The clinical spectrum of HbSC sickle cell disease-not a benign condition.

Sickle cell disease (SCD) includes a group of heterogenous disorders that result in significant morbidities. HbSS is the most common type of SCD and HbSC is the second most common type of SCD. The prevalence of HbSC disease in the United States and United Kingdom is ~1 in 7174 births and 1 in 6174 births respectively. Despite its frequency, however, HbSC disease has been insufficiently studied and was historically categorized as a more 'mild' form of SCD. We conducted this study of HbSC disease as part of the NHLBI funded Sickle Cell Disease Implementation Consortium (SCDIC). The SCDIC registry included 2282 individuals with SCD, ages 15-45 years of whom 502 (22%) had HbSC disease. Compared with people with sickle cell anaemia (SCA), the study found that people with HbSC disease had a higher frequency of splenomegaly (n (%) = 169 (33.7) vs. 392 (22.1)) and retinopathy (n (%) = 116 (23.1) vs. 189 (10.6)). A Many people with HbSC also had avascular necrosis (n (%) = 112 (22.3)), pulmonary embolism (n (%) = 43 (8.6)) and acute chest syndrome (n (%) = 228 (45.4)) demonstrating significant disease severity. HbSC disease is more clinically severe than was previously recognized and deserves additional evaluation and targeted treatments.

Effect of autologous hematopoietic stem cell transplant on the development of second primary malignancies in multiple myeloma patients.

Autologous stem cell transplant (aHSCT) is associated with improved survival for multiple myeloma (MM) patients but may be associated with second primary malignancy (SPM) development. Using the California Cancer Registry linked to statewide hospitalization data, we determined the cumulative incidence (CMI) of SPMs more than 1 year after MM diagnosis, accounting for the competing risk of death. AHSCT recipients were matched 1:2 to non-aHSCT patients. Adjusted hazard ratios (aHR) were estimated using the Fine and Gray method. Among 16,331 patients, 933 (5.7%) developed a SPM more than 1 year after diagnosis. The 10-year CMI of developing any SPM was 6.6%, 5.7% for solid tumor SPM and 0.9% for hematologic malignancies. The 10-year CMI of developing any SPM was similar among aHSCT [9.1% (7.7-10.7%)] and non-aHSCT [7.5% (6.5-8.6%)] (P = 0.26) recipients and there was no difference in solid-tumor SPMs (P = 0.98). The 10-year CMI of hematologic SPMs was higher among aHSCT recipients [2.1% (1.4-2.9%) vs. 0.8% (0.5-1.2%); P = 0.005], corresponding to a 1.3% absolute increase and an aHR of 1.51 (1.01-2.27). Ten-year myeloma-specific and non-cancer mortality rates were 59% (58.2-60.0%) and 18.1% (17.4-18.8%), respectively. Although aHSCT was associated with a small increase in hematologic SPMs, mortality was driven by MM and non-cancer causes.

Secondary acute lymphoblastic leukemia is a distinct clinical entity with prognostic significance.

The effect of prior malignancy on the risk of developing, and prognosis of, acute lymphoblastic leukemia (ALL) is unknown. This observational study utilized the California Cancer Registry to estimate the risk of developing ALL after a prior malignancy using standardized incidence ratios (SIRs, 95% confidence intervals). ALL occurring after a malignancy with an SIR>1 (increased-risk (IR) malignancies) was considered secondary ALL (s-ALL). Adjusted hazard ratios (aHRs, 95% confidence intervals) compared the effect of s-ALL with de novo ALL on overall survival. A total of 14 481 patients with ALL were identified (1988-2012) and 382 (3%) had a known prior malignancy. Any prior malignancy predisposed patients to developing ALL: SIR 1.62 (1.45-1.79). Hematologic malignancies (SIR 5.57, 4.38-6.98) and IR-solid tumors (SIR 2.11, 1.73-2.54) increased the risk of developing ALL. s-ALL increased the risk of death compared with de novo ALL (aHR 1.38 (1.16-1.63)) and this effect was more pronounced among younger patients (age<40 years: aHR 4.80 (3.15-7.30); age⩾40 years: aHR 1.40 (1.16-1.69)) (interaction P<0.001). This population-based study demonstrates that s-ALL is a distinct entity that occurs after specific malignancies and carries a poor prognosis compared with de novo ALL, particularly among patients <40 years of age.

Potent cardioprotection from ischemia-reperfusion injury by a two-domain fusion protein comprising annexin V and Kunitz protease inhibitor.

BACKGROUND: Considerable evidence suggests that coagulation proteases (tissue factor [TF]/activated factor VII [FVIIa]/FXa/thrombin) and their target protease activated receptors (PAR-1/PAR-2) play important roles in myocardial ischemia-reperfusion (I-R) injury. We hypothesized that localized inhibition of TF/FVIIa on the membrane surfaces of ischemic cells could effectively block coagulation cascade and subsequent PAR-1/PAR-2 cell signaling, thereby protecting the myocardium from I-R injury. OBJECTIVES: We recently developed an annexin V-Kunitz inhibitor fusion protein (ANV-6L15) that could specifically bind to anionic phospholipids on the membrane surfaces of apoptotic cells and efficiently inhibit the membrane-anchored TF/FVIIa. In this study, we investigated the cardioprotective effect of ANV-6L15 in a rat cardiac I-R model in comparison with that of hirudin. METHODS: Left coronary artery occlusion was maintained for 45 min followed by 4 h of reperfusion in anesthetized Sprague-Dawley rats. One minute before or 2 min after coronary ligation, rats received an intravenous bolus injection of ANV-6L15 (2.5-250 µg kg(-1) ), vehicle, or hirudin via bolus injection and continuous infusion. RESULTS AND CONCLUSIONS: ANV-6L15 dose-dependently reduced infarct size by up to 87% and decreased plasma levels of cardiac troponin I, tumor necrosis factor-α, and soluble intercellular adhesion molecule-1, by up to 97%, 96%, and 66%, respectively, with little impact on the coagulation parameters. ANV-6L15 also ameliorated hemodynamic derangements, attenuated neutrophil infiltration and reduced Terminal deoxynucleotidyl transferase dUTP nick end labeling-positive apoptotic cardiomyocytes. Hirudin was less efficacious even at supraclinical dose. ANV-6L15 confers exceptionally potent cardioprotection and is a promising drug candidate for the prevention of myocardial I-R injury.

Recurrent venous thromboembolism after surgery-provoked versus unprovoked thromboembolism.

SUMMARY BACKGROUND: The incidence of recurrent venous thromboembolism (VTE) varies depending on the nature of the initial provoking risk factor(s). OBJECTIVES: To compare the incidence and time course of recurrent VTE after unprovoked VTE vs. VTE provoked by nine different types of surgery. METHODS: Retrospective analysis of linked California hospital and emergency department discharge records. Between 1997 and 2007, all surgery-provoked VTE cases had a first-time VTE event diagnosed within 60 days after undergoing a major operation. The incidence of recurrent VTE was compared during specified follow-up periods by matching each surgery-provoked case with three unprovoked cases based on age, race, gender, VTE event, calendar year and co-morbidity. RESULTS: The 4-year Kaplan-Meier cumulative incidence of recurrent VTE was 14.7% (95%CI: 14.2-15.1) in the matched unprovoked VTE group vs. 7.6% (CI: 7.0-8.2) in 11 797 patients with surgery-provoked VTE (P < 0.001). The overall risk reduction was 48%, which ranged from 64% lower risk (P < 0.001) after coronary bypass surgery to 25% lower risk (P = 0.06) after disc surgery. The risk of recurrent VTE 1-5 years after the index event was significantly lower in the surgery group (HR = 0.47, CI: 0.41-0.53). Within the surgery-provoked group, the risk of recurrent VTE was similar in men and women (HR = 1.0, CI: 0.8-1.3). CONCLUSIONS: The risk of recurrent VTE after surgery-provoked VTE was approximately 50% lower than after unprovoked VTE, confirming the view that provoked VTE is associated with a lower risk of recurrent VTE. However, there was appreciable heterogeneity in the relative risk of recurrent VTE associated with different operations.

The incidence of venous thromboembolism among patients with primary lung cancer.

BACKGROUND: The incidence of venous thromboembolism (VTE) by lung cancer histology and stage is unknown. OBJECTIVES: To determine the incidence of VTE and the risk factors associated with development of VTE in a large population-based study of patients with non-small cell and small cell lung cancer. METHODS: The California Cancer Registry was merged with the Patient Discharge Data Set to determine the incidence of VTE among lung cancer cases diagnosed between 1993 and 1999. RESULTS: Among 91 933 patients with newly diagnosed lung cancer, the 1-year and 2-year cumulative VTE incidences were 3.0% and 3.4%, respectively, with a person-time rate of 7.2 events/100 patient-years during the first 6 months. The 1-year incidence of VTE was significantly increased in comparison to the general population [standardized incidence ratio = 21.2, 95% confidence interval (CI) = 20.4-22.0]. In a multivariate model, significant predictors of developing VTE within 1 year of non-small cell lung cancer (NSCLC) diagnosis were: younger age, the number of chronic medical comorbidities [hazard ratio (HR) = 2.8 if 3 vs. 0, 95% CI = 2.5-3.1], advancing cancer stage (HR = 4.0 for metastatic vs. local disease, 95% CI = 3.4-4.6) and adenocarcinoma histology (HR = 1.9 vs. squamous cell, 95% CI = 1.7-2.1). In multivariate models, VTE was a significant predictor of death within 2 years for both NSCLC and small cell lung cancer (SCLC), HR = 2.3, 95% CI = 2.2-2.4, and HR = 1.5, 95% CI = 1.3-1.7, respectively. CONCLUSIONS: Approximately 3% of lung cancer patients developed VTE within 2 years. The diagnosis of VTE was associated with a higher risk of death within 2 years for NSCLC and SCLC.

Filgrastim treatment of acute myelogenous leukemia (M7) relapse after allogeneic peripheral stem cell transplantation resulting in both graft-versus-leukemia effect with cytogenetic remission and chronic graft-versus-host disease manifesting as polyserositis and subsequent bronchiolitis obliterans with organizing pneumonia.

Filgrastim (granulocyte colony-stimulating factor) has recently been reported to successfully treat patients with leukemic relapse after allogeneic peripheral stem cell transplantation (PSCT). However, the majority of the patients who responded also developed graft-versus-host disease (GVHD). Polyserositis as a manifestation of GVHD is a rare phenomenon. We report the first case of polyserositis following the use of filgrastim to treat a patient with acute myelogenous leukemia (M7), who had relapsed after an initially successful allogeneic PSCT. The polyserositis manifested with effusions and was initially controlled with high doses of steroids and pericardial stripping; however, after a quiescent period the patient eventually developed bronchiolitis obliterans with organizing pneumonia that required additional immunosuppressive therapy. We review the literature on GVHD-associated polyserositis and offer potential explanations for its pathogenesis.

Isolated cavernous sinus extramedullary relapse of chronic myelogenous leukemia following allogeneic stem cell transplant.

Isolated extramedullary relapse of chronic myelogenous leukemia (CML) after allogeneic stem cell transplant is rare. A case is reported of a patient who developed a granulocytic sarcoma of the cavernous sinus 7 months after allogeneic transplant for CML. He presented with neurologic deficits, and a mass lesion was found on imaging. No evidence of hematologic relapse was identified by bone marrow histology or cytogenetics. A premortem diagnosis was not possible, and the patient died 2 months later of an intracerebral hemorrhage after receiving various therapies directed against a presumed infectious etiology. Granulocytic sarcoma should be considered in the differential diagnosis of mass lesions presenting after allogeneic transplant for CML, even if there is no evidence of medullary disease.

Purified poloxamer 188 for treatment of acute vaso-occlusive crisis of sickle cell disease: A randomized controlled trial.

CONTEXT: Sickle cell disease (SCD) can cause severe painful episodes that are often thought to be caused by vaso-occlusion. The current therapy for these uncomplicated painful episodes includes hydration, oxygen, and analgesics. Purified poloxamer 188 may increase tissue oxygenation and thereby reduce inflammation, pain, and the overall duration of such painful episodes in patients with SCD. OBJECTIVE: To compare the duration of painful episodes in patients with SCD treated with purified poloxamer 188 to that of similar episodes experienced by patients who receive a placebo. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled, intention-to-treat trial conducted between March 1998 and October 1999 in 40 medical centers in the United States. PARTICIPANTS: Two hundred fifty-five patients with SCD (aged 9-53 years) who had a painful episode sufficiently severe to require hospitalization and narcotic analgesics. INTERVENTION: Patients were randomly assigned to receive an intravenous infusion of purified poloxamer 188, 100 mg/kg for 1 hour followed by 30 mg/kg per hour for 47 hours (n = 127), or a matching volume of saline placebo (n = 128). MAIN OUTCOME MEASURE: Duration of the painful episode, from randomization to crisis resolution. RESULTS: Mean (SD) duration of the painful episodes was 141 (42) hours in the placebo group compared with 133 (41) hours in those treated with purified poloxamer 188, a 9-hour reduction (P =.04). Subset analyses indicated an even more pronounced purified poloxamer 188 effect in children aged 15 years or younger (21 hours; P =.01) and in patients who were receiving hydroxyurea (16 hours; P =.02). Finally, the proportion of patients achieving crisis resolution was increased by purified poloxamer 188 (65/126 [52%] vs 45/123 [37%]; P =.02). Similar results were observed in children aged 15 years or younger (22/37 [60%] vs 10/36 [28%]; P =.009) and in patients who were also receiving hydroxyurea (12/26 [46%] vs 4/28 [14%]; P =.02). CONCLUSIONS: A decrease in the duration of painful episodes and an increase in the proportion of patients who achieved resolution of the symptoms were observed when the purified poloxamer 188-treated patients were compared with the patients receiving placebo. However, the difference between these groups was significant but relatively small. In subgroup analysis, a more significant effect on both parameters was observed in children and in patients who were receiving concomitant hydroxyurea. It is important to confirm both of these observations in further prospective trials.

Radioimmunotherapy: potential as a therapeutic strategy in non-Hodgkin's lymphoma.

Lymphomas are the fifth most common malignancy in the United States and are increasing in incidence. Despite being among the most responsive malignancies to radiation and chemotherapy, the majority of patients relapse or have progressive disease. Monoclonal antibodies (MAbs) directed at cell-specific surface antigens have been useful in the diagnosis of lymphomas and, more recently, the therapeutic mouse-human chimeric MAb rituximab has demonstrated effectiveness in B cell lymphomas. Conjugating MAbs to radionuclides is a strategy for improving the efficacy of MAb lymphoma therapy by delivering radiation in close proximity to the tumour (radioimmunotherapy or RIT). In addition, the low dose rate of the delivered radiation may exert a greater antitumour activity than an equivalent dose of conventional external beam radiation. The antigenic targets for MAb therapy have included CD20, CD22, HLA-DR, and B cell idiotype. Radionuclides that have been used include iodine-131, yttrium-90, and copper-67; there are relative merits and disadvantages to each source of radiation. Clinical studies to date have focused on relapsed and refractory patients with both indolent and aggressive lymphomas, although more recent studies have included previously untreated patients with indolent lymphoma. Radioimmunoconjugate has been delivered as either single or multiple doses. Response rates have varied widely, dependent on the patient population and the response criteria. Of note, complete responses can be achieved in this typically refractory patient group. Toxicities have generally consisted of mild infusion-related nausea, fever, chills, and asthenia. Neutropenia and thrombocytopenia are the dose-limiting toxicities and have prompted the incorporation of autologous stem cell support as a means of achieving dose escalation. To date, RIT has been delivered to highly selected patients in relatively few centres with requisite equipment and specialised personnel. In addition to these requirements, cost is likely to be a barrier to widespread use. The combination of RIT with chemotherapy at conventional or high dose, or with biological agents is a fertile area for investigation. The potential of RIT in the treatment for lymphomas will be defined only by well designed comparative prospective clinical studies.

Recombinant tissue factor pathway inhibitor enhances the binding of factor Xa to human monocytes.

Tissue factor pathway inhibitor (TFPI) is a kunitz-type inhibitor of activated factor X (Xa). TFPI was reported to mediate Xa binding to a few of carcinoma cell lines. In this study it was observed that the Xa activity associated with human peripheral blood mononuclear cells (PBMC) incubated with Xa in the presence of recombinant TFPI (rTFPI) was much higher than with Xa alone. Xa activity on PBMC was also observed after whole blood was incubated with pre-formed Xa/TFPI complex. Further studies with flow cytometric analysis demonstrate that rTFPI enhances the binding of Xa to human monocytes. Western blot analysis showed that rTFPI was cleaved into a few of fragments after its incubation with monocytes either in the presence or absence of Xa. Based on these results and the observations reported by others, we speculate that Xa/TFPI complex may bind to human monocytes by a yet unidentified mechanism. The recovery of Xa activity from Xa/TFPI complex on PBMC may be related to the cleavage of rTFPI by Xa and/or monocyte proteases. This observation suggests a new mechanism by which monocytes become procoagulant in some pathological conditions in addition of the well known tissue factor expression on proinflammatic monocytes.

Correlation of abnormal intracranial vessel velocity, measured by transcranial Doppler ultrasonography, with abnormal conjunctival vessel velocity, measured by computer-assisted intravital microscopy, in sickle cell disease.

The Stroke Prevention Trial has confirmed that utilization of transcranial Doppler ultrasonography (TCD), which examines blood flow in large intracranial vessels, can identify children with sickle cell disease (SCD) who are at high risk of developing a premature stroke. It is not known to what extent the vasculopathy in SCD involves small vessels and whether the abnormalities, if present, correlate with large-vessel vasculopathy. Eighteen children with SCD were examined with TCD to determine middle cerebral artery (MCA) velocity and computer-assisted intravital microscopy (CAIM) to determine bulbar conjunctival vessel velocity during the same visit for vasculopathy correlation. High MCA velocity (> or = 200 cm/sec) was found by TCD in 4 patients who also showed abnormal conjunctival velocity (< 0.2 mm/sec or intermittent trickle flow) by CAIM. Three patients had conditional (> or = 170 cm/sec and < 200 cm/sec) MCA velocity: 2 showed abnormal (trickle) and 1 showed normal conjunctival velocity (1.9 mm/sec). One patient with unmeasurable MCA velocity had abnormal (trickle) conjunctival velocity. Of the remaining 10 patients who had normal MCA velocity, 2 showed abnormal (0.05 mm/sec and 0.1 mm/sec) and 8 showed normal conjunctival velocities (1.1-2.4 mm/sec). The MCA velocities correlated significantly with bulbar conjunctival flow velocities (P < or =.008, Fisher exact test). A correlation exists between MCA (large-vessel) and conjunctival (small-vessel) flow velocities. CAIM is a noninvasive quantitative technique that might contribute to the identification of SCD patients at high risk of stroke. Small-vessel vasculopathy might be an important pathological indicator and should be further explored in a large-scale study. (Blood. 2001;97:3401-3404)

Prospective evaluation of cancer clinical trial accrual patterns: identifying potential barriers to enrollment.

PURPOSE: Well-conducted cancer clinical trials are essential for improving patient outcomes. Unfortunately, only 3% of new cancer patients participate in clinical trials. Barriers to patient accrual in cancer clinical trials must be identified and overcome to increase patient participation. MATERIALS AND METHODS: We prospectively tracked factors that potentially affected patient accrual into cancer clinical trials at the University of California Davis Cancer Center. Oncologists seeing new outpatients were asked to complete questionnaires regarding patient characteristics and the physician's decision-making on patient eligibility, protocol availability, and patient opinions on participation. Statistical analysis was performed to correlate these parameters with subsequent protocol accrual. RESULTS: There were 276 assessable patients. At the initial visits, physicians did not consider clinical trials in 38% (105/276) of patients principally because of a perception of protocol unavailability and poor performance status. Physicians considered 62% (171/276) of patients for participation in clinical trials. Of these, only 53% (91/171) had an appropriate protocol available for site and stage of disease. Seventy-six of 90 patients (84%) with available protocols met eligibility criteria for a particular study. Only 39 of 76 patients (51%) agreed to participate in cancer clinical trials, for an overall accrual rate of 14% (39/276). The remainder (37/76, 49%) declined trial participation despite meeting eligibility criteria. The most common reasons were a desire for other treatment (34%), distance from the cancer center (13%), patient refusal to disclose reason (11%), and insurance denial (8%). Patients with private insurance were less likely to enroll in clinical trials compared to those with government-funded insurance (OR, 0.34; P =.03; 95% CI, 0.13 to 0.9). CONCLUSION: Barriers to cancer clinical trial accrual can be prospectively identified and addressed in the development and conduct of future studies, which may potentially lead to more robust clinical trials enrollment. Investigation of patient perceptions regarding the clinical trials process and the role of third party-payers is warranted.

Comparison of the L10M consolidation regimen to an alternative regimen including escalating methotrexate/L-asparaginase for adult acute lymphoblastic leukemia: a Southwest Oncology Group Study.

The effectiveness of intensive post-remission chemotherapy regimens for adult patients with acute lymphoblastic leukemia (ALL) is limited by both a high rate of disease recurrence and a substantial incidence of treatment toxicity. To evaluate a potentially more effective and less toxic approach, we conducted a multicenter phase III trial of consolidation therapies comparing the standard L10M regimen with one combining the brief, intensive L17M regimen and escalating methotrexate (MTX) and L-asparaginase (L-asp). Patients over age 15 with previously untreated ALL were eligible. Induction therapy included vincristine, prednisone, doxorubicin, cyclophosphamide and intrathecal methotrexate administered over 36 days. Patients who achieved complete remission (CR) were randomized to receive consolidation with either the L10M regimen or with DAT (daunomycin, cytosine arabinoside, 6-thioguanine) and escalating MTX and L-asp. The randomization was stratified by age, WBC and Ph chromosome status. Maintenance therapy was the same in both arms. Of 353 eligible patients, 218 (62%) achieved CR and 195 were randomized. The treatment arms did not differ significantly with respect to disease-free survival (DFS; P= 0.46) or overall survival (P= 0.39). Estimated DFS at 5 years was 32% (95% confidence interval (CI) 23-42%) in the L10M arm and 25% (95% CI 16-33%) in the DAT/MTX/L-asp arm. In each arm, 4% of patients died of toxicities (infection in all but one case). Infections and nausea/vomiting were somewhat more common in the L10M arm (occurring in 68% and 53% of patients respectively) than the DAT/MTX/L-asp arm (56% and 33%). The DAT/MTX/L-asp consolidation regimen was associated with some reduction in nonfatal toxicities, but no significant improvement in DFS, overall survival or non-relapse mortality when compared to the standard L10M regimen.

Cocoa and wine polyphenols modulate platelet activation and function.

There is speculation that dietary polyphenols can provide cardioprotective effects due to direct antioxidant or antithrombotic mechanisms. We report in vitro and postingestion ex vivo effects of cocoa procyanidins, a procyanidin-rich cocoa beverage and dealcoholized red wine (DRW) on human platelet activation. In a series of in vitro studies, cocoa procyanidin trimers, pentamers or DRW (3 and 10 micromol/L) were incubated with citrated peripheral whole blood in the presence and absence of platelet agonists. Platelet activation was detected using fluorescent-labeled monoclonal antibodies recognizing the fibrinogen binding conformation of GPIIb-IIIa (referred to herein as PAC-1 binding) and the activation-dependent platelet epitope CD62P (P-selectin). The percentage of CD42a-positive platelets coexpressing PAC-1 binding and/or CD62P was determined by multiparameter flow cytometry. Procyanidin trimers, pentamers and DRW added to whole blood in vitro increased PAC-1 binding and P-selectin expression. In contrast, procyanidin trimers, pentamers and DRW inhibited the platelet activation in response to epinephrine. The effects on platelet activation of cocoa beverage and DRW consumption were also studied in healthy subjects. Citrated blood was obtained before and 2 and 6 h after the ingestion of a cocoa beverage, a caffeine-containing beverage, DRW or water. Platelet activation was measured by flow cytometry. The consumption of DRW did not affect the expression of activation-dependent platelet antigens, either unstimulated or after ex vivo activation with epinephrine. However, the consumption of DRW increased PAC-1 binding in response to 100 micromol/L ADP ex vivo. Cocoa consumption reduced platelet response to agonists ex vivo. The ingestion of water had no effect on platelet activation, whereas a caffeine-containing beverage augmented the response of platelets to epinephrine. In summary, select cocoa procyanidins and DRW added to whole blood in vitro increased expression of platelet activation markers in unstimulated platelets but suppressed the platelet activation response to epinephrine. In contrast, cocoa consumption suppressed unstimulated and stimulated platelet activation in whole blood. This suppressive effect observed on platelet reactivity may explain in part the reported cardioprotective effects of dietary polyphenols.

Matrix metalloproteinases cleave tissue factor pathway inhibitor. Effects on coagulation.

The capacity of inflammatory cell-derived matrix metalloproteinases (MMPs) to cleave tissue factor pathway inhibitor (TFPI) and alter its activity was investigated. MMP-7 (matrilysin) rapidly cleaved TFPI to a major 35-kDa product. In contrast, MMP-1 (collagenase-1), MMP-9 (gelatinase B), and MMP-12 (macrophage elastase) cleaved TFPI into several fragments including the 35-kDa band. However, rates of cleavage were most rapid for MMP-7 and MMP-9. NH(2)-terminal amino acid sequencing revealed that MMP-12 cleaved TFPI at Lys(20)-Leu(21)(close to Kunitz I domain and producing a 35-kDa band), Arg(83)-Ile(84) (between Kunitz I and II domains), and Ser(174)-Thr(175) (between Kunitz II and III domains). MMP-7 and MMP-9 cleaved TFPI at Lys(20)-Leu(21) with additional COOH-terminal processing. These MMPs did not cleave tissue factor (TF), factor VII, and factor Xa. Proteolytic cleavage by MMP-1, MMP-7, MMP-9, and MMP-12 resulted in considerable loss of TFPI activity. These observations indicate specific cleavage of TFPI by MMPs, which broadens their substrate profile. Co-localization of MMPs, TF, and TFPI in atherosclerotic tissues suggests that release of MMPs from inflammatory cell leukocytes may effect TF-mediated coagulation.

Cocoa inhibits platelet activation and function.

BACKGROUND: Epidemiologic studies have shown inverse associations between dietary polyphenols and mortality from coronary heart disease. However, the basis for this protective association is uncertain. Food polyphenols reportedly have antioxidant properties and decrease platelet function in vitro. OBJECTIVE: This study sought to evaluate whether consumption of a polyphenol-rich cocoa beverage modulates human platelet activation and primary hemostasis. DESIGN: Peripheral blood was obtained from 30 healthy subjects before and 2 and 6 h after ingestion of a cocoa beverage (n = 10), a caffeine-containing control beverage (n = 10), or water (n = 10). Platelet activation was measured in terms of expression of activation-dependent platelet antigens and platelet microparticle formation by using fluorescent-labeled monoclonal antibodies and flow cytometry. Primary platelet-related hemostasis was measured with a platelet function analyzer. RESULTS: Ex vivo epinephrine- or ADP-stimulated expression of the fibrinogen-binding conformation of glycoprotein IIb-IIIa was lower 2 and 6 h after consumption of cocoa than before consumption. Cocoa consumption also decreased ADP-stimulated P-selectin expression. In contrast, epinephrine-induced platelet glycoprotein IIb-IIIa expression increased after consumption of the caffeine-containing beverage but not after water consumption. Platelet microparticle formation decreased 2 and 6 h after cocoa consumption but increased after caffeine and water consumption. Primary hemostasis in response to epinephrine in vitro was inhibited 6 h after cocoa consumption. The caffeine-containing beverage inhibited ADP-induced primary hemostasis 2 and 6 h after consumption. CONCLUSIONS: Cocoa consumption suppressed ADP- or epinephrine-stimulated platelet activation and platelet microparticle formation. Cocoa consumption had an aspirin-like effect on primary hemostasis.

A phase I study of 90Y-2IT-BAD-Lym-1 in patients with non-Hodgkin's lymphoma.

BACKGROUND: Prior clinical trials proved that all histologic grades of chemotherapy-resistant B-cell non-Hodgkin's lymphoma (NHL) could respond to radio-immunotherapy (RIT) with 131I-Lym-1 and 67Cu-2IT-BAT-Lym-1. This Phase I study was conducted to determine the safety and maximum tolerated dose (MTD) of 90Y-2IT-BAD-Lym-1. METHODS: Lym-1 is a mouse monoclonal antibody that preferentially targets malignant B-lymphocytes. 90Y has beta emissions suitable for therapy but no gamma emissions, therefore, 111In-2IT-BAD-Lym-1 is used for imaging. The macrocyclic chelator, DOTA, bound 90Y tightly to form a stable drug. Patients with chemotherapy-resistant NHL received 90Y-2IT-BAD-Lym-1 at administered doses of: 0.185, 0.278, or 0.370 GBq/m2. RESULTS: Myelotoxicity, especially thrombocytopenia, was dose-limiting. No significant non-hematologic toxicity occurred. Human anti-mouse antibody (HAMA) developed in 3/8 patients. The mean radiation dose to the 33 imaged tumors was 7.0 Gy/GBq. Lung, kidney and liver received mean radiation doses of 1.3, 2.4, and 6.4 Gy/GBq, respectively from 90Y-2IT-BAD-Lym-1. The tumor: body and tumor:bone marrow (by imaging) ratios were 16.4:1 and 5.8:1, respectively. In this Phase I study, 5/8 patients that failed prior chemotherapy had a partial response or stabilization of NHL after RIT. CONCLUSION: The safety and toxicity of 90Y-2IT-BAD-Lym-1 were determined and the MTD was 0.370 GBq/m2, a dose used in 4 patients. 90Y-2IT-BAD-Lym-1 may be useful for future clinical trials because 90Y is readily available and can deliver potent beta emissions to NHL. Bone marrow support however, will be required for further dose escalation.

The Role of Inflammation and Leukocytes in the Pathogenesis of Sickle Cell Disease.

Acute and chronic vascular occlusion underlies much of the morbidity and mortality in sickle disease. Abnormal polymerization of deoxygenated hemoglobin S (HbS) resulting in stiff, non-deformable erythrocytes is central to sickle cell pathogenesis. However, a complex interplay of many factors determines the balance between adequate blood flow and vessel obstruction. Serum markers of inflammation have provided evidence for a state of chronic inflammation in sickle cell disease (SCD). Inflammation promotes endothelial adherence to sickle erythrocytes. Studies demonstrating a beneficial effect of steroid therapy for painful episodes and acute chest syndrome provide indirect evidence for the role of inflammation in this disease. Leukocytosis, in the absence of infection, is common in SCD patients and predicts for stroke, acute chest syndrome, and overall mortality. Neutrophils and monocytes have been shown to be activated in these patients. Activated leukocytes further promote vascular inflammation and vessel damage. A reduction in leukocytes, and thus inflammation, may partially explain the beneficial effects of hydroxyurea in this disease. These data provide a strong rationale for clinical studies of therapy directed at inflammation and/or leukocytes in sickle cell disease.

Platelet-erythrocyte adhesion in sickle cell disease.

BACKGROUND: The abnormal adherence of sickle red blood cells (sRBC) to other cell types likely contributes to vaso-occlusion. Increased numbers of platelet-erythrocyte aggregates (PEA) and platelet activation have been described in sickle cell disease. The present study was undertaken to determine the contribution, if any, of the extracellular matrix protein thrombospondin to the adhesion of sRBC and platelets. METHODS: Platelet activation and PEA were measured using fluorescent-labeled monoclonal antibodies and flow cytometry. Platelet red-cell adhesion was measured by a gravity sedimentation assay. Erythrocyte-bound thrombospondin (TSP) was determined by enzyme-linked immunoabsorbant assay (ELISA). RESULTS: Our studies demonstrate significant platelet activation and adhesion of sRBC to platelets in sickle cell disease. Thrombospondin was detected on sRBC. There was variable inhibition of sRBC-platelet adhesion by antibodies to CD36 (thrombospondin receptor) and antibodies to thrombospondin. CONCLUSIONS: Thrombospondin on sRBC may mediate, at least in part, sRBC-platelet adhesion in sickle cell disease. The study of heterotypic cell-cell interactions is important in understanding the pathogenesis of vaso-occlusion in sickle cell disease.