Microcytic to hypochromic ratio as a discriminant index of thalassaemia trait in subjects with hypochromic anaemia

@#Introduction: Differentiating between thalassaemia and iron deficiency anaemia (IDA) in hypochromic anaemia is a challenge to pathologists as it influences the choice of subsequent specialized confirmatory tests. In this study, we aimed to evaluate the performance of microcytic to hypochromic ratio (MicroR/ Hypo-He, M/H ratio) as a discriminant index in hypochromic anaemia. Materials and Methods: A retrospective study was carried out on 318 subjects with hypochromic anaemia, which comprised 162 IDA and 156 thalassaemia trait subjects with α-thalassemia, β-thalassemia and HbE trait. Optimal cut-off value, sensitivity and specificity of M/H ratio for thalassaemia trait discrimination was determined using Receiver Operating Characteristic (ROC) analysis. Results: Subjects with thalassaemia trait showed higher MicroR compared to IDA ( p< 0.001) while subjects with IDA demonstrated higher Hypo-He than thalassaemia trait (p < 0.001). M/H ratio was significantly higher in thalassaemia trait compared to IDA, with medians of 3.77 (interquartile range: 2.57 – 6.52) and 1.73 (interquartile range: 1.27 – 2.38), respectively (p < 0.001). M/H ratio > 2.25 was the optimal cut-off value for discriminating thalassaemia trait from IDA in hypochromic anaemia, with the area under ROC curve (AUC) of 0.83, sensitivity of 80.8% and specificity of 71.6%. Conclusions: M/H ratio is a useful discriminant index to distinguish thalassaemia trait from IDA in hypochromic anaemia prior to diagnostic analysis for thalassaemia confirmation. High M/H ratio is suggestive of thalassaemia trait than of IDA. However, more studies are required to establish the role of M/H ratio as a screening tool for thalassaemia discrimination in hypochromic anaemia.

Usefulness of Red Blood Cell Size Factor (RSf) in Screening Genetic Variants of Alpha Thalassaemia Thalassaemia Trait Regardless of Iron Status

@#Introduction: Screening for alpha (α) thalassaemia trait (TT) is challenging especially in the presence of iron deficiency (ID). Red blood cell size factor (RSf) is a parameter introduced by Beckman Coulter capable of detecting acute and chronic changes to cellular haemoglobin status and iron supply. The research aimed to investigate the clinical usefulness of RSf as screening parameter for α TT and the effect of concomitant ID to RSf mean values (m.v) among respondents with α TT. Methods: A cross-sectional retrospective laboratory analysis involved 55 respondents’ data selected from January 2014 to December 2015 in Pathology Department, Hospital Tuanku Ja’afar Seremban, Negeri Sembilan. The significant difference at p <0.05 in the RSf m.v. among respondents with α0 TT, α+ TT, and ID groups and the effect concomitant ID to RSf m.v. were determined using statistical test, one-way analysis of variance (ANOVA). Results: Significant differences were detected in RSf m.v. i) between α0 TT, α+ TT and ID, F (2, 52) = 18.99, p=0.001. ii) between α TT without ID, α TT with ID and ID cohorts for both a) α0 TT [F (2, 33) = 23.77, p=0.001) and b) α+ TT [F (2, 28) = 5.37, p=0.011]. iii) between α TT and ID group regardless of the presence of ID for both a) α0 TT and b) α+ TT. Conclusion: RSf is a potential screening parameter in evaluating patients with hypochromic microcytosis in identifying possible cases of alpha TT regardless of iron status.