FH autoantibodies found in LA+, SLE and RA were directed against several epitopes across FH in contrast to those found in aHUS, which bound mainly to the C-terminus.
This attachment is highly relevant and has pathophysiological consequences in several human diseases, including Factor H-associated hemolytic uremic syndrome (FH-HUS), membrano-proliferative glomerulonephritis type II, recurrent microbial infections and chronic inflammation, e.g. rheumatoid arthritis and immune evasion of tumor cells.
This study shows a novel protective and anti-inflammatory role of the two important complement regulators FHL-1 and factor H in rheumatoid arthritis and suggests a disease controlling role of the two proteins.