Endothelial Activation Markers as Disease Activity and Damage Measures in Juvenile Dermatomyositis.

OBJECTIVE: Circulating endothelial cells (CEC), von Willebrand factor (vWF) antigen, P-selectin, and thrombomodulin are released from damaged endothelium, while decreases in circulating endothelial progenitor cells (CEPC) have been associated with poor vascular outcomes. We examined these markers in the peripheral blood of patients with juvenile dermatomyositis (JDM) and their correlations with disease assessments. METHODS: Peripheral blood endothelial cells and biomarkers were assessed in 20 patients with JDM and matched healthy controls. CEC and CEPC were measured by flow cytometry, while vWF antigen and activity, factor VIII, P-selectin, and thrombomodulin were measured in plate-based assays. Disease activity and damage, nailfold capillary density, and brachial artery flow dilation were assessed. Serum cytokines/chemokines were measured by Luminex. RESULTS: CEC, vWF antigen, factor VIII, and thrombomodulin, but not vWF activity, CEPC, or P-selectin, were elevated in the peripheral blood of patients with JDM. CEC correlated with pulmonary activity (rs = 0.56). The vWF antigen correlated with Patient's/Parent's Global, cutaneous, and extramuscular activity (rs = 0.47-0.54). CEPC negatively correlated with muscle activity and physical function (rs = -0.52 to -0.53). CEPC correlated inversely with endocrine damage. The vWF antigen and activity correlated with interleukin 10 and interferon-gamma inducible protein-10 (rs = 0.64-0.82). CONCLUSION: Markers of endothelial injury are increased in patients with JDM and correlate with extramuscular activity. CEPC correlate inversely with muscle activity, suggesting a functional disturbance in repair mechanisms.

Clinical and laboratory diagnosis of von Willebrand disease: a synopsis of the 2008 NHLBI/NIH guidelines.

Von Willebrand factor (VWF) mediates blood platelet adhesion and accumulation at sites of blood vessel injury, and also carries coagulation factor VIII (FVIII) that is important for generating procoagulant activity. Von Willebrand disease (VWD), the most common inherited bleeding disorder, affects males and females, and reflects deficiency or defects of VWF that may also cause decreased FVIII. It may also occur less commonly as an acquired disorder (acquired von Willebrand syndrome). This article briefly summarizes selected features of the March 2008 evidence-based clinical and laboratory diagnostic recommendations from the National Heart, Lung, and Blood Institute (NHLBI) Expert Panel for assessment for VWD or other bleeding disorders or risks. Management of VWD is also addressed in the NHLBI guidelines, but is not summarized here. The VWD guidelines are available at the NHLBI Web site (http://www.nhlbi.nih.gov/guidelines/vwd).

Diagnosis and management of von Willebrand disease: guidelines for primary care.

Von Willebrand disease is an inherited condition characterized by deficiency of von Willebrand factor, which is essential in hemostasis. The National Heart, Lung, and Blood Institute has released new evidence-based guidelines for the diagnosis and management of the disease. There are three major subtypes of von Willebrand disease, classified as partial quantitative deficiency (low levels) of von Willebrand factor (type 1), qualitative deficiency (type 2), or virtually complete deficiency (type 3). Diagnosis is usually made by reviewing the patient's personal and family history of bleeding and by clinical evaluation for more common reasons for bleeding, supplemented with laboratory tests. Assessment may be used to determine bleeding risk before surgery and other invasive procedures, and to diagnose reasons for unexplained hemorrhaging. Von Willebrand factor levels of 30 IU per dL or lower are required for the definite diagnosis of inherited von Willebrand disease. Persons with levels of 30 to 50 IU per dL may not have the disease, but may need agents to increase von Willebrand factor levels during invasive procedures or childbirth. Treatment is tailored to the subtype of the disease: increasing plasma concentration of von Willebrand factor by releasing endogenous stores with desmopressin or replacing nonexistent or ineffective von Willebrand factor by using human plasma-derived, viral-inactivated concentrates; treatment is often combined with hemostatic agents that have mechanisms other than increasing von Willebrand factor. Regular prophylaxis is seldom required, and treatment is initiated before planned invasive procedures or in response to bleeding.

The incidence and natural history of osteonecrosis in HIV-infected adults.

BACKGROUND: Osteonecrosis is increasingly recognized as a debilitating complication of human immunodeficiency virus (HIV) infection, but the natural history has not been well described. We previously documented a high prevalence (4.4%) of magnetic resonance imaging (MRI)-documented osteonecrosis of the hip in a cohort of 339 asymptomatic HIV-infected patients. The present study was designed to determine the incidence of newly diagnosed osteonecrosis in this cohort and to describe the natural history of osteonecrosis in HIV-infected patients. METHODS: Asymptomatic HIV-infected patients with a previous hip MRI negative for osteonecrosis underwent follow-up MRI. Patients with asymptomatic or symptomatic osteonecrosis were enrolled in a natural history study, which included serial MRIs and a physiotherapy follow-up. RESULTS: Two hundred thirty-nine patients underwent a second MRI a median of 23 months after the initial MRI. Osteonecrosis of the femoral head was diagnosed in 3 patients (incidence, 0.65 cases per 100 person-years). During the period of January 1999 through April 2006, symptomatic hip osteonecrosis developed in 13 clinic patients (incidence, 0.26 cases per 100 person-years). Among 22 patients enrolled with symptomatic hip osteonecrosis, 18 had bilateral involvement of the femoral heads, and 7 had osteonecrosis involving other bones. Two (11%) of 18 asymptomatic patients and 13 (59%) of 22 symptomatic patients underwent total hip replacement. The percentage of involvement of the weight-bearing surface of the femoral head and the rate of progression to total hip replacement was significantly greater (P<.001) in symptomatic patients than in asymptomatic patients. CONCLUSIONS: HIV-infected patients are at approximately 100-fold greater risk of developing osteonecrosis than the general population. Disease progression is slower in asymptomatic patients than in symptomatic patients. Given the high frequency of total hip replacement in symptomatic patients, studies to assess preventive and treatment strategies are essential.

Anti-interleukin-2 receptor antibody (daclizumab) treatment of corticosteroid-refractory autoimmune thrombocytopenic purpura.

We administered daclizumab, a humanized monoclonal anti-interleukin-2 receptor (IL-2R) antibody, to 11 patients with corticosteroid-refractory autoimmune thrombocytopenic purpura (AITP) every 2 weeks for five treatments. Of nine evaluable patients, one individual experienced a partial response. Lymphocyte phenotyping by flow cytometry indicated post-treatment binding of IL-2Ra by daclizumab in all patients. Mid-study serum soluble IL-2R levels in all patients increased 4-15 -fold over baseline values (p=0.004). Despite these measurable immunologic effects, blockade of the IL-2/IL-2R axis did not effectively abrogate the autoimmune response in this group of patients with corticosteroid-refractory AITP.

High prevalence of osteonecrosis of the femoral head in HIV-infected adults.

BACKGROUND: Osteonecrosis has been reported to occur occasionally among HIV-infected patients. The diagnosis of symptomatic osteonecrosis of the hip in two of the authors' patients, together with reports from community physicians, raised a concern that the prevalence of osteonecrosis is increasing. OBJECTIVE: To determine the prevalence of osteonecrosis of the hip in asymptomatic HIV-infected patients and to identify potential risk factors associated with osteonecrosis. DESIGN: Survey and comparison study. SETTING: The Clinical Center of the U.S. National Institutes of Health. PARTICIPANTS: 339 asymptomatic HIV-infected adults (of 364 asked to participate) and 118 age- and sex-matched HIV-negative volunteers enrolled between 1 June and 15 December 1999. MEASUREMENTS: Osteonecrosis of the hip, as documented by magnetic resonance imaging. Data from clinic records and a patient questionnaire administered before magnetic resonance imaging were used in an analysis of risk factors. A subset of patients was evaluated for hypercoagulable state. RESULTS: Fifteen (4.4% [95% CI, 2.5% to 7.2%]) of 339 HIV-infected participants had osteonecrosis lesions on magnetic resonance imaging, and no HIV-negative participants had similar lesions. Among HIV-infected participants, osteonecrosis occurred more frequently in those who used systemic corticosteroids, lipid-lowering agents, or testosterone; those who exercised routinely by bodybuilding; and those who had detectable levels of anticardiolipin antibodies. CONCLUSIONS: Patients infected with HIV have an unexpectedly high occurrence of osteonecrosis of the hip. Although screening asymptomatic patients is not warranted, HIV-infected patients with persistent groin or hip pain should be evaluated for this debilitating complication.

Clinical use of a rapid collagen binding assay for von Willebrand factor cleaving protease in patients with thrombotic thrombocytopenic purpura.

A simple collagen binding assay (CBA) for measuring activity of the von Willebrand factor cleaving protease in clinical samples is described, and results of fifty masked plasmapheresis samples rom patients with TTP/HUS and other diseases are presented. There was 97.5% concordance between the CBA and a multimer gel assay. The CBA identified low protease activity in 78% of patients who had a clinical syndrome consistent with TTP/HUS and in 2 of 10 sick controls, giving it a positive predictive value of 0.94. The heterogeneity regarding the presence or absence of vWF protease activity in patients with TTP/HUS was confirmed by finding a low negative predictive value of 0.50 with the CBA. The CBA detected inhibitors of the protease in 26 of 29 patients (90%) with TTP/HUS and low protease activity levels. The CBA is a useful clinical assay for examining von Willebrand factor protease activity and detecting inhibitors against the protease.

Albumin enhanced morphometric image analysis in CLL.

BACKGROUND: The heterogeneity of lymphocytes from patients with chronic lymphocytic leukemia (CLL) and blood film artifacts make morphologic subclassification of this disease difficult. METHODS: We reviewed paired blood films prepared from ethylene-diamine-tetraacetic acid (ETDA) samples with and without bovine serum albumin (BSA) from 82 CLL patients. Group 1 adhered to NCCLS specifications for the preparations of EDTA blood films. Group 2 consisted of blood films containing EDTA and a 1:12 dilution of 22% BSA. Eight patients were selected for digital photomicroscopy and statistical analysis. Approximately 100 lymphocytes from each slide were digitally captured. RESULTS: The mean cell area +/- standard error was 127.8 microm(2) +/- 1.42 for (n = 793) for group 1 versus 100.7 microm(2) +/- 1.39 (n = 831) for group 2. The nuclear area was 88.9 microm(2) +/- 0.85 for group 1 versus 76.4 microm(2) +/- 0.83 for group 2. For the nuclear transmittance, the values were 97.6 +/- 0.85 for group 1 and 104.1 +/- 0.83 for group 2. The nuclear:cytoplasmic ratios were 0.71 +/- 0.003 for group 1 and 0.78 +/- 0.003 for group 2. All differences were statistically significant (P < 0.001). CONCLUSIONS: BSA addition results in the reduction of atypical lymphocytes and a decrease in smudge cells. BSA also decreases the lymphocyte area and nuclear area, whereas nuclear transmittance and nuclear:cytoplasmic ratio are increased. A standardized method of slide preparation would allow accurate interlaboratory comparison. The use of BSA may permit better implementation of the blood film-based subclassification of CLL and lead to a better correlation of morphology with cytogenetics and immunophenotyping. Published 2003 Wiley-Liss, Inc.

Parameters of coagulant and fibrinolytic capacity and activity in postmenopausal women: within-subject variability.

We have analyzed the within-subject variability of a battery of parameters of coagulant and fibrinolytic capacity and activity in postmenopausal women. We observed large differences in within-subject variability among the tests and have demonstrated how such data can be used to estimate the number of times a parameter must be measured to produce a statistically adequate sample.

Selective serotonin reuptake inhibitors: measurement of effect on platelet function.

Selective serotonin reuptake inhibitors (SSRIs) reduce platelet serotonin and are associated with increased gastrointestinal bleeding, an effect that is enhanced when taken with NSAIDs or aspirin. The best method to evaluate hemorrhagic events in patients taking SSRIs has not been determined. Platelet aggregation, which is not widely available, shows SSRI inhibition of platelet function; we tested whether a platelet function analyzer could detect SSRI inhibition of platelet function. Two groups of outpatients with mood disorders were recruited; each patient was taking a stable dose of either an SSRI or bupropion for at least 6 weeks. They were tested using the platelet function analyzer-100 (PFA-100; Dade International Inc, Miami, Fla) concomitantly with platelet aggregation. Fifty-eight patients were analyzed. We detected significant differences between the groups using aggregation methods with arachidonic acid (aggregation, P = 0.00001; release, P = 0.009) and collagen (aggregation, P = 0.016; release, P = 0.006). The PFA-100 did not detect differences between the groups or results outside the reference range. The PFA-100 does not detect the inhibitory effects of SSRIs on platelet function, but it can be used to direct evaluation of bleeding in a patient taking an SSRI. Abnormal PFA-100 results suggest additional evaluation for von Willebrand disease, other platelet inhibitory medications, or underlying intrinsic platelet dysfunction.

Thrombospondin-1 stimulates platelet aggregation by blocking the antithrombotic activity of nitric oxide/cGMP signaling.

Platelet alpha-granules constitute the major rapidly releasable reservoir of thrombospondin-1 in higher animals. Although some fragments and peptides derived from thrombospondin-1 stimulate or inhibit platelet aggregation, its physiologic function in platelets has remained elusive. We now show that endogenous thrombospondin-1 is necessary for platelet aggregation in vitro in the presence of physiologic levels of nitric oxide (NO). Exogenous NO or elevation of cGMP delays thrombin-induced platelet aggregation under high shear and static conditions, and exogenous thrombospondin-1 reverses this delay. Thrombospondin-1-null murine platelets fail to aggregate in response to thrombin in the presence of exogenous NO or 8Br-cGMP. At physiologic concentrations of the NO synthase substrate arginine, thrombospondin-1-null platelets have elevated basal cGMP. Ligation of CD36 or CD47 is sufficient to block NO-induced cGMP accumulation and mimic the effect of thrombospondin-1 on aggregation. Exogenous thrombospondin-1 also reverses the suppression by NO of alphaIIb/beta3 integrin-mediated platelet adhesion on immobilized fibrinogen, mediated in part by increased GTP loading of Rap1. Thrombospondin-1 also inhibits cGMP-mediated activation of cGMP-dependent protein kinase and thereby prevents phosphorylation of VASP. Thus, release of thrombospondin-1 from alpha-granules during activation provides positive feedback to promote efficient platelet aggregation and adhesion by overcoming the antithrombotic activity of physiologic NO.

Agarose gel electrophoresis of proteins.

This unit describes electrophoretic separation and identification of large proteins from a complex protein mixture. Agarose gel is utilized for the electrophoretic matrix, and detection of proteins is accomplished by transfer of the proteins to a membrane that is probed with specific antibodies and chemiluminescence reagents. Alternatively the protein can be detected in the gel using radiolabeled antibodies and autoradiography.

Congenital bleeding disorders.

Both clinical and basic problems related to the congenital bleeding disorders continue to confront hematologists. On the forefront are efforts to bring genetic correction of the more common bleeding disorders such as hemophilia A to the clinic in a safe and accessible manner. A second issue, particularly for patients with hemophilia, is the development of inhibitors-questions of how they arise and how to prevent and treat these problems that confound otherwise very successful replacement therapy and allow patients to maintain normal lifestyles. A third issue is the continuing question of diagnosis and management of von Willebrand disease, the most common congenital bleeding disorder, especially in individuals who have borderline laboratory values, but have a history of clinical bleeding. In Section I, Dr. Christopher Walsh discusses general principles of effective gene transfer for the hemophilias, specific information about viral vectors and non-viral gene transfer, and alternative target tissues for factor VIII and factor IX production. He highlights information about the immune response to gene transfer and reviews data from the hemophilia gene transfer trials to date. The future prospects for newer methods of therapy such as RNA repair and the use of gene-modified circulating endothelial progenitors are presented as possible alternatives to the more traditional gene therapy approaches. In Section II, Dr. Nigel Key focuses on inhibitor development in patients with hemophilia A. He reviews the progress in our understanding of the risk factors and presents newer information about the immunobiology of inhibitor development. He discusses the natural history of these inhibitors and the screening, laboratory diagnosis, and treatment, including the use of different modalities for the treatment of acute bleeding episodes. Dr. Key also presents information about the eradication of inhibitors by immune tolerance induction and reviews recent information from the international registries regarding the status and success of immune tolerance induction. In Section III, Dr. Margaret Rick discusses the diagnosis, classification, and management of von Willebrand disease. Attention is given to the difficulty of diagnosis in patients with mild bleeding histories and borderline laboratory test results for von Willebrand factor. She presents the value of different laboratory assays for both diagnosis and classification, and she relates the classification of von Willebrand disease to the choice of treatment and to the known genetic mutations. Practical issues of diagnosis and treatment, including clinical cases, will be presented.

Management of severe VWD with cryoprecipitate collected by repeated apheresis of a single dedicated donor.

BACKGROUND: Rare and severe forms of VWD are associated with trace or absent VWF. The feasibility of supporting a child with severe VWD from birth through age 12 with cryoprecipitate derived from DDAVP-stimulated plasma exchange of a single dedicated donor is reported. STUDY DESIGN AND METHODS: An infant with excessive hemorrhage at circumcision was found to have Type 3 VWD. His father carried an allele with a mutation at the level of VWF mRNA expression but did not have a history of bleeding. Cryoprecipitate was prepared from serial DDAVP-stimulated plasma exchanges of the father. RESULTS: Repeated plasma-exchange donations were performed to provide all of the VWF needed for his son. An average of 14 cryoprecipitate units was prepared from each donation, and the units contained markedly elevated levels of FVIII:C. The cryoprecipitate was stored for up to 102 months. Components tested after more than 8 years of storage showed 48 to 130 percent of original FVIII:C activity. Ninety-seven percent of the bleeding episodes, such as epistaxis, tongue-biting accidents, and other minor lacerations, were successfully managed with a single 50- to 100-percent replacement dose of FVIII. The patient experienced normal growth and development and is free of any long-term sequelae attributable to his disease. CONCLUSIONS: Cryoprecipitate prepared by repeated plasma exchange of a VWD carrier provided excellent hemostatic function, even after storage intervals of more than a year. Plasma exchange of a committed donor was a cost-effective and safe option for long-term management of VWD.

Rituximab for treatment of refractory/relapsing thrombotic thrombocytopenic purpura (TTP).

Plasma exchange is the standard treatment for thrombotic thrombocytopenic purpura (TTP). For patients refractory to plasma exchange, treatment options are limited and often unsuccessful. The platelet thrombi that form in acquired TTP are believed to result from the presence of procoagulant ultralarge multimers of von Willebrand factor (VWF) in the circulation due to autoantibody inhibition of VWF cleaving protease (ADAMTS-13), the enzyme that normally cleaves the ultralarge multimers. Rituximab, a chimeric monoclonal antibody against CD20, has been recognized as a useful therapy for antibody-mediated autoimmune disease. We therefore treated four patients with recurrent TTP with 2 or 4 weekly doses of rituximab in addition to corticosteroids, vincristine, plasma, or continuing plasma exchange. Three patients responded with prompt improvement in microangiopathic hemolytic anemia and thrombocytopenia, which allowed plasma exchange to be discontinued or avoided and prednisone to be rapidly discontinued. Two of the 3 responders have remained in unmaintained complete remission for 13+ months. The third patient relapsed at 13 months; a second course of rituximab and prednisone resulted in an unmaintained remission for 6+ months. All four patients were tested for ADAMTS-13 activity and its inhibitor at a point in their course when samples were available. Low ADAMTS-13 activity was noted in 3 patients tested at relapse, and the inhibitor activity was detectable in 2 patients. ADAMTS-13 activity increased during remission in one of these 2 patients although the patient had a persistence of the inhibitor. One patient tested only during remission had a normal ADAMTS-13 level. We conclude that rituximab may have a role and deserves further study in the treatment of patients with relapsing TTP.

High-dose cyclophosphamide with autologous lymphocyte-depleted peripheral blood stem cell (PBSC) support for treatment of refractory chronic autoimmune thrombocytopenia.

Patients with refractory chronic autoimmune thrombocytopenia (AITP) have a significant risk of morbidity and mortality related to hemorrhage. High-dose (HD) cytotoxic therapy may produce remissions but entails risks related to myelosuppression. Hematopoietic stem cell support with lymphocyte-depleted grafts may accelerate hematologic recovery and concomitantly reduce repopulation by autoreactive immunocytes. Fourteen patients with chronic AITP, in whom multiple prior therapies including corticosteroids, splenectomy, intravenous immunoglobulin, and various cytotoxic or immunomodulatory regimens had failed, were treated with HD cyclophosphamide (50 mg/kg/d) and autologous granulocyte colony-stimulating factor (G-CSF)-mobilized leukocytes depleted of lymphocytes by immunomagnetic CD34(+) selection. There were no significant adverse events related to G-CSF, intravenous device insertion, or leukapheresis. Treatment-related complications included transient hemorrhagic cystitis (1 patient), vaginal bleeding (2 patients), gastrointestinal bleeding (1 patient), epistaxis (1 patient), and antibiotic-responsive febrile neutropenia (all patients). The mean time to absolute neutrophil count (ANC) more than 500/mm(3) was 9 +/- 0.6 days. Eight patients experienced antibiotic-responsive gram-positive bacteremia. A median of 2 platelet transfusions was required for stem cell mobilization, intravenous catheter insertion, and apheresis and a median of 9 platelet transfusions was required during hematopoietic recovery. Six patients obtained durable complete responses (platelet counts > 100 000/mm(3) without other therapy) with maximum follow-up of 42 months. Two additional patients obtained durable partial responses (platelet counts significantly increased over baseline with reduced medication requirements and cessation of bleeding complications). This therapeutic approach is feasible for patients with severe chronic AITP, a substantial proportion of whom may obtain durable remissions. Larger controlled trials are recommended.