ACUTE CHILDHOOD NEUROBORRELIOSIS WITH A SELECTIVE IMMUNE-RESPONSE TO A LOW-MOLECULAR-WEIGHT PROTEIN EXPRESSED BY BORRELIA-GARINII

In patients with Lyme borreliosis the early immune response to Borreli a burgdorferi is usually directed against the flagellin (41 kD) antige n. However, the sera of 4 out of 12 children with typical early neurob orreliosis contained antibodies to two low molecular weight proteins o f 19 and 23 kD. These antibodies were demonstrated in serological test s using Borrelia garinii as antigen source. B. garinii is the species of B. burgdorferi sensu lato associated with neuroborreliosis. In cont rast serological tests using B. burgdorferi sensu stricto, associated with arthritis, or using VS461 strains (B. afzelii), associated with c hronic skin disease, were false-negative. Monospecific rabbit sera rai sed against the 23 kD protein of B. garinii strain W1 detected the 23 kD epitope in B. garinii isolates only. Results of serological tests f or Lyme borreliosis may depend on the infecting strain and on the choi ce of the strain used as antigen source for diagnostic tests. The atte nding physician should interpret serological test results with care an d rely on astute clinical judgement.