A compound of formula (I) R-L-CO-X (I) (wherein R is a C unsaturated hydrocarbon group optionally interrupted by one or more heteroatoms or groups of heteroatoms selected from S, O, N, SO, SO, said hydrocarbon group comprising at least 4 non-conjugated double bonds L is a linking group forming a bridge of 1 to 5 atoms between the R group and the carbonyl CO and X is an electron withdrawing group) or a salt thereof for use in the treatment of glomerulonephritis.
