High false-positive rate of isopropanol test in patients with Hemoglobin Constant Spring: A diagnostic pitfall.

The isopropanol precipitation test is widely used as a screening tool for unstable haemoglobins, however, the specificity of this assay can be affected by hemoglobin variants. This study, was designed to assess the reliability of the isopropanol precipitation test for 100 patients with molecularly c...

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Bibliographic Details
Published in:Australian Journal of Medical Science Vol. 46; no. 4; pp. 178 - 181
Main Authors: Madadi, Mojdeh, Jamali, Elham, Rakhshandehroo, Shahrokh, Ranjbaran, Reza
Format: research tables/charts Journal Article
Published: Australian Institute of Medical Scientists Nov2025
Online Access:View this record in EBSCOhost
Description
Summary:The isopropanol precipitation test is widely used as a screening tool for unstable haemoglobins, however, the specificity of this assay can be affected by hemoglobin variants. This study, was designed to assess the reliability of the isopropanol precipitation test for 100 patients with molecularly confirmed Hemoglobin Constant Spring (Hb CS), comprising 97 heterozygotes and 3 homozygotes. All submitted samples underwent the isopropanol test. Among the cohort, 99 cases tested positive, despite lacking clinical or hematological features typical of unstable hemoglobinopathies. These findings indicate that Hb CS, even at low expression levels, can interfere with the test, leading to false-positive results. This highlights a potential diagnostic pitfall and underscores the need for molecular confirmation in suspected cases.