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D V Devine

Publications and source records attributed to D V Devine.

At least 19 recordsLinked to original sources
PubMed1992

Kinetic studies of the mechanism of thrombocytopenia in patients with human immunodeficiency virus infection.

BACKGROUND: Isolated thrombocytopenia accompanied by increased amounts of platelet-associated antibody is a common manifestation of human immunodeficiency virus (HIV) infection, and the thrombocytopenia often improves with zidovudine. It is not clear whether the mechanism of HIV-related thrombocytopenia primarily involves autoimmune destruction of platelets or reduced platelet production by megakaryocytes. METHODS: We studied the survival of 111In-labeled autologous platelets and performed platelet imaging in 24 men with isolated HIV-related thrombocytopenia (16 who received no treatment and 8 who received zidovudine). We also studied 20 HIV-infected men with normal platelet counts (10 who received no treatment and 10 who received zidovudine) and studied 12 healthy seronegative men as controls. RESULTS: Mean (+/- SD) platelet survival was significantly decreased in both the untreated and the zidovudine-treated patients with HIV-related thrombocytopenia (to 92 +/- 33 and 129 +/- 44 hours, respectively; both P < 0.001), as compared with the normal controls (198 +/- 15 hours). Mean platelet survival was also significantly decreased in the HIV-infected patients with normal platelet counts (untreated, 162 +/- 23 hours, P < 0.01; zidovudine-treated, 166 +/- 35 hours, P < 0.05). Imaging studies, however, revealed no evidence of increased clearance of autologous platelets in the liver or spleen in any of these groups. Mean platelet production was significantly depressed in the untreated patients with thrombocytopenia (23,000 +/- 11,000 platelets per cubic millimeter per day, P < 0.001) as compared with the healthy controls (45,000 +/- 6,000 per cubic millimeter per day). Mean platelet production was significantly increased, however, in the men treated with zidovudine, both in those with thrombocytopenia (60,000 +/- 31,000 platelets per cubic millimeter per day, P < 0.01 vs. controls) and in those without thrombocytopenia (68,000 +/- 22,000 per cubic millimeter per day, P < 0.01). CONCLUSIONS: Although there was a moderate reduction in platelet survival in HIV-infected persons, these patients, regardless of platelet counts, also had decreased production of platelets, possibly due to viral infection of the megakaryocytes. Zidovudine appears to improve platelet production.

Blood Platelets↗
PubMed1991

The role of surface charge in the activation of the classical and alternative pathways of complement by liposomes.

We have studied the complement-activating properties of liposomes. We show that surface charge is a key determinant of complement-activating liposomes. The nature of the charge, whether negative or positive, appears to dictate which pathway of the complement system is activated. Phosphatidylcholine:cholesterol (PC:CHOL, 55:45 mol/mol) liposomes were made to exhibit a positive or negative surface charge by the addition of cationic or anionic lipids, respectively. Normal human or guinea pig serum was incubated with liposomes, followed by determining the residual hemolytic activity of the serum as a measure of complement activation. Negatively charged liposomes containing phosphatidyl-glycerol, phosphatidic acid, cardiolipin, phosphatidylinositol, or phosphatidylserine activated complement in a Ca(2+)-dependent manner suggesting activation occurred via the classical pathway. Positively charged liposomes containing stearylamine or 1,2-bis(oleoyloxy)-3-(trimethylammonio)propane activated complement via the alternative pathway. Neutral liposomes, PC:CHOL (55:45) and PC:CHOL:dipalmitoylphosphatidylethanolamine (35:45:20), failed to activate complement as measured by the hemolytic assays. We show that unsaturated liposomes are more potent complement activators than saturated liposomes and that 45 mol% cholesterol promotes complement protein-liposome interactions. Immunoblot analysis of phosphatidylglycerol-containing liposomes showed that C3b and C9 were associated with these liposomes. Thus, the complement consumption measured in the hemolytic assays represents active cleavage of the complement components and not passive adsorption to the liposome surface. These studies suggest that membranes composed of net charged phospholipids can activate the complement system. This observation underlines the importance in biologic membranes of complement regulatory proteins that protect normal cells from complement attack.

Animals↗
PubMed1991

The regulation of complement on cell surfaces.

The regulation of complement at the surface of cells is mediated by both plasma and membrane proteins. These molecules act in concert to prevent the accelerated catabolism of complement proteins and the concomitant lysis of homologous blood cells. The deficiency of either a plasma or membrane protein predisposes to the development of disease.

Angioedema↗
PubMed1990

Steroid-responsive type II anti-factor VIII:C autoantibody in a nonhemophiliac child.

Acquired antibodies to factor VIII:C in nonhemophiliac patients are uncommon in adulthood and exceedingly rare in childhood. We report a girl, 9 years of age, with no personal or familial bleeding history who presented with hematuria and bruising 2 weeks after an upper respiratory infection. The activated partial thromboplastin time was 71.9 s (normal, 25-40 s) and did not correct by mixing 1:1 with normal plasma, suggesting the presence of an inhibitor. Factor VIII:C levels were detectable at 0.03 U/ml, but inhibition experiments demonstrated the presence of an inhibitor with an activity of 24 Bethesda U/ml. This inhibitor was localized to the immunoglobulin (IgG) fraction of the patient's plasma. Incubation of the patient's IgG with normal pooled plasma resulted in a 66% decrease in factor VIII:C activity. Unlike the antibodies found in most hemophilia patients, the autoantibody produced by this patient demonstrated type II kinetics and did not inhibit all factor VIII:C activity even at very high concentrations. In addition, the rate of factor VIII:C inactivation by this autoantibody was much slower than that seen with type I inhibitors. The treatment of the patient with prednisone, 2.5 mg/kg/day, resulted in the rapid disappearance of detectable inhibitor and a rise in factor VIII:C levels to 0.70 U/ml. Normal factor VIII:C levels persisted after the discontinuation of steroids. This case is most unusual in that it occurred in a child without any evidence of an underlying autoimmune disorder, and unlike classical hemophiliac factor VIII:C inhibitors, there was a rapid response to steroids.

Autoantibodies↗
PubMed1988

Cytofluorometric identification of plasmin-sensitive factor XIIIa binding to platelets.

We have investigated the binding of blood coagulation factor XIIIa to thrombin-stimulated platelets using cytofluorometric analysis. Washed thrombin-stimulated platelets bound exogenously added factor XIIIa in a calcium-dependent reaction. The expression of endogenous platelet factor XIII was also detected on the surface of thrombin-stimulated platelets. When fluorescence analysis was performed based on particle size, factor XIIIa bound to the surface of greater than 95% of particles which contained more than one platelet, but only 50% of single platelets. The binding of factor XIIIa to thrombin-stimulated platelets was inhibited by plasmin. Plasmin also inhibited thrombin-dependent expression of the factor XIIIa binding site on platelets. Experiments in which thrombin-stimulated platelets were incubated with factor XIIIa in the presence of 125I-dimethylcasein or 3H-putrescine demonstrated that platelets bear both glutamyl and lysyl substrates for factor XIIIa. Thrombin increased the expression of factor XIIIa substrates by platelets. Plasmin inhibited both the expression of factor XIIIa substrates and degraded them. The binding of factor XIIIa to thrombin-stimulated platelets and the availability of factor XIIIa substrates on the platelet surface could provide a mechanism by which factor XIIIa stabilizes the hemostatic plug by promoting crosslinking reactions between platelet membrane proteins and adhesive glycoproteins. In contrast, plasmin inhibition of factor XIIIa binding and crosslinking could disrupt hemostasis.

Blood Platelets↗
PubMed1988

Monoclonal antibody to fibrin D-dimer (DD-3B6) recognizes an epitope on the gamma-chain of fragment D.

Laboratory determination of fibrinolysis has been facilitated by diagnostic tests that use monoclonal antibody DD-3B6 to measure fibrin D-dimer levels in plasma. When DD-3B6 is reacted with soluble fibrin fragments, it is specific for fragment D-dimer. The authors have used immunoblot analysis of DD-3B6 binding to purified fragment D and fragment D-dimer to localize the binding site of the antibody. Although DD-3B6 recognizes only fragment D-dimer in solution, it binds to both immobilized fragment D-dimer and fragment D in immunoblots. When immunoblots were performed using protein which was electrophoresed under reducing conditions, DD-3B6 bound to the gamma-chain of fragments D1, D2, and D3. Therefore, the epitope recognized by DD-3B6 resides between amino acids 86 and 302 in the gamma-chain of fragment D. This epitope is masked in soluble non-cross-linked or nondegraded fibrin, but becomes expressed after cross-linked fibrin has been cleaved by plasmin.

Antibodies, Monoclonal↗
PubMed1988

The population of paroxysmal nocturnal hemoglobinuria neutrophils deficient in decay-accelerating factor is also deficient in alkaline phosphatase.

In patients with paroxysmal nocturnal hemoglobinuria (PNH) the RBCs, neutrophils (PMNs), monocytes, and platelets derived from the abnormal clone are deficient in the complement-regulatory protein decay-accelerating factor (DAF). RBC acetylcholinesterase (AChE) and leukocyte alkaline phosphatase (LAP) activities are also characteristically low. DAF, AChE, and LAP are known to be anchored within cell membranes to glycophospholipid-containing phosphatidylinositol (PI). Because PNH progenitors contain DAF that appears to be lost with maturation, it has been proposed that this disorder results from abnormal tethering of these and possibly other proteins to membrane PI. We were puzzled, therefore, that our two PNH patients consistently had normal LAP levels. Consequently, we studied their isolated PMNs to compare DAF and LAP activities in individual cells. PMNs were separated by flow cytometry into DAF-positive and -negative populations by using rabbit anti-DAF antiserum and fluorescein-conjugated goat antirabbit IgG. In both patients the majority of PMNs were DAF deficient, and these cells contained very little alkaline phosphatase activity. In contrast, the smaller, DAF-positive cell populations were phosphatase replete. This is the first demonstration that abnormalities in DAF and LAP activity occur in the same PNH PMN population and strengthens the hypothesis that defective anchoring of proteins to membrane glycophospholipid underlies the pathophysiology of this disorder.

Aged↗
PubMed1987

Evidence for the involvement of platelet glycoproteins other than GP Ib in heparin-associated thrombocytopenia and thrombosis.

Heparin-associated thrombocytopenia and thrombosis (HATT) is a potentially fatal complication of heparin therapy which is characterized by a progressive fall in the platelet count associated with arterial or venous thrombosis. The etiology is consistent with the development an antibody which, in the presence of heparin, induces intravascular platelet aggregation. Biochemical analysis has demonstrated that the platelet membrane glycoprotein (GP) Ib binds heparin. Recent studies have shown that polyclonal antisera or monoclonal antibodies to GP Ib can inhibit platelet aggregation induced by HATT plasma in the presence of heparin implicating GP Ib as the site of heparin-antibody interaction. The Bernard-Soulier syndrome (BSS) is an inherited bleeding disorder in which the platelets fail to adhere to exposed subendothelium due to a deficiency of GP Ib. We have used the platelets from a patient with documented BSS to further investigate the role of GP Ib in the heparin- dependent platelet aggregation induced by the plasma of three patients with HATT. We have shown that platelet aggregation by HATT plasma in the presence of heparin occurred as readily with BSS platelets as with normal donor platelets. These results indicate that glycoprotein Ib cannot be the only site of platelet-heparin-antibody interactions.

Bernard-Soulier Syndrome↗
PubMed1987

Regulation of the activity of platelet-bound C3 convertase of the alternative pathway of complement by platelet factor H.

The alternative pathway of complement is regulated on the surface of homologous blood cells at the C3 amplification step by the membrane protein decay-accelerating factor, as well as by the plasma protein factor H. We have reported elsewhere that platelets from patients with paroxysmal nocturnal hemoglobinuria regulate the activity of the C3 convertase C3bBb, even though they lack decay-accelerating factor. We now report that normal human platelets contain factor H, which was released from the platelet in response to complement deposition or thrombin stimulation. Factor H was localized to the platelet alpha granules by immunocytochemical techniques. As determined by a solid-phase radioimmunoassay, thrombin-stimulated platelets released approximately equal to 54 ng of factor H per 10(8) platelets. The release of factor H in response to complement or thrombin was inhibited by treating the platelets with metabolic inhibitors. Such inhibition resulted in a 3-fold increase in the activity of C3bBb. Platelets that released factor H bound only half as many molecules of radiolabeled factor B to platelet-bound C3b than platelets that could not release factor H. Treatment of platelets with anti-decay-accelerating factor antibody had no effect on the activity of C3bBb unless the release of factor H was blocked. Therefore, so far as we know, human platelets have a unique mechanism for the regulation of the alternative pathway of complement.

Complement Activating Enzymes↗
PubMed1987

Measurement of plasma fibrin D-dimer levels with the use of a monoclonal antibody coupled to latex beads.

Recently, monoclonal antibody (DD-3B6) to fibrin D-dimer was prepared and coupled to latex beads to provide a specific test (Dimertest) for fibrinolysis. The purpose of this study was to evaluate the Dimertest assay as a clinical laboratory test for the measurement of plasma fibrin D-dimer derivatives. The Dimer-test assay specifically detected 2 micrograms/mL of purified fibrin D-dimer or fibrin D-dimer/fragment E complex added to afibrinogenemic plasma but did not detect 500 micrograms/mL of either fibrinogen fragments X, D, E, or 160 micrograms/mL cross-linked fibrinogen. The fibrin(ogen) degradation product (FDP) assays of American Dade or Wellcome Diagnostics detected 5.0 micrograms/mL of fibrin D-dimer and from 1 to 10 micrograms/mL of the other FDPs. Twenty-eight percent of 150 random plasma samples assayed from hospitalized patients were positive for fibrin D-dimer derivatives. Plasma samples from 152 patients suspected of having disseminated intravascular coagulation (DIC) were assayed for serum FDP (Wellcome Diagnostics) and plasma fibrin D-dimer derivatives. Samples from 69% of patients with serum FDP levels less than 10 micrograms/mL, and more than 90% of those with serum FDP levels greater than 10 micrograms/mL, were positive for fibrin D-dimer derivatives. Dimertest results were not modified by heparin, streptokinase, freeze-thawing, or clotting plasma. Serum fibrinogen-related antigens were immunoadsorbed from Dimer-test positive sera by anti-fibrinogen antibody and formalin-fixed Cowan I strain Staphylococcus aureus. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting with the use of monoclonal antibody DD-3B6 demonstrated a protein band with similar mobility to purified D-dimer. The measurement of plasma fibrin D-dimer derivatives by the Dimertest assay is a rapid, sensitive, and specific laboratory test for fibrinolysis. The Dimertest assay has proven to be a useful addition to the clinical laboratory and should be helpful in the diagnosis and management of patients with diseases associated with fibrinolysis.

Antibodies, Monoclonal↗
PubMed1987

Interactions of the platelets in paroxysmal nocturnal hemoglobinuria with complement. Relationship to defects in the regulation of complement and to platelet survival in vivo.

The blood cells of patients with paroxysmal nocturnal hemoglobinuria (PNH) have abnormal interactions with complement. The activity of the alternative pathway C3 convertase on the platelets of 9 out of 19 patients with PNH was elevated. 10 patients had C3 convertase activity within the normal range even though 80-95% of their platelets lacked the complement regulatory protein decay accelerating factor (DAF) that is absent from the affected blood cells in PNH. PNH and normal platelets released factor H when C3 was bound to their surfaces. This may account for the apparent regulation of C3 convertase activity on platelets that lack DAF. The abnormal uptake of the membrane attack complex of complement by PNH III erythrocytes was not seen in PNH platelets. 111Indium-labeled platelet survival times were normal in five of eight patients, which suggests that the lack of the membrane attack complex defect results in normal platelet survival in PNH.

Blood Coagulation Factors↗
PubMed1987

Acute myeloblastic leukemia in paroxysmal nocturnal hemoglobinuria. Evidence of evolution from the abnormal paroxysmal nocturnal hemoglobinuria clone.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder in which the blood cells demonstrate aberrant interactions with serum complement. In part, this is due to the absence of the complement regulatory protein, decay accelerating factor (DAF). A small number of patients with PNH have gone on to develop acute nonlymphocytic leukemia, which is thought to arise from the injured marrow as a second hematopoietic disorder. We have studied a patient with PNH who developed acute myeloblastic leukemia (AML); the blasts from this patient were found to lack DAF as measured by polyclonal antibody binding and fluorescence flow cytometry as well as by immunoblotting. The blasts from 11 other patients with AML bound anti-DAF antibody in amounts similar to normal mononuclear cells from healthy donors. Cells of the human leukemia cell lines HL-60, K562, U937, and HEL also bound anti-DAF antibody. In addition to DAF deficiency, blasts from the PNH patient had undetectable alkaline phosphatase activity, in contrast to human leukemia cell lines. These data suggest that the leukemic cells of the PNH patient arose out of the PNH clone and that AML in the setting of PNH is not a separate disorder.

CD55 Antigens↗
PubMed1987

Pseudo-Bernard-Soulier syndrome: thrombocytopenia caused by autoantibody to platelet glycoprotein Ib.

The Bernard-Soulier syndrome is an inherited bleeding disorder that is due to a deficiency in platelet glycoprotein Ib. Bernard-Soulier platelets fail to agglutinate in response to ristocetin despite normal levels of factor VIII:von Willebrand factor. We report a patient who developed severe refractory thrombocytopenia postsurgically while receiving procainamide therapy. Thrombocytopenia was immune mediated since the patient's platelets bore high levels of antiplatelet antibody. Radioimmunoprecipitation studies demonstrated that the autoantibodies had specificity for platelet glycoproteins Ib and V as well as platelet HLA. The patient's plasma as well as purified immunoglobulin G completely inhibited the ristocetin-induced aggregation of normal platelets but did not inhibit adenosine diphosphate-induced aggregation. The laboratory studies revealed that this patient suffered from antibody-mediated thrombocytopenia with unusual characteristics that we have called pseudo-Bernard-Soulier syndrome.

Aged↗
PubMed1986

Restriction of the alternative pathway of human complement by intact Trypanosoma brucei subsp. gambiense.

We studied the interaction of African trypanosomes with human complement. Bloodstream forms of Trypanosoma brucei subsp. gambiense isolated from mice activated the alternative pathway of complement during a 30-min incubation in vitro. In human serum, all cells remained intact and motile during this period. C3 was detected on the surface by a direct binding assay with a monoclonal antibody which recognizes C3b and iC3b. C3 deposition could also be detected by this radioimmunoassay when parasites were incubated with purified C3. Such C3 binding was enhanced by factor B, factor D, and magnesium. Surface deposition of factor B was demonstrated both by flow immunofluorescence analysis and binding of radiolabeled factor B. C3 binding and factor B binding were inhibitable by EDTA but not by ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N' -tetraacetic acid (EGTA). The inhibited binding could be restored by addition of magnesium. No human immunoglobulin G or mouse immunoglobulin was detected on the trypanosome surface. By flow cytometry, neither human C5 nor polymerized C9 was detected on trypanosomes incubated in serum, although this assay was able to detect C5 and C9 on the surface of complement-treated human erythrocytes. Using a radioimmunoassay which measures C5b-9 in serum, we found that there was no generation of SC5b-9 in serum which had been incubated with trypanosomes. We concluded that, although trypanosomes activate the alternative pathway of complement, they are not lysed, because the cascade does not continue beyond the establishment of C3 convertase.

Animals↗
PubMed1986

Structural and functional differences between decay-accelerating factor and red cell acetylcholinesterase.

The abnormal erythrocytes in paroxysmal nocturnal hemoglobinuria, both PNH II (the moderately abnormal cells) and PNH III (the markedly abnormal cells), lack both acetylcholinesterase (AChE) activity and decay-accelerating factor (DAF) activity. Both of these activities are found on glycoprotein molecules with a molecular weight of about 70 Kd. To demonstrate that these two activities are in fact on different proteins, we have shown that binding to normal red cells of antibody to DAF does not inhibit the subsequent binding of monoclonal antibody to AChE nor AChE activity. Inhibition of DAF activity by polyclonal antibody increases the susceptibility of normal erythrocytes to lysis by complement but inhibition of AChE activity by antibody does not. The rate of decay of the C3 convertase complex of the classical pathway of complement activation was inhibited by DAF added in the fluid phase but not by AChE. When DAF was exhaustively immunoprecipitated from a solution of the erythrocyte membrane proteins, AChE remained and vice versa. These studies indicate that acetylcholinesterase and decay-accelerating factor are two different proteins, both of which are lacking on PNH II and PNH III erythrocytes.

Acetylcholinesterase↗