Summary. Systemic humoral factors have been studied in traumatic, chronic and acute spinal cord injured patients. Antibodies specific to nervous system auto antigens were detected in a majority of the sera obtained from these patients, at different periods after injury. Limited in vitro sprouting of dorsal root ganglia in chicken embryos was observed in the presence of serum from these patients. The possible association between growth inhibiting factors and the presence of antibodies against nervous tissue autoantigens is discussed.

Cranial idiopathic acute peripheral facial nerve paralysis (Bell palsy) has been used as a model disease in the present study mainly to investigate trophic capacity of serum components. The ability to induce sprouting from chick embryo dorsal root ganglia was used as the bioassay for trophic activity. Sera from normal patients induce neuritic outgrowth from dorsal root ganglia of chick embryo in the absence of any exogenous factor. Sprouting, to a very limited extent or none, has been induced by 80% of the sera derived from the Bell palsy patients. Further analysis of the biochemical nature of the reduced activity has revealed that in sera of Bell palsy patients the substances that are fractionated within the Ig fraction are responsible for the reduced capacity to induce sprouting without loss of supportive molecules.