Haemorheological parameters in alopecia areata.

Whole blood, plasma and relative viscosities and red cell filterability have been investigated in 15 patients with Alopecia areata (A.A.) and in 9, age and sex-matched, normal subjects. Erythrocyte filtration time resulted to be significantly increased in alopecic subjects as compared to the normal subjects. Such parameter also showed a good correlation (r = 0.752) with relative viscosity. Whole blood, plasma and relative viscosities were not significantly different from normal subjects.

A statistical analysis of some thromboelastographic parameters in normal subjects.

Thromboelastographic parameters r, k and am have been statistically evaluated in 777 normal subjects, 506 females and 271 males. The relationship existing among the parameters and their relationship with age have been investigated: r and k resulted to be correlated both in the male and female group. The same was true for k and am. On the contrary, a non-Gaussian distribution was noted together with the lack of correlation with age.

Further studies on factor VII Padua defect: the report of the fourth homozygous patient from the same valley.

A new patient with factor VII Padua abnormality is presented. The proposita is an 11-year-old girl who showed a mild bleeding tendency and a laboratory pattern characterized by a prolonged prothrombin time corrected by normal serum, normal partial thromboplastin time and normal Thrombotest. Factor VII assay was 10% using rabbit brain thromboplastin and 100% of normal using ox brain thromboplastin. Factor VII cross-reaction material was normal. The parents were not consanguineous but both came from the same area and were found to be heterozygous for the abnormality. The discovery of the present patient, the fourth in three years, indicates that the defect might be more frequent than originally thought.

Incidence, significance, and subtypes of hemophilia BM in a large population of hemophilia B patients.

Eleven patients with hemophilia BM were found out of a population of 66 patients with hemophilia B. Factor IX activity in the hemophilia BM varied between less than 1% and 1.6% of normal but factor IX antigen was normal or only slightly reduced in each instance. Thrombotest clotting time was variably prolonged and was not corrected by the addition of normal plasma. Thrombotest mixing experiments and dilution curve studies confirmed the presence of the inhibitor in every patient. There are at least two forms of hemophilia BM, a severe one and a mild one. In the first form, Thrombotest is severely prolonged (90-120 s). In the other, the prolongation is mild or moderate (60-80 s). A positive correlation exists between the antigen-activity difference (delta antigen-activity) and the prolongation of Thrombotest both in the propositi and in obligatory carriers. The criteria for the diagnosis of hemophilia BM are the following: prolonged PTT, prolonged Thrombotest, lack of correction of Thrombotest by the addition of normal plasma while PTT is fully corrected. The lack of correction of Thrombotest in the presence of a full correction of PTT, is the unique clotting feature.

Integral viscosity: a useful parameter in evaluating whole blood and plasma viscosities in health and disease.

An integral viscosity determination (Q) is proposed for whole blood (QB) and plasma (Qp). The integral viscosity determination was carried out at four shear rates in a Brookfield LTV Viscometer and calculation were obtained by means of a modification of Casson's mathematical model. Polycythemic and paraproteinemic patients resulted to be well differentiated from normals. The ratio QB/Qp represent a continuous sum of relative viscosities and may also supply information on erythrocytes deformability. Integral viscosity determinations are indicated for research purposes and for examining special cases.

Taipan viper venom and chromogenic substrate (chromozym Th). Prothrombin assay. No sensitivity to coumarin-induced prothrombin.

Prothrombin (factor II) was assayed in congenital or acquired prothrombin deficiencies and abnormalities using Taipan viper (Oxyuranus scutellatus) venom as activating agent and adsorbed normal plasma or a chromogenic compound (Chromozym-Th) as substrates. Prothrombin was found to be low, as expected in every instance, regardless of the substrate used. In coumarin treated patients the levels observed were similar to the prothrombin time percentile values and definitely lower than the immunological counterparts. Therefore, the Taipan viper venom appears suited for prothrombin assay even during anticoagulant therapy. Since the cost of the chromogenic substrate is about 20 times that of adsorbed normal plasma and since no special information is obtained by it, the use of the chromogenic method is not justified for routine purposes.

Rheological and clotting changes in chronic cor pulmonale.

53 patients with chronic or pulmonale and hospitalized for the occurrence of acute dyspnea were studied. The mean age was 67. The increase in blood and plasma viscosities is higher than the rise in hematocrit, total plasma proteins and fibrinogen. The levels of plasminogen and antithrombin III are significantly lower and the plasma euglobulin lysis time is shortened. On the contrary, fibrinogen levels are normal or near normal. This seems to confirm the frequent presence of clotting changes in chronic cor pulmonale facilitated by an altered pulmonary rheology.

Chromogenic substrate (S-2222) factor X assays in the follow-up of coumarin treated patients. No advantage over prothrombin time and/or thrombotest.

Factor X was assayed in 30 patients on long-term anticoagulation by means of a chromogenic substrate (S-2222) for a total of 120 determinations. The average level found was 25.38 +/- 9.38% of normal. A satisfactory correlation was found between the factor X chromogenic level and the prothrombin time or Thrombotest percental values. However, factor X levels as determined by the chromogenic assay were usually higher than the global tests percental figures. The factor X chromogenic level was also slightly higher than the RVV-cephalin factor X assay. Since the chromogenic assay does not allow any new information to be made on the coumarin induced defect and since the costs of the assay are about 20-30 times higher than those of a simple prothrombin time, the test seems to play no part in the follow-up of coumarin therapy.