A new type of anti-ganglioside antibodies present in neurological patients.

High titers of anti-GA1 antibodies have been associated with neurological syndromes. In most cases, these antibodies cross-react with the structurally related glycolipids GM1 and GD1b, although specific anti-GA1 antibodies have also been reported. The role of specific anti-GA1 antibodies is uncertain since the presence of GA1 in the human nervous system has not been clarified. A rabbit was immunized with GD1a and its sera were screened for antibody reactivity by standard immunoassay methods (HPTLC-immunostaining and ELISA). Anti-GD1a antibodies were not detected but, unexpectedly, anti-GA1 IgG-antibodies were found. Antibody binding to GA1 was inhibited by soluble GA1 but also by GD1a. These results indicate that the rabbit produced antibodies that recognize epitopes present on the glycolipids, that are absent or not exposed on solid phase adsorbed GD1a. We investigated the presence of these unusual anti-ganglioside antibodies in normal and neurological patient sera. Approximately, 10% of normal human sera contained low titer of specific anti-GA1 IgG-antibodies but none of them recognized soluble GD1a. High titers of IgG-antibodies reacting only with GA1 were detected in 12 patient sera out of 325 analyzed. Of these, 6 sera showed binding that was inhibited by soluble GD1a and four of them also by GM1. This new type of anti-ganglioside antibodies should be considered important elements for understanding of the pathogenesis of these diseases as well as their diagnosis.

Interferon beta-1a in chronic inflammatory demyelinating polyneuropathy: case report.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated neuropathy. It presents with a course of progression which may be slow and steady or step-wise or relapsing. Sensory ataxic polyneuropathy may be the only clinical manifestation of this disease. Treatment with interferon beta1a (INF beta1a) has been tried with different results in patients who were refractory to other, more conventional, immunomodulatory therapies. Here we report on a patient who had a relapsing form of pure sensory ataxic CIDP and who failed to respond to intravenous human immunoglobulin. He was put on INF beta1a for 3 years. During this period he suffered no relapses while his condition stabilized.

Interferon beta-1a in chronic inflammatory demyelinating polyneuropathy: case report

La polineuropatía crónica inflamatoria desmielinizante (PCID) es una neuropatía inmuno-mediada, que presenta un curso clínico primariamente progresivo o en forma de recaídas. Las manifestaciones sensoriales pueden ser su unica forma de expresión clínica. El tratamiento con interferon beta 1a (IFN beta 1a) ha sido ensayado en varias oportunidades, con diferentes respuestas terapéuticas, en pacientes refractarios a las terapias inmunomoduladoras convencionales. Nosotros comunicamos un paciente con una forma ataxica recurrente de PCID, que no respondió al tratamiento con inmunoglobulina endovenosa. Posteriormente fue tratado con IFN beta 1 a por tres años. Durante el período de seguimiento no mostró nuevas recaídas y su cuadro neurológico se estabilizó.

Evidence of oxidative stress in familial amyloidotic polyneuropathy type 1.

OBJECTIVE: To evaluate the oxidative state in patients with familial amyloidotic polyneuropathy type 1 (FAP1). DESIGN: From 3 unrelated families, patients with FAP1 carrying a transthyretin Met-30 mutation were studied. The diagnosis was confirmed by genetic analysis. Eleven of 21 patients carried the mutation; all were symptomatic and were clinically assessed using a clinical score. All of the patients were evaluated for copper-zinc superoxide dismutase type 1 activity in red blood cells using spectrophotometry. Plasma total reactive antioxidant potential was studied using a chemiluminescent method. The results were compared with those obtained from an age-matched control group. SETTING: A public and academic multidisciplinary research clinic. RESULTS: Six of the 11 FAP1-positive patients disclosed superoxide dismutase type 1 activity values greater than 55 U/mg of protein (upper control limit), whereas 9 of 10 patients in whom total reactive antioxidant potential was measured had values below the lower limit of the control group. No relationship was found between the levels of superoxide dismutase type 1 activity and the severity of the clinical involvement. CONCLUSIONS: Oxidative stress may be part of the mechanisms leading to tissue damage in patients with FAP1. The lack of correlation between the laboratory findings and the severity of clinical involvement may signal that oxidative processes are at work throughout the natural history of the disease.