Concise review: how do red blood cells born, live, and die?

The average life cycle of a human RBC is approximately 120 days. Generally, by this point, the cell is worn out and damaged. RBCs pass through both the spleen and liver, where specialised immune cells called macrophages are found. Macrophages recognise when an RBC is spent, and undergo a process called phagocytosis where they digest the cell. In this process, the iron in haemoglobin is recycled for use in new blood cells and the hem molecule is degraded, conjugated to bilirubin, and eliminated from the body. All the other cellular proteins are either recycled or eliminated. Historically, this process was thought to occur exclusively in the spleen, but recent studies have shown that it occurs in the bone marrow. The RBC has been analysed from many perspectives: cytological, haematological, and immunological, as well as from the focus of molecular biology, biophysics, and mathematics. Here we analyse how are red blood cells born and how they live and die in a brief overview of the whole process with special mention of the morphological aspects from bone marrow and spleen provided by transmission and scanning electron microscopy.

Neonatal haemoglobinopathy screening in Spain.

The prevalence of variant haemoglobins in Spain is increasing as a result of recent African immigration. Of the 19 regions of Spain, 13 have more than 1% of residents of African origin or ethnicity. Haemoglobinopathy prevalence is heterogeneous. Some cases of sickle cell disease (SCD) and sickle cell trait have been found in autochthonous individuals, but this is very rare. Most of the studies of SCD prevalence in Spain are incomplete or focused on a few geographical regions. When screening has been carried out regardless of ethnic origin, overall haemoglobinopathy prevalence has varied from 0.14% to 0.94% and the estimated prevalence of SCD has varied from 0.001 (in Extremadura) to 0.03 (in Aragón). A registry for SCD maintained by the Spanish Society of Paediatric Haematology shows that in the last 4 years the prevalence of SCD has increased threefold. Only two Spanish Communities (Extremadura and Madrid) are running an official neonatal screening programme for SCD. Other Spanish Communities have finished local pilot studies and are expected to establish neonatal screening programmes shortly. Catalonia, the Spanish community with the highest African immigration flow and SCD genetic impact, has not yet established an official programme for SCD neonatal screening; screening currently depends on individual hospital policies and is restricted to at-risk ethnic groups. Studies performed so far suggest that universal screening should be recommended for regions with a high annual birth rate and SCD prevalence (Catalonia and Madrid, for example), with a targeted policy being restricted to regions with low annual birth rate and SCD prevalence.

New haplotype for the Glu104Asp mutation in triose-phosphate isomerase deficiency and prenatal diagnosis in a Spanish family.

First-trimester prenatal diagnosis was undertaken by chorionic villus DNA analysis in a Spanish family with the inherited Glu104Asp triose-phosphate isomerase deficiency. The fetus was heterozygous for the mutation and therefore predicted to be clinically unaffected. To investigate the evolutionary origin of this mutation, studies were conducted on the intragenic 2262A/G polymorphism and the CD4 pentameric tandem repeat marker. A different haplotype was found to the one previously described, suggesting a different origin of the Spanish mutation.