Temporal Stability of Hemoglobin Variants and Convergent Validity of High-performance Liquid Chromatography Point-of-care and Solubility Test

Aims and background:The diagnosis of sickle cell disease (SCD) usually involves a blood test that looks for defective hemoglobin cells.Diagnosis and confirmatory tests of the blood samples are delayed in hospitals and diagnostic centers due to technical reasons, transportation, enormous sample size, or uncertain results.The present study aimed to determine the effect of storage time on the results of the diagnosis methods: solubility, point-of-care test (PoC), and high-performance liquid chromatography (HPLC).Materials and methods: Blood samples of the SCD and normal persons were collected and transported to the laboratory in a proper cold chain.Blood samples were kept at 4C in the laboratory and were tested at regular intervals (from day 5 to day 210) for the diagnosis of SCD by solubility, PoC, and HPLC.Thirty samples were analyzed in the study, and the stability of HbA0, HbA2, HbF, and HbS was measured from day 5 to day 210.Results: The concentration of HbF (0.4-2.4%), HbA0 (8.6-90.2%),HbA2 (1.7-4.1%), and HbS (21.1-79.9%)was varied among the values in parentheses.The difference in HbA0 and HbA2 concentration between day 0 and days 5, 10, 15, 30, and 60 was not significantly different (p > 0.05).The solubility method was found to be effective for the diagnosis of 150-day-old normal blood sample and 180-day-old SCD blood sample.Whereas, the PoC and HPLC methods were effective for diagnosis up to 210-day-old blood samples of both the SCD and normal populations.Conclusion: It may be concluded from the results of the study that samples of 7-month-old stored at 4C can also be used for the diagnosis of SCD.Samples stored for biobanking purposes will be used to determine the status of SCD.This will be useful for getting first-hand knowledge about the prevalence of SCD in the region.