Search

Three radioimmunoassays for the measurement of beta-thromboglobulin are described. The standard method, using antiserum in solution, could be used to measure plasma concentrations of beta-thromboglobulin with the results available after 2-3 d. The use of a greater dilution of antiserum and tracer, with delayed addition of tracer, resulted in a more sensitive assay suitable for measuring b-thromboglobulin in urine. The use of a solid-couples antiserum under non-equilibrium conditions allowed the measurement of plasma levels of beta-thromboglobulin after an assay incubation time of 1 h. These three radioimmunoassay systems for beta-thromboglobulin cover the likely clinical requirements for the measurement of this platelet specific protein.

The concentration of normal human platelet beta-thromboglobulin (beta-TG) was measured in various washed organ samples by a radioimmunoassay. As only trace amounts were detected, beta-TG appears to be a platelet specific protein. Assay of beta-thromboglobulin in plasma samples from 180 normal individuals gave a range of 10--65 mg/ml. In the 10 subjects studied, plasma beta-TG concentration was related to platelet lifespan but not to turnover. The plasma beta-TG concentration rose with increasing age but did not correlate with the whole blood platelet count or the percentage of megathrombocytes. These results provide further substantial evidence that measurement of plasma beta-TG concentration is useful for assessing the participation of platelets in various disease processes.

HIV p24 antigenaemia and virus detection in cultures of peripheral blood lymphocytes were examined in 16 of 18 haemophiliacs infected with HIV by a single batch of Scottish National Blood Transfusion Service factor VIII concentrate. Six (38%) had p24 antigenaemia and 11 (69%) had positive lymphocyte cultures. All seven patients with serious HIV disease (CDC group IV) had positive lymphocyte cultures whereas four (57%) had p24 antigenaemia. Four of nine (44%) patients with asymptomatic HIV disease (CDC groups II and III) had positive cultures and two (22%) had p24 antigenaemia. Twenty-eight of 36 samples from the symptomatic group were HIV culture positive compared with nine of 30 samples from the asymptomatic group (P less than 0.001). None of 14 antibody negative haemophiliacs who also received the implicated batch of factor VIII had p24 antigenaemia or positive HIV cultures. The ability to detect HIV in cultured lymphocytes correlates with the clinical severity of HIV disease in this cohort.

Markers of the immune system were examined in 47 patients with haemophilia A and B who had been treated exclusively with blood products from a population apparently free from acquired immunodeficiency syndrome (AIDS). In haemophilia A the absolute number of T helper cells was depressed, resulting in a reduction in the helper/suppressor ratio in about half the patients. The serum IgG and IgA concentrations were raised and the serum IgG correlated with serum alanine aminotransferase. In haemophilia B, the helper/suppressor ratio was also depressed but this was attributable to a slight increase in the mean suppressor cell number and a slight decrease in the helper cells. These observations suggest that the abnormalities result from transfusion of foreign proteins and not from a specific infective agent and, further, that individuals may differ in susceptibility to the induced disturbances of immunity.

A case of composite lymphoma consisting of Hodgkin's disease and B cell lymphocytic lymphoma is described. A diagnosis of lymphocyte predominant Hodgkin's disease was made initially by histology. The presence of a composite lymphoma was only appreciated once immunohistochemistry was available. The findings illustrate the importance of the use of immunological markers for the accurate diagnosis of lymphoma.

This study was designed to assess the density characteristics of platelets from controls (N = 10) and three groups of diabetics (N = 32) exhibiting various degrees of glycemic control. With continuous gradients of Percoll, platelets from controls and diabetics (N = 8) with an HbA1 less than or equal to 9% formed a band extending from 1.0625 g/ml to 1.0925 g/ml with a mean platelet density of 1.0775 g/ml. In the two groups of diabetics with HbA1 greater than or equal to 10%, there was an increase in the proportion of low-density platelets recovered on the gradients and the mean platelet density was reduced to 1.0750 g/ml (HbA1 = 10-13%) and 1.070 g/ml (HbA1 greater than or equal to 14%). All three groups of diabetics had normal levels of intraplatelet ATP/ADP and beta-thromboglobulin. It is unlikely that in vivo degranulation of platelets after activation was responsible for the altered density profiles. We propose that abnormal platelet subpopulations with low density but normal intraplatelet granule content were responsible for the changed density profiles.

Fifteen haemophiliac patients acquired antibodies to human T-lymphotropic virus type III during 1984. One batch of factor VIII concentrate given to all these patients is presumed to be the cause of the seroconversion. A further eighteen patients who received the same batch did not seroconvert and one other patient became seropositive but had not received this batch. Before transfusion of the implicated batch the patients had low T-helper-cell numbers and T-helper/suppressor ratios; neither changed in those who seroconverted. The probability of seroconversion was independently related to the pre-existing low T-helper/suppressor ratio, the number of vials of the implicated batch transfused, and the total annual factor VIII consumption. Ten other patients received a batch of factor IX concentrate from the same donor plasma; none of these patients seroconverted.

Of 32 patients exposed to a single batch of factor VIII contaminated with human immunodeficiency virus (HIV), 18 became antibody positive. Serial T cell subset analyses over the succeeding four years have shown a progressive decline in circulating T4 cells in those 18 but no change in the 14 who remain seronegative. 2 of the seroconverters have died and a further 7 have symptoms attributable to HIV infection. In the group as a whole, the HLA haplotype A1 B8 DR3 was weakly associated with an increased risk of seroconversion on exposure to the virus while, in those who seroconverted, it was strongly associated with a rapid decline in T4 cells and development of HIV-related symptoms within four years of infection.

The plasma concentration of the platelet-specific protein beta-thromboglobulin was measured in fourteen patients who had been investigated for deep venous thrombosis by venography or 125I-fibrinogen scanning. All six patients with a proven thrombus had a raised plasma concentration of beta-thromboglobulin. Eight patients in whom no thrombus could be demonstrated had plasma concentrations of beta-thromboglobulin similar to a control group of thirty-five normal individuals. These results indicate that the measurement of plasma beta-thromboglobulin concentrations may be of use in the diagnosis of deep venous thrombosis.

Deamino-8-D-argenine vasopressin (DDAVP) was given by intravenous infusion to normal subjects, haemophiliacs and patients with von Willebrand's disease (vWd) and the factor VIII and plasminogen activator response was studied. In normal subjects and most patients with mild haemophilia and mild (intermediate) von Willebrand's disease there was an increase in plasminogen activator and all factor VIII related activities. In patients with mild vWd the prolonged bleeding time was shortened by DDAVP despite only a modest rise in factor VIII related Ristocetin cofactor activity (VIIIR:RiCoF). Sub-groups of patients have been characterized in whom atypical responses was observed. In two brothers with clinically severe haemophilia, but with 5--6 u/dl procoagulant factor VIII (VIIIC), there was an increase in VIIIC but no rise of the corresponding antigen, suggesting increased release of an antigenically abnormal poorly functioning molecule. A patient with intermediate vWd was studied in whom neither DDAVP, adrenaline infusion, nor venous occlusion resulted in an increase in either plasminogen activator or factor VIII related antigen (VIIRAg), although there was a significant increase in VIIIC. In a further patient with severe vWd, DDAVP failed to elicit any plasminogen activator or VIII response. The results obtained from these two patients suggested that in some individuals the presumed endothelial cell abnormality in vWd may be more extensive than a defect in VIIIRAg synthesis. Sub-groups of patients have been identified for whom treatment with factor VIII concentrates would be more appropriate than DDAVP prior to minor surgery.

A platelet specific protein, beta-thromboglobulin, is liberated during the preparation of platelet poor plasma. Using combinations of different anticoagulant and anti-platelet compounds, this release can be significantly reduced. The best results were obtained when native blood was collected as soon as possible into a mixture of EDTA, prostaglandin E1 and theophylline and maintained and processed at a temperature between 0 and 4 degrees C. These technical innovations have permitted the use of a radioimmunoassay for beta-thromboglobulin on plasma samples in clinical practice.

Little has been written about the effects of hemophilic arthropathy on the function and radiography of the upper limb. Therefore, 14 moderate and 19 severe hemophiliacs between the ages of 10 and 57 years were examined clinically and radiographically. The extent of the arthropathic changes in the shoulders, elbows, wrists, and hands were classified according to the system proposed by the World Federation of Hemophilia. The severity of the arthropathy increased with the age of the patient and with the number of hemarthroses recorded, although the correlation between these parameters was variable. The elbow joints were the site of recognizable arthropathy in 87% of the cases, with a slight preponderance for the nondominant side. The glenohumeral and wrist joints were affected in a small proportion of patients, although symptoms were rarely experienced. Hemorrhages affecting the hands were uncommon and produced arthropathy infrequently.

Platelet density profiles, intraplatelet nucleotides, intraplatelet beta thromboglobulin (beta TG), plasma beta TG levels, intraplatelet cyclic AMP (cAMP) levels, platelet release reaction, platelet thromboxane (TX)B2 production and plasma fibrinogen levels were investigated in 24 newly diagnosed, non-insulin-dependent diabetic patients and 12 comparable controls. These variables were measured at diagnosis, after a 3-6 week dietary run-in period, and again after 6 months on treatment with either metformin or gliclazide therapy. With dietary restriction of refined carbohydrate and oral hypoglycaemic therapy, there was a reduction in platelet density (p less than 0.05), intraplatelet nucleotides (p less than 0.001), intraplatelet beta TG (p less than 0.001), plasma beta TG (p less than 0.001) and there was an increase in intraplatelet cAMP levels (p less than 0.05). Although these platelet variables returned towards normal, only the platelet density mean returned to within the normal range. There was no significant change in the platelet TXB2 production and plasma fibrinogen levels with treatment. Metformin and gliclazide were equally effective in the glycaemic control of non-insulin-dependent diabetes, and there was no difference between the platelet variables measured in the two groups. We would therefore suggest that improvement of glycaemic control, rather than any specific effect of the oral hypoglycaemic agent employed, is the most important factor in returning these parameters towards normality.

Formaldehyde or gluteraldehyde cells treated with tannic acid were coated with plasminogen. These cells are agglutinated by plasminogen antiserum and this reaction can be quantitatively inhibited by purified plasminogen, plasma, and euglobulin. Correlation between this haemagglutination assay and a caseinolytic method is good. The sensitivity of the technique is high and compares favourably with other immunological methods and is approximately 10 times more sensitive than caseinolytic assays. The merits of this type of assay are discussed.