TISSUE DISTRIBUTION OF PATHOLOGICAL LESIONS AND HU ANTIGEN EXPRESSIONIN PARANEOPLASTIC SENSORY NEURONOPATHY

We investigated the distribution of lesions and Hu antigen expression in two autopsied cases of anti-Hu antibody-positive paraneoplastic sen sory neuronopathy (carcinomatous subacute sensory neuropathy). Patholo gical changes in both patients were limited to the primary sensory neu rons, some of the sympathetic ganglia and hippocampal regions. The les ions showed a multifocal distribution that differed among the spinal s egmental levels and in the individual dorsal root ganglia as well as i n the nerve fascicles. Western blot analysis of the patients' serum re vealed that Hu antigens were extensively and widely expressed througho ut the central nervous system, sensory and sympathetic ganglia and can cer cells, but not in the non-neural visceral tissues. Reverse transcr iptase-polymerase chain reaction also showed that the Hu D, Hu C, Hel- N1 and Hel-N2 mRNAs were extensively and widely expressed through the neural tissues and cancer cells, but not in the visceral tissues. Thus , the distribution of antigen expression was very different from that of the lesions. Taken together with the distribution of lesions and Hu antigen expression, it is suggested that factors other than anti-Hu a ntibodies are also involved in the pathogenesis of this neuronopathy.