of adsorbed normal plasma but not by the addition of normal serum, hemophilia a plasma of another patient with combined factor V and factor viii deficiency. The thromboplastin generation test was clearly abnormal and was corrected by the addition of adsorbed normal plasma but not by addition of normal serum. Prothrombin consumption was also defective. prothrombin time was slightly prolonged too, Thrombin time, platelet and vascular tests were within normal limits and there was no hyperfibrinolysis. factor viii was 8% of normal, whereas factor V was 14% of normal. factor viii associated antigen was normal. All other clotting factors were within normal limits. The parents of the propositus were consanguineous (first cousins) but had normal factor V and factor viii activity and normal factor viii antigen. The same was true for other family members. The hereditary transmission of the condition appears autosomal recessive.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
8/64. Modified orthodontic treatment goals in a patient with multiple complicating factors.This paper reviews orthodontic care in patients who are in nontraditional categories. Specific orthodontic management of a patient who had severe hemophilia, seropositivity for anti-HIV Ab, and hepatitis b surface antigen is reviewed. The importance of defining acceptable treatment goals in these patients is of paramount importance.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/64. herpes simplex virus type 1 and human immunodeficiency virus type 1 antigens in platelets from a hemophilia b patient with human immunodeficiency virus type 1-related thrombocytopenia.We analyzed platelet-associated antigens from a hemophilia b patient with human immunodeficiency virus type 1 (hiv-1)-related thrombocytopenia. Two bands appeared at 31,000 and 37,000 daltons in the platelet lysate after reaction with autologous serum in SDS-PAGE and Western blots. The band at 37,000 daltons was obtained using anti-herpes simplex type 1 (HSV-1) rabbit antiserum. Doublet bands at 36,000 and 37,000 daltons also appeared after reaction with HSV-1 seropositive human serum. The band at 31,000 daltons appeared after reaction with anti-hiv-1 rabbit serum. These results suggest that the platelet-associated antigens in this patient are components of both HSV-1 and hiv-1 antigens. In addition, acyclovir decreased his PAIgG level and increased his platelet count, and zidovudine increased his platelet count. Thus, we concluded that each of the platelet-associated antigens is partially responsible for the thrombocytopenia by causing deposition of immune complexes in this patient.- - - - - - - - - - ranking = 8keywords = antigen (Clic here for more details about this article) |
10/64. Serological response and detection of viraemia in acute hepatitis c virus infection.The serological response during acute hepatitis c virus (HCV) infection was examined by enzyme-linked immunosorbent assay (ELISA) in sequential serum samples from 13 haemophiliacs following their first exposure to factor viii concentrates contaminated with HCV. The commercially available C100-3 peptide and a new 22 kDa recombinant protein (p22) encoded by the nucleocapsid region of the viral genome were used for antibody detection, whilst a nested polymerase chain reaction (PCR) method was used for the detection of viraemia. In addition, eight sporadic cases of acute HCV infection were studied. The results in haemophiliacs demonstrated that seroconversion to the C100-3 antigen occurred in only one-third of the patients within 12 weeks of disease onset, but all of the patients had a diagnostic serological response to p22 during this phase of the disease. The new test was positive in all the sporadic cases at a time when the commercially available test was negative. Although PCR offers a sensitive method for the detection of recent HCV infection, the complex methodology makes it unsuitable for diagnostic laboratories. The new ELISA test with p22 may therefore have a useful diagnostic role in acute disease.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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