Research Parameters in RBC Indices Shows Vital Importance in Screening α-Thalassemia.

Background: The percentage of microcytic cells (%MICRO) and the percentage of hypochromic cells (%HYPO) were very useful in differentiating microcytic anemia, and hematological parameters had significant potential as predictive markers of the degree of α-gene deletions. This study aims to evaluate the value of these research parameters in screening for α-thalassemia compared to classical indices.

Methods: We analyzed the data of 402 subjects with α-thalassemia deletions and 553 normal subjects and evaluated the performance of each parameter with receiver operating characteristic (ROC) curves, sensitivity, and specificity. The correlation between red blood cell (RBC) indices and the number of α-genes deleted was also assessed.

Results: A close correlation was observed between the degree of α-gene deletions and cellular hemoglobin content (CH) (r = -0.835, p < 0.001), mean corpuscular hemoglobin (MCH) (r = -0.825, p < 0.001), and %MICRO+%HYPO (M + H) (r = 0.811, p < 0.001). The area under the curve (AUC) of CH consistently exceeded that of MCH (0.8988 vs. 0.8812, 0.987 vs. 0.984, 0.988 vs. 0.980, respectively). M + H exhibited better diagnostic performance than MCH in predicting two and three α-gene deletions (AUC 0.987 vs. 0.984, and 0.991 vs. 0.980, respectively). A CH < 23.35 pg. strongly suggests the presence of two α-gene deletions; when M + H > 89.40% or CH < 19.35 pg, a precise preliminary diagnosis of Hb H disease could be made.

Conclusions: The research parameters in RBC indices have vital importance in screening for α-thalassemia and can serve as an effective preliminary screening tool to predict the number of α-gene deletions.