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Mark T Cunningham

Publications and source records attributed to Mark T Cunningham.

10 recordsLinked to original sources
PubMed2006

Infant acute lymphoblastic leukemia with t(11;16)(q23;p13.3) and lineage switch into acute monoblastic leukemia.

Rearrangements of the mixed-lineage leukemia (MLL) gene have been associated with a poor prognosis in infant acute lymphoblastic leukemia (ALL). Previously, MLL translocations involving the CREP-binding protein (CREBBP) gene at chromosome band 16p13.3 have primarily been reported in treatment-related acute myeloid leukemia, after chemotherapy for other primary malignancies using topoisomerase II inhibitors. We report a case of de novo infant ALL with t(11;16)(q23;p13.3). After chemotherapy, this patient developed an acute monoblastic leukemia (M5b) with retention of the t(11;16)(q23;p13.3), indicating that this is a lineage switch of the original leukemic clone. To our knowledge, these findings have not been previously reported.

Bone Marrow Cells↗
PubMed2006

External peer review quality assurance testing in von Willebrand disease: the recent experience of the United States College of American Pathologists proficiency testing program.

The U.S. College of American Pathologists (CAP) has conducted a focused study of the proficiency testing for von Willebrand disease (vWD) analysis from 2003 to 2005. This report summarizes the findings regarding the accuracy and precision of the various assays at different analyte levels, as well as the influence of the reference material used to construct the assay standard curve. The results show that testing of von Willebrand factor (vWF):antigen (vWF:Ag) and ristocetin cofactor activity (vWF:RCo) is reasonably accurate, with all-method mean values falling within 3.2 and 5.6%, respectively, of the International Society on Thrombosis and Haemostasis Secondary Coagulation Standard (lot 2) assigned values. vWF:Ag measurements are reasonably precise (all-method coefficients of variation [CVs] = 10.7 to 15.1%), even at lower levels of vWF. The highest precision was observed for immunoturbidometric assays (CVs, 6.3 to 9.7%). vWF:RCo measurements are less precise (all-method CVs, 23.3 to 30.9%). The reference materials used in the standard curves for immunoturbidometric vWF:Ag assays appear to have accurately assigned vWF values for the majority of commercial suppliers.

Antigens↗
PubMed2006

Effect of fondaparinux on coagulation assays: results of College of American Pathologists proficiency testing.

CONTEXT: Fondaparinux, a factor Xa inhibitor, is approved for thromboprophylaxis after orthopedic surgery and for treatment of venous thromboembolism. It may also be efficacious, safe, and cost-effective for other patients; thus, more widespread use of fondaparinux is likely. The effect of fondaparinux on coagulation testing needs to be thoroughly examined. OBJECTIVE: To report the effects of fondaparinux on coagulation tests (prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, factor VIII, thrombin time, anti-factor Xa) across diverse methodologies. DESIGN: Samples with different concentrations of fondaparinux (0, 0.4, 0.8, and 2.0 microg/mL) were sent to laboratories participating in the College of American Pathologists Comprehensive Coagulation proficiency survey (N = 898). Laboratory-specific methods were used to assay coagulation parameters. RESULTS: Prophylactic or therapeutic fondaparinux prolonged the prothrombin time by approximately 1 second and the activated partial thromboplastin time by 4 to 5 seconds, and reduced factor VIII from 119% to 107% and 102%, respectively. Supratherapeutic fondaparinux reduced factor VIII to 85%. The activated partial thromboplastin time was prolonged in 19%, 29%, and 52% of laboratories with prophylactic, therapeutic, and supratherapeutic fondaparinux levels, respectively. Fibrinogen, antithrombin, and thrombin time assays did not show clinically significant changes. When measuring fondaparinux concentration using an anti-factor Xa assay, the most accurate results were obtained when fondaparinux was used as the calibrator. CONCLUSIONS: Fondaparinux, even in prophylactic doses, slightly prolongs the prothrombin time and activated partial thromboplastin time and can interfere with factor VIII assays, but it has no clinically relevant effect on fibrinogen, antithrombin, or thrombin time. A fondaparinux standard curve should be used for reporting fondaparinux levels using an anti-factor Xa assay.

Anticoagulants↗
PubMed2004

Biphasic acute myeloid leukemia with near-tetraploidy and immunophenotypic transformation.

This report describes a case of acute myeloid leukemia (subtype M1) with biphasic morphology. The bone marrow biopsy showed 2 distinct regions of blasts, one containing large cells and the other small cells. Morphometric and DNA ploidy analysis showed that the mean nuclear area and mean DNA index for the large cell region were 2-fold higher than those for the small cell region. Cytogenetic analysis showed an abnormal near-tetraploid clone. The tumor relapsed following aggressive therapy. The cells from the relapse specimen were similar to the original small cell region with respect to nuclear area and DNA index; however, there was immunophenotypic transformation with gain of CD7 and gain of CD56. Cytogenetically, the relapse specimen showed no evidence of the near-tetraploid clone, but instead had a previously unidentified abnormal clone containing 46 chromosomes and structural abnormalities of 2q and 7q. Biphasic morphology in acute myeloid leukemia may be predictive of a near-tetraploid subclone and immunophenotypic transformation.

Adult↗
PubMed2003

Fatal dural sinus thrombosis associated with heterozygous factor V Leiden and a short activated partial thromboplastin time.

Inherited thrombophilia is a risk factor for dural sinus thrombosis (DST). To our knowledge, this is the first description with autopsy findings of a patient with DST associated with heterozygous factor V Leiden and a short activated partial thromboplastin time (aPTT). A 51-year-old woman presented with a 3-day history of headache, nausea, right-sided weakness, and focal motor seizure; she died 3 days after admission. At autopsy, a gross examination showed hemorrhage of bilateral parietal lobes and left primary motor cortex, uncal and tonsillar herniation, and pulmonary embolus of the right upper lobe. A microscopic examination of the brain showed an organizing thrombus in the superior sagittal sinus, diffuse cerebral edema, and extensive venous congestion. Laboratory studies showed heterozygous factor V Leiden by polymerase chain reaction and a very short aPTT of 17 seconds (reference range, 22-30 seconds). The combination of a heterozygous factor V Leiden mutation and a short aPTT may have contributed to the fatal DST in this patient.

Factor V↗
PubMed2002

Laboratory diagnosis of dysfibrinogenemia.

Dysfibrinogenemia is a coagulation disorder caused by a variety of structural abnormalities in the fibrinogen molecule that result in abnormal fibrinogen function. It can be inherited or acquired. The inherited form is associated with increased risk of bleeding, thrombosis, or both in the same patient or family. Traditionally, dysfibrinogenemia is diagnosed by abnormal tests of fibrin clot formation; the thrombin time and reptilase time are the screening tests, and the fibrinogen clotting activity-antigen ratio is the confirmatory test. The inherited form is diagnosed by demonstrating similar laboratory test abnormalities in family members, and if necessary by analysis of the fibrinogen protein or fibrinogen genes in the patient. The acquired form is diagnosed by demonstrating abnormal liver function tests and by ruling out dysfibrinogenemia in family members. This article reviews the laboratory testing of dysfibrinogenemia and presents an algorithm for sequential test selection that can be used for diagnosis.

Algorithms↗