Complement activating ABO anti-A IgM/IgG act synergistically to cause erythrophagocytosis: implications among minor ABO incompatible transfusions

Table 2 IgG/M anti-A titers, IgG subclass and complement activation status of sera samples

Hemolysin	IgG Anti-A	IgM Anti-A	Anti-A (2-ME treated)	IgG subclass (2-ME treated)	Anti-C3b/d
High titer
H1	>1024	32	1024	1	W
H2	>1024	32	512	1	W
H3	>1024	128	>1024	1, 2	2+
H4	>1024	256	>1024	3	2+s
H5	>1024	128	>1024	2	1+
Low titer
H6	32	32	–	–	W
H7	64	8	–	–	M+
H8	128	16	–	–	M+
H9	64	16	–	–	M+
H10	32	32	–	–	0

Hemagglutination grading: 0, no reaction/no agglutination; M+ , RBC agglutinates visible microscopically; W, weak reaction, many RBC tiny agglutinates; 1+ , many small agglutinates; 2+ , many medium sized visible agglutinates, – not done. IgG subclass evaluation was performed only for high titer samples as few of those samples only demonstrated significant (> 5%) erythrophagocytosis

ISSN: 1479-5876