IMPAIRMENT OF ELECTROPHYSIOLOGICAL FUNCTION OF ASTROCYTES BY CEREBROSPINAL-FLUID FROM A PATIENT WITH WALDENSTROMS MACROGLOBULINEMIA

Patients with the Bing Neel type of Waldenstrom's macroglobulinemia of ten present with global neurological symptoms. In this case report, we investigated the effects of cerebrospinal fluid (CSF) of a such a pat ient (CSF-WM), who presented with seizures and psychomotor slowing, on the electrophysiological properties of cultured rat neurons and astro cytes. Membrane potential and Na+ and K+ currents of neurons were unaf fected. Astrocytes, however, were significantly depolarized from -77.6 +/- 8.2 mV to -48.0 +/- 7.6 mV (38%) by CSF-WM. The depolarization wa s markedly reduced after CSF-WM heat inactivation or after pre-incubat ion of astrocytes with dexamethasone (1 mu M). Astrocytes are electrop hysiologically active cells, which control local ionic micro-environme nt. Therefore, we conclude that global neurological symptoms in the Bi ng Neel type of Waldenstrom's macroglobulinemia like generalized seizu res can result from an impairment of glial cells electrophysiological functions.