Study of normal values in coagulation profile.

The objective of the present work was to study normal values of hemostasis parameters in healthy volunteers using Behring Coagulation Timer (BCT). Plasma was divided into 2 parts fresh plasma and lyophilized plasma. It was found that the mean +/- SD of prothrombin time (PT) and activated partial thromboplastin time (APTT) in fresh plasma (n = 37) were 11.95 + 0.7 and 40.52 +/- 5.30 seconds respectively. The means + SD of coagulation factors I, II, VII, VIII and IX were 2.55 +/- 0.73 g/l (n = 36), 82.28 +/- 10.28 per cent (n = 37), 82.79 +/- 19.36 per cent (n=32), 89.13 +/- 24.17 per cent (n = 37), 94.11 +/- 16.29 per cent (n=31) respectively. The normal ranges (p5-p95) of PT, APTT and coagulation factors I, II, VII, VIII and IX were 10.8-13.3 sec, 31.4-48.0 sec and 1.82-4.65 g/l, 64.83-96.5 per cent, 46.88-113.5 per cent, 52.44-127.61 per cent and 67.87-116.94 per cent respectively. Comparison of PT, APTT between fresh plasma and lyophilized plasma were statistically different (Wilcoxon match-pair signed rank test, p < 0.05), while F I, II, VIII and F.IX in fresh plasma were increased more significantly than lyophilized plasma.

Experience with factor VIII: C inhibitors and acquired von Willebrand's disease in an adult at Ramathibodi Hospital.

Eleven cases of acquired inhibitors against factor VIII: C and von Willebrand's factor (vWF) seen at the Department of Medicine, Ramathibodi Hospital from 1979 to 1991 were reviewed. Factor VIII: C inhibitor was found in 6 of 36 patients (17%) with hemophilia A (median age 18 years). Three patients each were weak (titer < 10 Bethesda units/ml), and strong antibody producers. Two cases of weak antibody producers had spontaneous disappearance of inhibitor, while all 3 strong antibody producers required specific treatment (corticosteroids, immunosuppressive drugs, and plasmapheresis). The inhibitor level temporarily declined in 2 patients, and disappeared in one. Spontaneous acquired inhibitor to factor VIII: C was seen in 3 patients. One each respectively had pemphigus vulgaris and bullous pemphigoid, autoimmune disease, and NIDDM. They were characterized by older age (median age 54 years), frequent skin and soft-tissue hematoma, but less hemarthroses. Inhibitor titer ranged from 15-280 Bethesda units/ml. Disappearance of the inhibitor after treatment with corticosteroids and immunosuppressive drugs were observed in all patients. Acquired von Willebrand's disease developed in 2 previously healthy patients. One patient was in the postpartum period, while the other had simultaneous acute viral hepatitis A infection. Both presented with the recent onset of spontaneous severe gingival bleeding, and demonstrated a prolonged bleeding time, reduced vWF:Ag (F VIIIR:Ag), and ristocetin cofactor (F VIIIR:vWF). Treatment with cryoprecipitate and corticosteroid resulted in remission of bleeding symptoms. Despite the rarity of these disorders, the recognition and proper management are of importance.

Standardization of platelet aggregation test in normal Thai adults.

Platelet aggregation test was assessed by the turbidimetric method in 52 normal Thai adults consisting of 24 males and 28 females with ages ranging from 20 to 50 years. The aggregating agents used were adenosine diphosphate (ADP), adrenaline and collagen. It was found that the ranges of threshold concentration of ADP, adrenaline and collagen which gave maximal induction of platelet aggregation were 5-10 microM, 2.5-10 microM and 0.14-0.28 mg/mL, respectively. Collagen at the above concentration, showed lag phase within 2 minutes. This corresponds to that described in the reference method. Moreover, when induced by ADP and adrenaline 53-65 per cent and 81-87 per cent of the subjects, respectively, showed biphasic curve. The above concentration of ADP, adrenaline and collagen are suitable for the study of platelet aggregation in normal Thai adults.

Acute massive intravascular hemolysis and disseminated intravascular coagulation.

Two cases of acute intravascular hemolysis complicating acute disseminated intravascular coagulation were presented, one after normal delivery and the other after group A beta hemolytic streptococcal septicemia complicating acute myelomonoblastic leukemia. Neither case received heparin therapy. The first one survived while the latter succumbed. Intravascular hemolysis may not be a bad prognostic sign in such a condition.