Evaluation of the sensitivity and specificity of MCH and MCV for screening of Beta thalassemia minor

 Beta thalassemia minor (BTM) is a hypochromic and microcytic anemia that is determined by reduced mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH). The important screening methods for this disease are lack of patient recovery after 2 months of iron therapy and increased Hemoglobin A2 (HbA2). In this study, we evaluated the sensitivity and specificity of MCH and MCV for diagnosis of BTM. This cross-sectional study was performed among patients with BTM. CBC samples were taken and hematological parameters were measured. Two months of iron therapy and measurement of HbA2 were carried out for definitive diagnosis of beta-thalassemia. After definitive diagnosis, the specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) for MCV and MCH were calculated. To investigate the relationship between HbA2 and hematological parameters (MCV and MCH), the linear regression test was performed using the SPSS18 software. From 300 patients, 154 (51.3%) were men and 146 (48.7%) women. According to the results, the highest sensitivity was associated with MCH with 90% sensitivity and specificity, respectively. Linear regression analysis showed the negative correlation -0.53 and -0.51 between HbA2 and MCV, and MCH, respectively. According to the results, using parameters like MCH are more appropriate than time consuming and expensive HbA2 measurements for diagnosis of BTM. However, none of the aforementioned parameters showed 100% specificity and sensitivity.