**3. Measurement of RBC deformability**

The diagnostic procedures for the etiological investigation of HHAs have experienced a great progress in recent years [2]. The easy accessibility of RBCs from a single blood sample and the improvement of the methods used for their study have contributed to bring together the most recent knowledge in disciplines as diverse as optical and ultrastructural morphology, enzymology, metabolomics, proteomics, membrane ionic transport and, more recently, rheology or the behaviour of RBCs in suspension [36, 37]. However, the morphological examination of MGG stained blood smear still remains the simplest procedure and, in many cases, the most effective procedure for the diagnosis of HHA [1]. In the general laboratory, the classical RBC morphology examination is complemented by other simple laboratory tests such as the RBC osmotic fragility test (OFT) or the RBCs vital staining procedures with new methylene blue (NMB) for the reticulocyte count and the brilliant cresyl blue (ACB) for Heinz-bodies examination. Moreover, the incubation of a blood sample with oxidising agents, such as acetylphenylhydrazine (APH), is a very simple procedure to assess the RBC oxidant-reducing capacity. In this context, the implementation of the measure of RBC deformability may become another relatively simple diagnostic haemolysis tests. Unfortunately, the use of RBCs' deformability has not yet been

*Congenital Defects with Impaired Red Blood Cell Deformability – The Role of Next-Generation… DOI: http://dx.doi.org/10.5772/intechopen.109637*

**Figure 4.** *Intracellular RBC hemoglobin precipitates (Heinz bodies) in a patient with HbH disease.*

implemented in the diagnostic laboratories due to the several reasons that we describe here. One of these reasons is the different procedures that can be used currently to measure the deformability in both, individual or multiple RBCs.
