Acute promyelocytic leukemia. Management of the coagulopathy during daunorubicin-prednisone remission induction.

Seven adults with acute promyelocytic leukemia (APL) and disseminated intravascular coagulation were treated for remission induction with daunorubicin hydrochloride and prednisone. In all patients the coagulopathy was managed with continuous-infusion heparin sodium and vigorous transfusion with platelets, cryoprecipitate, and fresh frozen plasma. Five patients survived induction; they all achieved complete remission (CR). Median duration of CR was 27 + months; two patients presently survive in their initial CR at 28 and 48 months. Recognition of APL as a distinct type of acute leukemia and prompt initiation of treatment aimed at rapid cytoreduction and control of the coagulopathy has resulted in a prolonged disease-free survival for the majority of patients.

Antigenic differences among bovine and porcine Factor VIII concentrates.

Three anti-Factor-VIII antibodies from hemophiliacs were reacted with samples of batches of Maws commerical bovine and porcine Factor VIII concentrates manufactured over a 12-year period. The apparent antibody concentrations varied widely with the different batches of concentrates. The variations are probably due to intrinsic differences in the antigenic nature of the Factor VIII in the different preparations. With the older porcine concentrates, the low apparent concentrations may be in part due to the reaction of antibody with inactive Factor VIII. When animal Factor VIII concentrates are used in treating hemophiliac patients who have anti-Factor-VIII antibodies, the least reactive batch should be chosen. Random batches of animal concentrates are not suited as a standard for measuring anti-Factor-VIII antibody concentration.

Heparin cofactor II assay. Elimination of heparin and antithrombin-III effects.

Functional assays for heparin cofactor II (HC-II) are based on the inactivation of thrombin by HC-II in the presence of dermatan sulfate (DS). Residual thrombin is measured in a chromogenic assay. Interference by the antithrombin-III (AT-III)/heparin complex, which also rapidly inactivates thrombin, must be eliminated from the HC-II test system. Commercial DS is contaminated with heparin, while plasma specimens to be tested contain AT-III. After NaNO2/acetic acid treatment of DS (to inactivate heparin), there was enough residual heparin to cause AT-III interference. Treatment of plasma with commercially available anti-AT-III antiserum largely, but not completely, removed AT-III interference from the HC-II assay. With commercially available reagents, both NaNO2/acetic acid treatment of DS and anti-AT-III treatment of plasma were needed to eliminate heparin/AT-III interference. Protamine sulfate inactivated DS as well as heparin and could not be used to reduce AT-III/heparin interference with the HC-II assay.

Laboratory diagnosis of inherited protein S deficiency.

The authors investigated assays for free protein S (ProS) antigen, total ProS antigen, and ProS crossed immunoelectrophoresis (CIEP) in the diagnosis of type 1 inherited ProS deficiency. Accurate measurement of the hemostatically important free ProS required showing that, on each specimen, precipitation of the C4b-binding protein (C4b-BP)/protein S complex (C4b-BP/ProS) by polyethylene glycol-8,000 (PEG) was complete. The authors showed this by doing a ProS CIEP on the same PEG supernate that was used for quantitative measurement of free ProS. The +/- 2 standard deviation (+/- 2 SD) ranges for free ProS were 81-133% for males and 50-130% for females. This striking male-female difference has been reported only twice before. With the use of a graph of values for free ProS versus prothrombin time (PT), patients with inherited ProS deficiency segregated cleanly from normals and from patients on warfarin therapy without ProS deficiency until the PT was greater than 20 seconds. There is overlap of total ProS antigen values between normals and patients with inherited ProS deficiency.

A human myeloma-produced monoclonal protein directed against the active subpopulation of von Willebrand factor.

The authors present a study of a human myeloma-produced monoclonal protein (IgG-k) directed against von Willebrand factor that caused an acquired von Willebrand's disease (vWD)-like syndrome. The illness was characterized by upper gastrointestinal bleeding, prolonged bleeding time, decreased platelet adhesiveness, lack of platelet aggregation in response to ristocetin, and a qualitatively abnormal Factor VIII related antigen (vWF) by two-dimensional immunoelectropheresis. Patient plasma or IgG fraction mixed with normal platelet-rich plasma completely inhibited aggregation with ristocetin, but patient platelets resuspended in normal plasma aggregated normally with ristocetin. VWF was markedly elevated and the two-dimensional immunoelectropheresis of vWF revealed a vWD type II-like pattern with an absence of the higher molecular weight forms of the vWF. Marked inhibitory activity was observed in the ristocetin cofactor assay but disappeared at the highest dilutions of patient plasma used in the assay. Infusion of cryoprecipitate following plasmapheresis led to a correction of the bleeding time, improvement in platelet adhesiveness, transient disappearance of inhibitory activity in the Factor VIII ristocetin cofactor assay, and no significant normalization of two-dimensional immunoelectropheresis of vWF. This case demonstrated a myeloma-associated monoclonal antibody that interacted specifically with that part of the Factor VIII molecule necessary for Factor VIII ristocetin cofactor activity, normal platelet adhesiveness, and bleeding time.

Kallikrein inhibition and C1-esterase inhibitor levels in patients with the lupus inhibitor.

It has been suggested that kallikrein inhibition may predispose patients with the lupus inhibitor to thrombosis by interfering with the Factor XII-mediated activation of plasminogen. To further investigate this suggestion, the authors measured kallikrein inhibition in 19 patients with the lupus inhibitor. They found that kallikrein inhibition was greater than 100% of that of a normal plasma pool in all patients and greater than 125% in 11 of 19. Kallikrein inhibition was significantly correlated with C1-esterase inhibitor (C1S-INH) concentration, which they measured by rocket immunoelectrophoresis (r = +0.55, P less than 0.05). In three patients the C1S-INH was more than 30% greater than the kallikrein inhibition. Crossed immunoelectrophoresis for C1S-INH in these patients' plasma revealed an electrophoretic mobility identical with that of the normal plasma pool. The authors suggest that C1S-INH-mediated kallikrein inhibition, in conjunction with other coagulation abnormalities, predisposes patients with the lupus inhibitor to thrombosis.

Detection of the factor VLeiden mutation. Development of a testing algorithm combining a coagulation assay and molecular diagnosis.

The Coagulation and Molecular Diagnostic laboratories at the University of Minnesota Medical School (Minneapolis) have collaborated to develop a diagnostic algorithm to identify all factor VLeiden mutation carriers without performing unnecessary and expensive genetic testing. The algorithm uses a coagulation assay for activated protein C resistance (APCR) to determine the need for genetic testing. We report the results of our experience validating this program. We compared the sensitivity, specificity, and positive and negative predictive values of two measures of APCR, the APCR ratio and the normalized ratio. We found that the normalized ratio was the more sensitive but less specific parameter to determine the need for genetic testing. By using the normalized ratio as the standard by which to refer patients to the Molecular Diagnostics Laboratory, all mutation carriers were identified. We found a large overlap in both measures of APCR between symptomatic patients with normal genotype and mutation carriers. Furthermore, we demonstrated that increased factor VIII levels with a normal genotype are associated with apparent APCR. In this article we also review other correlates of apparent APCR.

Retinal surgery complicated by a spontaneously acquired factor VIII inhibitor.

We studied a factor VIII inhibitor spontaneously occurring in an otherwise healthy patient who underwent retinal reattachment. The clotting defect first manifested itself as a delayed hemorrhagic choroidal detachment. His bleeding diathesis was successfully managed by infusion of factor VIII concentrate, prednisone, and cyclophosphamide. Surgical procedures in patients with severe bleeding disorders present a difficult therapeutic problem which can be effectively managed by the close cooperation of the surgeon, hematologist, coagulation laboratory, and blood bank.

Tympanostomy tubes in children with hemophilia A.

With proper teamwork between the hemotologist and otolaryngologist, children with hemophilia A and otitis media can obtain the benefits of tympanostomy tubes; 90% phenol applied topically to the tympanic membrane is a useful hemostatic agent. The technique may allow the hemophiliac child to undergo myringotomy and insertion of tympanostomy tubes without the use of blood products. There is evidence that the use of such blood products derived from pooled human plasma may be associated with the development of acquired immune deficiency syndrome (AIDS).

Low platelet adhesiveness and other hemostatic abnormalities in hypothyroidism.

Fifteen patients with definite hypothyroidism and two with probable hypothyroidism had extensive hemostatic profiles done. In 12 of the 16 patients tested, the platelet adhesiveness (platelet retention in a glass bead column) was abnormal, and in 1 more it was borderline. In the six patients who were studied repeatedly, hemostatic abnormalities either markedly improved or disappeared after treatment with L-thyroxine. It is concluded that, in addition to the previously reported coagulation factor deficiencies (which we also observed in some of our patients), low platelet adhesiveness occurs frequently in patients with hypothyroidism.

Abnormal prothrombin crossed-immunoelectrophoresis in patients with lupus inhibitors.

Prothrombin deficiency has been known to occur in association with lupus inhibitors for over 25 years. We studied 21 patients with lupus inhibitors and found that four of five with prothrombin deficiency and ten of 16 with quantitatively normal prothrombin had abnormal prothrombin crossed-immunoelectrophoresis (CIEP) characterized by material moving slower in the first dimension of electrophoresis than normal prothrombin. In two patients with prothrombin deficiency, all prothrombin measured by quantitative assay and all slow-moving material on CIEP were removed by treatment with Staphylococcal protein A (SPA). These patients had free antibody, which bound to normal plasma prothrombin, forming larger amounts of slow-moving material on CIEP. A third patient with prothrombin deficiency had only partial removal of prothrombin after SPA treatment. Two patients with quantitatively normal prothrombin had all slow-moving material on CIEP and about one fourth of the prothrombin by quantitative assay removed by SPA treatment. There was no correlation among the strength of the inhibitor, the presence of a "cofactor effect," and the prothrombin abnormality. These data suggest that heterogeneous antiprothrombin antibodies, with or without prothrombin deficiency, are present in the majority of patients with lupus inhibitors.

The effect of L-asparaginase of plasma coagulation factors in acute lymphoblastic leukemia.

Serial coagulation studies were performed in 26 pediatric patients with acute lymphoblastic leukemia during initial induction therapy with vincristine, prednisone, and L-asparaginase. Prolongation of screening coagulation tests was frequent: prothrombin time (in 16 of 26 patients), partial thromboplastin time (23/26) and thrombin time (21/26). In all 26 patients fibrinogen levels fell below .20 g/100 ml and 16 had levels below .10 g/100 ml. Sixteen patients had plasma coagulation factor assays performed. In these 16 patients, Factor XI was less than 40% in 14 and Factor XI was less than 70% in 9, with only a few scattered low levels of other factors. There were no clinical bleeding episodes. Coagulation abnormalities returned to normal at the completion of L-asparaginase therapy while the patients remained on vincristine and prednisone.