Assessment and reliability of suspect flags in automated hematology analyzers for diagnosing white blood cell and platelet disorders

Background: The automated hematology analyzers have replaced the traditional manual methods for assessing hematological parameters. Most of the automated hematology analyzers are programmed to identify abnormalities in the form of “suspect flags.” Aims: The aim of the study was to correlate white blood cell (WBC) and platelet (PLT) flag messages provided by automated analyzers with their respective peripheral blood smear (PBS) findings. Materials and Methods: A descriptive cross-sectional study was undertaken on 100 patients who showed WBC and PLT suspect flags and/or abnormal peripheral smears. The flag messages were analyzed with their respective PBS findings. Pearson's Chi-square test was used for the statistical analysis. Results: Analyzer and PBS showed WBC defects (n = 46, 32), PLT defects (n = 39, 54), and combined defects (n = 36, 43) respectively. WBC defects included leukocytosis (n = 27, 22), leukopenia (n = 20, 18), immature granulocytes (n = 10, 3), left shift (n = 3, 2), myeloblast blast (n = 2, 1), and eosinophilia (n = 4, 4) on analyzer and PBS. Correlation between the WBC suspect flags and their peripheral smears was found to be statistically significant (P = 0.006). PLT defects included thrombocytopenia (n = 22, 30), thrombocytosis (n = 13, 17), giant PLTs (n = 10, 15), PLT clumps (n = 8, 12), and PLT debris (n = 2, 5) on analyzer and PBS. Correlation between the PLT characteristics in analyzers and in peripheral smears was statistically significant (P = 0.042). Conclusion: Suspect flags should be used as a screening tool to pick up pathological samples. These should then be followed up with a PBS examination for definitive diagnosis.