The Diagnostic Accuracy of Cryohaemolysis in Hereditary Spherocytosis

Abstract

Introduction: Hereditary spherocytosis (HS), a heterogenous disorder, requires a screening test with high predictive value in the absence of a family history and when diagnosis is equivocal. This study evaluates the validity and reliability of cryohaemolysis test (CHT) as a cost-effective, sensitive, and specific method in the diagnosis. Methods: An analytical cross-sectional study was done with a sample size of 62 divided between two groups. One group had diagnosed patients and their relatives with HS and the other group had spherocytes due to other causes. Results: The sensitivity and specificity of the CHT were 100% and 93.5% respectively. The predictive value of a positive and negative test was 93.9% and 100% respectively. The false negative and positive percentages were zero and 6.45, respectively. The CHT is affected neither by the number of reticulocytes nor spherocytes. The percentage of cryohaemolysis varied among the affected individuals of the same family. Conclusion: Our study showed that CHT is ideal in identifying patients and silent carriers as a quick, simple and economical method. The test is highly sensitive and specific making it the right choice for developing countries.