Evaluation of “Virus-Like” Particles in the Plasmas of 255 Patients with Leukemia and Related Diseases

The plasmas of 255 patients with neoplasms of the blood-forming organs and 44 controls were screened for virus-like particles. Plasma samples were banded by cesium chloride density-gradient centrifugation and negatively stained, and representative electron-microscope fields were photographed and particles counted. The number and distribution of particles were evaluated according to diagnosis, clinical status of the patient, white-cell count and platelet count. No relation between any of the classes of partides and clinical features were found. A large percentage of both control and disease groups had about the same numbers of particles. No common clinical characteristics of patients with extremely high particle counts were found. Virus-like particles seen by this technic in the plasmas of patients with leukemia and related disorders are considered to be unrelated to their disease. The importance of thin sectioning in future studies of this kind is emphasized.