Decoding the Ektacytometric Landscape of Hereditary Spherocytosis: Insights from 204 Cases

Background: Hereditary Spherocytosis (HS), the most common congenital hemolytic anemia, is characterized by highly heterogeneous clinical manifestations with variable hemolytic anemia, jaundice, reticulocytosis, splenomegaly, and gallstones. The ektacytometric analysis is considered a gold standard tool for HS diagnosis. Two distinct profiles may be observed: the typical bell-shaped profile (HS1) and a right-shifted curve (HS2); nonetheless, the clinical and biochemical significance of these differences, and their correlation with the clinical phenotype of HS remain poorly understood. Methods: We analyzed a large cohort of non-splenectomised HS patients, focusing on their ektacytometric curves and their hematologic and biochemical features. Results: We found that HS2 patients were significantly younger and showed a more severe anemia compared to HS1; in particular, HS2 patients had lower Hb levels and MCHC values, and higher RDW. Interestingly, only in the HS1 group, we observed a negative correlation between MCHC and all osmoscan parameters related to osmolality (Omin, Ohyper, and Omax). Conclusions: All the results indicate that HS may be characterized by two typical shapes of the ektacytometric curve, where HS2 profiles are associated with more severe and young patients, and that in the more HS severe cases red cells show a lower density.