Representative IgG line immunoblots of patient and control sera. Strains belong to the following species: B31 and PKa2 to B. burgdorferi sensu stricto, PKo to B. afzelii, PBr to B. garinii OspA type 3, PBi to B. garinii OspA type 4, and 20047 to B. garinii unknown OspA type. Sera were obtained from patients with EM, early neuroborreliosis (NB), acrodermatitis chronica atrophicans or Lyme arthritis (late LB), and controls. *, additional antigen on the IgG line blot.