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Biomedical subjects

C Pozzilli

Publications and source records attributed to C Pozzilli.

At least 55 records · Page 3Linked to original sources
PubMed1998

A longitudinal brain MRI study comparing the sensitivities of the conventional and a newer approach for detecting active lesions in multiple sclerosis.

Monthly dual-echo spin-echo (SE) and enhanced magnetic resonance imaging (MRI) after the injection of a standard dose (SD) of gadolinium (Gd) is the conventional approach to monitor short-term disease activity in multiple sclerosis (MS). In this study, the sensitivity of this approach in detecting active lesions in MS was compared with that of monthly fast fluid attenuated inversion recovery (FLAIR) scans associated with enhanced MRI after the injection of a triple dose (TD) of Gd. Thirteen patients with relapsing-remitting MS entered the study. Monthly MRI scans were obtained on four occasions in two separate sessions (interval between 12 and 24 h). In one session, dual-echo conventional SE and SD Tl-weighted scans were obtained; in the other, fast-FLAIR and TD Tl-weighted scans. The order of the two sessions was randomized. Three observers counted the number of active lesions detected by each of the two approaches. One hundred and four active lesions were detected by the conventional approach and 199 by the newer approach (average increase per patient = 75%, range = 0-325%). The mean number of active lesions per month per patient was 2.0 for the conventional approach and 3.8 for the new approach (P = 0.004). Scans with active lesions were 34/52 (65%) with the conventional approach and 37/52 (71%) with the new approach. Our data indicate that the combined use of monthly fast-FLAIR and TD enhanced Tl-weighted scans increases the number of active lesions detected on serial MRI scans from patients with MS.

Adult↗
PubMed1998

Development of neutralizing antibodies in patients with relapsing-remitting multiple sclerosis treated with IFN-beta1a.

Sixty-eight patients with relapsing-remitting multiple sclerosis (RRMS) were treated with 3 million or 9 million i.u. of recombinant interferon-beta1a (recIFN-beta1a) s.c. three times a week for 2 years. Their sera were tested for antibodies neutralizing the IFN (NAb) in a bioassay. Sera with titers > or = 1:20 were considered positive. We detected NAb in 3.2%, 13.8%, and 15.9% of the patients in sera obtained at 3, 6, and 24 months, respectively. The incidence was not related to the IFN dose. Interestingly, during the 6 month baseline period before the start of the study, relapse rates, baseline disability, and the volume of lesions on T2-weighted images were significantly higher in patients who developed NAb during treatment. Because of interpatient variability, no definitive relationship was observed between NAb formation and loss of clinical or magnetic resonance imaging (MRI) response.

Adolescent↗
PubMed1998

A multi-centre longitudinal study comparing the sensitivity of monthly MRI after standard and triple dose gadolinium-DTPA for monitoring disease activity in multiple sclerosis. Implications for phase II clinical trials.

In this study we assessed the safety, efficacy and cost-effectiveness of the use of triple dose gadolinium-DTPA (Gd) in serial monthly brain MRI of patients with multiple sclerosis, such as could be selected for clinical trials. The number of enhancing lesions, the number of new enhancing lesions and the number of active scans were used to evaluate the sensitivity of the contrast-enhanced MRI to disease activity. The dose of Gd, and the effect of introducing a delay between the contrast injection and the scan were both appraised. Every 4 weeks for 3 months, and in two separate sessions, scans were obtained from 40 patients with relapsing-remitting or secondary progressive multiple sclerosis, 5 min (early) and 20 min (delayed) after a standard dose (0.1 mmol/kg) or triple dose (0.3 mmol/kg) Gd injection. There were 435 enhancing lesions (242 of which were new) on the early standard dose scans, 479 (263 new) on the delayed standard dose, 772 (365 new) on the early triple dose and 827 (404 new) on the delayed triple dose. There were 109 scans revealing active disease on the early standard dose scans, 112 on the delayed standard dose, 119 on the early triple dose and 120 on the delayed triple dose. Statistical simulations indicated that the sample sizes needed for both cross-over and parallel-group trials with similar powers are lower if serial monthly triple dose MRI is used. No side-effects were reported and no significant changes in blood test parameters were found throughout the study. This study shows that the serial use of triple dose Gd is safe, and that it increases the sensitivity of serial monthly enhanced MRI in detecting multiple sclerosis activity significantly. Its use should enable preliminary trials of experimental therapies for multiple sclerosis to be conducted in small patient populations, over a short period of time.

Adult↗
PubMed1998

Determinants of Gd-enhanced MRI response to IFN-beta-1a treatment in relapsing-remitting multiple sclerosis.

The decision to use interferon beta (IFN-beta) as a treatment for relapsing-remitting multiple sclerosis (RRMS) is based on both clinical characteristics and course of the disease. To better identify the profile of responders, the relationships between baseline clinical/MRI characteristics and therapeutical response was analyzed in 49 patients with RRMS randomly assigned to receive subcutaneously 3 or 9 MIU of IFN-beta-1a. The therapeutical response was evaluated as a per cent change in the mean number and volume of monthly Gd-enhancing lesions in both first (early response) and second (late response) 6-month period of treatment, compared to the 6-month pre-treatment period. A better early response was seen in patients with a lower number of relapses during the pre-treatment period, while the late response was favourably influenced by a lower baseline EDSS and the high dose. Our findings suggest that the effect of IFN-beta-1 a on disease MRI activity is dose-related and dependent on the relapse rate and the level of disability before treatment.

Adjuvants, Immunologic↗
PubMed1998

Effect of steroids on Gd-enhancing lesions before and during recombinant beta interferon 1a treatment in relapsing remitting multiple sclerosis.

The aim of this study was to investigate whether a concomitant treatment with recombinant interferon beta 1a (rIFN beta-1a) modifies the effect of steroids on the blood-brain barrier (BBB) in relapsing remitting MS patients, as evaluated by enhanced MRI of the brain. We evaluated 19 patients with a clinical relapse treated only with intravenous methylprednisolone (IVMP; 1 g daily for 6 days), and 10 patients who experienced a clinical relapse and were treated with IVMP (1 g daily for 6 days) during an rIFN beta-1a treatment period. The number and volume of enhancing lesions were analyzed on four serial MR images obtained at monthly intervals (one scan before and three scans after IVMP treatment). A significant reduction in the mean number and volume of enhancing lesions was seen in the first scan after IVMP treatment in all patients. However, while persistently low enhancement was seen in the follow-up scans of patients treated with rIFN beta-1a, a rebound effect (i.e., increase in the number and volume of gadolinium-enhancing lesions) was observed in the other patients during the follow-up. These data suggest that rIFN beta-1a prolongs the beneficial effect of steroids on the BBB.

Adult↗
PubMed1997

Randomized placebo-controlled trial of mitoxantrone in relapsing-remitting multiple sclerosis: 24-month clinical and MRI outcome.

We designed a randomized, placebo-controlled, multicentre trial involving 51 relapsing-remitting multiple sclerosis patients to determine the clinical efficacy of mitoxantrone treatment over 2 years. Patients were allocated either to the mitoxantrone group (27 patients receiving I.V. infusion of mitoxantrone every month for 1 year at the dosage of 8 mg/m2) or to the placebo group (24 patients, receiving I.V. infusion of saline every month for 1 year) using a centralized randomization system. Disability at entry and at 12-24 months was evaluated by four blinded neurologists trained in the application of the Kurtzke Expanded Disability Scale (EDSS). In addition, the number and clinical characteristics of the exacerbations over the 24 months were recorded by the local investigators. MRI, at 0, 12 and 24 months, was performed with a 0.2 T permanent unit. MRI data were analysed by two blinded neuroradiologists. All patients underwent a clinical evaluation. A statistically significant difference in the mean number of exacerbations was observed between the mitoxantrone group and placebo group both during the 1st and the 2nd year. Although there was no statistically significant benefit in terms of mean EDSS progression over 2 years, the proportion of patients with confirmed progression of the disease, as measured by a one point increase on the EDSS scale, was significantly reduced at the 2nd year evaluation in the mitoxantrone group. Forty-two (23 mitoxantrone, 19 placebo) patients underwent all MRI examinations during the 24-month period. We observed a trend towards a reduction in the number of new lesions on T2-weighted images in the mitoxantrone group. Our study suggests that mitoxantrone might be effective in reducing disease activity, both by decreasing the mean number of exacerbations and by slowing the clinical progression sustained by most patients after 1 year from the end of treatment.

Adjuvants, Immunologic↗
PubMed1997

HLA-DM polymorphisms do not associate with multiple sclerosis: an association study with analysis of myelin basic protein T cell specificity.

The MHC region on 6p harbors at least one susceptibility gene for multiple sclerosis (MS). Within this region, HLA-DM loci are of interest being involved in class II antigen processing. We investigated the association of HLA-DM polymorphisms with MS. Sixty-three patients with MS and 46 healthy controls from continental Italy were typed for HLA-DM polymorphisms and HLA-DRB1 alleles. Besides, among the donors characterized for the DM polymorphisms, we considered 6 MS patients previously studied for the fine specificity of their MBP-specific T lymphocyte lines (TLL). The frequencies of allelic variants at the DMA and DMB loci were similar between MS patients and controls, even when HLA-DRB1*1501 positive and negative donors were analyzed separately. Patients with predominant responses to different MBP epitopes did not differ for their HLA-DM haplotype while patients with predominant responses to the same MBP epitope could present different HLA-DM haplotypes. HLA-DM polymorphisms do not associate with MS and may not affect specific patterns of T cell responses to MBP.

Adult↗
PubMed1997

Down-regulation of cell-surface CD4 co-receptor expression and modulation of experimental allergic encephalomyelitis.

Pre-immunization with autoantigens confers resistance in experimental models of autoimmune diseases. Since non-self molecules can also be protective, it is conceivable that part of the effect rests on a non-specific attenuation of the immune response. This study is aimed at identifying mechanisms by which pre-immunization with a moiety suspended in incomplete Freund's adjuvant (IFA) protects from experimental allergic encephalomyelitis (EAE). Lewis rats were immunized with each of either concanavalin A, lipopolysaccharide, bovine serum albumin, 70 or 65 kDa heat shock proteins, or myelin basic protein. All moieties were given in IFA 3 weeks prior to EAE induction. Serial cytofluorimetric monitoring of B cells and of the alpha beta TCR+, CD4+, CD8+, CD45high and CD45low cells was performed. IFN-gamma and IgG1 production was evaluated in parallel. All moieties were able to attenuate or abrogate the clinical signs of EAE. At day 4 and 10 after EAE induction, the surface expression of the CD4 molecule was down-regulated on T lymphocytes. This down-regulation was most evident in animals with the highest degree of clinical protection. By day 21 post-immunization, CD4 expression was restored. The same animals also showed an increase in the B cell percentage and Th2-related IgG1 production while IFN-gamma secretion was reduced. Pre-immunization with diverse antigens suspended in IFA confers resistance to EAE induction. The down-regulation of the CD4 co-receptor accompanied by events suggestive of an immune deviation may be a general mechanism that contributes to the protection.

Animals↗
PubMed1997

The influence of clinical relapses and steroid therapy on the development of Gd-enhancing lesions: a longitudinal MRI study in relapsing-remitting multiple sclerosis patients.

Fifty-three patients with relapsing-remitting multiple sclerosis who had monthly Gd (gadolinium) enhanced MRI (Magnetic Resonance Imaging) and clinical evaluation, were divided into two subgroups: 1) patients with a clinical relapse, treated with IVMP (intravenous methylprednisolone) and at least one enhancing lesion on MRI. 2) patients who did not have a clinical relapse but with at least one enhancing lesion on MRI. In group 1, we evaluated the number and volume of enhancing lesions on the scan before and three scans after IVMP therapy; in group 2, we considered the first scan with enhancing lesions and the subsequent three scans. The mean number and volume of enhancing lesions on the first scan was significantly higher in patients with clinical relapse compared to patients without clinical relapse. In group 1, we found a consistent reduction in the first scan following steroid treatment which returned to initial levels at the following scan. Both volumetric and numerical evaluation are appropriate MRI outcome measures in monitoring therapeutic trials.

Adult↗
PubMed1997

No increase of serum autoantibodies during therapy with recombinant human interferon-beta1a in relapsing-remitting multiple sclerosis.

OBJECTIVES: The present investigation was aimed at establishing whether interferon (IFN)-beta would induce the synthesis of autoantibodies in patients affected by multiple sclerosis (MS). MATERIALS AND METHODS: The titres of different autoantibodies were measured in a group of 68 relapsing-remitting MS patients before and during treatment with human recombinant IFN-beta1a (3 MIU or 9 MIU subcutaneously 3x a week). ANA, anti-thyroid, anticardiolipin serum autoantibodies were assayed in all cases: when patients were found positive to ANA > 1 : 40, they were also tested for anti-DNA and anti-ENA antibodies. RESULTS: No increase was found in autoantibodies synthesis during 6 months of r-hIFNbeta1a therapy, either at low or high dosages. The percentage of patients positive to different types of autoantibodies varied between 0 and 29%, which are values similar to those already reported in untreated MS patients. CONCLUSION: Our data indicate that the short-term use of IFN-beta1a in MS is safe in terms of the induction of humoral autoimmune responses: however, further follow-up is needed to confirm these findings during long-term treatments.

Adjuvants, Immunologic↗
PubMed1997

Gadolinium enhanced MRI predicts clinical and MRI disease activity in relapsing-remitting multiple sclerosis.

The aim of the study was to evaluate the predictive power of baseline gadolinium (Gd) enhanced MRI in relation to subsequent clinical and MRI activity. Sixty eight patients with clinically definite relapsing-remitting multiple sclerosis had a baseline Gd enhanced MRI and were followed up clinically and by monthly Gd enhanced MRI for six months. The occurrence of relapses during the follow up period was predicted by the presence of at least one enhancing lesion on the baseline MRI (P < 0.05). The number and volume of enhancing lesions at baseline were significantly associated with both enhancing lesions observed during the follow up period (P < 0.0001) and the accumulation of abnormality on T2 weighted images (P < 0.0001). Moreover, the presence of three or more enhancing lesions at baseline scan was consistently associated with the development of permanent abnormalities on T2 weighted images six months later. The study suggests that the number and volume of Gd enhancing lesions at a single examination are strong short term predictors of subsequent clinical and MRI activity.

Adult↗
PubMed1997

Multiple sclerosis in childhood: clinical features of 149 cases.

From the retrospective study of 3375 patients affected by clinically definite or probable multiple sclerosis (MS), 149 patients were collected with onset of the disease before the age of 16 years (4.4%). Female/male ratio was higher than that of the adult onset MS (AOMS) population (2.2 vs 1.6) particularly at ages of onset after 12 years (3.0, P = 0.007 vs AOMS). Among initial symptoms, those suggesting brainstem dysfunction (25%) were more frequent compared to other systems and compared to AOMs symptoms; motor and sensory disturbances were slightly less frequent (respectively 17.5% and 18.3%). Optic neuritis appeared in 16.5% of cases with onset in childhood and in 16.2% of cases with AOMS, cerebellar disturbances respectively in 9.1% and 7.7%. The first interattack-interval and the clinical course of early onset MS did not differ significantly from AOMS. In early onset MS patients with disease duration < 8 years, cases with EDSS > 6 were slightly more frequent than in the AOMS group (P = 0.04). The frequency of cases for different levels of disability was similar for disease duration > 8 years.

Adolescent↗
PubMed1997

MRI measures and their relations with clinical disability in relapsing-remitting and secondary progressive multiple sclerosis.

To further evaluate the relationship between clinical disability and Magnetic Resonance Imaging (MRI) lesion burden, we examined 85 patients with clinically definite multiple sclerosis (54 relapsing-remitting and 31 secondary progressive). This cross-sectional study reports on the correlations between total and infratentorial lesion volume on both T1 and T2 weighted images, and overall physical disability measured by Expanded Disability Status Scale, ambulation index and individual functional systems. Assessment of the hypointense lesion load on T1 weighted images rather than the hyperintense lesion load on T2 weighted images at brain MRI was shown to be useful for differentiating relapsing-remitting from secondary progressive Multiple Sclerosis. A weak relationship between disability and total lesion volume on both T1 and T2 weighted images was found in relapsing-remitting Multiple Sclerosis. In secondary progressive Multiple Sclerosis, infratentorial lesion volume on T2 weighted images represents the only marker of disability. Finally, the presence of cerebellar, brainstem and mental impairment was significantly associated to a greater total lesion volume on MRI, while no relationship was found with other functional systems.

Adolescent↗
PubMed1997

Interferon beta 1a.

An improved understanding of the immunopathogenesis of multiple sclerosis (MS) has led to therapeutic attempts using immunoregulatory agents in patients with MS, including interferon beta. IFN-beta 1a has been tested in relapsing-remitting MS and its effectiveness in reducing exacerbation rate and in slowing sustained worsening of disability after 2 years has been shown. Magnetic resonance imaging results supported the clinical findings, showing a significant reduction in Gd-enhancing lesion frequency and new lesion formation on T2-weighted images. This type of interferon is well tolerated and most adverse events are mild and transient. Further trials are in progress to amplify and clarify the observed benefits of IFN-beta 1a.

Adjuvants, Immunologic↗
PubMed1997

Fast spin-echo and fast fluid-attenuated inversion-recovery versus conventional spin-echo sequences for MR quantification of multiple sclerosis lesions.

PURPOSE: To compare fast spin-echo (FSE) and fast fluid-attenuated inversion recovery (FLAIR) sequences with conventional spin-echo (CSE) MR imaging in the quantification of the number and volume of multiple sclerosis lesions. METHODS: In 30 patients with relapsing-remitting multiple sclerosis, we calculated the total number and volume of lesions detected with each of the three sequences using a semiautomated program. RESULTS: On CSE sequences, we calculated a total of 2,583 lesions with a global volume of 836.3 cm3. With FSE sequences, we observed a 16% relative reduction in the number of lesions detected and a 25% relative reduction in global volume as compared with CSE. With fast FLAIR sequences, we detected a significantly lower number and volume of infratentorial lesions, whereas at the cortical/subcortical level the lesions were both more numerous and bulkier than on CSE sequences. Finally, we observed a higher lesion/white matter contrast, a significant reduction in time required for the quantification of lesion load, and a very low interobserver variability in favor of fast FLAIR sequences. CONCLUSION: Despite its limitations in the detection of infratentorial lesions, the fast FLAIR sequence in conjunction with a semiautomated quantification program provides a reliable means to evaluate the total lesion burden in patients with MS.

Adult↗
PubMed1996

Involvement of the limbic system in multiple sclerosis patients with depressive disorders.

This study investigates the relationship between depression and both anatomic and cerebral blood flow abnormalities in multiple sclerosis (MS) patients. Ten nondepressed MS patients were compared with 10 depressed MS patients matched for age, sex, and functional disability. Both groups were evaluated by means of neuropsychological tests, magnetic resonance imaging, and single-photon emission tomography imaging. There was no difference between the two groups with regard to the global cognitive score. Magnetic resonance imaging data showed no significant differences in the number, side, location, and area of the demyelinating lesions between the two groups; however, regional cerebral blood flow asymmetries in the limbic cortex did distinguish the two groups. Analysis of variance showed a significant effect of depression on the perfusion asymmetries in the limbic cortex. Finally, perfusion asymmetries in limbic cortex significantly correlated with depression test scores. Our findings suggest that depression in MS patients could be induced by a disconnection between subcortical and cortical areas involved in the function of the limbic system.

Adult↗