PMID- 19570063
OWN - NLM
STAT- MEDLINE
DCOM- 20100108
LR  - 20121115
IS  - 1423-0410 (Electronic)
IS  - 0042-9007 (Linking)
VI  - 97
IP  - 4
DP  - 2009 Nov
TI  - A pair of naturally occurring antibodies may dampen complement-dependent 
      phagocytosis of red cells with a positive antiglobulin test in healthy blood 
      donors.
PG  - 338-47
LID - 10.1111/j.1423-0410.2009.001214.x [doi]
AB  - BACKGROUND AND OBJECTIVE: It is known that red blood cells (RBC) from healthy 
      blood donors with a positive direct antiglobulin test (DAT) for IgG continue to 
      circulate despite carrying elevated numbers of IgG molecules. To unravel the 
      properties of these RBC-bound IgG, we studied them not only on whole RBC 
      populations, but also on density-fractionated RBCs. MATERIALS AND METHODS: The 
      properties of acid-eluted RBC-bound IgG and plasma IgG were studied by ELISA for 
      binding to RBC proteins and opsonins, and by blotting. In vitro phagocytosis was 
      studied on density-separated RBCs. RESULTS: IgG-DAT-positive blood donors carried 
      most IgG molecules on dense RBCs and had more RBCs of high density than 
      DAT-negative controls. Their densest RBCs were older than the oldest RBCs of 
      DAT-negative controls, based on the band 4.1a/b ratio. In vitro phagocytosis of 
      senescent RBCs from IgG-DAT-positive donors was 1.5 to 2 fold higher than that of 
      senescent control cells, but the same or less in the presence of physiological 
      IgG concentrations, implying that RBC-bound IgGs impaired complement-dependent 
      uptake. The IgG molecules on these DAT-positive RBCs comprised anti-band 3 
      naturally occurring antibodies (NAbs) and were two- to fivefold enriched in 
      anti-C3 and framework-specific anti-idiotypic NAbs as compared to controls. 
      Correspondingly, anti-C3 and framework-specific anti-idiotypic NAbs were 
      proportionally elevated in the plasma of two-thirds of DAT+ donors. CONCLUSIONS: 
      Extra-binding of anti-C3 together with anti-idiotypic NAbs to senescent 
      RBC-associated C3 fragments may suppress complement-dependent RBC phagocytosis 
      and may prolong the in vivo life span of RBCs.
FAU - Alaia, V
AU  - Alaia V
AD  - Institute of Biochemistry, Department of Biology, ETH Zurich, Zurich, 
      Switzerland.
FAU - Frey, B M
AU  - Frey BM
FAU - Siderow, A
AU  - Siderow A
FAU - Stammler, P
AU  - Stammler P
FAU - Kradolfer, M
AU  - Kradolfer M
FAU - Lutz, H U
AU  - Lutz HU
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20090630
PL  - England
TA  - Vox Sang
JT  - Vox sanguinis
JID - 0413606
RN  - 0 (Antibodies, Anti-Idiotypic)
RN  - 0 (Complement C3)
RN  - 0 (Immunoglobulin G)
SB  - IM
MH  - Antibodies, Anti-Idiotypic/*immunology
MH  - *Blood Donors
MH  - Complement C3/*immunology
MH  - *Coombs Test
MH  - Erythrocytes/*immunology
MH  - Humans
MH  - Immunoglobulin G/*immunology
MH  - Phagocytosis/*immunology
EDAT- 2009/07/03 09:00
MHDA- 2010/01/09 06:00
CRDT- 2009/07/03 09:00
PHST- 2009/07/03 09:00 [entrez]
PHST- 2009/07/03 09:00 [pubmed]
PHST- 2010/01/09 06:00 [medline]
AID - VOX1214 [pii]
AID - 10.1111/j.1423-0410.2009.001214.x [doi]
PST - ppublish
SO  - Vox Sang. 2009 Nov;97(4):338-47. doi: 10.1111/j.1423-0410.2009.001214.x. Epub 
      2009 Jun 30.