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Biomedical subjects

Francesco Rodeghiero

Publications and source records attributed to Francesco Rodeghiero.

29 records · Page 2Linked to original sources
PubMed2003

Multiplex amplification and fluorimetric detection of short tandem repeats for mixed chimerism after bone marrow transplant.

We present the clinical application of a simple method for mixed chimerism analysis after allogeneic bone marrow (BM) or peripheral blood stem cell (PBSC) transplant. A commercial kit which enables multiplex amplification of 9 highly polymorphic short tandem repeats in a single reaction tube was used. Molecular size and relative quantities of each amplified fragment are subsequently measured using an automated fluorimeter. The sensitivity and linearity were tested using whole blood or genomic DNA from two subjects, mixed in various proportions from 0.25% to 99.75%. In 70 donor-recipient pairs the median number of informative alleles for the assessment of relapse was 5.9 (range 3-11). Results showed that the linearity between the measured and expected relative quantities of amplified DNA showed a regression coefficient of 0.99 in the interval 10-90%. The mean sensitivity was 1.5% (range 0.5-2.5), greater than previously reported. A total of 70 cases of allogeneic transplant (49 with family and 21 with unrelated donors) were monitored before transplant and after 1, 2, 4, 6 or 12 months thereafter and then at 6 months intervals (range 6-36). In 18 patients mixed chimerism was observed 1 month from transplant, with donor allele percentage ranging from 1 to 6%. Fragment dimension reproducibility (CV 0.34, range 0.52-0.66) was confirmed by an internal DNA control and by amelogenin fragment length repeatability on all patients. In conclusion, the proposed method is sufficiently simple, rapid, sensible, specific and cost effective for the evaluation of mixed chimerism after BM or PBSC transplant in a clinical setting.

Bone Marrow Cells↗
PubMed2003

Von Willebrand's disease in the year 2003: towards the complete identification of gene defects for correct diagnosis and treatment.

BACKGROUND: Von Willebrand's disease (VWD) is an autosomally inherited bleeding disorder caused by a deficiency or abnormality of von Willebrand factor (VWF). VWF is a multimeric adhesive protein which plays an important role in primary hemostasis by promoting platelet adhesion to the subendothelium at sites of vascular injury and platelet-platelet interactions in high shear-rate conditions. It is also the carrier of factor VIII (FVIII), thus indirectly contributing to the coagulation process. VWD has a prevalence of about 1% in the general population, but the figure for clinically relevant cases is lower (about 100/million inhabitants). Bleeding manifestations are heterogeneous: mucosal bleeding is typical of all VWD cases but hemarthrosis and hematomas may also be present when FVIII levels are low. INFORMATION SOURCES: Most cases appear to have a partial quantitative deficiency of VWF (type 1 VWD) with variable bleeding tendency, whereas qualitative variants (type 2 VWD), due to a dysfunctional VWF, are clinically more homogeneous. Type 3 VWD is rare and the patients have a moderate to severe bleeding diathesis because of the virtual absence of VWF, and a recessive pattern of inheritance. The diagnosis of VWD, especially type I, may be difficult, because the laboratory phenotype is highly heterogeneous and is confounded by the fact that factors outside the VWF gene (e.g., blood group) influence VWF levels. An array of tests is usually required to characterize the VWD types of the disorder and establish the best treatment modality. CONCLUSIONS: The aim of treatment is to correct the dual defect of hemostasis, i.e. abnormal coagulation expressed by low levels of FVIII and abnormal platelet adhesion expressed by the prolonged bleeding time (BT). Desmopressin (DDAVP) is the treatment of choice for type 1 VWD because it corrects the FVIII/VWF levels and the prolonged BT in the majority of cases. In type 3 and in severe forms of type 1 and 2 VWD, DDAVP is not effective and for these patients plasma virally-inactivated concentrates containing FVIII and VWF are the mainstay of treatment. These concentrates are clinically effective and safe, although they do not always correct the BT.

Deamino Arginine Vasopressin↗
PubMed2002

A novel family with recessive von Willebrand disease due to compound heterozygosity for a splice site mutation and a missense mutation in the von Willebrand factor gene.

We report a new family with autosomal recessive von Willebrand disease (VWD) in which the propositus was compound heterozygous for a missense mutation in exon 42 (G7085T, C2362F) and a C-->A splice site mutation in intron 13 of the von Willebrand factor (VWF) gene. The propositus had factor VIII:C approximately equal to 20 IU/dl, VWF antigen 5-7 IU/dl and ristocetin cofactor activity <3-7 IU/dl. The bleeding time (BT) was markedly prolonged (>15 min). Haplotype analysis and mutation screening were conducted by polymerase chain reaction (PCR)-based methodology. Each mutation appeared to be linked to a haplotype that was identical to the haplotype previously detected in subjects in the Veneto region carrying these mutations, suggesting a founder effect. In the propositus' family six subjects were heterozygotes for the C2362F mutation and five were heterozygotes for the splice site mutation. None of the heterozygotes had suffered from significant bleeding. The mutation C2362F and the splice site mutation in intron 13 are commonly observed in subjects with recessive von Willebrand disease in the Veneto region. These mutations are truly recessive and cause bleeding only in the compound heterozygous or homozygous state.

Adult↗
PubMed2002

Factor V Leiden mutation carriership and venous thromboembolism in polycythemia vera and essential thrombocythemia.

Polycythemia Vera (PV) and Essential Thrombocythemia (ET) are chronic myeloproliferative disorders complicated by a high incidence of thrombotic complications. Extensive coagulation studies failed to demonstrate a consistent pattern of abnormalities associated with thrombosis. Recently, a poor anticoagulant response to activated protein C (APC), due to a mutation of factor V (FV Leiden), has been identified as the most frequent hereditary disorder associated with venous thrombophilia. We investigated in 304 patients with PV and ET whether the presence of FV Leiden could be a risk factor for thrombosis. FV Leiden was found in 14/304 patients (4.6%) and was associated with venous thromboembolism (VTE) occurred before and at diagnosis (5/27,16%, with a significant difference of prevalence in comparison of that observed in asymptomatic patients, 9/263, 3%, p = 0.003). Carriership of FV Leiden was associated with VTE relapse, with a prevalence of 3.6% in asymptomatic patients, 6.9% in patients with a single episode of VTE and 18.1% in patients with recurrent VTE. The prevalence of FV Leiden in patients with and without arterial thrombosis was similar (5/79, 6% and 9/211, 4%, respectively, p = 0.337). This study indicates that the prevalence of the FV Leiden mutation in patients with PV and ET is comparable with that observed in the general population. FV Leiden mutation is a risk factor for VTE before and at time of diagnosis and for VTE recurrences. Screening for FV Leiden may be considered to identify PV and ET patients at higher risk of recurrences.

Activated Protein C Resistance↗
PubMed2002

Mutations in the thrombomodulin gene are rare in patients with severe thrombophilia.

Because thrombomodulin plays a key role in the protein C pathway, we evaluated the contribution of thrombomodulin gene mutations to venous thrombosis. We examined 38 patients with recurrent, documented thrombotic events at a young age and a positive family history. Twelve individuals with low levels of soluble thrombomodulin in plasma were also studied. Finally, the allelic frequency of the Ala455Val polymorphism was estimated in 192 patients with at least one thrombotic event and in 369 age- and sex-matched asymptomatic controls. Two mutations were identified; G/A-201, in a severely thrombophilic patient and G/T 1456, in a patient with low soluble thrombomodulin levels. The first mutation has been reported by some, but not others, to be associated with moderately reduced levels of thrombomodulin. The second was identified previously in a patient with low soluble thrombomodulin, but expression studies failed to show functional changes in the mutant. Thrombomodulin gene mutations thus appear to be rare even in highly selected thrombophilic patients, and possibly functionally irrelevant. The allelic frequency of the Ala455Val polymorphism was identical in patients and controls. Considering the lack of a phenotype and the costly screening procedure, we recommend that thrombomodulin defects be sought only for research purposes.

Adolescent↗
PubMed2002

Prognostic significance of CD56 antigen expression in acute myeloid leukemia.

BACKGROUND AND OBJECTIVES: CD56 antigen expression has been reported in several hematologic malignancies. In acute myeloid leukemia (AML)M2 with t(8;21) and acute promyelocytic leukemia (APL) it has been found to be consistently associated with an unfavorable prognosis, whereas in other AML subtypes its role remains uncertain. We investigated CD56 expression in a cohort of AML patients in order to assess its frequency and prognostic relevance. DESIGN AND METHODS: Immunophenotypic analysis including that of CD56 antigen was available for 171 consecutive AML patients (139 with AML and 32 with APL), enrolled between December 1995 and December 1999 at a single institution. A sample of fresh bone marrow cells taken at diagnosis was recorded as positive when at least 20% of the cells double-stained with specific monoclonal antibodies against CD56 and CD33 antigens. RESULTS: CD56 positivity was demonstrated in 37 cases (21.6%). Its frequency was lower in M4 (6%) and higher in M5 (37%). The median percentage for CD56+ blasts was 56% (range 21-99%). CD56 positivity did not correlate with age, sex, blast count, favorable or unfavorable cytogenetics at diagnosis, nor did it influence the outcome in terms of complete remission (CR) duration (606 vs. 417 days, p=n.s.) or overall survival (OS) (210 vs. 277 days, p= n.s.). In the APL subgroup a significant difference in relapse rate was found at 3 years (71.4% in the CD56 positive group vs. 12% in the CD56 negative group, p=0.005). INTERPRETATION AND CONCLUSIONS: Our data confirm that CD56 positivity in APL patients at diagnosis is associated with a worse prognosis, suggesting that close molecular monitoring is necessary in CD56 positive APL patients. In contrast, the prognostic role of CD56 remains uncertain in the other AML subtypes.

Adolescent↗
PubMed2002

Fluorescent polymerase chain reaction and capillary electrophoresis for IgH rearrangement and minimal residual disease evaluation in multiple myeloma.

BACKGROUND AND OBJECTIVES: Several polymerase chain reaction (PCR)-based techniques for tracking minimal residual disease (MRD) in B-lymphoproliferative disorders have been recently proposed. These procedures show significant variation in sensitivity and specificity. We describe an alternative assay based on fluorescent PCR combined with capillary electrophoresis and GeneScan analysis, to identify the monoclonal immunoglobulin heavy chain (IgH) rearrangement in multiple myeloma (MM) and to provide a semi-quantitative evaluation of MRD by limiting dilutions. DESIGN AND METHODS: Different sets of family specific primers derived from the leader region and from the framework-1 of IgH were used, with a unique reverse fluorescent primer JH. The malignant clone was identified by GeneScan and sequenced. Two tumor primers, mapping in the complementarity determining regions CDRII and CDRIII, were designed for each patient. A comparison between the nested-PCR approach and direct fluorescent PCR was performed for three patients in complete clinical remission after autologous or allogeneic bone marrow transplantation. RESULTS: Thirty-six consecutive patients with MM were screened and monoclonality was identified in about 70% of the cases. Molecular MRD evaluation was performed in 18 patients using tumor primers. This method allowed identification of 1 neoplastic cell among 10(4)-10(6) normal cells. In three cases, negative by nested-PCR and agarose gel electrophoresis, gene scanning showed persistence of the neoplastic clone, despite the negativity of the immunofixation. INTERPRETATION AND CONCLUSIONS: Capillary electrophoresis of fluorescent fragments with gene scanning provides a simple, rapid and reproducible method to detect IgH rearrangement and to evaluate MRD. Furthermore, the sensitivity reached is up to 1 log higher than that of the conventional approach with nested-PCR, even though two steps of specificity are maintained.

Adult↗