Studies on spontaneous in vitro autohemolysis in hemolytic disorders.

El) BLOOD CELLS from patiemits with hereditary spherocytosis (HS) and certaimi other hemolytic disorders umidergo lysis more readily than normal cells w’hemi incubated in vitro at body temperature for periods of 24 to 96 hours. Measurement of such spontaneous hemolysis, called “autohemolysis,” frequently aids in demonstrating abnormality of red cells, especially in cases of hereditary spherocytosis. It is possible, moreover-, that changes in red cells leading to in vitro lysis are similar to those occurrimig in vivo in certain disease.s in which abnormal cells tend to stagnate withimi the spleen. Spontaneous autohemolysis in vitro is thus a phenomenon of practical importance in the clinical laboratory amid of great interest imi the study of hemolytic mechanisms. Ham amid Castle’ in 1940 described observatiomis on lysis and increase iii volumne and osmotic fragility of spheroidal red cells during in vitro incubatiomi for 24 hours. They suggested that similar changes in abnormal red cells trapped within the spleemi might largely account for accelerated red cell destruction. Evidence of trapping of spherocytes by the spleen has since been reported by a number of investigators, each of whom has related his findings to the uniformly beneficial effect of splenectomy imi hereditary spherocytosis .