MRI activity and neutralising antibody as predictors of response to interferon beta treatment in multiple sclerosis.

OBJECTIVE: To prospectively validate MRI activity and neutralising anti-interferon antibody (NAb) during the first 6 months of interferon beta treatment as response indicators in multiple sclerosis (MS). METHODS: Patients with relapsing-remitting MS were followed during the first 2 years of treatment. Neurological assessments were performed every 3 months or when a relapse was suspected. MRI scans performed at baseline and at 3, 4, 5 and 6 months after the start of treatment were assessed centrally for disease activity: new T2 or gadolinium enhancing T1 lesions. NAb were assessed using the MxA protein assay; positivity was defined as two consecutive titres >or=20 NU/ml. We evaluated the predictivity of an active scan, NAb positivity, or both, during the first 6 months of treatment, on the occurrence of clinical disease activity in the following 18 months. RESULTS: 147 patients were assessed at 16 centres. Predictivity parameters (with confidence intervals) were as follows: active scan, sensitivity (SN) 52% (34-69%), specificity (SP) 80% (65-91%), negative predictive value (NPV) 73% (58-77%), positive predictive value (PPV) 62% (42-79%), p = 0.002; NAb positivity, SN 71% (45-88%), SP 66% (55-76%), NPV 92% (82-97%), PPV 29% (16-45%), p = 0.01; active scan and NAb positivity, SN 71% (38-91%), SP 86% (73-94%), NPV 94% (86-98%), PPV 50% (29-70%), p = 0.0003. CONCLUSIONS: MRI activity and NAb occurrence during the first 6 months of interferon beta treatment were reliable predictors of long term clinical response, particularly when combined. Patients with negative predictors showed a less than 10% risk of developing clinical activity. Patients with positive predictors showed a 50% risk of further clinical activity. These patients need to be followed carefully with further MRI and NAb tests.

Normovolemic hemodilution in head and neck surgery.

As the transfusion risks to which patients are exposed are gradually understood, every effort is being made to find both a valid and safe alternative to homologous blood transfusions. Bearing this in mind, the most sensible solution appears to be the practice of a self-donor procedure with normovolemic hemodilution prior to elective surgery. However, even repeated bloodlettings do not modify the oxygen delivery to tissues since, with a reduction in the hemoglobin content of the circulating blood, there is a corresponding increase in oxygen availability. Since the reduction of circulating erythrocytes brings with it a reduction in blood viscosity, there is in turn an improvement in the microcirculation. The generally better tissue oxygenation, the reduction of the blood's viscosity and the increased circulatory perfusion all also favor a prophylaxis against deep vein thrombosis. We have currently performed 72 surgical procedures for head and neck neoplasms that were undertaken at the Clinical ENT Division of Treviso Hospital precisely with the normovolemic hemodilution described above. The self-donor transfusion technique was adopted with the help of the hospital's transfusion service. We have analyzed the data relative to this method and have found that the normovolemic hemodilution represents the treatment of choice in surgery-induced stress, particularly since this approach allows a better tissue oxygenation.