Delay from treatment start to full effect of immunotherapies for multiple sclerosis

In multiple sclerosis, treatment start or switch is prompted by evidence of disease activity. Whilst immunomodulatory therapies reduce disease activity, the time required to attain maximal effect is unclear. In this study we aimed to develop a method that allows identification of the time to manifest fully and clinically the effect of multiple sclerosis treatments (‘therapeutic lag’) on clinical disease activity represented by relapses and progression-of-disability events. Data from two multiple sclerosis registries, MSBase (multinational) and OFSEP (French), were used. Patients diagnosed with multiple sclerosis, minimum 1-year exposure to treatment, minimum 3-year pretreatment follow-up and yearly review were included in the analysis. For analysis of disability progression, all events in the subsequent 5-year period were included. Density curves, representing incidence of relapses and 6-month confirmed progression events, were separately constructed for each sufficiently represented therapy. Monte Carlo simulations were performed to identify the first local minimum of the first derivative after treatment start; this point represented the point of stabilization of treatment effect, after the maximum treatment effect was observed. The method was developed in a discovery cohort (MSBase), and externally validated in a separate, non-overlapping cohort (OFSEP). A merged MSBase-OFSEP cohort was used for all subsequent analyses. Annualized relapse rates were compared in the time before treatment start and after the stabilization of treatment effect following commencement of each therapy. We identified 11 180 eligible treatment epochs for analysis of relapses and 4088 treatment epochs for disability progression. External validation was performed in four therapies, with no significant difference in the bootstrapped mean differences in therapeutic lag duration between registries. The duration of therapeutic lag for relapses was calculated for 10 therapies and ranged between 12 and 30 weeks. The duration of therapeutic lag for disability progression was calculated for seven therapies and ranged between 30 and 70 weeks. Significant differences in the pre- versus post-treatment annualized relapse rate were present for all therapies apart from intramuscular interferon beta-1a. In conclusion we have developed, and externally validated, a method to objectively quantify the duration of therapeutic lag on relapses and disability progression in different therapies in patients more than 3 years from multiple sclerosis onset. Objectively defined periods of expected therapeutic lag allows insights into the evaluation of treatment response in randomized clinical trials and may guide clinical decision-making in patients who experience early on-treatment disease activity. This method will subsequently be applied in studies that evaluate the effect of patient and disease characteristics on therapeutic lag.

Epidemiology of familial multiple sclerosis in Hungary

The prevalence of familial aggregation of multiple sclerosis (MS) is estimated between 5 and 10%. Studies emphasize the effect of genetic factors over the environment of the patients in the development of the disease. We investigated familial accumulation of MS in the cases of 1500 patients in five Hungarian MS centers. According to our data, the risk of familial MS in Hungary is lower than in other countries for which literature data are accessible. The literature does not contain any data for the prevalence of familial MS in Hungary and middle-eastern Europe.

Hungarian multicentre epidemiologic study of the warning and initial symptoms (prodrome, aura) of epileptic seizures

We carried out a Hungarian multicentre study to assess the frequency of the occurrence of warning symptoms preceding epileptic seizure. The data of 562 patients with epilepsy out of a total of 1124 were analysed on the basis of questionnaires filled in under standard conditions. About 50% of the patients experienced warning symptoms before a smaller or greater part of their seizures. Their appearance was fairly consistent and became mainly manifested in the form of headache, epigastric sensation and dysphoria. In relation to epileptological basic data, it was found that warning symptoms appeared primarily in focal epilepsies and among them they mainly preceded generalized tonic clonic and complex partial seizures. Between the warning symptom and the onset of the seizure there was usually a longer interval during which (and generally also during the warning symptom) the patient remained able to act. About 20% of the patients enrolled in the study tried to inhibit the onset or mitigate the course of the seizure and about 10% judged their spontaneous activity carried out in that direction to be successful. The frequency of the occurrence of independent prognostic symptoms not followed by a seizure was relatively low, and among epileptics with warning symptoms the incidence of seizures occurring without a preceding event was not high either. Based on our experiences, we have drawn the conclusion that, in a significant part of epileptic patients, the warning symptoms render possible the supplementation of the therapy by the development of seizure-inhibiting or seizure-avoiding behaviour or activity.

Twenty-four-hour ambulatory blood pressure profiles in pediatric patients after renal transplantation

Ambulatory blood pressure monitoring was applied in 27 pediatric patients aged 6.3-24.3 (median 15.0) years who had been transplanted 1.5-8.4 years previously. Daytime values were compared with the mean of 10 concomitant casual blood pressure recordings. At the time of the study, antihypertensive drugs were given to 17 patients. Inulin clearance ranged from 18 to 116 (median 66) ml/min per 1.73 m2. Ambulatory blood pressure monitoring confirmed hypertension or normotension determined by casual blood pressure measurements in 63% of patients. The physiological nocturnal dip in blood pressure was attenuated or reversed in 8 of 27 patients. It was reduced in all 3 patients with renal artery stenosis of the graft, in 3 of 4 patients with chronic rejection, in the only patient with recurrent focal segmental glomerulosclerosis, and in 1 of 6 patients with past acute rejection. The dipping was not related to inulin clearance. In conclusion, casual blood pressure measurements do not accurately reflect blood pressure in pediatric patients transplanted more than 1.5 years previously. A reduced nocturnal dip in blood pressure may indicate an underlying renovascular or renoparenchymal pathology. Ambulatory blood pressure monitoring should regularly be applied in patients with renal transplants.

Nocturnal blood pressure elevation in transplanted pediatric patients

Ambulatory blood pressure monitoring during 24 hours was applied in 34 pediatric patients aged 6.3 to 24.3 (median 14.0) years who had been transplanted 0.3 to 8.4 years previously. The mean arterial blood pressure levels measured during the daytime and at night correlated positively (r = 0.70), but 14 of the 28 patients with nocturnal hypertension were normotensive during the day. A reduced nocturnal dip (< 5.5%) of mean arterial blood pressure was detected in 11 of 34 patients. In the first year post-transplantation 4 of 7 patients had an attenuated dip without any obvious cause. Beyond the first year a reduced dip was always associated with a renal pathology. In conclusion, a high prevalence of nocturnal hypertension was detected in grafted pediatric patients, even in presence of normal daytime blood pressures. An attenuated nocturnal dip was found in association with an underlying renal pathology or within the first post-transplant year.

[Comparative study of acetate and bicarbonate hemodialysis in children with chronic uremia]

Comparative studies on 5 children suffering from chronic uremia were performed regarding the efficacy of acetate and bicarbonate hemodialysis. Clinical symptoms, acid-base and blood gas analysis, serum osmolality, blood pressure and EEG were examined. On authors experience the patients tolerated better the bicarbonate dialysis. Laboratory data and blood pressure were found to be closer to the normal values too. The abnormality of EEG made after bicarbonate dialysis were not so expressed than that of acetate dialysis. On the basis of this examinations the authors suggest the bicarbonate hemodialysis in uremic patients with severe cardiovascular and/or neurological complications.

Erythrocyte defense mechanisms against free oxygen radicals in haemodialysed uraemic children

Changes in erythrocyte lipid peroxidation (measured as the concentration of malonyl dialdehyde), glutathione metabolism, antioxidant enzyme activities (glutathione peroxidase, catalase, and superoxide dismutase), the oxidized products of haemoglobin (Hb), and hydrogen peroxide (H2O2)-induced haemolysis were studied in six children with chronic renal failure treated with serial acetate and bicarbonate haemodialysis (HD). Ten age- and sex-matched children acted as controls. Malonyl dialdehyde levels were significantly higher and antioxidant enzyme activities lower in uraemic red blood cells (RBCs) compared with controls (P less than 0.05). Incubation of RBCs for 1 h with acetylphenylhydrazine induced a decrease in the concentration of reduced glutathione (P less than 0.001) and an increase in the level of oxidized products of Hb (P less than 0.001), but only in the uraemic patients. The H2O2 haemolysis test revealed a mild (n = 3) to increased (n = 3) haemolysis in the uraemic RBCs. Oxidative haemolysis is probably a multifactorial process in uraemic patients, and may be an important risk factor in HD therapy.