Abstract
Platelet aggregation test was originated from Breddin which determined degree of platelet aggregation in vitro by mechanical stimuli such as contact of platelets on siliconized glass surface. We have carried out the PAT test using 45 subjects including 6 patients with ITP, 5 with uremia, 7 with hepatitis, 6 with carcinoma, 13 with other miscellaneous diseases and 9 healthy volunteers. In the result of PAT test, degrees of platelet aggregation were graded to I-V scales. At the same time, platelet spreadability (PSA) test following Breddin and ADP-induced platelet aggregation test were performed. We have modified PSA test to use a pair of clean plastic slide arranging parallel with one cm in distance in which the specimen was filled. Using this modified method, a reasonably high reproducibility was obtained. The degree of PSA was recorded as mean diameters of spreading platelets on plastic surface. In ADP-induced aggregation, 10μM ADP was added into platelet rich plasma using Evans aggregometer. In 8 out of 9 healthy subjects, grade III PAT was observed, whereas in 5 ITP patients, markedly lowered ability of platelets to aggregate grade I was observed. The PAT was found enhanced in the cases of uremia. Most patient with carcinoma displayed an enhanced PAT while it was depressed in the few remainders. Statistical analysis of the data revealed no significant interrelation between PAT and PSA. However, the combination with both the test, characteristic changes were noted in each of diseases. There was a statistical evidence of significant correlatation between PAT and ADP-induced platelet aggregation, with the equation of regression:
Y=1.72+0.28X, r=0.492, P=0.02
The above results would suggest that PAT and PSA test may be useful to determine some clinical conditions, when both the methods are used in a combination.
