The detection of apoptosis in a human in vitro skin explant assay for graft versus host reactions

AIMS: Keratinocyte apoptosis is a major pathogenic mechanism in dermal complications, such as graft versus host disease (GVHD), after allogeneic bone marrow transplantation. However, the mechanisms by which recipient target cells undergo apoptosis in GVHD are still unclear, but may result from DNA damage caused by chemotherapeutic agents and/or by direct cytokine action. The basis of this investigation was to correlate keratinocyte apoptosis with (1) the severity of graft versus host reactions (GVHR) in vitro and (2) the clinical grade (0--III) of GVHD. METHODS: Skin sections generated from an in vitro skin explant model for detecting experimental or clinically relevant GVHR were investigated for the detection of apoptotic nuclei using the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) technique. This investigation also aimed to establish whether the TUNEL assay could be used as an additional, predictive method for the severity of GVHD before transplantation in potential patient/donor pairs given standard GVHD prophylaxis (cyclosporin A and methotrexate). RESULTS: By comparing mean values of apoptosis for each GVHR grade in a cohort of 83 retrospective skin sections it was shown that as the severity of GVHR increased there was a parallel increase in the percentage of apoptotic cells (p < 0.0001). However, the correlation between clinical GVHD grade II--III and overall keratinocyte apoptosis (> 2.6%) did not reach this degree of significance (chi(2): 4.2; degrees of freedom, 1; p = 0.04; Fisher's exact test: p = 0.06). CONCLUSIONS: The detection of apoptosis correlated with degree of GVHR using an in vitro assay and a higher degree of apoptosis tended to correlate with more severe GVHD. Further studies in a larger cohort of patients, using other methods to detect apoptosis in conjunction with the TUNEL assay, may give additional insight into the complex immunopathophysiology of GVHD.     

Haemophilia A and haemophilia B: molecular insights.

This review focuses on selected areas that should interest both the scientist and the clinician alike: polymorphisms within the factor VIII and factor IX genes, their linkage, and their ethnic variation; a general assessment of mutations within both genes and a detailed inspection of the molecular pathology of certain mutations to illustrate the diverse cause-effect relations that exist; a summary of current knowledge on molecular aspects of inhibitor production; and an introduction to the new areas of factor VIII and factor IX catabolism. An appendix defining various terms encountered in the molecular genetics of the haemophilias is included, together with an appendix providing accession numbers and locus identification links for accessing gene and sequence information in the international nucleic acid databases.     

Haemophilia A and haemophilia B: molecular insights.

This review focuses on selected areas that should interest both the scientist and the clinician alike: polymorphisms within the factor VIII and factor IX genes, their linkage, and their ethnic variation; a general assessment of mutations within both genes and a detailed inspection of the molecular pathology of certain mutations to illustrate the diverse cause-effect relations that exist; a summary of current knowledge on molecular aspects of inhibitor production; and an introduction to the new areas of factor VIII and factor IX catabolism. An appendix defining various terms encountered in the molecular genetics of the haemophilias is included, together with an appendix providing accession numbers and locus identification links for accessing gene and sequence information in the international nucleic acid databases.     

Hemophilia A and B — two years ex-perience of genetic counselling and prenatal diagnosis

Haemophilia A . Thirty-one pregnant women, obligate or probable carriers of haemophilia A, requested prenatal diagnosis if sex determination showed the foetus to be a male. In 11 of the 31 cases the foetuses were females; in two, the genetic variant of the disease rendered prenatal diagnosis impossible; and in two, the mother aborted spontaneously. From the remaining 16 male foetuses, blood samples were obtained in uteri in the 17th to 20th week of gestation. Examination of the samples showed that 11 of the foetuses were unaffected and five affected. Haemophilia B . Three carriers of haemophilia B had male foetuses. Examination of foetal blood obtained in utero showed that these three foetuses were affected. Confirmation . All women with an affected foetus requested termination of pregnancy. In one of thecdses of abortion, no blood was obtained for confirmative examination. In the remaining cases, the prenatal prediction was confirmed in the abortus or in the child after birth; three women are still pregnant.     

Origin of mutation in sporadic cases of severe haemophilia A in Sweden

Many newly diagnosed Swedish severe haemophilia A (HA) patients are sporadic cases. Some genotypically non‐carrier mothers have gone on to have two descendants with the same mutation, presumably because of mosaicism. Aims: To define the origin of mutation in sporadic cases of HA, reveal possible sex‐specific differences in mutagenesis and identify potential mosaics among non‐carrier mothers. Method: Sanger sequencing characterized the mutations and microsatellite haplotyping determined the origin of the X chromosome carrying the mutation in 3 generations of 45 families with sporadic severe HA. Droplet digital polymerase chain reaction (ddPCR) was used in five cases to reveal that mosaicism mutations are not found on conventional DNA sequencing. Results: In 23 out of 45 families, the mother carried the mutation and in 5 out of 28 families, the grandmother was also a carrier. The X chromosome was of grandpaternal origin in 17 out of 23 cases. One of five tested mothers was a mosaic with a mutation frequency of 7%. Conclusion: In 40 out of 45 families, the sporadic case resulted from a mutation in the last two generations. In 82% (23/28), the carrier mothers had a de novo mutation where the X chromosome was of paternal origin in 74% (17/23). ddPCR is a potentially powerful and promising analysis for mosaicism in HA.     

Histocompatibility antigens and alleles in Japanese haemophilia A patients with or without factor VIII antibodies

We carried out human leukocyte antigen (HLA)-A, B, Cw, DR and DQ serological typing and HLA-DQA1, DQB1, DRB1 and DPB1 genetic typing for 46 Japanese haemophilia A patients, including 20 who had developed an antibody to factor VIII. It appears that anti FVIII inhibitor formation is associated with the major histocompatibility complex in Japanese haemophilia A patients. Absence of HLA-A24 is a principal risk factor for inhibitor formation in Japanese haemophilia A patients. As supplemental risk factors, HLA-DR4.1, DQ4 and DQA1*0301=2 are positively associated with patients exhibiting inhibitor compared with normal subjects. This and previous studies show that the association between HLA antigens and the formation of inhibitor depends on race. Data of HLA typing may be useful for the recognition of groups at high risk for the possible formation of inhibitor among Japanese haemophilia A patients.     

Acquired haemophilia due to factor VIII inhibitors in ovarian hyperstimulation syndrome: case report

A 31-year-old nulligravida woman developed an acquired factor VIII inhibitor associated with severe ovarian hyperstimulation syndrome (OHSS). She developed haematouria, ecchymosis, and intramuscular bleeding following the severe OHSS. Laboratory examinations showed a markedly prolonged activated partial thromboplastin time and a low level of factor VIII activity. Treatment with prothrombin complex concentrate and factor VIII inhibitor bypassing agent was successful in reducing the inhibitor so that she delivered a healthy baby via spontaneous vaginal delivery. Acquired haemophilia is a life-threatening disorder. This is the first case report of acquired haemophilia in OHSS.     

Fanconi's anaemia associated with haemophilia A

Fanconi's anaemia and haemophilia A are both inherited diseases creating haemostatic defects. The association of these two rare diseases in one patient is described. The patient's haemophilia was studied with a newly developed immunological technique determining the plasma antigen associated with Factor VIII activity, and was found to be a genetic variant of moderately severe haemophilia A. It was not possible to demonstrate a common bone marrow defect or a common immunological or genetical background of the two diseases. The double haemostatic defect created, i.e. Factor VIII deficiency and thrombocytopenia, resulted in only a slight increase in bleeding tendency. A favourable result was obtained with corticosteroid and androgenic treatment.     

First trimester prenatal diagnosis of haemophilia a using factor VIII gene probe

Accurate first-trimester prenatal diagnosis was achieved in a Japanese haemophilia A family by the use of a restriction fragment length polymorphism (RFLP) located within the F.VIII gene. Since the pregnant woman's heterozygosity forBclI polymorphism in F.VIII/intron 18 (F8A) probe was informative, chorionic villus sampling (CVS) was performed at 9 weeks of gestation. Restriction analysis showed that the fetus was heterozygous for theBclI site and had received a normal paternal X chromosome (0.9 kb) and a normal maternal X (1.2 kb). Therefore, we concluded that the fetus was a non-carrier female. Pregnancy went to term and woman gave birth to an apparently healthy female. At one week after birth a coagulation study confirmed that the newborn infant is not a carrier. The first-trimester prenatal diagnosis of haemophilia A is possible by CVS due to a RFLP in the F.VIII gene.     

Haemophilia B caused by a missense mutation in the prepeptide sequence of factor IX

In the course of analysing mutation in the factor IX gene from 200 haemophilia B patients in Sweden and the UK, we have identified one patient with a prepeptide missense mutation He has severe, antigen negative haemophilia, and complete analysis of his coding sequence reveals a single base transversion (A → T) causing substitution of isoleucine by asparagine at position ?30. This change disrupts the hydrophobic core of the prepeptide, a feature which is required for secretion. Thus, haemophilia in this patient is caused by a failure to secrete factor IX from the hepatocytes. © 1993 Wiley-Liss, Inc.     

Prenatal diagnosis of haemophilia B by the use of polymerase chain reaction and direct sequencing

Summary A second prenatal diagnosis of severe haemophilia B was carried out in a family with no prior history of the disease. The first prenatal diagnosis was based on linkage analysis and showed the male fetus not to be affected because he had inherited the same X-chromosome as his healthy brother. Carrier status in the female at risk could not be assessed by restriction fragment length polymorphisms (RFLPs). She was found to have inherited the same marker constellation as her affected brother. However, due to the fact that a pedigree with no prior history of haemophilia B has been examined diagnosis was impossible. In addition factor IX coagulant and antigen values gave no definitive clue to a haemophilia B carriership. The problems with RFLP analysis in this pedigree were circumvented by polymerase chain reaction (PCR) based direct sequencing of the factor IX gene. A previously unknown mutation could be detected in patient haemophilia B (Kleve) and the carrier status in the female at risk could be confirmed. The second prenatal diagnosis showed that the male fetus had inherited the mutation and will therefore be afflicted with haemophilia B.Abbreviations bp basepairs - FIX:Ag factor IX antigen - FIX:C factor IX activity - kb kilobasepairs - PCR polymerase chain reaction - RFLP restriction fragment length polymorphism     

Efficacy,Safety, and Pharmacokinetics of Beroctocog Alfa in Patients Previously Treated for Hemophilia A

Purpose

Beroctocog alfa is a second generation recombinant factor VIII manufactured by removing the B-domain from factor VIII. This prospective clinical trial was conducted to evaluate the efficacy, safety, and pharmacokinetics of beroctocog alfa in patients of ages ≥12 years previously treated for severe hemophilia A.

Materials and Methods

Seventy subjects received beroctocog alfa as an on-demand treatment for acute hemorrhage.

Results

The final hemostatic effect was excellent in 35 subjects (50%) and good in 26 subjects (37.1%). The drug showed an overall efficacy rate of 87.1%. The majority of acute hemorrhages was treated by administering the study drug once (86.2%) or twice (10.0%), and the mean dose administered per single infusion was 28.55±6.53 IU/kg. Ten subjects underwent 12 surgical procedures, and hemostatic efficacy was excellent in seven cases (58.3%) and good in five cases (41.7%), showing a 100% efficacy rate. A total of 52 of 88 subjects (59.0%) experienced 168 adverse events. There were 18 serious adverse events (10.7%) in 11 subjects, and two (mild dyspnea and facial edema) in one subject were related to the study drug. Only one subject formed a de novo factor VIII inhibitor, for an occurrence rate of 1.4% (one-sided 95% upper confidence limit: 3.85%). The final elimination half-life was 13.3 h and 12.6 h at baseline and 6 months after administration, respectively.

Conclusion

Our results suggest that beroctocog alfa is safe and efficacious as either an on-demand treatment for acute hemorrhage or a surgical prophylaxis in patients with hemophilia A.     

Maternally transferred anti-factor VIII IgG reduce the anti-factor VIII humoral immune response in factor VIII-deficient mice

Replacement therapy with exogenous factor VIII (FVIII) to treat haemorrhages or used in prophylaxis induces inhibitory anti‐FVIII immunoglobulin G (IgG) in some patients with haemophilia A. Therapeutic strategies to prevent the onset of the deleterious anti‐FVIII immune response are still lacking. Maternal IgG is transferred to the offspring during fetal and neonatal life. While protecting the offspring from bacterial and viral infections, maternal IgG may alter the repertoires of T and B lymphocytes, and may impair vaccination in early infancy. Using haemophilic mice, we demonstrate that the transfer of maternal anti‐FVIII IgG modulates the onset of anti‐FVIII inhibitory IgG in early adulthood. The protective effect is reproduced upon reconstitution of naive mice with anti‐FVIII IgG, suggesting that the reduced ability to mount an anti‐FVIII immune response is the result of an interference between circulating anti‐FVIII IgG and the administered FVIII rather than to a profound remodelling of lymphocyte repertoires occurring during the ontogeny of the immune system.     

Determination of haemophilia A carrier status from hair samples using polymerase chain reaction technique

The usefulness of intragenic restriction fragment length polymorphisms (RFLPs) for Bc1I, HindIII and XbaI, adapted for polymerase chain reaction (PCR), was tested for the detection of haemophilia A carrier status in the consultand of a family in which only haematological information was available on the inheritance of the trait. Hair follicles were used as the non-invasive source of DNA. The mother was found to be homozygous for Bc1I and heterozygous for HindIII sites, whereas her status as regards informativeness could not be established for XbaI. On the basis of HindIII RFLP, the daughter was found to be a carrier of the haemophilia trait. This was confirmed by sequencing the amplified intron 19 of the mother and the daughter. The RFLP for XbaI did not appear to be suitable for carrier detection using PCR due to the difficulty of establishing homozygosity or heterozygosity from the results of digestion of the amplified product.     

Novel HLA B*2714 and B*2708 allele associations in seronegative spondarthritis patients and haemophilia patients with chronic synovitis in India

HLA B27 association with seronegative spondarthritis (SSA) has been recognized for over a decade and its association with chronic synovitis in Haemophilia patients has been recently reported. We characterized the HLA B27 subtypes in a cohort of 98 B27 positive individuals with SSA (n = 45), haemophilia with chronic synovitis (n = 21) and normal controls (n = 32), using polymerase chain reaction-based sequence specific primers (PCR-SSP) and reverse line strip (RLS) techniques. The results revealed a significant association for a novel allele B*2714 in SSA along with the previously reported B*2705 allele. We also found a significant association between haemophilia patients with chronic synovitis from India and a hitherto unidentified allele, B*2708.     

Carrier detection of haemophilia A using DNA markers in families with an isolated affected male

The carrier status of women in five families with an isolated haemophilia male was assessed by pedigree analysis, coagulation factor assays and DNA markers. In three families, ten women could be given very low risks of being carriers based on DNA analysis. In two of the families the DNA markers identified the mutation as originating in either the maternal or maternal grandfather's germ cell. Combined DNA and coagulation data suggested that the affected male in a third family was a de novo mutation. DNA analysis of the affected male in another family identified a large deletion of the F8 gene which was present in his mother and three sisters, suggesting that the grandmother was a carrier. A combination of coagulation factor data and DNA marker assessment can determine the carrier status of the majority of females in families with isolated affected haemophilia A males.     

Sanfilippo B syndrome: molecular defects in Greek patients

Sanfilippo syndrome type B [mucopolysaccharidosis IIIB (MPS IIIB] is the most prevalent type of MPS III in Greece, accounting for 81% of all MPS III cases diagnosed at the Institute of Child Health (Athens) over the last 20 years. The majority of the patients originated from East Central/Central Greece, Thessaly, and Macedonia. We present the results of mutation analysis in 21 Greek patients from 18 different families, all of whom had the severe form of the disorder. Patients were initially screened for five previously known mutations by restriction enzyme digestion of polymerase chain reaction products. Unknown mutations were identified by single-strand conformation polymorphism analysis and DNA sequencing and were confirmed by restriction enzyme analysis. Seven previously described mutations (Y140C, R626X, 503-512del, H414R, G292R, 334del25, and E452K) and four novel mutations (P516L, L242P, E446K, and R482Q) were identified. Expression of the latter and H414R showed that they were all null activity mutations. Considerable genetic heterogeneity has been described in MPS IIIB patients of different origins. In our population, Y140C, H414R, and R626X account for approximately 70% of the studied alleles. Our findings, especially in combination with the origin of individual patients, can improve carrier detection and genetic counseling in affected families.     

Indirect prenatal molecular diagnostic of haemophilia A and B

Haemophilia A (HA) and B (HB) are the most common inherited bleeding diseases. HA and HB are X-linked recessive disorders caused by mutation in the factor VIII gene which maps to Xq28 and factor IX located at Xq27, respectively; resulting in absence or deficiency of these proteins. Several mutations have been reported as responsible for the disturbance of these genes; therefore, the use of direct molecular techniques to analyze the carrier status of women and their affected fetuses in not easy to perform. Thus, gene linked polymorphisms analysis is the most convenient molecular test since it is independent from the nature of the mutation, allowing the identification of the mutant X chromosome by following its segregation along the pedigree. The main objective of this research was to perform the molecular diagnosis of HA or HB carrier status in pregnant women and male fetuses affected or not, who were referred to the Medical Genetic Unit of the University of Zulia (UGM-LUZ), Maracaibo, Venezuela. Molecular analysis for HA and HB was performed in 32 DNA samples from 8 pregnant women, 8 fetuses, 8 affected and 8 healthy males. Using the Polymerase Chain Reaction (PCR), a 142 bp (bases pairs) fragment, which corresponds to intron 18 of the Factor VIII gene, was amplified. This fragment has a restriction polymorphism for the enzyme Bcl I. Additionally, a Duplex PCR was performed for the STRs (short tandem repeat) of introns 13 and 22 of the same gene. On the other hand, Hinf I, Xmn I y Taq I polymorphism in the factor IX gene were also amplified, so, we were able to build the haplotypes for each one of the key members in the families affected. The latter, allowed us to identify, in five of the eight cases, the mutant X chromosome responsible of HA and HB, thus, prenatal diagnosis was possible with the following results: three healthy males fetuses, two affected males fetuses with HA and three females fetuses.