The anti-Mia antibody – Report of four cases in a tertiary care hospital with review of literature

Anti – Mia antibody is antibody reacting with Mi III phenotype of the Miltenberger (Mi) subsystem. It is rarely reported in the West, however, it is common in Chinese and South East Asian populations. Very few cases have been reported in India. Here, we report 4 cases of the Anti - Mia antibody picked up on antibody screening of samples (which was performed using Asia ID-Diacell I-II-III Asia (Mia +) 3 cell panel). Patients: In all the four cases, ICT was positive. Antibody screening and Identification was done with 3 cell panel (ID-Diacell I-II-III (Asia)) and 11 cell panel (ID-DiaPanel) respectively. Antibody screening showed reaction in “Asia” cell (carrying Mia Antigen) of 3 cell panel. Antibody identification by 11 cell panel was negative ruling out antibodies of Rh, Kell, Duffy, Kidd, Lewis, P, Lutheran and MNS systems. Reaction with the “Asia” cell suggested the presence of Anti-Mia antibody which was confirmed by obtaining the same result when screening was repeated with 2 different lots of 3 cell panel. Discussion and Conclusion: The Miltenberger (Mi) subsystem comprises of a group of phenotypes of red cells that carry low frequency antigens associated with the MNSs blood group system. The Anti- Mia antibody was first described in 1951 in the serum of Mrs Miltenberger. Anti- Mia antibody is clinically significant and can cause Hemolytic disease of newborn (HDN) and mild to moderate haemolytic transfusion reactions (HTR). Most of the antibody screening and identification panels used in India are imported and represent the Western population. They do not have representation of the Mia antigen on their red cells. This leads to missing out of the Anti- Mia antibody which may cause HDN and HTR leading to significant consequences. Thus, the Mia antigen should be incorporated in our screening panels.