Anti-ganglioside antibodies and elevated CSF IgG levels in Guillain-Barre´ syndrome S. Mata`, E. Galli, A. Amantini, F. Pinto, S. Sorbi and F. Lolli Department of Neurological and Psychiatric Science, University of Firenze, Firenze, Italy Keywords: anti-ganglioside antibody, blood–CSF barrier, F wave, Guillain-Barre´ syndrome, immunoglobulin Received 23 October 2004 Accepted 7 February 2005 Anti-ganglioside antibody production and dysfunction of blood-cerebrospinal fluid (CSF) barrier (BCB) are frequent findings in dysimmune neuropathy patients, whereas intrathecal synthesis of immunoglobulins is still a matter of debate. We examined the CSF, immunological and electrophysiological characteristics from a cohort of patients with Guillain-Barre´ syndrome (GBS) and chronic inflammatory demyelinating poly- neuropathy (CIDP), and from patients with other neurological diseases as control. Thirty-eight percent of GBS patients and 28% of CIDP patients had detectable serum titers of anti-ganglioside antibodies, which were associated with a high incidence of motor conduction block and increased F wave latencies. In GBS patients, but not in CIDP or control patients, there was an association between anti-ganglioside anti- bodies and increased CSF immunoglobulin-G (IgG) levels as determined by the IgG index. However, none of the GBS patients had CSF oligoclonal bands (OBs) or indications of intrathecal anti-ganglioside antibody synthesis. The possibility of an abnormal CSF concentration of immunoglobulins from serum through dysfunctional BCB or damaged nerve roots, and the role of serum anti-ganglioside reactivity in this process are discussed. Introduction Guillain-Barre´ syndrome (GBS) is an immune-medi- ated demyelinating disease of the peripheral nerves and spinal roots, characterized by rapidly progressing symmetrical weakness with disappearance of tendon reflex, electrophysiological features of demyelination and blood–cerebrospinal fluid (CSF) barrier (BCB) dysfunction with normal cell count [1]. Signs indic- ative of intrathecal immunoglobulin-G (IgG) synthesis have been reported with variable frequency, especially during the stage of stabilized paralysis [2–4]. Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic autoimmune peripheral nerve disease which shares with GBS many immunopathological findings [5]. A frequent observation in dysimmune neuropathy patients is a raised serum anti-ganglioside antibody titer (for a review see ref. no. [6]. Several studies suggested a possible role of these antibodies in GBS and CIDP pathogenesis, particularly in deter- mining motor conduction blockade [7–10] and, even- tually, blood–nerve (BNB) and BCB leakage [11]. The relationship between CSF findings, immunological and electrophysiological characteristics in dysimmune neuropathies is unclear. To address this issue we compared indexes of BCB damage and of intrathecal IgG production with anti-ganglioside antibodies and with electrophysiological data from a group of GBS and CIDP patients and, as control, from patients with other peripheral and central nervous system disorders. Materials and methods Patients Seventy-three subjects (45 males, age 15–85 years, mean 50) were diagnosed as GBS and 43 subjects (28 males, age 23–75 years, mean 54) were diagnosed as CIDP according to established clinical, laboratory and elec- trophysiological criteria [1,12]. Clinical assessment and functional disability were scored according to the Hughes’s scale [13]. Blood and CSF samples were ob- tained before treatment on admission within the active phase of disease (2–12 days after onset, mean 7). Samples were stored in aliquots at )20°C until analysis. As controls for the study of association between CSF parameters, serum anti-ganglioside antibodies and neurophysiological findings, we enrolled 117 patients with sensory and sensory-motor chronic polyneuro- pathy (n ¼ 70) and amyotrophic lateral sclerosis (ALS, n ¼ 47). For the study of association between CSF parameters and serum anti-ganglioside antibodies, we Correspondence: Dr S. Mata`, Department of Neurological and Psychiatric Science, University of Firenze, Viale Morgagni 85, I50135, Firenze, Italy (tel.: +39 55 4279788; fax: +39 55 4279409; e-mail: masa@unifi.it). Ó 2006 EFNS 153 European Journal of Neurology 2006, 13: 153–160