PERCENTAGE OF REVERSIBLY AND IRREVERSIBLY SICKLED CELLS ARE ALTERED BY THE METHOD OF BLOOD DRAWING AND STORAGE-CONDITIONS

We previously reported that the percentage of reversibly and irreversi bly sickled cells (RSC and ISC, respectively) in the blood of patients with sickle cell disease is strongly influenced by the method of bloo d drawing (PNAS 91:12589, 1994), We now document the effect of blood s torage conditions on the percentage of RSC and ISC, The percentage of RSC was lowest when blood was stored at 0 degrees C, while the percent age of RSC was highest in specimens kept at 37 degrees C, At room temp erature, the percentage of RSC increased slightly over 8 hours, The pe rcentage of ISC was also temperature dependent and was reduced signifi cantly upon cooling, Our results showed that many ISC reverted to a di scoidal shape after 3 hrs of cooling after treatment of blood with oxy gen or carbon monoxide, Since no Hb S polymers were detected in ISC tr eated with oxygen or carbon monoxide, the time required for shape rest oration may be attributed to the membrane, We measured ISC levels of 1 0 patients with consideration of storage temperature and compared the values with those determined by the conventional method and also with those published previously.