Prospective evaluation of pregnancy outcome in an Italian woman with late-onset combined homocystinuria and methylmalonic aciduria.

BACKGROUND: Cobalamin metabolism disorders are rare, inherited diseases which cause megaloblastic anaemia and other clinical manifestations. Early diagnosis of these conditions is essential, in order to allow appropriate treatment as early as possible. CASE PRESENTATION: Here we report the case of a patient who was apparently healthy until the age of 20, when she presented with impaired renal function and normocytic anaemia. At the age of 34, when her first pregnancy resulted in an intrauterine death of a morphologically normal growth-restricted foetus, she was diagnosed with homocystinuria and methylmalonic aciduria due to cyanocobalamin C (cblC) defect, which was confirmed by molecular investigation. Consequently, hydroxocobalamin was administered to correct homocysteine plasma levels. This treatment was efficacious in lowering homocysteine plasma levels and restored anaemia and renal function. During a second pregnancy, the patient was also administered a prophylactic dose of low molecular -weight heparin. The pregnancy concluded with a full-term delivery of a healthy male. CONCLUSIONS: This case emphasises the importance of awareness and appropriate management of rare metabolic diseases during pregnancy. We suggest that women with late-onset cblC defect can have a positive pregnancy outcome if this metabolic disease is treated adequately.

Venous thromboembolism in assisted reproductive technologies: comparison between unsuccessful versus successful cycles in an Italian cohort.

Pregnancies after assisted reproductive technologies (ART) have been associated with an increased risk of venous thromboembolism (VTE). On the contrary, the magnitude of this risk in unsuccessful ART cycles (not resulting in a clinical pregnancy) has not yet been clearly defined. In this study, we evaluated the incidence of VTE in unsuccessful cycles and compared it with that recorded in successful cycles in the same study population. From a cohort of 998 women consecutively referred by local Fertility Clinics to our Atherosclerosis and Thrombosis Unit (April 2002-July 2011), we identified and included women with at least one cycle of ovarian stimulation and a negative history for VTE. Overall, 661 women undergone 1518 unsuccessful and 318 successful cycles of ovarian stimulation, respectively, were analysed. VTE events occurred in 2/1518 (1.3‰) unsuccessful cycles compared with 3/318 (9.4‰) successful cycles, (Two-tailed Fisher exact test, p = 0.04, OR 0.14, 95% CI 0.02-1.02). Both cases observed in unsuccessful cycles were isolated pulmonary embolism occurred after OHSS; no antithrombotic prophylaxis had been prescribed. At logistic regression analysis, the occurrence of successful cycle and BMI were significantly and independently associated with the occurrence of VTE with an OR of 13.94 (95% CI 1.41-137.45) and 1.23 (95% CI 1.01-1.49), respectively. VTE incidence is significantly lower in unsuccessful cycles as compared to that of successful ones. However, although rare, thrombotic risk during ovarian stimulation cannot be excluded and, when it occurs, can be life-threatening. Therefore, particular attention should be paid to these women, independently of ART outcome.

Characterization of patients with angioedema without wheals: the importance of F12 gene screening.

Sporadic and familiar forms of non-histaminergic angioedema and normal C1 inhibitor encompass a group of disorders possibly caused by bradikinin. We aimed to study the subgroups of hereditary angioedema with FXII mutation (FXII-HAE), unknown genetic defect (U-HAE) and idiopathic non-histaminergic acquired angioedema (InH-AAE). We screened the F12 locus in our cohort and delineated the clinical, laboratory and genetic features. Four families carried the p.Thr309Lys mutation in F12 gene. Haplotyping confirmed the hypothesis of a common founder. Six families were affected by U-HAE and 13 patients by sporadic InH-AAE. C4 levels were significantly lower in FXII-HAE than in InH-AAE. In the FXII-HAE group, none had attacks exclusively in high estrogenic states; acute attacks were treated with icatibant. Prophylaxis with tranexamic acid reduced the attack frequency in most patients. Our study provides new data on the diagnosis, clinical features and treatment of non-histaminergic angioedema, underlying the role of the screening for F12 mutations.

A novel CISD2 intragenic deletion, optic neuropathy and platelet aggregation defect in Wolfram syndrome type 2.

BACKGROUND: Wolfram Syndrome type 2 (WFS2) is considered a phenotypic and genotypic variant of WFS, whose minimal criteria for diagnosis are diabetes mellitus and optic atrophy. The disease gene for WFS2 is CISD2. The clinical phenotype of WFS2 differs from WFS1 for the absence of diabetes insipidus and psychiatric disorders, and for the presence of bleeding upper intestinal ulcers and defective platelet aggregation. After the first report of consanguineous Jordanian patients, no further cases of WFS2 have been reported worldwide. We describe the first Caucasian patient affected by WFS2. CASE PRESENTATION: The proband was a 17 year-old girl. She presented diabetes mellitus, optic neuropathy, intestinal ulcers, sensorineural hearing loss, and defective platelet aggregation to ADP. Genetic testing showed a novel homozygous intragenic deletion of CISD2 in the proband. Her brother and parents carried the heterozygous mutation and were apparently healthy, although they showed subclinical defective platelet aggregation. Long runs of homozygosity analysis from SNP-array data did not show any degree of parental relationship, but the microsatellite analysis confirmed the hypothesis of a common ancestor. CONCLUSION: Our patient does not show optic atrophy, one of the main diagnostic criteria for WFS, but optic neuropathy. Since the "asymptomatic" optic atrophy described in Jordanian patients is not completely supported, we could suppose that the ocular pathology in Jordanian patients was probably optic neuropathy and not optic atrophy. Therefore, as optic atrophy is required as main diagnostic criteria of WFS, it might be that the so-called WFS2 could not be a subtype of WFS. In addition, we found an impaired aggregation to ADP and not to collagen as previously reported, thus it is possible that different experimental conditions or inter-patient variability can explain different results in platelet aggregation. Further clinical reports are necessary to better define the clinical spectrum of this syndrome and to re-evaluate its classification.

Role of cytochrome P4502D6 functional polymorphisms in the efficacy of donepezil in patients with Alzheimer's disease.

OBJECTIVE: Cytochrome P450 (CYP) 2D6 enzyme is the major responsible for the metabolism of donepezil, an inhibitor of acetyl cholinesterase currently used for the symptomatic treatment of mild-to-moderate Alzheimer's disease (AD). Functional polymorphisms in the CYP2D6 gene may affect enzyme activity and thus, the metabolism of donepezil. The aim of this study was to evaluate the effect of 16 functional polymorphisms in the CYP2D6 gene on the clinical response to donepezil treatment in patients with mild-to-moderate AD. METHODS: In this multicenter prospective cohort study we evaluated 57 unrelated Caucasians clinically diagnosed as AD according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association Work Group criteria. Patients were treated with donepezil (5-10 mg/daily) for 6 months. The response to donepezil treatment was evaluated at 6-month follow-up according to the National Institute for Health and Clinical Excellence requirements. The identification of 16 clinically relevant CYP2D6 gene variants was performed by a high-throughput genetic analysis. RESULTS: Thirty-eight of 57 patients (67%) were responders and 19 patients (33%) were nonresponders to donepezil treatment. A significantly higher frequency of gene variants conferring decreased or absent enzyme activity was observed in responder than in nonresponder patients (73.68% vs. 36.84%; P=0.005). The presence of gene variants conferring decreased or absent activity of the CYP2D6 enzyme was significantly associated with a clinical response to donepezil treatment (odds ratio=6.286; 95% confidence interval=1.828-21.667). CONCLUSIONS: Functional polymorphisms in the CYP2D6 gene can influence the clinical efficacy of donepezil. The analysis of CYP2D6 genotypes may be useful in identifying subgroups of AD patients with different clinical response to donepezil treatment.

A beta3 Asp217-->Val substitution in a patient with variant Glanzmann Thrombasthenia severely affects integrin alphaIIBbeta3 functions.

A dysfunctional Glanzmann Thrombasthenia (variant) is a rare bleeding disorder due to qualitative abnormalities of platelets alphaIIBbeta3 heterodimers. Dynamically conformational change of alphaIIBbeta3 is a complex mechanism that is not fully understood. For these reasons, genotyping and functional analysis of variant Glanzmann Thrombasthenia is important to elucidate the molecular basis of alphaIIBbeta3 receptor functions. In this report, we have analyzed the molecular effects of an A>T substitution leading to an amino acid change, D217>V, in the beta3 integrin gene identified in patients with variant Glanzmann Thrombasthenia. As the D217 residue is highly conserved among all seven beta integrin subunits and among beta3 integrins of different species, we tested the effect on the phenotype of the D217V mutation by cotransfecting the beta3 mutant (V217) or wild-type beta3 (D217) construct with the wild-type alphaIIb into eukaryotic Chinese hamster ovary cells. Levels of mutant alphaIIBbeta3 heterodimers on Chinese hamster ovary cell surface were lightly reduced as compared with the wild type. Functional investigation of alphaIIBbeta3 V217 on Chinese hamster ovary cell surface was carried out, as fibrinogen binding, adhesion and aggregation tests showed a substantial reduction in respect to the control sample. Our results confirm ex-vivo data and suggest that the D217 amino acid is required for alphaIIBbeta3 receptor interactions with fibrinogen.

Screening of mutations of hemophilia A in 40 Italian patients: a novel G-to-A mutation in intron 10 of the F8 gene as a putative cause of mild hemophilia A in southern Italy.

Hemophilia A is an X-linked bleeding disorder caused by widespread mutations in the human coagulation factor 8 gene. We have searched for mutations in factor 8 gene DNAs from 40 unrelated Italian patients with hemophilia A. All patients came from the same region (Calabria) and were followed-up at the same hemophilia center. Of the 40 patients, 20 (50%) had severe hemophilia A, 19 (47.5%) had moderate hemophilia A, and one (2.5%) had mild hemophilia A. All patients were first screened for the common intron 22 and intron 1 inversions. Inversion-negative samples were screened for point mutations by direct sequencing of all coding regions and intron-exon boundaries of the factor 8 gene. Mutations previously reported as causative of hemophilia A were identified in 14 of the 40 patients. These included five (12.5%) intron 22 inversions, one (2.5%) small deletion, one (2.5%) small insertion and seven (17.5%) point mutations. In all patients with moderate and mild hemophilia A, a nucleotide change in the c.1538 -18G>A in intron 10, not reported in the HAMSTeRS factor 8 mutation database (http://europium.csc.mrc.ac.uk/), was found. The G-to-A change predicts the appearance of a new acceptor splice site. We have also demonstrated that all patients share a common haplotype, suggesting that the mutation probably occurred in a single ancestor. In conclusion, we suggest that the c.1538-18G>A transition can be the putative mutation, which probably occurred in a common ancestor and then spread in neighbours, in patients with moderate-mild hemophilia A investigated in the present study.

A rapid method for the quantification of the enantiomers of Warfarin, Phenprocoumon and Acenocoumarol by two-dimensional-enantioselective liquid chromatography/electrospray tandem mass spectrometry.

We describe a new fully validated enantioselective LC-MS/MS method for stereospecific quantification of both the racemic forms of Warfarin (WF), Phenprocoumon and Acenocoumarol in human plasma. Measurement specificity was assessed by using different blank donor plasma samples, where no interfering reagent peak appeared at the retention time (RT) of the targeted analytes. Response was linear for all analytes. Typical linear regression coefficients have >0.99. The recoveries ranged from 98% to 118%. Determinations in 10 normal healthy individuals revealed a high reproducibility of RTs. These findings confer to the method suitability for large population studies.

Homocysteine levels in amniotic fluid. Relationship with birth-weight.

Hyperhomocysteinemia could play a similar role in the placenta to that played in adults at risk of thrombosis. Moreover, hyperhomocysteinemia in women is described to be associated with the birth of small for gestational age (SGA) newborns, although there are discrepancies on this issue. To date, there is no biochemical marker predictive of SGA in a given pregnancy. We verified the presence of a relationship between homocysteine in amniotic fluid at mid-pregnancy and birth-weight. Amniotic fluid was obtained from 459 healthy women undergoing midtrimester amniocentesis (17.1 +/- 1.2 weeks) because of maternal age. Homocysteine levels were measured in 434 (10 twin) pregnancies. In addition, femur length (FL) and biparietal diameter (BPD) were measured. Outcome of pregnancy was recorded. 233 (53.7%) foetuses were males, 201 (46.3%) females. The mean homocysteine concentration was 1.04 +/- 0.72 microM, (95% C.I. 0.43-2.41). An univariate analysis showed the presence of an association with gestational age, FL, BPD. A multiple linear regression showed that homocysteine levels were significantly associated with FL (p < 0.001) and BPD (p = 0.011). After excluding twin pregnancies, 31 newborns (7.3%) were classified as SGA. Mean birth-weight was 2390 g in SGA, whereas it was 3360 g in 393 adequate for gestational age (AGA) newborns (p < 0.001). The adjusted mean level of homocysteine was significantly lower in AGA (1.01 microM; 95% C.I: 0.94-1.08) than that recorded in pregnancies resulting in a SGA (1.29 microM; 95% CI: 1.05-1.51; p = 0.03). In a large setting, these data provide reference values for homocysteine in amniotic fluids. Moreover, they suggest that homocysteine levels in amniotic fluids may be higher in pregnancies with a SGA newborn.

A new method for determination of plasma homocystine by isotope dilution and electrospray tandem mass spectrometry.

A new analytical determination method of homocystine in human plasma has been developed. The method utilises liquid chromatography coupled to ionspray tandem mass spectrometry. Quantitative analysis was achieved using as an internal standard homocystine-d8. Mass spectrometer operated in the multiple reaction mode: homocystine and homocystine-d8 were detected through the transition from the precursor to the product ion (from m/z 269.3 to 90.0, and m/z 277.3 to 94.0, respectively). The method is extremely sensitive, with limit of detection in the range of 6 fmol/L. The interassay and intraassay coefficients of variation for homocystine were 6.22% and 3.4%, respectively. The accuracy for the added homocystine ranged from 85% to 110%. High specificity of tandem mass spectrometry coupled with a fast chromatographic process is suitable for a rapid and reliable assay of homocystine.

Pharmacogenetics of dabigatran etexilate interindividual variability.

INTRODUCTION: Dabigatran etexilate is given in fixed doses without coagulation monitoring for the prevention of blood clots in at risk adults. A high inter-individual variability in blood concentrations of the active metabolite of dabigatran has been reported. ABCB1 and CES1 exert an important effect in the metabolism of dabigatran etexilate and allele variants at these two loci are likely to play a pivotal role. To investigate whether screening for polymorphisms within the ABCB1 and the CES1 genes would explain a portion of the inter-individual variability in blood concentrations of the active metabolite of dabigatran. MATERIAL AND METHODS: In a cohort of patients who had atrial fibrillation and on anticoagulant prophylaxis with dabigatran etexilate, we investigated whether genotypes at rs4148738 (ABCB1), rs8192935 (CES1), and rs2244613 (CES1) loci would affect plasma dabigatran trough and peak concentrations. RESULTS AND DISCUSSION: Among 92 patients (median age: 72.0years, range: 52-92) analyzed, no clinical variable or genotype was associated with a significant difference in dabigatran peak concentrations. As for trough concentrations, in addition to creatinine clearance, and sex a significant association with the CES1 SNP rs8192935 (p=0.023) was detected. The mean adjusted plasma levels were higher among patients with the CC genotype (86.3ng/dl) than in those carrying the T allele (62.1ng/dl). No significant effect was found for the ABCB1 SNP rs4148738. The CES1 SNP rs8192935 significantly influenced the dabigatran trough concentrations and carriers of the T allele showed significantly lower concentrations than did carriers of the CC genotype.

Glanzmann's thrombasthenia: identification of 19 new mutations in 30 patients.

Glanzmann's thrombasthenia (GT) is a genetically heterogeneous autosomal recessive syndrome associated with a bleeding tendency. To elucidate molecular basis of GT we have screened for mutations 30 GT patients. On the whole, 21 different candidate causal mutations, 17 in the alphaIIb and 4 in the beta3 gene have been found. Only two (alphaIIb Pro145Ala and IVS3(-3)-418del) have been previously reported. Nine mutations (42.9%) were likely to produce truncated proteins, whereas the remaining 12 were missense mutations that affected highly conserved residues in alphaIIb and beta3 genes. Six mutations were found in different patients suggesting a possible founder effect. The wide spectrum of expressivity, ranging from mild to severe also among patients carrying the same mutations, provided evidence for a role of different loci or circumstantial factors. In conclusion, we have identified a spectrum of unreported mutations that may be of value to unravel the role of specific regions of alphaIIb and beta3 genes.

Does endothelial nitric oxide synthase gene variation play a role in the occurrence of hypertension in pregnancy?

OBJECTIVE: Nitric oxide is suggested to play a role in the development of preeclampsia. METHODS: We studied 61 patients with gestational hypertension (GH), 77 with GH and significant proteinuria (urine protein excretion > or = 300 mg/24 h), 82 with essential hypertension (EH) and 188 normotensive women with at least one normal pregnancy. MAIN OUTCOME MEASURE(S): A polymorphism within the constitutive endothelial nitric oxide synthase (ecNOS) gene in various types of hypertension in pregnancy was explored. RESULTS: Allelic and genotypic frequencies did not differ between controls and case groups. A significant difference was observed between the frequency of the rare allele in GH patients and that in EH group (chi2: 4.47, P <.04). This difference approximated the significance when GH subjects with or without proteinuria were grouped (chi2 square: 3.33; P =.068). Cigarette smoking or gravidity did not interact with the ecNOS polymorphism in identifying different types of hypertension in this setting. CONCLUSION: Our findings argue against an association between ecNOS polymorphism and preeclampsia and support the hypothesis for a different pathogenesis of GH in respect to EH.

Liquid chromatography-tandem mass spectrometry method as the golden standard for therapeutic drug monitoring in renal transplant.

Kidney transplanted patients need immunosuppressant therapies. Therapeutic drug monitoring approaches produce the optimal clinical outcome is still under debate. This review details strength and limits of methods available: immunoassay and chromatography-based. Liquid chromatography with mass spectrometry detection is a major breakthrough in therapeutic drug monitoring of immunosuppressive agents and is considered as the method of choice in therapeutic drug monitoring (TDM) of immunosuppressants. Despite the initial high cost for the instrumentation, HPLC-MS is more cost effective than microparticle enzyme immunoassay. The main important features of LC-MS/MS methodology for immunosuppressive drugs are the shortened analysis time, an increased throughput, higher selectivity, specificity, and sensitivity, and low cost of analysis.

A reliable and rapid tool for plasma quantification of 18 psychotropic drugs by ESI tandem mass spectrometry.

A simple liquid chromatographic tandem mass spectrometry (LC-MS/MS) method has been developed for simultaneous analysis of 17 basic and one acid psychotropic drugs in human plasma. The method relies on a protein precipitation step for sample preparation and offers high sensitivity, wide linearity without interferences from endogenous matrix components. Chromatography was run on a reversed-phase column with an acetonitrile-H2O mixture. The quantification of target compounds was performed in multiple reaction monitoring (MRM) and by switching the ionization polarity within the analytical run. A further sensitivity increase was obtained by implementing the functionality "scheduled multiple reaction monitoring" (sMRM) offered by the recent version of the software package managing the instrument. The overall injection interval was less than 5.5 min. Regression coefficients of the calibration curves and limits of quantification (LOQ) showed a good coverage of over-therapeutic, therapeutic and sub-therapeutic ranges. Recovery rates, measured as percentage of recovery of spiked plasma samples, were ≥ 94%. Precision and accuracy data have been satisfactory for a therapeutic drug monitoring (TDM) service as for managing plasma samples from patients receiving psycho-pharmacological treatment.

Fatal pulmonary thromboembolism. A retrospective autopsy study: searching for genetic thrombophilias (Factor V Leiden (G1691A) and FII (G20210A) gene variants) and dating the thrombus.

The accuracy of antemortem diagnosis of pulmonary embolism is within the range of just 10-30%, so representing one of the most frequent missed diagnosis in sudden, unexpected death. We describe 43 fatal cases of pulmonary embolism as confirmed by post-mortem examination. The aim of our study was to verify the systematic search for the most common genetic thrombophilias (Factor V Leiden (G1691A) and FII (G20210A) gene variants) and dating the thrombus. As a whole, 41 patients (95.3%) had at least one risk factor. Pre-existing symptoms are described just before fatal embolism in 18 (41.9%) out 43 patients. In 18 out of 43 (41.9%) it was not possible to find the thrombotic site. In 24 out of the remaining 25 cases the involvement of the deep veins of one leg was shown; in 1 case the thrombus was localised in the inferior caval vein. 10 (41.7%) were iliac vein thromboses, 7 (29.1%) femoral, 2 (8.3%) popliteal, 3 (12.6%) posterior-tibial, 1 (4.1%) anterior-tibial and 1 (4.1%) peroneal vein thromboses. In our cohort of patients, 4 (10%) out of 40 cases carried the 20210A prothrombin gene variant in heterozygosis. One (2.5%) out of 40 carried the Factor V Leiden (G1691A) gene variant in heterozygosis. Patients carrying these gene variants in homozygosis or carrying both were not present in our case-series. We strongly underline the relevance of a complete methodological approach, integrating clinical data by means of autopsy findings and histological study. On the contrary, investigating common inherited thrombophilia is not warranted.

Stable-isotope dilution LC-ESI-MS/MS techniques for the quantification of total homocysteine in human plasma.

Homocysteine is an endogenous sulphydryl aminoacid irreversibly catabolized by transsulfuration to cysteine or remethylated to methionine. Increased plasma levels of homocysteine are an independent risk factor for atherosclerosis and cardiovascular disease. Accurate and reliable quantification of this amino acid in plasma samples is essential in clinical practice to explore the presence of a hyperhomocysteinemia, for instance after an ischemic event, or to control a possible adjunctive risk factor in patients at higher risk. In this review, LC-ESI-MS/MS methods are discussed and compared with other analytical methods for plasma homocysteine. LC-ESI-MS/MS is a technique combining the physicochemical separation of liquid chromatography with the analysis of mass spectrometry. It is based on stable-isotope dilution and possesses inherent accuracy and precision. Quantitative analysis is achieved by using commercially available homocystine-d(8) as an internal standard. Taking advantage of the high sensitivity and specificity, approaches involving LC-ESI-MS/MS require less laborious sample preparation, no derivatization and produce reliable results.