If a person receives bone marrow from someone of a different ABO type (e.g., a type A patient receives a type O bone marrow), the patients blood type should eventually become the donors type, as the patients hematopoietic stem cells (HSCs) are destroyed, either by ablation of the bone marrow or by the donors T-cells. Once all the patients original red blood cells have died, they will have been fully replaced by new cells derived from the donor HSCs. Provided the donor had a different ABO type, the new cells surface antigens will be different from those on the surface of the patients original red blood cells.Some blood types are associated with inheritance of other diseases; for example, the Kell antigen is sometimes associated with McLeod syndrome. Certain blood types may affect susceptibility to infections, an example being the resistance to specific malaria species seen in individuals lacking the Duffy antigen. The Duffy antigen, presumably as a result of natural selection, is less common in population groups from areas having a high incidence of malaria. ABO blood group system
The ABO blood group system involves two antigens and two antibodies found in human blood. The two antigens are antigen A and antigen B. The two antibodies are antibody A and antibody B. The antigens are present on the red blood cells and the antibodies in the serum.
Pterygium inversum unguis or ventral pterygium is characterized by the adherence of the distal portion of the nailbed to the ventral surface of the nail plate. : 788   The condition may be present at birth or acquired, and may cause pain with manipulation of small objects, typing, and close manicuring of the nail. : 788  secondary due to connective tissue disorders

See also
Pterygium unguis
Nail
List of cutaneous conditions


== References ==