RHEOLOGIC PARAMETERS IN DISEASE STATES OF INFANCY AND CHILDHOOD

Alterations in rheologic parameters may play an important role in many disease states. Hyperviscosity secondary to polycythemia, leukocytosis or abnormal blood proteins may contribute to the pathogenesis of serious symptomatology due to sludging of blood flow. Decreased erythrocyte (RBC) deformability may contribute both to hyperviscosity and to the premature removal of sclerocytic erythrocytes by the spleen.In a study of 68 patients during 1970-73 the following rheologic abnormalities were found.(1) Hyperviscosity due to polycythemia in: neonatal hyperviscosity, cyanotic heart disease and cystic fibrosis.(2) Decreased RBC deformability alone in: respiratory distress syndrome, infants of diabetic mothers, immune hemolysis, infantile pyknocytosis, advanced liver disease, nephrosls, renal failure and intrinsic RBC defects.(3) Hyperviscosity of whole blood due to both polycythemia and decreased RBC deformability in: neonatal hyperviscosity syndrome, infants of diabetic mothers and cystic fibrosis.(4) Hyperviscosity due to increased leukocytes in: the myeloproliferative syndrome of trisomy 21 and acute leukemia.(5) Hyperviscosity due to parenteral protein concentrates in: hemophilia after intensive transfusion.Investigation into the role of altered rheology in these conditions may increase our knowledge of disease mechanisms and associated laboratory and clinical findings.