Universal pooled plasma (Uniplas(®)) does not induce complement-mediated hemolysis of human red blood cells in vitro.

BACKGROUND: Pooling of plasma of different blood groups before large scale manufacturing of Uniplas(®) results in the formation of low levels of soluble immune complexes (CIC). The aim of this study was to investigate the level and removal of CIC during Uniplas(®) manufacturing. In addition, an in vitro hemolysis assay should be developed and investigate if Uniplas(®) does induce complement-mediated hemolysis of human red blood cells (RBC). MATERIALS AND METHODS: In-process samples from Uniplas(®) (universal plasma) and Octaplas(LG)(®) (blood group specific plasma) routine manufacturing batches were tested on CIC using commercially available ELISA test kits. In addition, CIC was produced by admixing heat-aggregated immunoglobulins or monoclonal anti-A/anti-B antibodies to plasma and removal of CIC was followed in studies of the Uniplas(®) manufacturing process under down-scale conditions. The extent of RBC lysis was investigated in plasma samples using the in-house hemolysis assay. RESULTS: Levels of CIC in Uniplas(®) are within the normal ranges for plasma and comparable to that found in Octaplas(LG)(®). Down-scale experiments showed that both IgG/IgM-CIC levels are significantly removed on average by 40-50% during Uniplas(®) manufacturing. Uniplas(®) does not induce hemolysis of RBCs in vitro. Hemolysis occurs only after spiking with high titers of anti-A/anti-B antibodies and depends on the antibody specificity (i.e. titer) in the plasma sample. CONCLUSION: The results of this study confirm the safety of Uniplas(®) regarding transfusion to patients of all ABO blood groups.

Complement factor H binds malondialdehyde epitopes and protects from oxidative stress.

Oxidative stress and enhanced lipid peroxidation are linked to many chronic inflammatory diseases, including age-related macular degeneration (AMD). AMD is the leading cause of blindness in Western societies, but its aetiology remains largely unknown. Malondialdehyde (MDA) is a common lipid peroxidation product that accumulates in many pathophysiological processes, including AMD. Here we identify complement factor H (CFH) as a major MDA-binding protein that can block both the uptake of MDA-modified proteins by macrophages and MDA-induced proinflammatory effects in vivo in mice. The CFH polymorphism H402, which is strongly associated with AMD, markedly reduces the ability of CFH to bind MDA, indicating a causal link to disease aetiology. Our findings provide important mechanistic insights into innate immune responses to oxidative stress, which may be exploited in the prevention of and therapy for AMD and other chronic inflammatory diseases.