Erythrocyte Hyperchromia Measured by Flow Cytometry:a Marker for Body Iron Overload?

Summary: Using the classical cryolysis test suggested by Rosas and coworkers, it is shown that hyperchromic erythrocytes correspond to spherocytes destined for rapid elimination by lysis in the reticulo-endothelial cells. The percentage of hyperchromioc erythrocytes is determined without further cost by the H*-1, H*-2, and ADVIA 120 haematological analysers. An increased percentage of hyperchromic red blood cells thus emphasises increased haemolysis. It is shown that approximately 80 % of adult men with a percentage of hyperchromic erythrocytes exceeding 9.4 % have serious iron overload evidenced by high ferritin. The percentage in women with hyperchromia is much lower, eventually due to menstrual blood loss. Significant hyperchromia in adult men represents a marker of iron overload, justifying further investigation.