Increased Blood Platelet Clumping in Thromboembolic Disease

Abstract

Ordinary routine differential blood films were made on glass slides, stained with Wright's solution and observed under the oil immersion lens. The presence of blood platelet clumps and the number of platelets per clump were noted and recorded. Clumping was considered normal if the blood film did not reveal more than 10 platelets to the clump (Fig. 1), as increased or abnormal if there were more than 10 platelets to the clump (Fig. 2). Clumps containing more than 15 platelets not infrequently presented a syncytial arrangement with an almost transparent hyaline matrix in which platelets of varying sizes and shapes were embedded (Fig. 3). In 100 presumably normal control subjects (Table 1) without detectable clinical disease, clumping was normal in 92 per cent and designated as increased or abnormal in only 8 per cent. Of 100 patients with various types of thromboembolic disease, clumping was of normal type in 19 per cent and designated as increased in 81 per cent.