This invention relates to methods and compositions for the treatment or alleviation of Alzheimer's
disease and of other conditions related to
abnormal protein aggregation. In particular, the invention relates to methods and compositions for the
immunotherapy of Alzheimer's
disease, Parkinson's
disease, and cataract. In one aspect the invention provides a method of prophylaxis, treatment or alleviation of a condition characterized by
pathological aggregation and accumulation of a
specific protein associated with an immunizing-effective
dose of one or more
tyrosine cross-linked compounds, and optionally also comprising
copper ions complexed to the compound. Alternatively passive immunization against a
tyrosine cross-linked compound may be used. Prophylactic or therapeutic compositions and
diagnostic methods are also disclosed and claimed.