Karen Valentine

Early outcomes after allogeneic stem cell transplantation for leukemia and myelodysplasia without protective isolation: A 10-year experience

Although it is common practice to use some form of isolation to protect allogeneic stem cell transplant patients from infection, the necessity for these practices in all environments has not been demonstrated. The current study evaluated patterns of infection and 100-day transplant-related mortality in 288 patients with myelodysplasia and leukemia transplanted without isolation. Patients were allowed out of hospital at any time within constraints of the medication schedule. Fever, foci of infection, and positive cultures within 28 days and death within 100 days because of the transplant procedure were recorded. Fever occurred in 57% of patients, and 10% had a clinical or radiographic focus of infection. Most infections were apparently endogenous; blood cultures from 24% of recipients grew organisms, 87% of which were gram-positive bacteria. Four patients (1%) died with aspergillus infection in circumstances indicating that isolation would not have been helpful. Twenty percent of patients remained without evidence of infection throughout. Transplant-related mortality at 100 days was 1% for 108 patients with early leukemia receiving transplants from matched siblings. For patients at higher risk, by virtue of donor and/or disease status, mortality was 21%. These figures compare favorably with those reported to the International Bone Marrow Transplant Registry, the majority of patients having been subjected to some form of isolation. We conclude that allogeneic stem cell transplantation can be safely performed in some environments without confining patients continuously to the hospital.

Life-threatening hemolytic anemia due to an autoanti-Pr cold agglutinin: evidence that glycophorin A antibodies may induce lipid bilayer exposure and cation permeability independent of agglutination

BACKGROUND: The hemoglobin of a 29‐year‐old man fell below 35 g/L over 5 days, despite 14 units of red blood cells (RBCs), due to an anti‐Pr cold agglutinin (CA). His hemolytic anemia necessitated respiratory support in intensive care for 4 weeks.

Iliac Vein Compression Syndrome in an Active and Healthy Young Female

Iliac vein compression syndrome is a condition involving external compression of the left common iliac vein by the right iliac artery, which was first described in the 1850s. It predominates in females typically between the third and fourth decade of life and has been associated with thrombophilias. Importantly, the syndrome is amenable to endovascular treatment. Here, we describe a case of a young athletic female with an incidental finding of a left iliac vein thrombosis while taking oral contraceptives, who was identified as having iliac vein compression syndrome on follow-up MR venography with positive testing for Factor V Leiden mutation.

Adult sickle cell disease epidemiology and the potential role of a multidisciplinary comprehensive care center in a city with low prevalence.

Abstract The aim of this study was to determine the characteristics of the sickle cell disease population in a city of low prevalence and compare them to those reported in the literature. We performed a retrospective cross-sectional study of all sickle cell disease patients seen in the Calgary Health Region, Calgary, Alberta, Canada from 2006 to 2010. Data on clinical endpoints including emergency department (ED) visits, hospital admissions, transfusions, as well as laboratory parameters were collected. A total of 37 adult sickle cell disease patients were identified. Over 5 years, they were represented by a total of 49.2 ED presentations/year, 29.2 (59.0%) of these requiring admission. Eighty-three percent of these presentations were for acute pain episodes. We concluded that the number of ED visits, hospital admissions and several other parameters in our cohort were similar to those in other centers of higher prevalence. This suggests that guidelines representing regions of high prevalence may be applicable to smaller centers, where patients experience similar clinical outcomes.

Acquired von Willebrand syndrome: von Willebrand factor propeptide to von Willebrand factor antigen ratio predicts remission status

We investigated a case of acquired von Willebrand syndrome (AVWS) secondary to a nonneutralizing anti-von Willebrand factor (VWF) antibody associated with an autoimmune disorder. At diagnosis, VWF activity (VWF:Act), antigen (VWF:Ag), multimers, and factor VIII coagulant activity were virtually absent. VWF propeptide (VWFpp) was elevated with an infinitely high VWFpp to VWF:Ag ratio (VWFpp:Ag) consistent with rapid VWF clearance. Immunosuppressive treatment resulted in phenotypic remission 1 with normalization of VWF/factor VIII levels and multimer pattern. However, VWFpp:Ag remained elevated (∼2× normal), consistent with ongoing VWF clearance by the remaining anti-VWF antibody still present by enzyme-linked immunosorbent assay. This suggests that increased VWF secretion was compensating for the incomplete remission state. Relapse occurred when VWFpp:Ag was again infinitely high, with associated decreased VWFpp but unchanged anti-VWF titers; switching the balance to favor VWF clearance over secretion. Complete remission with undetectable anti-VWF occurred only when VWFpp:Ag was normal. This case of relapsing-remitting AVWS demonstrates the use of VWFpp:Ag for predicting remission status.

Low-Molecular-Weight Heparin Therapy and Mortality

There is ample evidence from clinical trials to justify giving certain low-molecular-weight heparins (LMWHs) subcutaneously rather than administering continuous intravenous unfractionated heparin for the initial treatment of venous thromboembolic disease. The LMWHs given by subcutaneous injection have a predictable anticoagulant response and prolonged duration of action. They can, therefore, be administered once or twice daily to treat venous thrombosis. Furthermore, treatment with these agents does not require laboratory monitoring. Eliminating the need for intravenous therapy and for laboratory monitoring should allow patients to be discharged earlier, and eventually lead to the outpatient treatment of venous thromboembolism. Studies to date indicate that LMWH is safer and as effective as continuous intravenous heparin in the treatment of venous thrombosis. The decreased mortality rates seen in two clinical trials, particularly in patients with metastatic cancer, were an unexpected but intriguing findin...

Low-Molecular-Weight Heparin in the Initial Treatment of Proximal Deep Vein Thrombosis

Intravenous unfractionated heparin followed by oral warfarin is the current standard of care for the treatment of acute venous thrombosis. More recently, several low-molecular-weight heparin preparations have been shown to be as effective and safe as unfractionated heparin for the initial therapy of acute proximal vein thrombosis. These drugs have a number of advantages over unfractionated heparin, and will undoubtedly replace the current standard for the initial treatment of venous thromboembolism.