Association of inherited thrombophilia mutations and their combinations among palestinian women with unexplained recurrent miscarriage

BACKGROUND

Inherited thrombophilia (IT) has a complex pathophysiology and is associated with recurrent miscarriage (RM) by causing placental insufficiency and inhibiting fetal development. However, thrombophilia screening in unexplained RM cases is still questionable. This study aimed to investigate the association between the common eight IT mutations and their combinations among Palestinian women with unexplained RM.

METHODS

This is an unmatched case-control study with 200 women (100 unexplained RM cases, 100 controls). Eight common IT mutations namely Factor V Leiden (FVL), prothrombin gene (FII) G202120A, Methylenetetrahydrofolate Reductase (MTHFR) gene (C677T and A1298C), B-fibrinogen gene - 455G > A, FV HR2 A4070G, Plasminogen activator inhibitor 1 (PAI1) 5G/4G and Factor XIIIA (FXIIIA) V34L; were analyzed. The first five mutations were analyzed by Restriction Fragment Length Polymorphism PCR and the other three mutations were analyzed using Amplification Refractory Mutation System PCR.

RESULTS

The prevalence of the eight IT mutations among the control group was in the order PAI1 5G/4G (69%), MTHFR C677T (53%) and A1298C (47%), BFG - 455G > A (35%), FVL and FV HR2 (each 18%), FXIIIA V34L (16%) and FII G20210A (3%). Patients had a higher percentage of MTHFR A1298C (heterozygotes and mutant homozygote) compared to controls (p = 0.016). Frequencies of mutant alleles MTHFR A1298C (p < 0.001) and FXIIIA V34L (p = 0.009) were higher among patients compared to controls. No significant differences were observed for all other mutations or mutant alleles. Most patients (75%) and controls (75%) have 2-4 mutant alleles out of 8 mutant alleles studied, while 1% of patients and 2% of controls have zero mutant alleles. None of the combinations of the most often studied mutations (FVL, FII G20210A, MTHFR C1677T, and MTHFR A1298C) showed a significant difference between patients and controls.

CONCLUSIONS

There was a significant association between unexplained RM and the mutant alleles of MTHFR A1298C and FXIIIA V34L. No significant association was observed between unexplained RM and the combination of both mutant alleles for the mutations studied. This study is the first Palestinian report that evaluates eight inherited thrombophilia mutations and their alleles' combinations in unexplained RM cases.

Evaluation of platelet parameters, coagulation markers, antiphospholipid syndrome, and thyroid function in palestinian women with recurrent pregnancy loss

BACKGROUND

Multiple etiologies contribute to recurrent pregnancy loss (RPL) including immunological, endocrine, anatomical, genetic and infection but more than 50% of cases remain unexplained. Evidences of thrombotic and inflammatory processes were observed at maternal-fetal interface and considered pathological findings in most RPL cases including unexplained cases. This study aimed to evaluate the association between RPL and several risk factors: platelet parameters, coagulation factors, antiphospholipid syndrome, and thyroid function.

METHODS

This is an unmatched case-control study that included 100 RPL and 100 control women. Anthropometric and health data were collected and a gynecologist examined participants to assure fitting the inclusion criteria. Platelet parameters [including Mean Platelet Mass (MPM), Concentration (MPC) and Volume (MPV)] and ratios (MPV/Platelet, MPC/Platelet, MPM/Platelet, Platelet/Mononuclear cells), coagulation markers [Protein C (PC), Protein S (PS), Antithrombin III, D-dimer], antiphospholipid antibodies [Anti-phospholipid (APA), Anti-cardiolipin (ACA) and anti-B2-glycoprotein 1], Lupus anticoagulant, Antinuclear antibodies, and thyroid function (Thyroid stimulating hormone and anti-thyroid peroxidase) were measured.

RESULTS

Mean ages of cases and controls at marriage were 22.5 years for both, and their current ages were 29.4 and 33.0, respectively. 92% of cases and 99% of controls aged blow 30 years at marriage. 75% of cases have 3-4 miscarriages and 9% have ≥ 7 miscarriages. Our results indicated significantly lower male/female age ratio (p = .019), PC (p = .036) and PS (p = .025) in cases compared to controls. Plasma D-dimer (p = .020) and antiphospholipid antibodies [ACA (IgM and IgG), APA (IgM)] were significantly higher in cases compared to controls. No significant differences were observed between cases and controls concerning APA (IgG), anti-B2-glycoprotein 1 (IgM and IgG), Lupus anticoagulant, Antinuclear antibodies, platelet parameters, thyroid markers, family history of miscarriage, consanguineous marriage, and other health data.

CONCLUSIONS

This is the first study that investigated the association between platelet, coagulation, antiphospholipid, autoimmune and thyroid parameters, and RPL in Palestinian women. Significant associations between male/female age ratio, PC, PS, D-dimer, ACA (IgM, IgG), APA (IgM) and RPL were observed. These markers could be used in evaluating RPL. These findings confirm the heterogeneous nature of RPL and emphasize the need for further studies to find out risk factors for RPL.

An unusual report of anti-N antibody presenting as ABO discrepancy in an old female patient in Palestine

The MNS is a highly complex immune blood group system which is almost equal to Rh in size and complexity. Anti-N antibody is naturally occurring in general, cold reactive IgM or IgG saline agglutinin and relatively rare when compared with anti-M. The immune type anti-N is seldom encountered. Anti-N antibody is not clinically significant unless it reacts at 37°C. Clinically significant anti-N antibody is reactive at 37°C or in the anti-human globulin phase, which may cause delayed hemolytic transfusion reactions or hemolytic disease of newborn. Here, we report a rare case presented as blood group discrepancy of a naturally occurring anti-N that reacts at 37°C.

Expression of the GBGT1 Gene and the Forssman Antigen in Red Blood Cells in a Palestinian Population

Background

The Forssman antigen (FORS1 Ag) is expressed on human red blood cells (RBCs). We investigated its presence on RBCs from Palestinian subjects and Swedish subjects by serological testing and by sequencing part of exon 7 of the GBGT1 gene, which encodes Forssman synthase.

Materials and Methods

Blood samples from Palestinian subjects (n = 211 adults and n = 73 newborns) and from Swedish subjects (n = 47 adults) were analyzed in the study. RBCs from the Palestinian samples were typed for the FORS1 Ag using a monoclonal anti-Forssman antibody. The GBGT1 gene was genotyped by DNA sequencing (all adult samples) or by using amplification refractory mutation system PCR (newborn samples).

Results

All of the studied samples were negative for the FORS1 Ag by serologic typing. DNA sequencing of the 3' end of exon 7 of the GBGT1 gene, which includes Arg296, showed that all samples had the wild-type Arg296 sequence, which is associated with an inactive form of Forssman synthase. We detected four single nucleotide polymorphisms in the adult samples; two were silent (p.Tyr232=, p. Gly290=), and two were missense (p. Arg243Cys, p. Arg243His). The allele frequencies ranged from 0.2 to 3.6%. The p. Arg243Cys SNP was a novel SNP that was detected in one Palestinian sample.

Conclusion

Our results confirmed the allelic diversity of GBGT1 and identified a novel nucleotide polymorphism in this gene, p. Arg243Cys. Our results also confirmed that the FORS blood group system is a low-frequency system.

Molecular characterization of β-thalassemia intermedia in the West Bank, Palestine

BACKGROUND

We aimed to investigate the molecular basis of β-Thalassemia intermedia (TI) in the West Bank region and its management practices.

METHODS

This was a case series multi-center study and included 51 cases of TI. DNA sequencing was used to analyze β-globin gene mutations. Common α-globin gene mutations were screened by Gap-PCR (-α3.7, -α4.2, --MED, αααanti3.7) or DNA sequencing (α2-IVS II 5 nt del). XmnI -158 C > T polymorphisms of Gγ-globin gene was determined by RFLP-PCR.

RESULTS

Seven β-globin gene mutations were observed, namely IVS-I -6 C > T, IVS-I-110 G > A, IVS-II-1 G > A, IVS-I-1 G > A, Codon 37 Trp > Stop, beta - 101 and IVS-II-848 C > A. Ten genotypes were observed. Homozygosity for IVS-I-6 accounted for the majority of TI cases with a frequency of 74.5%. The second common β-globin gene genotype was homozygote IVS-I-110 G > A (5.8%) and homozygote IVS-II-1 G > A (5.8%). The remaining seven genotypes were each detected in about 2% of patients. α-Thalassemia mutations were seen in five patients (9.8%), and included (-α3.7, αααanti3.7 and α2-IVSII-5 nt del). XmnI polymorphism was observed in four patients (7.8%), three homozygotes and one heterozygote.

CONCLUSIONS

Homozygosity for the mild β-globin gene IVS-I-6 allele was the major contributing factor for the TI phenotype among the study subjects. The role of XmnI SNP and α-thalassemia mutations in ameliorating the TI phenotype was observed in few patients for each factor. The beta - 101 C > T mutation was diagnosed in one patient in homozygote state for the first time in Palestine.

Factor V Leiden G1691A and prothrombin G20210A mutations among Palestinian patients with sickle cell disease

Background

Vascular thrombosis is an important pathophysiological aspect of sickle cell disease (SCD). This study aimed to investigate the prevalence and clinical impact of factor V Leiden G1691A (FVL) and prothrombin G20210A mutations among Palestinian sickle cell disease (SCD) patients.

Methods

A total of 117 SCD patients, including 59 patients with sickle cell anemia (SS), 33 patients with sickle β-thalassemia and 25 individuals with sickle cell trait (AS) were studied. The control group consisted of 118 healthy individuals. FVL and prothrombin G20210A mutations were determined by RFLP PCR.

Results

Analysis of the clinical history of SCD patients revealed that seven patients have had vascular complications such as ischemic stroke or deep vein thrombosis. In SCD patients, the inheritance of the FVL mutation showed a significantly higher incidence of pain in joints, chest and abdomen as well as regular dependence on blood transfusion compared to SCD with the wild type. Age- and sex-adjusted logistic regression analysis revealed a significant association between FVL and sickle cell anemia with an odds ratio (OR) of 5.6 (95% confidence intervals [CI] of 1.91–39.4, P = 0.039) in SS patients. However, increased prevalence of the FVL in AS subjects and sickle β-thalassemia patients was not statistically significant compared to controls (OR 3.97, 95% CI 0.51–28.6, P = 0.17 and OR 3.59, 95% CI 0.35–41.6, P = 0.26, respectively). The distribution of prothrombin G20210A mutation among SCD patients compared to controls was not significantly different, thus our findings do not support an association of this mutation with SCD.

Conclusions

FVL was more prevalent among SS patients compared to controls and it was associated with higher incidence of disease complications among SCD patients.

Modified expression of coagulation factor VIII by addition of a glycosylation site at the N terminus of the protein

Recently, it was shown that glycoproteins with N-glycans close to the NH(2) terminus can directly enter the calnexin/calreticulin cycle and bypass BiP binding. This should allow efficient secretion of glycoproteins such as factor VIII (FVIII) whose secretion is negatively affected by BiP interaction. Examination of the glycosylation pattern of the NH(2) terminus of FV and FVIII revealed N-glycans at positions 23 and 27 in FV and at position 41 in FVIII. To improve FVIII secretion, a 14-amino-acid-long polypeptide with (G3) or without (G0; control) three N-linked glycosylation consensus sites was inserted upstream of the NH(2) terminus of a B-domain deleted FVIII protein. Expression of G3- and G0-constructs in three different cell lines resulted in the same or even higher expression rate of protein as found for the B-domain deleted FVIII. However, as demonstrated by Western blot analysis, the G3- as well as the G0-protein variants were mainly retained inside the cells in similar amounts. Thus, glycosylation alone does not automatically lead to higher secretion rates, but must be in context to the normal structure of the FVIII protein.

Regulation of human factor IX expression using doxycycline-inducible gene expression system

Following substitution therapy with human factor IX (hFIX) concentrate, therapy of haemophilia B by viral gene transfer has become an attractive alternative therapy in recent years. However, high doses of expressed hFIX, which can already be achieved in animal studies, may cause thrombosis in humans (van Hylckama Vlieg et al., 2000). Thus, it should be possible to maintain transgene expression within the therapeutic range. Therefore, we inserted elements of the tetracycline (Tet)-dependent Tet-On gene regulatory system into replication deficient adenovectors. The new system consists of two adenovectors: a response vector expressing hFIX (Ad5.TRE.hFIX), and a regulator vector expressing a second generation reverse tetracycline transactivator controlled by a CMV- (Ad5.CMV.rtTA) or human alpha1-antitrypsin-promoter (Ad5.hAAT.rtTA). Expression studies in four human cell lines showed high expression of hFIX from Ad5.TRE.hFIX in all cell lines in combination with Ad5.CMV.rtTA regulator vector, but only high specific expression in HepG2-cells in combination with Ad5.hAAT.rtTA regulator vector. Additionally, up- and down-regulation of hFIX expression could be demonstrated in vitro with the Ad5.TRE.hFIX/Ad5.CMV.rtTA combination and modulating doxycycline concentrations. When SCID-mice were infected with the Ad5.TRE.hFIX/Ad5.CMV.rtTA combination, up- and down-regulation of hFIX expression was achieved by oral doses of doxycycline for a period of at least two months. Replacement of the Ad5.CMV.rtTA vector by the Ad5.hAAT.rtTA vector showed minimal expression of hFIX in vivo. Although hFIX expression showed a slow and gradual decrease over time in vivo with the Ad5.CMV.rtTA vector, it remained within the therapeutic range. To date, regulation of hFIX has not been described in this way.

Evaluation of different methods used to measure malonyldialdehyde in human erythrocytes

Malonyldialdehyde (MDA), a secondary product of lipid peroxidation is widely used as an indicator of lipid peroxidation. Eight of the most frequently used methods for measuring MDA have been evaluated with regard to their sensitivity and reproducibility. The sensitivity of these methods for pure MDA solution was in the order: Satoh's > Stocks and Dormandy's >> Buege and Aust's > Dresel's >> Slater's > Yoshioka's et al. > Yagi's > Jain's method. Whereas the sensitivity of the first four methods for erythrocyte MDA was in the order: Stocks and Dormandy's >> Buege and Aust's > Satoh's > Dresel's method. The reproducibility (expressed as coefficient of variation) of these four methods for erythrocyte MDA were: 3.5%, 17.9%, 31.5% and 16.1%, respectively. These results indicate that Stocks and Dormandy's method has the highest sensitivity and an excellent reproducibility for erythrocyte MDA. Also, it was found to be simple and many samples can be treated in a relatively short time. When standard MDA (0.1-15 nmol/ml) was incubated with erythrocytes, the percentage recovery of MDA (using Stocks and Dormandy's method) has ranged from 50-85%. This result indicates that a considerable amount of MDA formed in erythrocytes probably reacts with other cell components and becomes undetectable. Despite this, the determination of MDA level remains a useful indicator of lipid peroxidation and correlates well with the degree of oxidative stress.

Susceptibility of erythrocytes from non-insulin-dependent diabetes mellitus and hemodialysis patients, cigarette smokers and normal subjects to in vitro oxidative stress and loss of deformability

Incubation of normal erythrocytes with 10 mM H2O2 has caused a loss of deformability. This loss of deformability was correlated with the extent of malonyldialdehyde, MDA (an indicator of lipid peroxidation) and alanine production (an indicator of protein degradation). The susceptibility of erythrocytes from 21 non-insulin-dependent diabetes mellitus (NIDDM) and 18 hemodialysis patients, 21 cigarette smokers and 25 healthy controls to in vitro oxidative stress with H2O2 has been measured as MDA production. Besides this, their erythrocytes reduced glutathione (GSH; an antioxidant) level has also been determined, but before exposure to H2O2. Erythrocytes from NIDDM and hemodialysis patients have shown significant increase in MDA production and a significantly low GSH level, compared to healthy controls. In cigarette smokers, although the GSH level was significantly low, but there was no significant difference in MDA production, compared to healthy controls. The low GSH level in NIDDM and hemodialysis patients, and smokers indicates that their erythrocytes were exposed to oxidative stress (an increase in free radical load) in vivo, resulting in an overconsumption and/or decreased production of GSH. The increased susceptibility to oxidative stress along with the decrease in some antioxidants (e.g., GSH) may explain the significant increase in MDA production in NIDDM and hemodialysis patients. But in cigarette smokers, the increased susceptibility to oxidative stress is probably not sufficient to cause a significant increase in MDA production. The results may also indicate an increased susceptibility to the loss of erythrocyte deformability in NIDDM and hemodialysis patients compared to healthy controls.