Hypertonic cryohemolysis: a diagnostic test for hereditary spherocytosis.

Red blood cells of subjects with hereditary spherocytosis are specifically susceptible to temperature changes while suspended in hypertonic solutions. Based on this property, a new diagnostic test for hereditary spherocytosis is presented. The suggested method is 100% sensitive in the diagnosis of all patients, including asymptomatic obligate carriers with hereditary spherocytosis, and is very specific in different control groups. Unlike other methods designed for the diagnosis of hereditary spherocytosis, this test does not depend on the cells' surface- area-to-volume ratio. Normal red blood cells that were induced to become spherocytes by different means (i.e., vinblastine, lysophosphatidyl choline, and heat) and showed increased osmotic fragility did not become susceptible to the hypertonic cryohemolysis conditions.