Thermogravimetry coupled with chemometrics has proved to be a rapid and cost effective diagnostic tool for ß-thalassemia screening. This model, consisting of Partial Least Square-Discriminant Analysis (PLS-DA), permitted the discrimination of thalassemic patients and healthy individuals, using thermogravimetric curves of blood samples.[1]
In this study, the capability of thermogravimetry in conjuction with a multivariate statistical analysis, was investigated for the screening of hereditary haemolytic anaemias due to different erythrocyte defects. Two groups of anaemias were considered: the hemoglobinopathies (sickle cells anemia and thalassemia) and erythrocyte membrane defects (hereditary elliptocytosis and hereditary spherocytosis).
Whole blood samples from patients with congenital defects were analyzed by the TG7 thermobalance (Perkin Elmer) without any pretreatment and the resulting curves were compared to those typical of healthy individuals. The TG and DTG curves of blood samples from anemic patients were clearly distinct from those of healthy individuals as result of the different amounts of water content and corpuscular fraction.
The chemometric approach based on Principal Components Analysis (PCA) allowed a quick identification of differences between healthy and anemic patients in order to point out a model of prediction in patients with heterogeneous congenital hematological disorders.
Results allow to consider the coupling TGA/Chemometrics as a promising diagnostic approach to provide a high-throughput and sensitive tool to obtain an early detection of hereditary haemolytic anemias.
[1] R. Risoluti, S. Materazzi, F. Sorrentino, L. Maffei, P. Caprari . Thermogravimetric analysis coupled with chemometrics as a powerful predictive tool for ß-thalassemia screening. Talanta 159 (2016) 425-432 DOI: 10.1016/j.talanta.2016.06.037
The aim of this study is to propose a novel way to obtain an early detection of hereditary hemolytic anemias, a method that requires few microliters of blood sample, directly analyzed, and reflects the true composition of the complex matrix, as no sample pretreatment is required. In some cases, little sample-to-sample differences can cause very small differences in thermogravimetric profile. This means that the resulting TG data obtained (measured weight loss percentages) depends on more than one variable simultaneously and thus is multivariate. The chemometric approach will allow a quick identification of differences between healthy and anemic patients.
Furthermore, a model for ß-thalassemia classification will be also built and validate consisting in the Partial Least Square-Discriminant Analysis (PLS-DA). This novel diagnostic approach will permit the detection of hereditary hemolytic anemias in patients with heterogeneous clinical severity, not only in presence of hypochromic and microcytic anemia, but also in transfused patients, that is generally not possible by the common first level protocols; in addiction it will allow to screen for anemia even in the presence of combined defects, conditions that need molecular analysis for diagnosis. The use of thermogravimetry in conjunction with chemometrics is a rapid and cost effective diagnostic tool for ß-thalassemia screening.
The realization of this project will provide a new screening tool for patients, saving in terms of number of analyses and related costs, reducing protocols involving a large number of preliminary diagnosis investigations. The ability of this diagnostic tool to detect the presence of hemoglobin defect also in transfused patients during the neonatal period and in cases of associations of different hemoglobin defects, makes it a valuable screening method in cases of hemolytic anemia of nature to be determined.