Hereditary spherocytosis: how to optimize its diagnosis

Abstract

Objectives: Hereditary spherocytosis is the most frequent inherited hemolytic anemia. Through an observational retrospective study of 8 years, this review aims at optimizing hereditary spherocytosis diagnostic approach. Our objectives were to characterize our population, adjust local cut-offs for confirmatory tests and revise our diagnostic algorithm on basis of international guidelines.

Method: Clinical and laboratory data of a Belgian cohort of 33 patients with hereditary spherocytosis were analyzed and compared to 44 non-spherocytosis patients.

Results: Hereditary spherocytosis patients were mostly children (median age of 6 years), jaundice and splenomegaly were rather common. The most discriminating routine tests between hereditary spherocytosis and patients with other hemolytic conditions were red blood cell distribution width and most of the reticulocyte parameters measured (p≤0.01). While confirmatory tests for hereditary spherocytosis, e.g., cryohemolysis, eosin-5’-maleimide binding test, ektacytometry O min and ektacytometry area under the curve were also discriminating between those two populations (p≤0.0001) with cut-off values for an AUC on ROC curve ≥ 0.8 of 15%, 14%, 17% and -24.5%, respectively. Compared to an international algorithm, no false positive or false negative cases were found with our simplified algorithm and the application of the new cut-off values for confirmatory tests.

Conclusion:  The use of reticulocyte parameters is a simple tool as a first step in screening for hereditary spherocytosis in a large number of laboratories. It allows to select patients who need further or not more complex analysis in a context where optimal healthcare costs repartition seems more important than ever.